Audio signal processing has the requirement for memory to
memory similar as Video.
This patch is to add this support in v4l2 framework, defined
new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
for audio case usage.
The created audio device is named "/dev/v4l-audioX".
Signed-off-by: Shengjiu Wang <[email protected]>
---
.../userspace-api/media/v4l/buffer.rst | 6 ++
.../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
.../userspace-api/media/v4l/devices.rst | 1 +
.../media/v4l/vidioc-enum-fmt.rst | 2 +
.../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
.../media/videodev2.h.rst.exceptions | 2 +
.../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
include/media/v4l2-dev.h | 2 +
include/media/v4l2-ioctl.h | 34 +++++++++
include/uapi/linux/videodev2.h | 17 +++++
13 files changed, 222 insertions(+)
create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
index 52bbee81c080..a3754ca6f0d6 100644
--- a/Documentation/userspace-api/media/v4l/buffer.rst
+++ b/Documentation/userspace-api/media/v4l/buffer.rst
@@ -438,6 +438,12 @@ enum v4l2_buf_type
* - ``V4L2_BUF_TYPE_META_OUTPUT``
- 14
- Buffer for metadata output, see :ref:`metadata`.
+ * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
+ - 15
+ - Buffer for audio capture, see :ref:`audio`.
+ * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
+ - 16
+ - Buffer for audio output, see :ref:`audio`.
.. _buffer-flags:
diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
new file mode 100644
index 000000000000..68faecfe3a02
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
@@ -0,0 +1,71 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _audiomem2mem:
+
+********************************
+Audio Memory-To-Memory Interface
+********************************
+
+An audio memory-to-memory device can compress, decompress, transform, or
+otherwise convert audio data from one format into another format, in memory.
+Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
+Examples of memory-to-memory devices are audio codecs, audio preprocessing,
+audio postprocessing.
+
+A memory-to-memory audio node supports both output (sending audio frames from
+memory to the hardware) and capture (receiving the processed audio frames
+from the hardware into memory) stream I/O. An application will have to
+setup the stream I/O for both sides and finally call
+:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
+start the hardware.
+
+Memory-to-memory devices function as a shared resource: you can
+open the audio node multiple times, each application setting up their
+own properties that are local to the file handle, and each can use
+it independently from the others. The driver will arbitrate access to
+the hardware and reprogram it whenever another file handler gets access.
+
+Audio memory-to-memory devices are accessed through character device
+special files named ``/dev/v4l-audio``
+
+Querying Capabilities
+=====================
+
+Device nodes supporting the audio memory-to-memory interface set the
+``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
+:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
+ioctl.
+
+Data Format Negotiation
+=======================
+
+The audio device uses the :ref:`format` ioctls to select the capture format.
+The audio buffer content format is bound to that selected format. In addition
+to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
+supported as well.
+
+To use the :ref:`format` ioctls applications set the ``type`` field of the
+:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
+``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
+remainder of the :c:type:`v4l2_format` structure to 0.
+
+.. c:type:: v4l2_audio_format
+
+.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
+
+.. flat-table:: struct v4l2_audio_format
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u32
+ - ``pixelformat``
+ - The sample format, set by the application. see :ref:`pixfmt-audio`
+ * - __u32
+ - ``channels``
+ - The channel number, set by the application. channel number range is
+ [1, 32].
+ * - __u32
+ - ``buffersize``
+ - Maximum buffer size in bytes required for data. The value is set by the
+ driver.
diff --git a/Documentation/userspace-api/media/v4l/devices.rst b/Documentation/userspace-api/media/v4l/devices.rst
index 8bfbad65a9d4..758bd90f1c26 100644
--- a/Documentation/userspace-api/media/v4l/devices.rst
+++ b/Documentation/userspace-api/media/v4l/devices.rst
@@ -24,3 +24,4 @@ Interfaces
dev-event
dev-subdev
dev-meta
+ dev-audio-mem2mem
diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
index 000c154b0f98..42deb07f4ff4 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
@@ -96,6 +96,8 @@ the ``mbus_code`` field is handled differently:
``V4L2_BUF_TYPE_VIDEO_OVERLAY``,
``V4L2_BUF_TYPE_SDR_CAPTURE``,
``V4L2_BUF_TYPE_SDR_OUTPUT``,
+ ``V4L2_BUF_TYPE_AUDIO_CAPTURE``,
+ ``V4L2_BUF_TYPE_AUDIO_OUTPUT``,
``V4L2_BUF_TYPE_META_CAPTURE`` and
``V4L2_BUF_TYPE_META_OUTPUT``.
See :c:type:`v4l2_buf_type`.
diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
index 675c385e5aca..528fd9df41aa 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
@@ -130,6 +130,10 @@ The format as returned by :ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>` must be identical
- ``meta``
- Definition of a metadata format, see :ref:`meta-formats`, used by
metadata capture devices.
+ * - struct :c:type:`v4l2_audio_format`
+ - ``audio``
+ - Definition of a audio data format, see :ref:`audiomem2mem`, used by
+ audio memory-to-memory devices
* - __u8
- ``raw_data``\ [200]
- Place holder for future extensions.
diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
index da6d0b8e4c2c..e61152bb80d1 100644
--- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
+++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
@@ -29,6 +29,8 @@ replace symbol V4L2_FIELD_SEQ_TB :c:type:`v4l2_field`
replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field`
# Documented enum v4l2_buf_type
+replace symbol V4L2_BUF_TYPE_AUDIO_CAPTURE :c:type:`v4l2_buf_type`
+replace symbol V4L2_BUF_TYPE_AUDIO_OUTPUT :c:type:`v4l2_buf_type`
replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type`
replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type`
replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 54d572c3b515..16ab204d15b0 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -791,6 +791,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
case V4L2_BUF_TYPE_META_OUTPUT:
requested_sizes[0] = f->fmt.meta.buffersize;
break;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ requested_sizes[0] = f->fmt.audio.buffersize;
+ break;
default:
return -EINVAL;
}
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 8c07400bd280..5e94db8dfdae 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -101,6 +101,7 @@ struct v4l2_format32 {
struct v4l2_sliced_vbi_format sliced;
struct v4l2_sdr_format sdr;
struct v4l2_meta_format meta;
+ struct v4l2_audio_format audio;
__u8 raw_data[200]; /* user-defined */
} fmt;
};
@@ -166,6 +167,10 @@ static int get_v4l2_format32(struct v4l2_format *p64,
case V4L2_BUF_TYPE_META_OUTPUT:
return copy_from_user(&p64->fmt.meta, &p32->fmt.meta,
sizeof(p64->fmt.meta)) ? -EFAULT : 0;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ return copy_from_user(&p64->fmt.audio, &p32->fmt.audio,
+ sizeof(p64->fmt.audio)) ? -EFAULT : 0;
default:
return -EINVAL;
}
@@ -216,6 +221,10 @@ static int put_v4l2_format32(struct v4l2_format *p64,
case V4L2_BUF_TYPE_META_OUTPUT:
return copy_to_user(&p32->fmt.meta, &p64->fmt.meta,
sizeof(p64->fmt.meta)) ? -EFAULT : 0;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ return copy_to_user(&p32->fmt.audio, &p64->fmt.audio,
+ sizeof(p64->fmt.audio)) ? -EFAULT : 0;
default:
return -EINVAL;
}
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index d13954bd31fd..bac008fcedc6 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -553,6 +553,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH;
bool is_meta = vdev->vfl_type == VFL_TYPE_VIDEO &&
(vdev->device_caps & meta_caps);
+ bool is_audio = vdev->vfl_type == VFL_TYPE_AUDIO;
bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;
@@ -666,6 +667,19 @@ static void determine_valid_ioctls(struct video_device *vdev)
SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_meta_out);
SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_meta_out);
}
+ if (is_audio && is_rx) {
+ /* audio capture specific ioctls */
+ SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_cap);
+ SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_cap);
+ SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_cap);
+ SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_cap);
+ } else if (is_audio && is_tx) {
+ /* audio output specific ioctls */
+ SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_out);
+ SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_out);
+ SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_out);
+ SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_out);
+ }
if (is_vbi) {
/* vbi specific ioctls */
if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
@@ -929,6 +943,9 @@ int __video_register_device(struct video_device *vdev,
case VFL_TYPE_TOUCH:
name_base = "v4l-touch";
break;
+ case VFL_TYPE_AUDIO:
+ name_base = "v4l-audio";
+ break;
default:
pr_err("%s called with unknown type: %d\n",
__func__, type);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 33076af4dfdb..e7be7c2f302d 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -188,6 +188,8 @@ const char *v4l2_type_names[] = {
[V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out",
[V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap",
[V4L2_BUF_TYPE_META_OUTPUT] = "meta-out",
+ [V4L2_BUF_TYPE_AUDIO_CAPTURE] = "audio-cap",
+ [V4L2_BUF_TYPE_AUDIO_OUTPUT] = "audio-out",
};
EXPORT_SYMBOL(v4l2_type_names);
@@ -276,6 +278,7 @@ static void v4l_print_format(const void *arg, bool write_only)
const struct v4l2_sliced_vbi_format *sliced;
const struct v4l2_window *win;
const struct v4l2_meta_format *meta;
+ const struct v4l2_audio_format *audio;
u32 pixelformat;
u32 planes;
unsigned i;
@@ -346,6 +349,13 @@ static void v4l_print_format(const void *arg, bool write_only)
pr_cont(", dataformat=%p4cc, buffersize=%u\n",
&pixelformat, meta->buffersize);
break;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ audio = &p->fmt.audio;
+ pixelformat = audio->audioformat;
+ pr_cont(", format=%p4cc, channels=%u, buffersize=%u\n",
+ &pixelformat, audio->channels, audio->buffersize);
+ break;
}
}
@@ -927,6 +937,7 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
bool is_tch = vfd->vfl_type == VFL_TYPE_TOUCH;
bool is_meta = vfd->vfl_type == VFL_TYPE_VIDEO &&
(vfd->device_caps & meta_caps);
+ bool is_audio = vfd->vfl_type == VFL_TYPE_AUDIO;
bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
@@ -992,6 +1003,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
if (is_meta && is_tx && ops->vidioc_g_fmt_meta_out)
return 0;
break;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ if (is_audio && is_rx && ops->vidioc_g_fmt_audio_cap)
+ return 0;
+ break;
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ if (is_audio && is_tx && ops->vidioc_g_fmt_audio_out)
+ return 0;
+ break;
default:
break;
}
@@ -1597,6 +1616,16 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
break;
ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg);
break;
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ if (unlikely(!ops->vidioc_enum_fmt_audio_cap))
+ break;
+ ret = ops->vidioc_enum_fmt_audio_cap(file, fh, arg);
+ break;
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ if (unlikely(!ops->vidioc_enum_fmt_audio_out))
+ break;
+ ret = ops->vidioc_enum_fmt_audio_out(file, fh, arg);
+ break;
}
if (ret == 0)
v4l_fill_fmtdesc(p);
@@ -1673,6 +1702,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
case V4L2_BUF_TYPE_META_OUTPUT:
return ops->vidioc_g_fmt_meta_out(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ return ops->vidioc_g_fmt_audio_cap(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ return ops->vidioc_g_fmt_audio_out(file, fh, arg);
}
return -EINVAL;
}
@@ -1784,6 +1817,16 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
break;
memset_after(p, 0, fmt.meta);
return ops->vidioc_s_fmt_meta_out(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ if (unlikely(!ops->vidioc_s_fmt_audio_cap))
+ break;
+ memset_after(p, 0, fmt.audio);
+ return ops->vidioc_s_fmt_audio_cap(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ if (unlikely(!ops->vidioc_s_fmt_audio_out))
+ break;
+ memset_after(p, 0, fmt.audio);
+ return ops->vidioc_s_fmt_audio_out(file, fh, arg);
}
return -EINVAL;
}
@@ -1892,6 +1935,16 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
break;
memset_after(p, 0, fmt.meta);
return ops->vidioc_try_fmt_meta_out(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_CAPTURE:
+ if (unlikely(!ops->vidioc_try_fmt_audio_cap))
+ break;
+ memset_after(p, 0, fmt.audio);
+ return ops->vidioc_try_fmt_audio_cap(file, fh, arg);
+ case V4L2_BUF_TYPE_AUDIO_OUTPUT:
+ if (unlikely(!ops->vidioc_try_fmt_audio_out))
+ break;
+ memset_after(p, 0, fmt.audio);
+ return ops->vidioc_try_fmt_audio_out(file, fh, arg);
}
return -EINVAL;
}
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index d82dfdbf6e58..82b63f82d43f 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -30,6 +30,7 @@
* @VFL_TYPE_SUBDEV: for V4L2 subdevices
* @VFL_TYPE_SDR: for Software Defined Radio tuners
* @VFL_TYPE_TOUCH: for touch sensors
+ * @VFL_TYPE_AUDIO: for audio memory-to-memory devices
* @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
*/
enum vfl_devnode_type {
@@ -39,6 +40,7 @@ enum vfl_devnode_type {
VFL_TYPE_SUBDEV,
VFL_TYPE_SDR,
VFL_TYPE_TOUCH,
+ VFL_TYPE_AUDIO,
VFL_TYPE_MAX /* Shall be the last one */
};
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index edb733f21604..f840cf740ce1 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -45,6 +45,12 @@ struct v4l2_fh;
* @vidioc_enum_fmt_meta_out: pointer to the function that implements
* :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
* for metadata output
+ * @vidioc_enum_fmt_audio_cap: pointer to the function that implements
+ * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
+ * for audio capture
+ * @vidioc_enum_fmt_audio_out: pointer to the function that implements
+ * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
+ * for audio output
* @vidioc_g_fmt_vid_cap: pointer to the function that implements
* :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
* in single plane mode
@@ -79,6 +85,10 @@ struct v4l2_fh;
* :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
* @vidioc_g_fmt_meta_out: pointer to the function that implements
* :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output
+ * @vidioc_g_fmt_audio_cap: pointer to the function that implements
+ * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio capture
+ * @vidioc_g_fmt_audio_out: pointer to the function that implements
+ * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio output
* @vidioc_s_fmt_vid_cap: pointer to the function that implements
* :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
* in single plane mode
@@ -113,6 +123,10 @@ struct v4l2_fh;
* :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
* @vidioc_s_fmt_meta_out: pointer to the function that implements
* :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output
+ * @vidioc_s_fmt_audio_cap: pointer to the function that implements
+ * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio capture
+ * @vidioc_s_fmt_audio_out: pointer to the function that implements
+ * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio output
* @vidioc_try_fmt_vid_cap: pointer to the function that implements
* :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
* in single plane mode
@@ -149,6 +163,10 @@ struct v4l2_fh;
* :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
* @vidioc_try_fmt_meta_out: pointer to the function that implements
* :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output
+ * @vidioc_try_fmt_audio_cap: pointer to the function that implements
+ * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio capture
+ * @vidioc_try_fmt_audio_out: pointer to the function that implements
+ * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio output
* @vidioc_reqbufs: pointer to the function that implements
* :ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
* @vidioc_querybuf: pointer to the function that implements
@@ -315,6 +333,10 @@ struct v4l2_ioctl_ops {
struct v4l2_fmtdesc *f);
int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh,
struct v4l2_fmtdesc *f);
+ int (*vidioc_enum_fmt_audio_cap)(struct file *file, void *fh,
+ struct v4l2_fmtdesc *f);
+ int (*vidioc_enum_fmt_audio_out)(struct file *file, void *fh,
+ struct v4l2_fmtdesc *f);
/* VIDIOC_G_FMT handlers */
int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,
@@ -345,6 +367,10 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_g_fmt_audio_cap)(struct file *file, void *fh,
+ struct v4l2_format *f);
+ int (*vidioc_g_fmt_audio_out)(struct file *file, void *fh,
+ struct v4l2_format *f);
/* VIDIOC_S_FMT handlers */
int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,
@@ -375,6 +401,10 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_s_fmt_audio_cap)(struct file *file, void *fh,
+ struct v4l2_format *f);
+ int (*vidioc_s_fmt_audio_out)(struct file *file, void *fh,
+ struct v4l2_format *f);
/* VIDIOC_TRY_FMT handlers */
int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,
@@ -405,6 +435,10 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_try_fmt_audio_cap)(struct file *file, void *fh,
+ struct v4l2_format *f);
+ int (*vidioc_try_fmt_audio_out)(struct file *file, void *fh,
+ struct v4l2_format *f);
/* Buffer handlers */
int (*vidioc_reqbufs)(struct file *file, void *fh,
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 6cd65969c2b5..57c82eb158f1 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -153,6 +153,8 @@ enum v4l2_buf_type {
V4L2_BUF_TYPE_SDR_OUTPUT = 12,
V4L2_BUF_TYPE_META_CAPTURE = 13,
V4L2_BUF_TYPE_META_OUTPUT = 14,
+ V4L2_BUF_TYPE_AUDIO_CAPTURE = 15,
+ V4L2_BUF_TYPE_AUDIO_OUTPUT = 16,
/* Deprecated, do not use */
V4L2_BUF_TYPE_PRIVATE = 0x80,
};
@@ -169,6 +171,7 @@ enum v4l2_buf_type {
|| (type) == V4L2_BUF_TYPE_VBI_OUTPUT \
|| (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT \
|| (type) == V4L2_BUF_TYPE_SDR_OUTPUT \
+ || (type) == V4L2_BUF_TYPE_AUDIO_OUTPUT \
|| (type) == V4L2_BUF_TYPE_META_OUTPUT)
#define V4L2_TYPE_IS_CAPTURE(type) (!V4L2_TYPE_IS_OUTPUT(type))
@@ -2423,6 +2426,18 @@ struct v4l2_meta_format {
__u32 buffersize;
} __attribute__ ((packed));
+/**
+ * struct v4l2_audio_format - audio data format definition
+ * @audioformat: little endian four character code (fourcc)
+ * @channels: channel numbers
+ * @buffersize: maximum size in bytes required for data
+ */
+struct v4l2_audio_format {
+ __u32 audioformat;
+ __u32 channels;
+ __u32 buffersize;
+} __attribute__ ((packed));
+
/**
* struct v4l2_format - stream data format
* @type: enum v4l2_buf_type; type of the data stream
@@ -2431,6 +2446,7 @@ struct v4l2_meta_format {
* @win: definition of an overlaid image
* @vbi: raw VBI capture or output parameters
* @sliced: sliced VBI capture or output parameters
+ * @audio: definition of an audio format
* @raw_data: placeholder for future extensions and custom formats
* @fmt: union of @pix, @pix_mp, @win, @vbi, @sliced, @sdr, @meta
* and @raw_data
@@ -2445,6 +2461,7 @@ struct v4l2_format {
struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */
struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */
+ struct v4l2_audio_format audio; /* V4L2_BUF_TYPE_AUDIO_CAPTURE */
__u8 raw_data[200]; /* user-defined */
} fmt;
};
--
2.34.1
Em Thu, 18 Jan 2024 20:32:00 +0800
Shengjiu Wang <[email protected]> escreveu:
> Audio signal processing has the requirement for memory to
> memory similar as Video.
>
> This patch is to add this support in v4l2 framework, defined
> new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
> V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
> for audio case usage.
>
> The created audio device is named "/dev/v4l-audioX".
>
> Signed-off-by: Shengjiu Wang <[email protected]>
> ---
> .../userspace-api/media/v4l/buffer.rst | 6 ++
> .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
> .../userspace-api/media/v4l/devices.rst | 1 +
> .../media/v4l/vidioc-enum-fmt.rst | 2 +
> .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
> .../media/videodev2.h.rst.exceptions | 2 +
> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
> drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
> drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
> include/media/v4l2-dev.h | 2 +
> include/media/v4l2-ioctl.h | 34 +++++++++
> include/uapi/linux/videodev2.h | 17 +++++
> 13 files changed, 222 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>
> diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> index 52bbee81c080..a3754ca6f0d6 100644
> --- a/Documentation/userspace-api/media/v4l/buffer.rst
> +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> @@ -438,6 +438,12 @@ enum v4l2_buf_type
> * - ``V4L2_BUF_TYPE_META_OUTPUT``
> - 14
> - Buffer for metadata output, see :ref:`metadata`.
> + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
> + - 15
> + - Buffer for audio capture, see :ref:`audio`.
> + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
> + - 16
Hmm... alsa APi define input/output as:
enum {
SNDRV_PCM_STREAM_PLAYBACK = 0,
SNDRV_PCM_STREAM_CAPTURE,
SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
};
I would use a namespace as close as possible to the
ALSA API. Also, we're not talking about V4L2, but, instead
audio. so, not sure if I like the prefix to start with
V4L2_. Maybe ALSA_?
So, a better namespace would be:
${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
and
${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
> + - Buffer for audio output, see :ref:`audio`.
>
>
> .. _buffer-flags:
> diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> new file mode 100644
> index 000000000000..68faecfe3a02
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> @@ -0,0 +1,71 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +
> +.. _audiomem2mem:
> +
> +********************************
> +Audio Memory-To-Memory Interface
> +********************************
> +
> +An audio memory-to-memory device can compress, decompress, transform, or
> +otherwise convert audio data from one format into another format, in memory.
> +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
> +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
> +audio postprocessing.
> +
> +A memory-to-memory audio node supports both output (sending audio frames from
> +memory to the hardware) and capture (receiving the processed audio frames
> +from the hardware into memory) stream I/O. An application will have to
> +setup the stream I/O for both sides and finally call
> +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
> +start the hardware.
> +
> +Memory-to-memory devices function as a shared resource: you can
> +open the audio node multiple times, each application setting up their
> +own properties that are local to the file handle, and each can use
> +it independently from the others. The driver will arbitrate access to
> +the hardware and reprogram it whenever another file handler gets access.
> +
> +Audio memory-to-memory devices are accessed through character device
> +special files named ``/dev/v4l-audio``
> +
> +Querying Capabilities
> +=====================
> +
> +Device nodes supporting the audio memory-to-memory interface set the
> +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
> +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
> +ioctl.
> +
> +Data Format Negotiation
> +=======================
> +
> +The audio device uses the :ref:`format` ioctls to select the capture format.
> +The audio buffer content format is bound to that selected format. In addition
> +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
> +supported as well.
> +
> +To use the :ref:`format` ioctls applications set the ``type`` field of the
> +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
> +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
> +remainder of the :c:type:`v4l2_format` structure to 0.
> +
> +.. c:type:: v4l2_audio_format
> +
> +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
> +
> +.. flat-table:: struct v4l2_audio_format
> + :header-rows: 0
> + :stub-columns: 0
> + :widths: 1 1 2
> +
> + * - __u32
> + - ``pixelformat``
> + - The sample format, set by the application. see :ref:`pixfmt-audio`
pixelformat doesn't make any sense for audio: there are no pixels on a
PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
the values for snd_pcm_format_t.
Yet, I would keep defining it as u32 (or u64?) instead of using a
typedef int field there (snd_pcm_format_t), as the size of integer
is different on 32 and 64 bit kernels.
> + * - __u32
> + - ``channels``
> + - The channel number, set by the application. channel number range is
> + [1, 32].
Why not start on zero?
> + * - __u32
> + - ``buffersize``
> + - Maximum buffer size in bytes required for data. The value is set by the
> + driver.
> diff --git a/Documentation/userspace-api/media/v4l/devices.rst b/Documentation/userspace-api/media/v4l/devices.rst
> index 8bfbad65a9d4..758bd90f1c26 100644
> --- a/Documentation/userspace-api/media/v4l/devices.rst
> +++ b/Documentation/userspace-api/media/v4l/devices.rst
> @@ -24,3 +24,4 @@ Interfaces
> dev-event
> dev-subdev
> dev-meta
> + dev-audio-mem2mem
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> index 000c154b0f98..42deb07f4ff4 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> @@ -96,6 +96,8 @@ the ``mbus_code`` field is handled differently:
> ``V4L2_BUF_TYPE_VIDEO_OVERLAY``,
> ``V4L2_BUF_TYPE_SDR_CAPTURE``,
> ``V4L2_BUF_TYPE_SDR_OUTPUT``,
> + ``V4L2_BUF_TYPE_AUDIO_CAPTURE``,
> + ``V4L2_BUF_TYPE_AUDIO_OUTPUT``,
> ``V4L2_BUF_TYPE_META_CAPTURE`` and
> ``V4L2_BUF_TYPE_META_OUTPUT``.
> See :c:type:`v4l2_buf_type`.
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> index 675c385e5aca..528fd9df41aa 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> @@ -130,6 +130,10 @@ The format as returned by :ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>` must be identical
> - ``meta``
> - Definition of a metadata format, see :ref:`meta-formats`, used by
> metadata capture devices.
> + * - struct :c:type:`v4l2_audio_format`
> + - ``audio``
> + - Definition of a audio data format, see :ref:`audiomem2mem`, used by
> + audio memory-to-memory devices
> * - __u8
> - ``raw_data``\ [200]
> - Place holder for future extensions.
> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> index da6d0b8e4c2c..e61152bb80d1 100644
> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> @@ -29,6 +29,8 @@ replace symbol V4L2_FIELD_SEQ_TB :c:type:`v4l2_field`
> replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field`
>
> # Documented enum v4l2_buf_type
> +replace symbol V4L2_BUF_TYPE_AUDIO_CAPTURE :c:type:`v4l2_buf_type`
> +replace symbol V4L2_BUF_TYPE_AUDIO_OUTPUT :c:type:`v4l2_buf_type`
> replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type`
> replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type`
> replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 54d572c3b515..16ab204d15b0 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -791,6 +791,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> case V4L2_BUF_TYPE_META_OUTPUT:
> requested_sizes[0] = f->fmt.meta.buffersize;
> break;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + requested_sizes[0] = f->fmt.audio.buffersize;
> + break;
> default:
> return -EINVAL;
> }
> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> index 8c07400bd280..5e94db8dfdae 100644
> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> @@ -101,6 +101,7 @@ struct v4l2_format32 {
> struct v4l2_sliced_vbi_format sliced;
> struct v4l2_sdr_format sdr;
> struct v4l2_meta_format meta;
> + struct v4l2_audio_format audio;
> __u8 raw_data[200]; /* user-defined */
> } fmt;
> };
> @@ -166,6 +167,10 @@ static int get_v4l2_format32(struct v4l2_format *p64,
> case V4L2_BUF_TYPE_META_OUTPUT:
> return copy_from_user(&p64->fmt.meta, &p32->fmt.meta,
> sizeof(p64->fmt.meta)) ? -EFAULT : 0;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + return copy_from_user(&p64->fmt.audio, &p32->fmt.audio,
> + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
> default:
> return -EINVAL;
> }
> @@ -216,6 +221,10 @@ static int put_v4l2_format32(struct v4l2_format *p64,
> case V4L2_BUF_TYPE_META_OUTPUT:
> return copy_to_user(&p32->fmt.meta, &p64->fmt.meta,
> sizeof(p64->fmt.meta)) ? -EFAULT : 0;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + return copy_to_user(&p32->fmt.audio, &p64->fmt.audio,
> + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
> default:
> return -EINVAL;
> }
> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> index d13954bd31fd..bac008fcedc6 100644
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -553,6 +553,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
> bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH;
> bool is_meta = vdev->vfl_type == VFL_TYPE_VIDEO &&
> (vdev->device_caps & meta_caps);
> + bool is_audio = vdev->vfl_type == VFL_TYPE_AUDIO;
> bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
> bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
> bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;
> @@ -666,6 +667,19 @@ static void determine_valid_ioctls(struct video_device *vdev)
> SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_meta_out);
> SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_meta_out);
> }
> + if (is_audio && is_rx) {
> + /* audio capture specific ioctls */
> + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_cap);
> + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_cap);
> + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_cap);
> + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_cap);
> + } else if (is_audio && is_tx) {
> + /* audio output specific ioctls */
> + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_out);
> + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_out);
> + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_out);
> + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_out);
> + }
> if (is_vbi) {
> /* vbi specific ioctls */
> if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
> @@ -929,6 +943,9 @@ int __video_register_device(struct video_device *vdev,
> case VFL_TYPE_TOUCH:
> name_base = "v4l-touch";
> break;
> + case VFL_TYPE_AUDIO:
> + name_base = "v4l-audio";
> + break;
> default:
> pr_err("%s called with unknown type: %d\n",
> __func__, type);
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 33076af4dfdb..e7be7c2f302d 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -188,6 +188,8 @@ const char *v4l2_type_names[] = {
> [V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out",
> [V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap",
> [V4L2_BUF_TYPE_META_OUTPUT] = "meta-out",
> + [V4L2_BUF_TYPE_AUDIO_CAPTURE] = "audio-cap",
> + [V4L2_BUF_TYPE_AUDIO_OUTPUT] = "audio-out",
> };
> EXPORT_SYMBOL(v4l2_type_names);
>
> @@ -276,6 +278,7 @@ static void v4l_print_format(const void *arg, bool write_only)
> const struct v4l2_sliced_vbi_format *sliced;
> const struct v4l2_window *win;
> const struct v4l2_meta_format *meta;
> + const struct v4l2_audio_format *audio;
> u32 pixelformat;
> u32 planes;
> unsigned i;
> @@ -346,6 +349,13 @@ static void v4l_print_format(const void *arg, bool write_only)
> pr_cont(", dataformat=%p4cc, buffersize=%u\n",
> &pixelformat, meta->buffersize);
> break;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + audio = &p->fmt.audio;
> + pixelformat = audio->audioformat;
> + pr_cont(", format=%p4cc, channels=%u, buffersize=%u\n",
> + &pixelformat, audio->channels, audio->buffersize);
> + break;
> }
> }
>
> @@ -927,6 +937,7 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
> bool is_tch = vfd->vfl_type == VFL_TYPE_TOUCH;
> bool is_meta = vfd->vfl_type == VFL_TYPE_VIDEO &&
> (vfd->device_caps & meta_caps);
> + bool is_audio = vfd->vfl_type == VFL_TYPE_AUDIO;
> bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
> bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
>
> @@ -992,6 +1003,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
> if (is_meta && is_tx && ops->vidioc_g_fmt_meta_out)
> return 0;
> break;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + if (is_audio && is_rx && ops->vidioc_g_fmt_audio_cap)
> + return 0;
> + break;
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + if (is_audio && is_tx && ops->vidioc_g_fmt_audio_out)
> + return 0;
> + break;
> default:
> break;
> }
> @@ -1597,6 +1616,16 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
> break;
> ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg);
> break;
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + if (unlikely(!ops->vidioc_enum_fmt_audio_cap))
> + break;
> + ret = ops->vidioc_enum_fmt_audio_cap(file, fh, arg);
> + break;
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + if (unlikely(!ops->vidioc_enum_fmt_audio_out))
> + break;
> + ret = ops->vidioc_enum_fmt_audio_out(file, fh, arg);
> + break;
> }
> if (ret == 0)
> v4l_fill_fmtdesc(p);
> @@ -1673,6 +1702,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
> return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
> case V4L2_BUF_TYPE_META_OUTPUT:
> return ops->vidioc_g_fmt_meta_out(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + return ops->vidioc_g_fmt_audio_cap(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + return ops->vidioc_g_fmt_audio_out(file, fh, arg);
> }
> return -EINVAL;
> }
> @@ -1784,6 +1817,16 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
> break;
> memset_after(p, 0, fmt.meta);
> return ops->vidioc_s_fmt_meta_out(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + if (unlikely(!ops->vidioc_s_fmt_audio_cap))
> + break;
> + memset_after(p, 0, fmt.audio);
> + return ops->vidioc_s_fmt_audio_cap(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + if (unlikely(!ops->vidioc_s_fmt_audio_out))
> + break;
> + memset_after(p, 0, fmt.audio);
> + return ops->vidioc_s_fmt_audio_out(file, fh, arg);
> }
> return -EINVAL;
> }
> @@ -1892,6 +1935,16 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
> break;
> memset_after(p, 0, fmt.meta);
> return ops->vidioc_try_fmt_meta_out(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> + if (unlikely(!ops->vidioc_try_fmt_audio_cap))
> + break;
> + memset_after(p, 0, fmt.audio);
> + return ops->vidioc_try_fmt_audio_cap(file, fh, arg);
> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> + if (unlikely(!ops->vidioc_try_fmt_audio_out))
> + break;
> + memset_after(p, 0, fmt.audio);
> + return ops->vidioc_try_fmt_audio_out(file, fh, arg);
> }
> return -EINVAL;
> }
> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> index d82dfdbf6e58..82b63f82d43f 100644
> --- a/include/media/v4l2-dev.h
> +++ b/include/media/v4l2-dev.h
> @@ -30,6 +30,7 @@
> * @VFL_TYPE_SUBDEV: for V4L2 subdevices
> * @VFL_TYPE_SDR: for Software Defined Radio tuners
> * @VFL_TYPE_TOUCH: for touch sensors
> + * @VFL_TYPE_AUDIO: for audio memory-to-memory devices
> * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
> */
> enum vfl_devnode_type {
> @@ -39,6 +40,7 @@ enum vfl_devnode_type {
> VFL_TYPE_SUBDEV,
> VFL_TYPE_SDR,
> VFL_TYPE_TOUCH,
> + VFL_TYPE_AUDIO,
> VFL_TYPE_MAX /* Shall be the last one */
> };
>
> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> index edb733f21604..f840cf740ce1 100644
> --- a/include/media/v4l2-ioctl.h
> +++ b/include/media/v4l2-ioctl.h
> @@ -45,6 +45,12 @@ struct v4l2_fh;
> * @vidioc_enum_fmt_meta_out: pointer to the function that implements
> * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> * for metadata output
> + * @vidioc_enum_fmt_audio_cap: pointer to the function that implements
> + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> + * for audio capture
> + * @vidioc_enum_fmt_audio_out: pointer to the function that implements
> + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> + * for audio output
> * @vidioc_g_fmt_vid_cap: pointer to the function that implements
> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
> * in single plane mode
> @@ -79,6 +85,10 @@ struct v4l2_fh;
> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> * @vidioc_g_fmt_meta_out: pointer to the function that implements
> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> + * @vidioc_g_fmt_audio_cap: pointer to the function that implements
> + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> + * @vidioc_g_fmt_audio_out: pointer to the function that implements
> + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio output
> * @vidioc_s_fmt_vid_cap: pointer to the function that implements
> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
> * in single plane mode
> @@ -113,6 +123,10 @@ struct v4l2_fh;
> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> * @vidioc_s_fmt_meta_out: pointer to the function that implements
> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> + * @vidioc_s_fmt_audio_cap: pointer to the function that implements
> + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> + * @vidioc_s_fmt_audio_out: pointer to the function that implements
> + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio output
> * @vidioc_try_fmt_vid_cap: pointer to the function that implements
> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
> * in single plane mode
> @@ -149,6 +163,10 @@ struct v4l2_fh;
> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> * @vidioc_try_fmt_meta_out: pointer to the function that implements
> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> + * @vidioc_try_fmt_audio_cap: pointer to the function that implements
> + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> + * @vidioc_try_fmt_audio_out: pointer to the function that implements
> + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio output
> * @vidioc_reqbufs: pointer to the function that implements
> * :ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
> * @vidioc_querybuf: pointer to the function that implements
> @@ -315,6 +333,10 @@ struct v4l2_ioctl_ops {
> struct v4l2_fmtdesc *f);
> int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh,
> struct v4l2_fmtdesc *f);
> + int (*vidioc_enum_fmt_audio_cap)(struct file *file, void *fh,
> + struct v4l2_fmtdesc *f);
> + int (*vidioc_enum_fmt_audio_out)(struct file *file, void *fh,
> + struct v4l2_fmtdesc *f);
>
> /* VIDIOC_G_FMT handlers */
> int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,
> @@ -345,6 +367,10 @@ struct v4l2_ioctl_ops {
> struct v4l2_format *f);
> int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh,
> struct v4l2_format *f);
> + int (*vidioc_g_fmt_audio_cap)(struct file *file, void *fh,
> + struct v4l2_format *f);
> + int (*vidioc_g_fmt_audio_out)(struct file *file, void *fh,
> + struct v4l2_format *f);
>
> /* VIDIOC_S_FMT handlers */
> int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,
> @@ -375,6 +401,10 @@ struct v4l2_ioctl_ops {
> struct v4l2_format *f);
> int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh,
> struct v4l2_format *f);
> + int (*vidioc_s_fmt_audio_cap)(struct file *file, void *fh,
> + struct v4l2_format *f);
> + int (*vidioc_s_fmt_audio_out)(struct file *file, void *fh,
> + struct v4l2_format *f);
>
> /* VIDIOC_TRY_FMT handlers */
> int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,
> @@ -405,6 +435,10 @@ struct v4l2_ioctl_ops {
> struct v4l2_format *f);
> int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh,
> struct v4l2_format *f);
> + int (*vidioc_try_fmt_audio_cap)(struct file *file, void *fh,
> + struct v4l2_format *f);
> + int (*vidioc_try_fmt_audio_out)(struct file *file, void *fh,
> + struct v4l2_format *f);
>
> /* Buffer handlers */
> int (*vidioc_reqbufs)(struct file *file, void *fh,
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 6cd65969c2b5..57c82eb158f1 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -153,6 +153,8 @@ enum v4l2_buf_type {
> V4L2_BUF_TYPE_SDR_OUTPUT = 12,
> V4L2_BUF_TYPE_META_CAPTURE = 13,
> V4L2_BUF_TYPE_META_OUTPUT = 14,
> + V4L2_BUF_TYPE_AUDIO_CAPTURE = 15,
> + V4L2_BUF_TYPE_AUDIO_OUTPUT = 16,
> /* Deprecated, do not use */
> V4L2_BUF_TYPE_PRIVATE = 0x80,
> };
> @@ -169,6 +171,7 @@ enum v4l2_buf_type {
> || (type) == V4L2_BUF_TYPE_VBI_OUTPUT \
> || (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT \
> || (type) == V4L2_BUF_TYPE_SDR_OUTPUT \
> + || (type) == V4L2_BUF_TYPE_AUDIO_OUTPUT \
> || (type) == V4L2_BUF_TYPE_META_OUTPUT)
>
> #define V4L2_TYPE_IS_CAPTURE(type) (!V4L2_TYPE_IS_OUTPUT(type))
> @@ -2423,6 +2426,18 @@ struct v4l2_meta_format {
> __u32 buffersize;
> } __attribute__ ((packed));
>
> +/**
> + * struct v4l2_audio_format - audio data format definition
> + * @audioformat: little endian four character code (fourcc)
Don't use fourcc here. Instead, use the types defined at snd_pcm_format_t.
> + * @channels: channel numbers
> + * @buffersize: maximum size in bytes required for data
> + */
> +struct v4l2_audio_format {
> + __u32 audioformat;
> + __u32 channels;
> + __u32 buffersize;
> +} __attribute__ ((packed));
> +
> /**
> * struct v4l2_format - stream data format
> * @type: enum v4l2_buf_type; type of the data stream
> @@ -2431,6 +2446,7 @@ struct v4l2_meta_format {
> * @win: definition of an overlaid image
> * @vbi: raw VBI capture or output parameters
> * @sliced: sliced VBI capture or output parameters
> + * @audio: definition of an audio format
> * @raw_data: placeholder for future extensions and custom formats
> * @fmt: union of @pix, @pix_mp, @win, @vbi, @sliced, @sdr, @meta
> * and @raw_data
> @@ -2445,6 +2461,7 @@ struct v4l2_format {
> struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
> struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */
> struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */
> + struct v4l2_audio_format audio; /* V4L2_BUF_TYPE_AUDIO_CAPTURE */
> __u8 raw_data[200]; /* user-defined */
> } fmt;
> };
Thanks,
Mauro
Hi Mauro, Hans
On Sat, Feb 17, 2024 at 5:42 PM Mauro Carvalho Chehab
<[email protected]> wrote:
>
> Em Thu, 18 Jan 2024 20:32:00 +0800
> Shengjiu Wang <[email protected]> escreveu:
>
> > Audio signal processing has the requirement for memory to
> > memory similar as Video.
> >
> > This patch is to add this support in v4l2 framework, defined
> > new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
> > V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
> > for audio case usage.
> >
> > The created audio device is named "/dev/v4l-audioX".
> >
> > Signed-off-by: Shengjiu Wang <[email protected]>
> > ---
> > .../userspace-api/media/v4l/buffer.rst | 6 ++
> > .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
> > .../userspace-api/media/v4l/devices.rst | 1 +
> > .../media/v4l/vidioc-enum-fmt.rst | 2 +
> > .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
> > .../media/videodev2.h.rst.exceptions | 2 +
> > .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
> > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
> > drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
> > drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
> > include/media/v4l2-dev.h | 2 +
> > include/media/v4l2-ioctl.h | 34 +++++++++
> > include/uapi/linux/videodev2.h | 17 +++++
> > 13 files changed, 222 insertions(+)
> > create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> >
> > diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> > index 52bbee81c080..a3754ca6f0d6 100644
> > --- a/Documentation/userspace-api/media/v4l/buffer.rst
> > +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> > @@ -438,6 +438,12 @@ enum v4l2_buf_type
> > * - ``V4L2_BUF_TYPE_META_OUTPUT``
> > - 14
>
> > - Buffer for metadata output, see :ref:`metadata`.
> > + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
> > + - 15
> > + - Buffer for audio capture, see :ref:`audio`.
> > + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
> > + - 16
>
> Hmm... alsa APi define input/output as:
> enum {
> SNDRV_PCM_STREAM_PLAYBACK = 0,
> SNDRV_PCM_STREAM_CAPTURE,
> SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
> };
>
>
> I would use a namespace as close as possible to the
> ALSA API. Also, we're not talking about V4L2, but, instead
> audio. so, not sure if I like the prefix to start with
> V4L2_. Maybe ALSA_?
>
> So, a better namespace would be:
>
> ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
> and
> ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
>
Ok, So can I use the name below?
V4L2_BUF_TYPE_PCM_STREAM_PLAYBACK
V4L2_BUF_TYPE_PCM_STREAM_CAPTURE
> > + - Buffer for audio output, see :ref:`audio`.
> >
> >
> > .. _buffer-flags:
> > diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > new file mode 100644
> > index 000000000000..68faecfe3a02
> > --- /dev/null
> > +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > @@ -0,0 +1,71 @@
> > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> > +
> > +.. _audiomem2mem:
> > +
> > +********************************
> > +Audio Memory-To-Memory Interface
> > +********************************
> > +
> > +An audio memory-to-memory device can compress, decompress, transform, or
> > +otherwise convert audio data from one format into another format, in memory.
> > +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
> > +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
> > +audio postprocessing.
> > +
> > +A memory-to-memory audio node supports both output (sending audio frames from
> > +memory to the hardware) and capture (receiving the processed audio frames
> > +from the hardware into memory) stream I/O. An application will have to
> > +setup the stream I/O for both sides and finally call
> > +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
> > +start the hardware.
> > +
> > +Memory-to-memory devices function as a shared resource: you can
> > +open the audio node multiple times, each application setting up their
> > +own properties that are local to the file handle, and each can use
> > +it independently from the others. The driver will arbitrate access to
> > +the hardware and reprogram it whenever another file handler gets access.
> > +
> > +Audio memory-to-memory devices are accessed through character device
> > +special files named ``/dev/v4l-audio``
> > +
> > +Querying Capabilities
> > +=====================
> > +
> > +Device nodes supporting the audio memory-to-memory interface set the
> > +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
> > +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
> > +ioctl.
> > +
> > +Data Format Negotiation
> > +=======================
> > +
> > +The audio device uses the :ref:`format` ioctls to select the capture format.
> > +The audio buffer content format is bound to that selected format. In addition
> > +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
> > +supported as well.
> > +
> > +To use the :ref:`format` ioctls applications set the ``type`` field of the
> > +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
> > +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
> > +remainder of the :c:type:`v4l2_format` structure to 0.
> > +
> > +.. c:type:: v4l2_audio_format
> > +
> > +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
> > +
> > +.. flat-table:: struct v4l2_audio_format
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u32
> > + - ``pixelformat``
> > + - The sample format, set by the application. see :ref:`pixfmt-audio`
>
> pixelformat doesn't make any sense for audio: there are no pixels on a
> PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
> the values for snd_pcm_format_t.
>
> Yet, I would keep defining it as u32 (or u64?) instead of using a
> typedef int field there (snd_pcm_format_t), as the size of integer
> is different on 32 and 64 bit kernels.
>
>
> > + * - __u32
> > + - ``channels``
> > + - The channel number, set by the application. channel number range is
> > + [1, 32].
>
> Why not start on zero?
channels in audio are at least 1.
>
> > + * - __u32
> > + - ``buffersize``
> > + - Maximum buffer size in bytes required for data. The value is set by the
> > + driver.
> > diff --git a/Documentation/userspace-api/media/v4l/devices.rst b/Documentation/userspace-api/media/v4l/devices.rst
> > index 8bfbad65a9d4..758bd90f1c26 100644
> > --- a/Documentation/userspace-api/media/v4l/devices.rst
> > +++ b/Documentation/userspace-api/media/v4l/devices.rst
> > @@ -24,3 +24,4 @@ Interfaces
> > dev-event
> > dev-subdev
> > dev-meta
> > + dev-audio-mem2mem
> > diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> > index 000c154b0f98..42deb07f4ff4 100644
> > --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> > +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
> > @@ -96,6 +96,8 @@ the ``mbus_code`` field is handled differently:
> > ``V4L2_BUF_TYPE_VIDEO_OVERLAY``,
> > ``V4L2_BUF_TYPE_SDR_CAPTURE``,
> > ``V4L2_BUF_TYPE_SDR_OUTPUT``,
> > + ``V4L2_BUF_TYPE_AUDIO_CAPTURE``,
> > + ``V4L2_BUF_TYPE_AUDIO_OUTPUT``,
> > ``V4L2_BUF_TYPE_META_CAPTURE`` and
> > ``V4L2_BUF_TYPE_META_OUTPUT``.
> > See :c:type:`v4l2_buf_type`.
> > diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> > index 675c385e5aca..528fd9df41aa 100644
> > --- a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> > +++ b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
> > @@ -130,6 +130,10 @@ The format as returned by :ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>` must be identical
> > - ``meta``
> > - Definition of a metadata format, see :ref:`meta-formats`, used by
> > metadata capture devices.
> > + * - struct :c:type:`v4l2_audio_format`
> > + - ``audio``
> > + - Definition of a audio data format, see :ref:`audiomem2mem`, used by
> > + audio memory-to-memory devices
> > * - __u8
> > - ``raw_data``\ [200]
> > - Place holder for future extensions.
> > diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> > index da6d0b8e4c2c..e61152bb80d1 100644
> > --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> > +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> > @@ -29,6 +29,8 @@ replace symbol V4L2_FIELD_SEQ_TB :c:type:`v4l2_field`
> > replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field`
> >
> > # Documented enum v4l2_buf_type
> > +replace symbol V4L2_BUF_TYPE_AUDIO_CAPTURE :c:type:`v4l2_buf_type`
> > +replace symbol V4L2_BUF_TYPE_AUDIO_OUTPUT :c:type:`v4l2_buf_type`
> > replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type`
> > replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type`
> > replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`
> > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > index 54d572c3b515..16ab204d15b0 100644
> > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > @@ -791,6 +791,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> > case V4L2_BUF_TYPE_META_OUTPUT:
> > requested_sizes[0] = f->fmt.meta.buffersize;
> > break;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + requested_sizes[0] = f->fmt.audio.buffersize;
> > + break;
> > default:
> > return -EINVAL;
> > }
> > diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> > index 8c07400bd280..5e94db8dfdae 100644
> > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> > @@ -101,6 +101,7 @@ struct v4l2_format32 {
> > struct v4l2_sliced_vbi_format sliced;
> > struct v4l2_sdr_format sdr;
> > struct v4l2_meta_format meta;
> > + struct v4l2_audio_format audio;
> > __u8 raw_data[200]; /* user-defined */
> > } fmt;
> > };
> > @@ -166,6 +167,10 @@ static int get_v4l2_format32(struct v4l2_format *p64,
> > case V4L2_BUF_TYPE_META_OUTPUT:
> > return copy_from_user(&p64->fmt.meta, &p32->fmt.meta,
> > sizeof(p64->fmt.meta)) ? -EFAULT : 0;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + return copy_from_user(&p64->fmt.audio, &p32->fmt.audio,
> > + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
> > default:
> > return -EINVAL;
> > }
> > @@ -216,6 +221,10 @@ static int put_v4l2_format32(struct v4l2_format *p64,
> > case V4L2_BUF_TYPE_META_OUTPUT:
> > return copy_to_user(&p32->fmt.meta, &p64->fmt.meta,
> > sizeof(p64->fmt.meta)) ? -EFAULT : 0;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + return copy_to_user(&p32->fmt.audio, &p64->fmt.audio,
> > + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
> > default:
> > return -EINVAL;
> > }
> > diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> > index d13954bd31fd..bac008fcedc6 100644
> > --- a/drivers/media/v4l2-core/v4l2-dev.c
> > +++ b/drivers/media/v4l2-core/v4l2-dev.c
> > @@ -553,6 +553,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
> > bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH;
> > bool is_meta = vdev->vfl_type == VFL_TYPE_VIDEO &&
> > (vdev->device_caps & meta_caps);
> > + bool is_audio = vdev->vfl_type == VFL_TYPE_AUDIO;
> > bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
> > bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
> > bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;
> > @@ -666,6 +667,19 @@ static void determine_valid_ioctls(struct video_device *vdev)
> > SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_meta_out);
> > SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_meta_out);
> > }
> > + if (is_audio && is_rx) {
> > + /* audio capture specific ioctls */
> > + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_cap);
> > + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_cap);
> > + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_cap);
> > + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_cap);
> > + } else if (is_audio && is_tx) {
> > + /* audio output specific ioctls */
> > + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_out);
> > + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_out);
> > + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_out);
> > + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_out);
> > + }
> > if (is_vbi) {
> > /* vbi specific ioctls */
> > if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
> > @@ -929,6 +943,9 @@ int __video_register_device(struct video_device *vdev,
> > case VFL_TYPE_TOUCH:
> > name_base = "v4l-touch";
> > break;
> > + case VFL_TYPE_AUDIO:
> > + name_base = "v4l-audio";
> > + break;
> > default:
> > pr_err("%s called with unknown type: %d\n",
> > __func__, type);
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index 33076af4dfdb..e7be7c2f302d 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -188,6 +188,8 @@ const char *v4l2_type_names[] = {
> > [V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out",
> > [V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap",
> > [V4L2_BUF_TYPE_META_OUTPUT] = "meta-out",
> > + [V4L2_BUF_TYPE_AUDIO_CAPTURE] = "audio-cap",
> > + [V4L2_BUF_TYPE_AUDIO_OUTPUT] = "audio-out",
> > };
> > EXPORT_SYMBOL(v4l2_type_names);
> >
> > @@ -276,6 +278,7 @@ static void v4l_print_format(const void *arg, bool write_only)
> > const struct v4l2_sliced_vbi_format *sliced;
> > const struct v4l2_window *win;
> > const struct v4l2_meta_format *meta;
> > + const struct v4l2_audio_format *audio;
> > u32 pixelformat;
> > u32 planes;
> > unsigned i;
> > @@ -346,6 +349,13 @@ static void v4l_print_format(const void *arg, bool write_only)
> > pr_cont(", dataformat=%p4cc, buffersize=%u\n",
> > &pixelformat, meta->buffersize);
> > break;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + audio = &p->fmt.audio;
> > + pixelformat = audio->audioformat;
> > + pr_cont(", format=%p4cc, channels=%u, buffersize=%u\n",
> > + &pixelformat, audio->channels, audio->buffersize);
> > + break;
> > }
> > }
> >
> > @@ -927,6 +937,7 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
> > bool is_tch = vfd->vfl_type == VFL_TYPE_TOUCH;
> > bool is_meta = vfd->vfl_type == VFL_TYPE_VIDEO &&
> > (vfd->device_caps & meta_caps);
> > + bool is_audio = vfd->vfl_type == VFL_TYPE_AUDIO;
> > bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
> > bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
> >
> > @@ -992,6 +1003,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
> > if (is_meta && is_tx && ops->vidioc_g_fmt_meta_out)
> > return 0;
> > break;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + if (is_audio && is_rx && ops->vidioc_g_fmt_audio_cap)
> > + return 0;
> > + break;
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + if (is_audio && is_tx && ops->vidioc_g_fmt_audio_out)
> > + return 0;
> > + break;
> > default:
> > break;
> > }
> > @@ -1597,6 +1616,16 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
> > break;
> > ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg);
> > break;
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + if (unlikely(!ops->vidioc_enum_fmt_audio_cap))
> > + break;
> > + ret = ops->vidioc_enum_fmt_audio_cap(file, fh, arg);
> > + break;
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + if (unlikely(!ops->vidioc_enum_fmt_audio_out))
> > + break;
> > + ret = ops->vidioc_enum_fmt_audio_out(file, fh, arg);
> > + break;
> > }
> > if (ret == 0)
> > v4l_fill_fmtdesc(p);
> > @@ -1673,6 +1702,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
> > return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
> > case V4L2_BUF_TYPE_META_OUTPUT:
> > return ops->vidioc_g_fmt_meta_out(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + return ops->vidioc_g_fmt_audio_cap(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + return ops->vidioc_g_fmt_audio_out(file, fh, arg);
> > }
> > return -EINVAL;
> > }
> > @@ -1784,6 +1817,16 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
> > break;
> > memset_after(p, 0, fmt.meta);
> > return ops->vidioc_s_fmt_meta_out(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + if (unlikely(!ops->vidioc_s_fmt_audio_cap))
> > + break;
> > + memset_after(p, 0, fmt.audio);
> > + return ops->vidioc_s_fmt_audio_cap(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + if (unlikely(!ops->vidioc_s_fmt_audio_out))
> > + break;
> > + memset_after(p, 0, fmt.audio);
> > + return ops->vidioc_s_fmt_audio_out(file, fh, arg);
> > }
> > return -EINVAL;
> > }
> > @@ -1892,6 +1935,16 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
> > break;
> > memset_after(p, 0, fmt.meta);
> > return ops->vidioc_try_fmt_meta_out(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
> > + if (unlikely(!ops->vidioc_try_fmt_audio_cap))
> > + break;
> > + memset_after(p, 0, fmt.audio);
> > + return ops->vidioc_try_fmt_audio_cap(file, fh, arg);
> > + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
> > + if (unlikely(!ops->vidioc_try_fmt_audio_out))
> > + break;
> > + memset_after(p, 0, fmt.audio);
> > + return ops->vidioc_try_fmt_audio_out(file, fh, arg);
> > }
> > return -EINVAL;
> > }
> > diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> > index d82dfdbf6e58..82b63f82d43f 100644
> > --- a/include/media/v4l2-dev.h
> > +++ b/include/media/v4l2-dev.h
> > @@ -30,6 +30,7 @@
> > * @VFL_TYPE_SUBDEV: for V4L2 subdevices
> > * @VFL_TYPE_SDR: for Software Defined Radio tuners
> > * @VFL_TYPE_TOUCH: for touch sensors
> > + * @VFL_TYPE_AUDIO: for audio memory-to-memory devices
> > * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
> > */
> > enum vfl_devnode_type {
> > @@ -39,6 +40,7 @@ enum vfl_devnode_type {
> > VFL_TYPE_SUBDEV,
> > VFL_TYPE_SDR,
> > VFL_TYPE_TOUCH,
> > + VFL_TYPE_AUDIO,
> > VFL_TYPE_MAX /* Shall be the last one */
> > };
> >
> > diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> > index edb733f21604..f840cf740ce1 100644
> > --- a/include/media/v4l2-ioctl.h
> > +++ b/include/media/v4l2-ioctl.h
> > @@ -45,6 +45,12 @@ struct v4l2_fh;
> > * @vidioc_enum_fmt_meta_out: pointer to the function that implements
> > * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> > * for metadata output
> > + * @vidioc_enum_fmt_audio_cap: pointer to the function that implements
> > + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> > + * for audio capture
> > + * @vidioc_enum_fmt_audio_out: pointer to the function that implements
> > + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
> > + * for audio output
> > * @vidioc_g_fmt_vid_cap: pointer to the function that implements
> > * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
> > * in single plane mode
> > @@ -79,6 +85,10 @@ struct v4l2_fh;
> > * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> > * @vidioc_g_fmt_meta_out: pointer to the function that implements
> > * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> > + * @vidioc_g_fmt_audio_cap: pointer to the function that implements
> > + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> > + * @vidioc_g_fmt_audio_out: pointer to the function that implements
> > + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio output
> > * @vidioc_s_fmt_vid_cap: pointer to the function that implements
> > * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
> > * in single plane mode
> > @@ -113,6 +123,10 @@ struct v4l2_fh;
> > * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> > * @vidioc_s_fmt_meta_out: pointer to the function that implements
> > * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> > + * @vidioc_s_fmt_audio_cap: pointer to the function that implements
> > + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> > + * @vidioc_s_fmt_audio_out: pointer to the function that implements
> > + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio output
> > * @vidioc_try_fmt_vid_cap: pointer to the function that implements
> > * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
> > * in single plane mode
> > @@ -149,6 +163,10 @@ struct v4l2_fh;
> > * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
> > * @vidioc_try_fmt_meta_out: pointer to the function that implements
> > * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output
> > + * @vidioc_try_fmt_audio_cap: pointer to the function that implements
> > + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio capture
> > + * @vidioc_try_fmt_audio_out: pointer to the function that implements
> > + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio output
> > * @vidioc_reqbufs: pointer to the function that implements
> > * :ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
> > * @vidioc_querybuf: pointer to the function that implements
> > @@ -315,6 +333,10 @@ struct v4l2_ioctl_ops {
> > struct v4l2_fmtdesc *f);
> > int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh,
> > struct v4l2_fmtdesc *f);
> > + int (*vidioc_enum_fmt_audio_cap)(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f);
> > + int (*vidioc_enum_fmt_audio_out)(struct file *file, void *fh,
> > + struct v4l2_fmtdesc *f);
> >
> > /* VIDIOC_G_FMT handlers */
> > int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,
> > @@ -345,6 +367,10 @@ struct v4l2_ioctl_ops {
> > struct v4l2_format *f);
> > int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh,
> > struct v4l2_format *f);
> > + int (*vidioc_g_fmt_audio_cap)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> > + int (*vidioc_g_fmt_audio_out)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> >
> > /* VIDIOC_S_FMT handlers */
> > int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,
> > @@ -375,6 +401,10 @@ struct v4l2_ioctl_ops {
> > struct v4l2_format *f);
> > int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh,
> > struct v4l2_format *f);
> > + int (*vidioc_s_fmt_audio_cap)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> > + int (*vidioc_s_fmt_audio_out)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> >
> > /* VIDIOC_TRY_FMT handlers */
> > int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,
> > @@ -405,6 +435,10 @@ struct v4l2_ioctl_ops {
> > struct v4l2_format *f);
> > int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh,
> > struct v4l2_format *f);
> > + int (*vidioc_try_fmt_audio_cap)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> > + int (*vidioc_try_fmt_audio_out)(struct file *file, void *fh,
> > + struct v4l2_format *f);
> >
> > /* Buffer handlers */
> > int (*vidioc_reqbufs)(struct file *file, void *fh,
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 6cd65969c2b5..57c82eb158f1 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -153,6 +153,8 @@ enum v4l2_buf_type {
> > V4L2_BUF_TYPE_SDR_OUTPUT = 12,
> > V4L2_BUF_TYPE_META_CAPTURE = 13,
> > V4L2_BUF_TYPE_META_OUTPUT = 14,
> > + V4L2_BUF_TYPE_AUDIO_CAPTURE = 15,
> > + V4L2_BUF_TYPE_AUDIO_OUTPUT = 16,
> > /* Deprecated, do not use */
> > V4L2_BUF_TYPE_PRIVATE = 0x80,
> > };
> > @@ -169,6 +171,7 @@ enum v4l2_buf_type {
> > || (type) == V4L2_BUF_TYPE_VBI_OUTPUT \
> > || (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT \
> > || (type) == V4L2_BUF_TYPE_SDR_OUTPUT \
> > + || (type) == V4L2_BUF_TYPE_AUDIO_OUTPUT \
> > || (type) == V4L2_BUF_TYPE_META_OUTPUT)
> >
> > #define V4L2_TYPE_IS_CAPTURE(type) (!V4L2_TYPE_IS_OUTPUT(type))
> > @@ -2423,6 +2426,18 @@ struct v4l2_meta_format {
> > __u32 buffersize;
> > } __attribute__ ((packed));
> >
> > +/**
> > + * struct v4l2_audio_format - audio data format definition
> > + * @audioformat: little endian four character code (fourcc)
>
> Don't use fourcc here. Instead, use the types defined at snd_pcm_format_t.
In the earlier version of this patch series, fourcc is not used in this
struct v4l2_audio_format.
I use "__u32 audioformat", the value is from snd_pcm_format_t.
Using "__u32" is in order to avoid including the include/uapi/sound/asound.h
header.
And defined V4L2_AUDIO_FMT_LPCM for the v4l2_fmtdesc.pixelformat
#define V4L2_AUDIO_FMT_LPCM v4l2_fourcc('L', 'P', 'C', 'M') /*
audio lpcm */
After discussing with Hans, I use the current way for v4l audio.
Hans:
Not sure if you can accept going back to the previous solution?
You have already done similar changes in v4l-utils.
Best regards
Shengjiu Wang
>
> > + * @channels: channel numbers
> > + * @buffersize: maximum size in bytes required for data
> > + */
> > +struct v4l2_audio_format {
> > + __u32 audioformat;
> > + __u32 channels;
> > + __u32 buffersize;
> > +} __attribute__ ((packed));
> > +
> > /**
> > * struct v4l2_format - stream data format
> > * @type: enum v4l2_buf_type; type of the data stream
> > @@ -2431,6 +2446,7 @@ struct v4l2_meta_format {
> > * @win: definition of an overlaid image
> > * @vbi: raw VBI capture or output parameters
> > * @sliced: sliced VBI capture or output parameters
> > + * @audio: definition of an audio format
> > * @raw_data: placeholder for future extensions and custom formats
> > * @fmt: union of @pix, @pix_mp, @win, @vbi, @sliced, @sdr, @meta
> > * and @raw_data
> > @@ -2445,6 +2461,7 @@ struct v4l2_format {
> > struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
> > struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */
> > struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */
> > + struct v4l2_audio_format audio; /* V4L2_BUF_TYPE_AUDIO_CAPTURE */
> > __u8 raw_data[200]; /* user-defined */
> > } fmt;
> > };
>
>
>
> Thanks,
> Mauro
On Sat, Feb 17, 2024 at 6:42 PM Mauro Carvalho Chehab
<[email protected]> wrote:
>
> Em Thu, 18 Jan 2024 20:32:00 +0800
> Shengjiu Wang <[email protected]> escreveu:
>
> > Audio signal processing has the requirement for memory to
> > memory similar as Video.
> >
> > This patch is to add this support in v4l2 framework, defined
> > new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
> > V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
> > for audio case usage.
> >
> > The created audio device is named "/dev/v4l-audioX".
> >
> > Signed-off-by: Shengjiu Wang <[email protected]>
> > ---
> > .../userspace-api/media/v4l/buffer.rst | 6 ++
> > .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
> > .../userspace-api/media/v4l/devices.rst | 1 +
> > .../media/v4l/vidioc-enum-fmt.rst | 2 +
> > .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
> > .../media/videodev2.h.rst.exceptions | 2 +
> > .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
> > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
> > drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
> > drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
> > include/media/v4l2-dev.h | 2 +
> > include/media/v4l2-ioctl.h | 34 +++++++++
> > include/uapi/linux/videodev2.h | 17 +++++
> > 13 files changed, 222 insertions(+)
> > create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> >
> > diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> > index 52bbee81c080..a3754ca6f0d6 100644
> > --- a/Documentation/userspace-api/media/v4l/buffer.rst
> > +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> > @@ -438,6 +438,12 @@ enum v4l2_buf_type
> > * - ``V4L2_BUF_TYPE_META_OUTPUT``
> > - 14
>
> > - Buffer for metadata output, see :ref:`metadata`.
> > + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
> > + - 15
> > + - Buffer for audio capture, see :ref:`audio`.
> > + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
> > + - 16
>
> Hmm... alsa APi define input/output as:
> enum {
> SNDRV_PCM_STREAM_PLAYBACK = 0,
> SNDRV_PCM_STREAM_CAPTURE,
> SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
> };
>
>
> I would use a namespace as close as possible to the
> ALSA API. Also, we're not talking about V4L2, but, instead
> audio. so, not sure if I like the prefix to start with
> V4L2_. Maybe ALSA_?
>
> So, a better namespace would be:
>
> ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
> and
> ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
>
The API is still V4L2, and all the other non-video buf types also use
the V4L2_ prefix, so perhaps that's good here as well?
Whether AUDIO or PCM_STREAM makes more sense goes outside of my
expertise. Subjectively, a PCM stream sounds more specific than an
audio stream. Do those buf types also support non-PCM audio streams?
> > + - Buffer for audio output, see :ref:`audio`.
> >
> >
> > .. _buffer-flags:
> > diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > new file mode 100644
> > index 000000000000..68faecfe3a02
> > --- /dev/null
> > +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > @@ -0,0 +1,71 @@
> > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> > +
> > +.. _audiomem2mem:
> > +
> > +********************************
> > +Audio Memory-To-Memory Interface
> > +********************************
> > +
> > +An audio memory-to-memory device can compress, decompress, transform, or
> > +otherwise convert audio data from one format into another format, in memory.
> > +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
> > +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
> > +audio postprocessing.
> > +
> > +A memory-to-memory audio node supports both output (sending audio frames from
> > +memory to the hardware) and capture (receiving the processed audio frames
> > +from the hardware into memory) stream I/O. An application will have to
> > +setup the stream I/O for both sides and finally call
> > +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
> > +start the hardware.
> > +
> > +Memory-to-memory devices function as a shared resource: you can
> > +open the audio node multiple times, each application setting up their
> > +own properties that are local to the file handle, and each can use
> > +it independently from the others. The driver will arbitrate access to
> > +the hardware and reprogram it whenever another file handler gets access.
> > +
> > +Audio memory-to-memory devices are accessed through character device
> > +special files named ``/dev/v4l-audio``
> > +
> > +Querying Capabilities
> > +=====================
> > +
> > +Device nodes supporting the audio memory-to-memory interface set the
> > +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
> > +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
> > +ioctl.
> > +
> > +Data Format Negotiation
> > +=======================
> > +
> > +The audio device uses the :ref:`format` ioctls to select the capture format.
> > +The audio buffer content format is bound to that selected format. In addition
> > +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
> > +supported as well.
> > +
> > +To use the :ref:`format` ioctls applications set the ``type`` field of the
> > +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
> > +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
> > +remainder of the :c:type:`v4l2_format` structure to 0.
> > +
> > +.. c:type:: v4l2_audio_format
> > +
> > +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
> > +
> > +.. flat-table:: struct v4l2_audio_format
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u32
> > + - ``pixelformat``
> > + - The sample format, set by the application. see :ref:`pixfmt-audio`
>
> pixelformat doesn't make any sense for audio: there are no pixels on a
> PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
> the values for snd_pcm_format_t.
>
+1
FWIW v4l2_meta_format uses the name "dataformat".
Actually, I just realized that the C code actually uses the name
"audioformat". Tbh., after reading the kerneldoc comment, my
subjective preference would be on "sample_format", since that's
exactly what it is.
> Yet, I would keep defining it as u32 (or u64?) instead of using a
> typedef int field there (snd_pcm_format_t), as the size of integer
> is different on 32 and 64 bit kernels.
+1
Best regards,
Tomasz
On Thu, Jan 18, 2024 at 10:15 PM Shengjiu Wang <[email protected]> wrote:
>
> Audio signal processing has the requirement for memory to
> memory similar as Video.
>
> This patch is to add this support in v4l2 framework, defined
> new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
> V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
> for audio case usage.
>
> The created audio device is named "/dev/v4l-audioX".
>
> Signed-off-by: Shengjiu Wang <[email protected]>
> ---
> .../userspace-api/media/v4l/buffer.rst | 6 ++
> .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
> .../userspace-api/media/v4l/devices.rst | 1 +
> .../media/v4l/vidioc-enum-fmt.rst | 2 +
> .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
> .../media/videodev2.h.rst.exceptions | 2 +
> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
> drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
> drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
> include/media/v4l2-dev.h | 2 +
> include/media/v4l2-ioctl.h | 34 +++++++++
> include/uapi/linux/videodev2.h | 17 +++++
> 13 files changed, 222 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
For drivers/media/common/videobuf2:
Acked-by: Tomasz Figa <[email protected]>
Best regards,
Tomasz
On Wed, Feb 21, 2024 at 12:30 PM Tomasz Figa <[email protected]> wrote:
>
> On Sat, Feb 17, 2024 at 6:42 PM Mauro Carvalho Chehab
> <[email protected]> wrote:
> >
> > Em Thu, 18 Jan 2024 20:32:00 +0800
> > Shengjiu Wang <[email protected]> escreveu:
> >
> > > Audio signal processing has the requirement for memory to
> > > memory similar as Video.
> > >
> > > This patch is to add this support in v4l2 framework, defined
> > > new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
> > > V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
> > > for audio case usage.
> > >
> > > The created audio device is named "/dev/v4l-audioX".
> > >
> > > Signed-off-by: Shengjiu Wang <[email protected]>
> > > ---
> > > .../userspace-api/media/v4l/buffer.rst | 6 ++
> > > .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
> > > .../userspace-api/media/v4l/devices.rst | 1 +
> > > .../media/v4l/vidioc-enum-fmt.rst | 2 +
> > > .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
> > > .../media/videodev2.h.rst.exceptions | 2 +
> > > .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
> > > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
> > > drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
> > > drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
> > > include/media/v4l2-dev.h | 2 +
> > > include/media/v4l2-ioctl.h | 34 +++++++++
> > > include/uapi/linux/videodev2.h | 17 +++++
> > > 13 files changed, 222 insertions(+)
> > > create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > >
> > > diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> > > index 52bbee81c080..a3754ca6f0d6 100644
> > > --- a/Documentation/userspace-api/media/v4l/buffer.rst
> > > +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> > > @@ -438,6 +438,12 @@ enum v4l2_buf_type
> > > * - ``V4L2_BUF_TYPE_META_OUTPUT``
> > > - 14
> >
> > > - Buffer for metadata output, see :ref:`metadata`.
> > > + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
> > > + - 15
> > > + - Buffer for audio capture, see :ref:`audio`.
> > > + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
> > > + - 16
> >
> > Hmm... alsa APi define input/output as:
> > enum {
> > SNDRV_PCM_STREAM_PLAYBACK = 0,
> > SNDRV_PCM_STREAM_CAPTURE,
> > SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
> > };
> >
> >
> > I would use a namespace as close as possible to the
> > ALSA API. Also, we're not talking about V4L2, but, instead
> > audio. so, not sure if I like the prefix to start with
> > V4L2_. Maybe ALSA_?
> >
> > So, a better namespace would be:
> >
> > ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
> > and
> > ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
> >
>
> The API is still V4L2, and all the other non-video buf types also use
> the V4L2_ prefix, so perhaps that's good here as well?
>
> Whether AUDIO or PCM_STREAM makes more sense goes outside of my
> expertise. Subjectively, a PCM stream sounds more specific than an
> audio stream. Do those buf types also support non-PCM audio streams?
Currently I use it for PCM, but I think it can also be used for non-PCM.
So use the below name?
V4L2_BUF_TYPE_AUDIO_CAPTURE
V4L2_BUF_TYPE_AUDIO_PLAYBACK
>
> > > + - Buffer for audio output, see :ref:`audio`.
> > >
> > >
> > > .. _buffer-flags:
> > > diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > > new file mode 100644
> > > index 000000000000..68faecfe3a02
> > > --- /dev/null
> > > +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
> > > @@ -0,0 +1,71 @@
> > > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> > > +
> > > +.. _audiomem2mem:
> > > +
> > > +********************************
> > > +Audio Memory-To-Memory Interface
> > > +********************************
> > > +
> > > +An audio memory-to-memory device can compress, decompress, transform, or
> > > +otherwise convert audio data from one format into another format, in memory.
> > > +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
> > > +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
> > > +audio postprocessing.
> > > +
> > > +A memory-to-memory audio node supports both output (sending audio frames from
> > > +memory to the hardware) and capture (receiving the processed audio frames
> > > +from the hardware into memory) stream I/O. An application will have to
> > > +setup the stream I/O for both sides and finally call
> > > +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
> > > +start the hardware.
> > > +
> > > +Memory-to-memory devices function as a shared resource: you can
> > > +open the audio node multiple times, each application setting up their
> > > +own properties that are local to the file handle, and each can use
> > > +it independently from the others. The driver will arbitrate access to
> > > +the hardware and reprogram it whenever another file handler gets access.
> > > +
> > > +Audio memory-to-memory devices are accessed through character device
> > > +special files named ``/dev/v4l-audio``
> > > +
> > > +Querying Capabilities
> > > +=====================
> > > +
> > > +Device nodes supporting the audio memory-to-memory interface set the
> > > +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
> > > +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
> > > +ioctl.
> > > +
> > > +Data Format Negotiation
> > > +=======================
> > > +
> > > +The audio device uses the :ref:`format` ioctls to select the capture format.
> > > +The audio buffer content format is bound to that selected format. In addition
> > > +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
> > > +supported as well.
> > > +
> > > +To use the :ref:`format` ioctls applications set the ``type`` field of the
> > > +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
> > > +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
> > > +remainder of the :c:type:`v4l2_format` structure to 0.
> > > +
> > > +.. c:type:: v4l2_audio_format
> > > +
> > > +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
> > > +
> > > +.. flat-table:: struct v4l2_audio_format
> > > + :header-rows: 0
> > > + :stub-columns: 0
> > > + :widths: 1 1 2
> > > +
> > > + * - __u32
> > > + - ``pixelformat``
> > > + - The sample format, set by the application. see :ref:`pixfmt-audio`
> >
> > pixelformat doesn't make any sense for audio: there are no pixels on a
> > PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
> > the values for snd_pcm_format_t.
> >
>
> +1
>
> FWIW v4l2_meta_format uses the name "dataformat".
>
> Actually, I just realized that the C code actually uses the name
> "audioformat". Tbh., after reading the kerneldoc comment, my
> subjective preference would be on "sample_format", since that's
> exactly what it is.
>
Ok, I will change it to sampleformat.
Best Regards
Shengjiu Wang
> > Yet, I would keep defining it as u32 (or u64?) instead of using a
> > typedef int field there (snd_pcm_format_t), as the size of integer
> > is different on 32 and 64 bit kernels.
>
> +1
>
> Best regards,
> Tomasz
On 17/02/2024 10:42, Mauro Carvalho Chehab wrote:
> Em Thu, 18 Jan 2024 20:32:00 +0800
> Shengjiu Wang <[email protected]> escreveu:
>
>> Audio signal processing has the requirement for memory to
>> memory similar as Video.
>>
>> This patch is to add this support in v4l2 framework, defined
>> new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
>> V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
>> for audio case usage.
>>
>> The created audio device is named "/dev/v4l-audioX".
>>
>> Signed-off-by: Shengjiu Wang <[email protected]>
>> ---
>> .../userspace-api/media/v4l/buffer.rst | 6 ++
>> .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
>> .../userspace-api/media/v4l/devices.rst | 1 +
>> .../media/v4l/vidioc-enum-fmt.rst | 2 +
>> .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
>> .../media/videodev2.h.rst.exceptions | 2 +
>> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
>> drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
>> drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
>> include/media/v4l2-dev.h | 2 +
>> include/media/v4l2-ioctl.h | 34 +++++++++
>> include/uapi/linux/videodev2.h | 17 +++++
>> 13 files changed, 222 insertions(+)
>> create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>>
>> diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
>> index 52bbee81c080..a3754ca6f0d6 100644
>> --- a/Documentation/userspace-api/media/v4l/buffer.rst
>> +++ b/Documentation/userspace-api/media/v4l/buffer.rst
>> @@ -438,6 +438,12 @@ enum v4l2_buf_type
>> * - ``V4L2_BUF_TYPE_META_OUTPUT``
>> - 14
>
>> - Buffer for metadata output, see :ref:`metadata`.
>> + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
>> + - 15
>> + - Buffer for audio capture, see :ref:`audio`.
>> + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
>> + - 16
>
> Hmm... alsa APi define input/output as:
> enum {
> SNDRV_PCM_STREAM_PLAYBACK = 0,
> SNDRV_PCM_STREAM_CAPTURE,
> SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
> };
>
>
> I would use a namespace as close as possible to the
> ALSA API. Also, we're not talking about V4L2, but, instead
> audio. so, not sure if I like the prefix to start with
> V4L2_. Maybe ALSA_?
>
> So, a better namespace would be:
>
> ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
> and
> ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
>
>> + - Buffer for audio output, see :ref:`audio`.
>>
>>
>> .. _buffer-flags:
>> diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>> new file mode 100644
>> index 000000000000..68faecfe3a02
>> --- /dev/null
>> +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>> @@ -0,0 +1,71 @@
>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
>> +
>> +.. _audiomem2mem:
>> +
>> +********************************
>> +Audio Memory-To-Memory Interface
>> +********************************
>> +
>> +An audio memory-to-memory device can compress, decompress, transform, or
>> +otherwise convert audio data from one format into another format, in memory.
>> +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
>> +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
>> +audio postprocessing.
>> +
>> +A memory-to-memory audio node supports both output (sending audio frames from
>> +memory to the hardware) and capture (receiving the processed audio frames
>> +from the hardware into memory) stream I/O. An application will have to
>> +setup the stream I/O for both sides and finally call
>> +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
>> +start the hardware.
>> +
>> +Memory-to-memory devices function as a shared resource: you can
>> +open the audio node multiple times, each application setting up their
>> +own properties that are local to the file handle, and each can use
>> +it independently from the others. The driver will arbitrate access to
>> +the hardware and reprogram it whenever another file handler gets access.
>> +
>> +Audio memory-to-memory devices are accessed through character device
>> +special files named ``/dev/v4l-audio``
>> +
>> +Querying Capabilities
>> +=====================
>> +
>> +Device nodes supporting the audio memory-to-memory interface set the
>> +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
>> +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
>> +ioctl.
>> +
>> +Data Format Negotiation
>> +=======================
>> +
>> +The audio device uses the :ref:`format` ioctls to select the capture format.
>> +The audio buffer content format is bound to that selected format. In addition
>> +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
>> +supported as well.
>> +
>> +To use the :ref:`format` ioctls applications set the ``type`` field of the
>> +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
>> +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
>> +remainder of the :c:type:`v4l2_format` structure to 0.
>> +
>> +.. c:type:: v4l2_audio_format
>> +
>> +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
>> +
>> +.. flat-table:: struct v4l2_audio_format
>> + :header-rows: 0
>> + :stub-columns: 0
>> + :widths: 1 1 2
>> +
>> + * - __u32
>> + - ``pixelformat``
>> + - The sample format, set by the application. see :ref:`pixfmt-audio`
>
> pixelformat doesn't make any sense for audio: there are no pixels on a
Ah, that's a doc bug: this field is called audioformat in the struct, not
pixelformat. I missed this one in my review.
Regards,
Hans
> PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
> the values for snd_pcm_format_t.
>
> Yet, I would keep defining it as u32 (or u64?) instead of using a
> typedef int field there (snd_pcm_format_t), as the size of integer
> is different on 32 and 64 bit kernels.
>
>
>> + * - __u32
>> + - ``channels``
>> + - The channel number, set by the application. channel number range is
>> + [1, 32].
>
> Why not start on zero?
>
>> + * - __u32
>> + - ``buffersize``
>> + - Maximum buffer size in bytes required for data. The value is set by the
>> + driver.
>> diff --git a/Documentation/userspace-api/media/v4l/devices.rst b/Documentation/userspace-api/media/v4l/devices.rst
>> index 8bfbad65a9d4..758bd90f1c26 100644
>> --- a/Documentation/userspace-api/media/v4l/devices.rst
>> +++ b/Documentation/userspace-api/media/v4l/devices.rst
>> @@ -24,3 +24,4 @@ Interfaces
>> dev-event
>> dev-subdev
>> dev-meta
>> + dev-audio-mem2mem
>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> index 000c154b0f98..42deb07f4ff4 100644
>> --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> @@ -96,6 +96,8 @@ the ``mbus_code`` field is handled differently:
>> ``V4L2_BUF_TYPE_VIDEO_OVERLAY``,
>> ``V4L2_BUF_TYPE_SDR_CAPTURE``,
>> ``V4L2_BUF_TYPE_SDR_OUTPUT``,
>> + ``V4L2_BUF_TYPE_AUDIO_CAPTURE``,
>> + ``V4L2_BUF_TYPE_AUDIO_OUTPUT``,
>> ``V4L2_BUF_TYPE_META_CAPTURE`` and
>> ``V4L2_BUF_TYPE_META_OUTPUT``.
>> See :c:type:`v4l2_buf_type`.
>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
>> index 675c385e5aca..528fd9df41aa 100644
>> --- a/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
>> +++ b/Documentation/userspace-api/media/v4l/vidioc-g-fmt.rst
>> @@ -130,6 +130,10 @@ The format as returned by :ref:`VIDIOC_TRY_FMT <VIDIOC_G_FMT>` must be identical
>> - ``meta``
>> - Definition of a metadata format, see :ref:`meta-formats`, used by
>> metadata capture devices.
>> + * - struct :c:type:`v4l2_audio_format`
>> + - ``audio``
>> + - Definition of a audio data format, see :ref:`audiomem2mem`, used by
>> + audio memory-to-memory devices
>> * - __u8
>> - ``raw_data``\ [200]
>> - Place holder for future extensions.
>> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> index da6d0b8e4c2c..e61152bb80d1 100644
>> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> @@ -29,6 +29,8 @@ replace symbol V4L2_FIELD_SEQ_TB :c:type:`v4l2_field`
>> replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field`
>>
>> # Documented enum v4l2_buf_type
>> +replace symbol V4L2_BUF_TYPE_AUDIO_CAPTURE :c:type:`v4l2_buf_type`
>> +replace symbol V4L2_BUF_TYPE_AUDIO_OUTPUT :c:type:`v4l2_buf_type`
>> replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type`
>> replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type`
>> replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index 54d572c3b515..16ab204d15b0 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -791,6 +791,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>> case V4L2_BUF_TYPE_META_OUTPUT:
>> requested_sizes[0] = f->fmt.meta.buffersize;
>> break;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + requested_sizes[0] = f->fmt.audio.buffersize;
>> + break;
>> default:
>> return -EINVAL;
>> }
>> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> index 8c07400bd280..5e94db8dfdae 100644
>> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> @@ -101,6 +101,7 @@ struct v4l2_format32 {
>> struct v4l2_sliced_vbi_format sliced;
>> struct v4l2_sdr_format sdr;
>> struct v4l2_meta_format meta;
>> + struct v4l2_audio_format audio;
>> __u8 raw_data[200]; /* user-defined */
>> } fmt;
>> };
>> @@ -166,6 +167,10 @@ static int get_v4l2_format32(struct v4l2_format *p64,
>> case V4L2_BUF_TYPE_META_OUTPUT:
>> return copy_from_user(&p64->fmt.meta, &p32->fmt.meta,
>> sizeof(p64->fmt.meta)) ? -EFAULT : 0;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + return copy_from_user(&p64->fmt.audio, &p32->fmt.audio,
>> + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
>> default:
>> return -EINVAL;
>> }
>> @@ -216,6 +221,10 @@ static int put_v4l2_format32(struct v4l2_format *p64,
>> case V4L2_BUF_TYPE_META_OUTPUT:
>> return copy_to_user(&p32->fmt.meta, &p64->fmt.meta,
>> sizeof(p64->fmt.meta)) ? -EFAULT : 0;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + return copy_to_user(&p32->fmt.audio, &p64->fmt.audio,
>> + sizeof(p64->fmt.audio)) ? -EFAULT : 0;
>> default:
>> return -EINVAL;
>> }
>> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
>> index d13954bd31fd..bac008fcedc6 100644
>> --- a/drivers/media/v4l2-core/v4l2-dev.c
>> +++ b/drivers/media/v4l2-core/v4l2-dev.c
>> @@ -553,6 +553,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
>> bool is_tch = vdev->vfl_type == VFL_TYPE_TOUCH;
>> bool is_meta = vdev->vfl_type == VFL_TYPE_VIDEO &&
>> (vdev->device_caps & meta_caps);
>> + bool is_audio = vdev->vfl_type == VFL_TYPE_AUDIO;
>> bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
>> bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
>> bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;
>> @@ -666,6 +667,19 @@ static void determine_valid_ioctls(struct video_device *vdev)
>> SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_meta_out);
>> SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_meta_out);
>> }
>> + if (is_audio && is_rx) {
>> + /* audio capture specific ioctls */
>> + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_cap);
>> + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_cap);
>> + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_cap);
>> + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_cap);
>> + } else if (is_audio && is_tx) {
>> + /* audio output specific ioctls */
>> + SET_VALID_IOCTL(ops, VIDIOC_ENUM_FMT, vidioc_enum_fmt_audio_out);
>> + SET_VALID_IOCTL(ops, VIDIOC_G_FMT, vidioc_g_fmt_audio_out);
>> + SET_VALID_IOCTL(ops, VIDIOC_S_FMT, vidioc_s_fmt_audio_out);
>> + SET_VALID_IOCTL(ops, VIDIOC_TRY_FMT, vidioc_try_fmt_audio_out);
>> + }
>> if (is_vbi) {
>> /* vbi specific ioctls */
>> if ((is_rx && (ops->vidioc_g_fmt_vbi_cap ||
>> @@ -929,6 +943,9 @@ int __video_register_device(struct video_device *vdev,
>> case VFL_TYPE_TOUCH:
>> name_base = "v4l-touch";
>> break;
>> + case VFL_TYPE_AUDIO:
>> + name_base = "v4l-audio";
>> + break;
>> default:
>> pr_err("%s called with unknown type: %d\n",
>> __func__, type);
>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>> index 33076af4dfdb..e7be7c2f302d 100644
>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>> @@ -188,6 +188,8 @@ const char *v4l2_type_names[] = {
>> [V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out",
>> [V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap",
>> [V4L2_BUF_TYPE_META_OUTPUT] = "meta-out",
>> + [V4L2_BUF_TYPE_AUDIO_CAPTURE] = "audio-cap",
>> + [V4L2_BUF_TYPE_AUDIO_OUTPUT] = "audio-out",
>> };
>> EXPORT_SYMBOL(v4l2_type_names);
>>
>> @@ -276,6 +278,7 @@ static void v4l_print_format(const void *arg, bool write_only)
>> const struct v4l2_sliced_vbi_format *sliced;
>> const struct v4l2_window *win;
>> const struct v4l2_meta_format *meta;
>> + const struct v4l2_audio_format *audio;
>> u32 pixelformat;
>> u32 planes;
>> unsigned i;
>> @@ -346,6 +349,13 @@ static void v4l_print_format(const void *arg, bool write_only)
>> pr_cont(", dataformat=%p4cc, buffersize=%u\n",
>> &pixelformat, meta->buffersize);
>> break;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + audio = &p->fmt.audio;
>> + pixelformat = audio->audioformat;
>> + pr_cont(", format=%p4cc, channels=%u, buffersize=%u\n",
>> + &pixelformat, audio->channels, audio->buffersize);
>> + break;
>> }
>> }
>>
>> @@ -927,6 +937,7 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
>> bool is_tch = vfd->vfl_type == VFL_TYPE_TOUCH;
>> bool is_meta = vfd->vfl_type == VFL_TYPE_VIDEO &&
>> (vfd->device_caps & meta_caps);
>> + bool is_audio = vfd->vfl_type == VFL_TYPE_AUDIO;
>> bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
>> bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
>>
>> @@ -992,6 +1003,14 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
>> if (is_meta && is_tx && ops->vidioc_g_fmt_meta_out)
>> return 0;
>> break;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + if (is_audio && is_rx && ops->vidioc_g_fmt_audio_cap)
>> + return 0;
>> + break;
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + if (is_audio && is_tx && ops->vidioc_g_fmt_audio_out)
>> + return 0;
>> + break;
>> default:
>> break;
>> }
>> @@ -1597,6 +1616,16 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>> break;
>> ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg);
>> break;
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + if (unlikely(!ops->vidioc_enum_fmt_audio_cap))
>> + break;
>> + ret = ops->vidioc_enum_fmt_audio_cap(file, fh, arg);
>> + break;
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + if (unlikely(!ops->vidioc_enum_fmt_audio_out))
>> + break;
>> + ret = ops->vidioc_enum_fmt_audio_out(file, fh, arg);
>> + break;
>> }
>> if (ret == 0)
>> v4l_fill_fmtdesc(p);
>> @@ -1673,6 +1702,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
>> return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
>> case V4L2_BUF_TYPE_META_OUTPUT:
>> return ops->vidioc_g_fmt_meta_out(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + return ops->vidioc_g_fmt_audio_cap(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + return ops->vidioc_g_fmt_audio_out(file, fh, arg);
>> }
>> return -EINVAL;
>> }
>> @@ -1784,6 +1817,16 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
>> break;
>> memset_after(p, 0, fmt.meta);
>> return ops->vidioc_s_fmt_meta_out(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + if (unlikely(!ops->vidioc_s_fmt_audio_cap))
>> + break;
>> + memset_after(p, 0, fmt.audio);
>> + return ops->vidioc_s_fmt_audio_cap(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + if (unlikely(!ops->vidioc_s_fmt_audio_out))
>> + break;
>> + memset_after(p, 0, fmt.audio);
>> + return ops->vidioc_s_fmt_audio_out(file, fh, arg);
>> }
>> return -EINVAL;
>> }
>> @@ -1892,6 +1935,16 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
>> break;
>> memset_after(p, 0, fmt.meta);
>> return ops->vidioc_try_fmt_meta_out(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_CAPTURE:
>> + if (unlikely(!ops->vidioc_try_fmt_audio_cap))
>> + break;
>> + memset_after(p, 0, fmt.audio);
>> + return ops->vidioc_try_fmt_audio_cap(file, fh, arg);
>> + case V4L2_BUF_TYPE_AUDIO_OUTPUT:
>> + if (unlikely(!ops->vidioc_try_fmt_audio_out))
>> + break;
>> + memset_after(p, 0, fmt.audio);
>> + return ops->vidioc_try_fmt_audio_out(file, fh, arg);
>> }
>> return -EINVAL;
>> }
>> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
>> index d82dfdbf6e58..82b63f82d43f 100644
>> --- a/include/media/v4l2-dev.h
>> +++ b/include/media/v4l2-dev.h
>> @@ -30,6 +30,7 @@
>> * @VFL_TYPE_SUBDEV: for V4L2 subdevices
>> * @VFL_TYPE_SDR: for Software Defined Radio tuners
>> * @VFL_TYPE_TOUCH: for touch sensors
>> + * @VFL_TYPE_AUDIO: for audio memory-to-memory devices
>> * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
>> */
>> enum vfl_devnode_type {
>> @@ -39,6 +40,7 @@ enum vfl_devnode_type {
>> VFL_TYPE_SUBDEV,
>> VFL_TYPE_SDR,
>> VFL_TYPE_TOUCH,
>> + VFL_TYPE_AUDIO,
>> VFL_TYPE_MAX /* Shall be the last one */
>> };
>>
>> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
>> index edb733f21604..f840cf740ce1 100644
>> --- a/include/media/v4l2-ioctl.h
>> +++ b/include/media/v4l2-ioctl.h
>> @@ -45,6 +45,12 @@ struct v4l2_fh;
>> * @vidioc_enum_fmt_meta_out: pointer to the function that implements
>> * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
>> * for metadata output
>> + * @vidioc_enum_fmt_audio_cap: pointer to the function that implements
>> + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
>> + * for audio capture
>> + * @vidioc_enum_fmt_audio_out: pointer to the function that implements
>> + * :ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
>> + * for audio output
>> * @vidioc_g_fmt_vid_cap: pointer to the function that implements
>> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
>> * in single plane mode
>> @@ -79,6 +85,10 @@ struct v4l2_fh;
>> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
>> * @vidioc_g_fmt_meta_out: pointer to the function that implements
>> * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output
>> + * @vidioc_g_fmt_audio_cap: pointer to the function that implements
>> + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio capture
>> + * @vidioc_g_fmt_audio_out: pointer to the function that implements
>> + * :ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for audio output
>> * @vidioc_s_fmt_vid_cap: pointer to the function that implements
>> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
>> * in single plane mode
>> @@ -113,6 +123,10 @@ struct v4l2_fh;
>> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
>> * @vidioc_s_fmt_meta_out: pointer to the function that implements
>> * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output
>> + * @vidioc_s_fmt_audio_cap: pointer to the function that implements
>> + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio capture
>> + * @vidioc_s_fmt_audio_out: pointer to the function that implements
>> + * :ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for audio output
>> * @vidioc_try_fmt_vid_cap: pointer to the function that implements
>> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
>> * in single plane mode
>> @@ -149,6 +163,10 @@ struct v4l2_fh;
>> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
>> * @vidioc_try_fmt_meta_out: pointer to the function that implements
>> * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output
>> + * @vidioc_try_fmt_audio_cap: pointer to the function that implements
>> + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio capture
>> + * @vidioc_try_fmt_audio_out: pointer to the function that implements
>> + * :ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for audio output
>> * @vidioc_reqbufs: pointer to the function that implements
>> * :ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
>> * @vidioc_querybuf: pointer to the function that implements
>> @@ -315,6 +333,10 @@ struct v4l2_ioctl_ops {
>> struct v4l2_fmtdesc *f);
>> int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh,
>> struct v4l2_fmtdesc *f);
>> + int (*vidioc_enum_fmt_audio_cap)(struct file *file, void *fh,
>> + struct v4l2_fmtdesc *f);
>> + int (*vidioc_enum_fmt_audio_out)(struct file *file, void *fh,
>> + struct v4l2_fmtdesc *f);
>>
>> /* VIDIOC_G_FMT handlers */
>> int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,
>> @@ -345,6 +367,10 @@ struct v4l2_ioctl_ops {
>> struct v4l2_format *f);
>> int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh,
>> struct v4l2_format *f);
>> + int (*vidioc_g_fmt_audio_cap)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>> + int (*vidioc_g_fmt_audio_out)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>>
>> /* VIDIOC_S_FMT handlers */
>> int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,
>> @@ -375,6 +401,10 @@ struct v4l2_ioctl_ops {
>> struct v4l2_format *f);
>> int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh,
>> struct v4l2_format *f);
>> + int (*vidioc_s_fmt_audio_cap)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>> + int (*vidioc_s_fmt_audio_out)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>>
>> /* VIDIOC_TRY_FMT handlers */
>> int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,
>> @@ -405,6 +435,10 @@ struct v4l2_ioctl_ops {
>> struct v4l2_format *f);
>> int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh,
>> struct v4l2_format *f);
>> + int (*vidioc_try_fmt_audio_cap)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>> + int (*vidioc_try_fmt_audio_out)(struct file *file, void *fh,
>> + struct v4l2_format *f);
>>
>> /* Buffer handlers */
>> int (*vidioc_reqbufs)(struct file *file, void *fh,
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 6cd65969c2b5..57c82eb158f1 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -153,6 +153,8 @@ enum v4l2_buf_type {
>> V4L2_BUF_TYPE_SDR_OUTPUT = 12,
>> V4L2_BUF_TYPE_META_CAPTURE = 13,
>> V4L2_BUF_TYPE_META_OUTPUT = 14,
>> + V4L2_BUF_TYPE_AUDIO_CAPTURE = 15,
>> + V4L2_BUF_TYPE_AUDIO_OUTPUT = 16,
>> /* Deprecated, do not use */
>> V4L2_BUF_TYPE_PRIVATE = 0x80,
>> };
>> @@ -169,6 +171,7 @@ enum v4l2_buf_type {
>> || (type) == V4L2_BUF_TYPE_VBI_OUTPUT \
>> || (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT \
>> || (type) == V4L2_BUF_TYPE_SDR_OUTPUT \
>> + || (type) == V4L2_BUF_TYPE_AUDIO_OUTPUT \
>> || (type) == V4L2_BUF_TYPE_META_OUTPUT)
>>
>> #define V4L2_TYPE_IS_CAPTURE(type) (!V4L2_TYPE_IS_OUTPUT(type))
>> @@ -2423,6 +2426,18 @@ struct v4l2_meta_format {
>> __u32 buffersize;
>> } __attribute__ ((packed));
>>
>> +/**
>> + * struct v4l2_audio_format - audio data format definition
>> + * @audioformat: little endian four character code (fourcc)
>
> Don't use fourcc here. Instead, use the types defined at snd_pcm_format_t.
>
>> + * @channels: channel numbers
>> + * @buffersize: maximum size in bytes required for data
>> + */
>> +struct v4l2_audio_format {
>> + __u32 audioformat;
>> + __u32 channels;
>> + __u32 buffersize;
>> +} __attribute__ ((packed));
>> +
>> /**
>> * struct v4l2_format - stream data format
>> * @type: enum v4l2_buf_type; type of the data stream
>> @@ -2431,6 +2446,7 @@ struct v4l2_meta_format {
>> * @win: definition of an overlaid image
>> * @vbi: raw VBI capture or output parameters
>> * @sliced: sliced VBI capture or output parameters
>> + * @audio: definition of an audio format
>> * @raw_data: placeholder for future extensions and custom formats
>> * @fmt: union of @pix, @pix_mp, @win, @vbi, @sliced, @sdr, @meta
>> * and @raw_data
>> @@ -2445,6 +2461,7 @@ struct v4l2_format {
>> struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
>> struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */
>> struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */
>> + struct v4l2_audio_format audio; /* V4L2_BUF_TYPE_AUDIO_CAPTURE */
>> __u8 raw_data[200]; /* user-defined */
>> } fmt;
>> };
>
>
>
> Thanks,
> Mauro
On 21/02/2024 11:11, Shengjiu Wang wrote:
> On Wed, Feb 21, 2024 at 12:30 PM Tomasz Figa <[email protected]> wrote:
>>
>> On Sat, Feb 17, 2024 at 6:42 PM Mauro Carvalho Chehab
>> <[email protected]> wrote:
>>>
>>> Em Thu, 18 Jan 2024 20:32:00 +0800
>>> Shengjiu Wang <[email protected]> escreveu:
>>>
>>>> Audio signal processing has the requirement for memory to
>>>> memory similar as Video.
>>>>
>>>> This patch is to add this support in v4l2 framework, defined
>>>> new buffer type V4L2_BUF_TYPE_AUDIO_CAPTURE and
>>>> V4L2_BUF_TYPE_AUDIO_OUTPUT, defined new format v4l2_audio_format
>>>> for audio case usage.
>>>>
>>>> The created audio device is named "/dev/v4l-audioX".
>>>>
>>>> Signed-off-by: Shengjiu Wang <[email protected]>
>>>> ---
>>>> .../userspace-api/media/v4l/buffer.rst | 6 ++
>>>> .../media/v4l/dev-audio-mem2mem.rst | 71 +++++++++++++++++++
>>>> .../userspace-api/media/v4l/devices.rst | 1 +
>>>> .../media/v4l/vidioc-enum-fmt.rst | 2 +
>>>> .../userspace-api/media/v4l/vidioc-g-fmt.rst | 4 ++
>>>> .../media/videodev2.h.rst.exceptions | 2 +
>>>> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++
>>>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++
>>>> drivers/media/v4l2-core/v4l2-dev.c | 17 +++++
>>>> drivers/media/v4l2-core/v4l2-ioctl.c | 53 ++++++++++++++
>>>> include/media/v4l2-dev.h | 2 +
>>>> include/media/v4l2-ioctl.h | 34 +++++++++
>>>> include/uapi/linux/videodev2.h | 17 +++++
>>>> 13 files changed, 222 insertions(+)
>>>> create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>>>>
>>>> diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
>>>> index 52bbee81c080..a3754ca6f0d6 100644
>>>> --- a/Documentation/userspace-api/media/v4l/buffer.rst
>>>> +++ b/Documentation/userspace-api/media/v4l/buffer.rst
>>>> @@ -438,6 +438,12 @@ enum v4l2_buf_type
>>>> * - ``V4L2_BUF_TYPE_META_OUTPUT``
>>>> - 14
>>>
>>>> - Buffer for metadata output, see :ref:`metadata`.
>>>> + * - ``V4L2_BUF_TYPE_AUDIO_CAPTURE``
>>>> + - 15
>>>> + - Buffer for audio capture, see :ref:`audio`.
>>>> + * - ``V4L2_BUF_TYPE_AUDIO_OUTPUT``
>>>> + - 16
>>>
>>> Hmm... alsa APi define input/output as:
>>> enum {
>>> SNDRV_PCM_STREAM_PLAYBACK = 0,
>>> SNDRV_PCM_STREAM_CAPTURE,
>>> SNDRV_PCM_STREAM_LAST = SNDRV_PCM_STREAM_CAPTURE,
>>> };
>>>
>>>
>>> I would use a namespace as close as possible to the
>>> ALSA API. Also, we're not talking about V4L2, but, instead
>>> audio. so, not sure if I like the prefix to start with
>>> V4L2_. Maybe ALSA_?
>>>
>>> So, a better namespace would be:
>>>
>>> ${prefix}_BUF_TYPE_PCM_STREAM_PLAYBACK
>>> and
>>> ${prefix}_BUF_TYPE_PCM_STREAM_CAPTURE
>>>
>>
>> The API is still V4L2, and all the other non-video buf types also use
>> the V4L2_ prefix, so perhaps that's good here as well?
>>
>> Whether AUDIO or PCM_STREAM makes more sense goes outside of my
>> expertise. Subjectively, a PCM stream sounds more specific than an
>> audio stream. Do those buf types also support non-PCM audio streams?
>
> Currently I use it for PCM, but I think it can also be used for non-PCM.
> So use the below name?
> V4L2_BUF_TYPE_AUDIO_CAPTURE
> V4L2_BUF_TYPE_AUDIO_PLAYBACK
I really prefer keeping the names as they are in this patch. CAPTURE/OUTPUT
is consistent with V4L2 nomenclature, and since this is a M2M device 'PLAYBACK'
isn't really a good name either. It's not an audio playback device, it's a
rate converter.
Regards,
Hans
>
>>
>>>> + - Buffer for audio output, see :ref:`audio`.
>>>>
>>>>
>>>> .. _buffer-flags:
>>>> diff --git a/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>>>> new file mode 100644
>>>> index 000000000000..68faecfe3a02
>>>> --- /dev/null
>>>> +++ b/Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
>>>> @@ -0,0 +1,71 @@
>>>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
>>>> +
>>>> +.. _audiomem2mem:
>>>> +
>>>> +********************************
>>>> +Audio Memory-To-Memory Interface
>>>> +********************************
>>>> +
>>>> +An audio memory-to-memory device can compress, decompress, transform, or
>>>> +otherwise convert audio data from one format into another format, in memory.
>>>> +Such memory-to-memory devices set the ``V4L2_CAP_AUDIO_M2M`` capability.
>>>> +Examples of memory-to-memory devices are audio codecs, audio preprocessing,
>>>> +audio postprocessing.
>>>> +
>>>> +A memory-to-memory audio node supports both output (sending audio frames from
>>>> +memory to the hardware) and capture (receiving the processed audio frames
>>>> +from the hardware into memory) stream I/O. An application will have to
>>>> +setup the stream I/O for both sides and finally call
>>>> +:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` for both capture and output to
>>>> +start the hardware.
>>>> +
>>>> +Memory-to-memory devices function as a shared resource: you can
>>>> +open the audio node multiple times, each application setting up their
>>>> +own properties that are local to the file handle, and each can use
>>>> +it independently from the others. The driver will arbitrate access to
>>>> +the hardware and reprogram it whenever another file handler gets access.
>>>> +
>>>> +Audio memory-to-memory devices are accessed through character device
>>>> +special files named ``/dev/v4l-audio``
>>>> +
>>>> +Querying Capabilities
>>>> +=====================
>>>> +
>>>> +Device nodes supporting the audio memory-to-memory interface set the
>>>> +``V4L2_CAP_AUDIO_M2M`` flag in the ``device_caps`` field of the
>>>> +:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
>>>> +ioctl.
>>>> +
>>>> +Data Format Negotiation
>>>> +=======================
>>>> +
>>>> +The audio device uses the :ref:`format` ioctls to select the capture format.
>>>> +The audio buffer content format is bound to that selected format. In addition
>>>> +to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
>>>> +supported as well.
>>>> +
>>>> +To use the :ref:`format` ioctls applications set the ``type`` field of the
>>>> +:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_AUDIO_CAPTURE`` or to
>>>> +``V4L2_BUF_TYPE_AUDIO_OUTPUT``. Both drivers and applications must set the
>>>> +remainder of the :c:type:`v4l2_format` structure to 0.
>>>> +
>>>> +.. c:type:: v4l2_audio_format
>>>> +
>>>> +.. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}|
>>>> +
>>>> +.. flat-table:: struct v4l2_audio_format
>>>> + :header-rows: 0
>>>> + :stub-columns: 0
>>>> + :widths: 1 1 2
>>>> +
>>>> + * - __u32
>>>> + - ``pixelformat``
>>>> + - The sample format, set by the application. see :ref:`pixfmt-audio`
>>>
>>> pixelformat doesn't make any sense for audio: there are no pixels on a
>>> PCM stream. Please use call it, instead: `snd_pcm_format`, making it match
>>> the values for snd_pcm_format_t.
>>>
>>
>> +1
>>
>> FWIW v4l2_meta_format uses the name "dataformat".
>>
>> Actually, I just realized that the C code actually uses the name
>> "audioformat". Tbh., after reading the kerneldoc comment, my
>> subjective preference would be on "sample_format", since that's
>> exactly what it is.
>>
> Ok, I will change it to sampleformat.
>
> Best Regards
> Shengjiu Wang
>
>>> Yet, I would keep defining it as u32 (or u64?) instead of using a
>>> typedef int field there (snd_pcm_format_t), as the size of integer
>>> is different on 32 and 64 bit kernels.
>>
>> +1
>>
>> Best regards,
>> Tomasz