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From:   "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>
To:     mchehab+huawei@kernel.org, sean@mess.org,
        kstewart@linuxfoundation.org, allison@lohutok.net,
        tglx@linutronix.de
Cc:     "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>,
        linux-media@vger.kernel.org, skhan@linuxfoundation.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-kernel@vger.kernel.org
Subject: [RFC, WIP, v4 10/11] media: vidtv: Implement a SMPTE 302M encoder
Date:   Sat,  2 May 2020 00:22:15 -0300
Message-Id: <20200502032216.197977-11-dwlsalmeida@gmail.com>
In-Reply-To: <20200502032216.197977-1-dwlsalmeida@gmail.com>
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From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>

Implement a S302M encoder to make it possible to insert PCM audio data
in the generated MPEG Transport Stream.

This shall enable passing an audio signal into userspace so it can be
decoded and played by media software.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
---
 drivers/media/test-drivers/vidtv/Makefile     |   3 +-
 .../media/test-drivers/vidtv/vidtv_common.h   |   2 +
 .../media/test-drivers/vidtv/vidtv_encoder.h  | 103 +++
 .../media/test-drivers/vidtv/vidtv_s302m.c    | 608 ++++++++++++++++++
 .../media/test-drivers/vidtv/vidtv_s302m.h    |  99 +++
 5 files changed, 814 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/test-drivers/vidtv/vidtv_encoder.h
 create mode 100644 drivers/media/test-drivers/vidtv/vidtv_s302m.c
 create mode 100644 drivers/media/test-drivers/vidtv/vidtv_s302m.h

diff --git a/drivers/media/test-drivers/vidtv/Makefile b/drivers/media/test-drivers/vidtv/Makefile
index e3a6540f50e87..c916eb19d73bb 100644
--- a/drivers/media/test-drivers/vidtv/Makefile
+++ b/drivers/media/test-drivers/vidtv/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 vidtv_demod-objs := vidtv_common.o
-vidtv_bridge-objs := vidtv_common.o vidtv_ts.o vidtv_psi.o vidtv_pes.o
+vidtv_bridge-objs := vidtv_common.o vidtv_ts.o vidtv_psi.o vidtv_pes.o \
+		     vidtv_s302m.o
 
 obj-$(CONFIG_DVB_VIDTV)	+= vidtv_tuner.o vidtv_demod.o vidtv_bridge.o
diff --git a/drivers/media/test-drivers/vidtv/vidtv_common.h b/drivers/media/test-drivers/vidtv/vidtv_common.h
index 3b68f95c5f6c8..170646497eb58 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_common.h
+++ b/drivers/media/test-drivers/vidtv/vidtv_common.h
@@ -13,6 +13,8 @@
 #include <linux/types.h>
 #include <media/dvb_frontend.h>
 
+#define CLOCK_UNIT_90KHZ 90000
+
 u32 vidtv_memcpy(void *to,
 		 const void *from,
 		 size_t len,
diff --git a/drivers/media/test-drivers/vidtv/vidtv_encoder.h b/drivers/media/test-drivers/vidtv/vidtv_encoder.h
new file mode 100644
index 0000000000000..f483200fd781c
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_encoder.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Vidtv serves as a reference DVB driver and helps validate the existing APIs
+ * in the media subsystem. It can also aid developers working on userspace
+ * applications.
+ *
+ * This file contains a generic encoder type that can provide data for a stream
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#ifndef VIDTV_ENCODER_H
+#define VIDTV_ENCODER_H
+
+#include <linux/types.h>
+
+enum vidtv_encoder_id {
+	/* add IDs here when implementing new encoders */
+	S302M,
+};
+
+struct vidtv_encoder {
+	/* so we can cast to a concrete implementation when needed */
+	enum vidtv_encoder_id id;
+	/* usually same as the stream name */
+	char *name;
+
+	/* the encoder's internal buffer for the access units */
+	u8 *encoder_buf;
+	/* the encoder buffer size, in bytes */
+	u32 encoder_buf_sz;
+
+	/* our byte position in the encoder buffer */
+	u32 encoder_buf_offset;
+
+	/* how many samples we have encoded in total */
+	u32 sample_count;
+
+	u32 previous_sample_count;
+
+	/* the number of access units ready */
+	u32 nunits;
+	/* the number of samples per access unit */
+	u32 *samples_per_unit;
+	/* pts array mapping pts[i] -> AU[i] */
+	u64 *pts;
+	/* dts array mapping dts[i] -> AU[i] */
+	u64 *dts;
+	/* array mapping how many bytes were written per AU */
+	u32 *nbytes;
+	/* array keeping track of AU offsets in buffer */
+	u32 *offsets;
+
+	/*
+	 * the source of raw data to be encoded, encoder might set a default
+	 * source if NULL
+	 */
+	void *src_buf;
+	/* the source buffer size, in bytes */
+	u32 src_buf_sz;
+
+	/* our byte position in the src buffer */
+	u32 src_buf_offset;
+
+	bool video; /* either video or audio */
+	void *ctx; /* encoder-specific state */
+
+	/* Examples: Audio streams (0xc0-0xdf), Video streams (0xe0-0xef) */
+	u16 stream_id;
+
+	/* the TS PID to use for the elementary stream in this encoder */
+	u16 es_pid;
+
+	/* prepare enough AUs for the given amount of time */
+	void *(*encode)(struct vidtv_encoder *e, u64 elapsed_time_usecs);
+
+	/* clear the encoder output */
+	u8 (*clear)(struct vidtv_encoder *e);
+
+	/* attempt to synchronize with the encoder below */
+	struct vidtv_encoder *sync;
+
+	u32 sampling_rate_hz; /* or fps, if video */
+
+	/* controls dynamic memory allocation for the arrays */
+	u8 access_unit_capacity;
+
+	/*
+	 * called when the encoder runs out of data
+	 * the encoder might optionally wrap around the src data if this is not
+	 * implemented
+	 * this is so the source can read data in a piecemeal fashion instead
+	 * of having to provide it all at once
+	 */
+	void (*last_sample_cb)(u32 sample_no);
+
+	/* destroy this encoder, freeing any allocated resources */
+	void (*destroy)(struct vidtv_encoder *e);
+
+	struct vidtv_encoder *next;
+};
+
+#endif /* VIDTV_ENCODER_H */
diff --git a/drivers/media/test-drivers/vidtv/vidtv_s302m.c b/drivers/media/test-drivers/vidtv/vidtv_s302m.c
new file mode 100644
index 0000000000000..b08bfff7b8f27
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_s302m.c
@@ -0,0 +1,608 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Vidtv serves as a reference DVB driver and helps validate the existing APIs
+ * in the media subsystem. It can also aid developers working on userspace
+ * applications.
+ *
+ * This file contains the code for an AES3 (also known as AES/EBU) encoder.
+ * It is based on EBU Tech 3250 and SMPTE 302M technical documents.
+ *
+ * This encoder currently supports 16bit AES3 subframes using 16bit signed
+ * integers.
+ *
+ * Note: AU stands for Access Unit, and AAU stands for Audio Access Unit
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/vmalloc.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+
+#include "vidtv_s302m.h"
+#include "vidtv_encoder.h"
+#include "vidtv_common.h"
+
+#define S302M_SAMPLING_RATE_HZ 48000
+
+/* see EBU Tech 3250 2004 clause 4 */
+#define CHANNEL_STATUS_BIT_LEN 92
+
+#define S302M_2CHANNELS 0
+#define S302M_BITS_PER_SAMPLE_16 0
+
+/* see preamble definition in EBU Tech 3250 2004 clause 2.4 */
+#define PREAMBLE_X_F0 0xe2 /* sub-frame 1 */
+#define PREAMBLE_Y_F0 0xe4 /* sub-frame 2 */
+#define PREAMBLE_Z_F0 0xe8 /* sub-frame 1 + block start */
+/* F0 and F1 refer to whether the F bit was set in the previous sub-frame */
+#define PREAMBLE_X_F1 0x1d /* sub-frame 1 */
+#define PREAMBLE_Y_F1 0X1b /* sub-frame 2 */
+#define PREAMBLE_Z_F1 0x17 /* sub-frame 1 + block start */
+
+#define S302M_BLOCK_SZ 192
+#define S302M_SIN_LUT_SZ 1024
+
+static int s302m_sin_lut[S302M_SIN_LUT_SZ] = {
+	0x8000, 0x80c9, 0x8192, 0x825b, 0x8324, 0x83ed, 0x84b6, 0x857e,
+	0x8647, 0x8710, 0x87d9, 0x88a1, 0x896a, 0x8a32, 0x8afb, 0x8bc3,
+	0x8c8b, 0x8d53, 0x8e1b, 0x8ee3, 0x8fab, 0x9072, 0x9139, 0x9201,
+	0x92c7, 0x938e, 0x9455, 0x951b, 0x95e1, 0x96a7, 0x976d, 0x9833,
+	0x98f8, 0x99bd, 0x9a82, 0x9b47, 0x9c0b, 0x9ccf, 0x9d93, 0x9e56,
+	0x9f19, 0x9fdc, 0xa09f, 0xa161, 0xa223, 0xa2e5, 0xa3a6, 0xa467,
+	0xa527, 0xa5e8, 0xa6a7, 0xa767, 0xa826, 0xa8e5, 0xa9a3, 0xaa61,
+	0xab1f, 0xabdc, 0xac98, 0xad55, 0xae10, 0xaecc, 0xaf87, 0xb041,
+	0xb0fb, 0xb1b5, 0xb26e, 0xb326, 0xb3de, 0xb496, 0xb54d, 0xb603,
+	0xb6b9, 0xb76f, 0xb824, 0xb8d8, 0xb98c, 0xba3f, 0xbaf2, 0xbba4,
+	0xbc56, 0xbd07, 0xbdb7, 0xbe67, 0xbf17, 0xbfc5, 0xc073, 0xc121,
+	0xc1cd, 0xc279, 0xc325, 0xc3d0, 0xc47a, 0xc524, 0xc5cc, 0xc675,
+	0xc71c, 0xc7c3, 0xc869, 0xc90f, 0xc9b3, 0xca57, 0xcafb, 0xcb9d,
+	0xcc3f, 0xcce0, 0xcd81, 0xce20, 0xcebf, 0xcf5d, 0xcffb, 0xd097,
+	0xd133, 0xd1ce, 0xd268, 0xd302, 0xd39a, 0xd432, 0xd4c9, 0xd55f,
+	0xd5f5, 0xd689, 0xd71d, 0xd7b0, 0xd842, 0xd8d3, 0xd964, 0xd9f3,
+	0xda82, 0xdb0f, 0xdb9c, 0xdc28, 0xdcb3, 0xdd3d, 0xddc7, 0xde4f,
+	0xded7, 0xdf5d, 0xdfe3, 0xe068, 0xe0eb, 0xe16e, 0xe1f0, 0xe271,
+	0xe2f1, 0xe370, 0xe3ee, 0xe46b, 0xe4e8, 0xe563, 0xe5dd, 0xe656,
+	0xe6cf, 0xe746, 0xe7bc, 0xe831, 0xe8a6, 0xe919, 0xe98b, 0xe9fc,
+	0xea6d, 0xeadc, 0xeb4a, 0xebb7, 0xec23, 0xec8e, 0xecf8, 0xed61,
+	0xedc9, 0xee30, 0xee96, 0xeefa, 0xef5e, 0xefc1, 0xf022, 0xf083,
+	0xf0e2, 0xf140, 0xf19d, 0xf1f9, 0xf254, 0xf2ae, 0xf307, 0xf35e,
+	0xf3b5, 0xf40a, 0xf45f, 0xf4b2, 0xf504, 0xf555, 0xf5a5, 0xf5f3,
+	0xf641, 0xf68d, 0xf6d8, 0xf722, 0xf76b, 0xf7b3, 0xf7fa, 0xf83f,
+	0xf884, 0xf8c7, 0xf909, 0xf94a, 0xf989, 0xf9c8, 0xfa05, 0xfa41,
+	0xfa7c, 0xfab6, 0xfaee, 0xfb26, 0xfb5c, 0xfb91, 0xfbc5, 0xfbf8,
+	0xfc29, 0xfc59, 0xfc88, 0xfcb6, 0xfce3, 0xfd0e, 0xfd39, 0xfd62,
+	0xfd89, 0xfdb0, 0xfdd5, 0xfdfa, 0xfe1d, 0xfe3e, 0xfe5f, 0xfe7e,
+	0xfe9c, 0xfeb9, 0xfed5, 0xfeef, 0xff09, 0xff21, 0xff37, 0xff4d,
+	0xff61, 0xff74, 0xff86, 0xff97, 0xffa6, 0xffb4, 0xffc1, 0xffcd,
+	0xffd8, 0xffe1, 0xffe9, 0xfff0, 0xfff5, 0xfff9, 0xfffd, 0xfffe,
+	0xffff, 0xfffe, 0xfffd, 0xfff9, 0xfff5, 0xfff0, 0xffe9, 0xffe1,
+	0xffd8, 0xffcd, 0xffc1, 0xffb4, 0xffa6, 0xff97, 0xff86, 0xff74,
+	0xff61, 0xff4d, 0xff37, 0xff21, 0xff09, 0xfeef, 0xfed5, 0xfeb9,
+	0xfe9c, 0xfe7e, 0xfe5f, 0xfe3e, 0xfe1d, 0xfdfa, 0xfdd5, 0xfdb0,
+	0xfd89, 0xfd62, 0xfd39, 0xfd0e, 0xfce3, 0xfcb6, 0xfc88, 0xfc59,
+	0xfc29, 0xfbf8, 0xfbc5, 0xfb91, 0xfb5c, 0xfb26, 0xfaee, 0xfab6,
+	0xfa7c, 0xfa41, 0xfa05, 0xf9c8, 0xf989, 0xf94a, 0xf909, 0xf8c7,
+	0xf884, 0xf83f, 0xf7fa, 0xf7b3, 0xf76b, 0xf722, 0xf6d8, 0xf68d,
+	0xf641, 0xf5f3, 0xf5a5, 0xf555, 0xf504, 0xf4b2, 0xf45f, 0xf40a,
+	0xf3b5, 0xf35e, 0xf307, 0xf2ae, 0xf254, 0xf1f9, 0xf19d, 0xf140,
+	0xf0e2, 0xf083, 0xf022, 0xefc1, 0xef5e, 0xeefa, 0xee96, 0xee30,
+	0xedc9, 0xed61, 0xecf8, 0xec8e, 0xec23, 0xebb7, 0xeb4a, 0xeadc,
+	0xea6d, 0xe9fc, 0xe98b, 0xe919, 0xe8a6, 0xe831, 0xe7bc, 0xe746,
+	0xe6cf, 0xe656, 0xe5dd, 0xe563, 0xe4e8, 0xe46b, 0xe3ee, 0xe370,
+	0xe2f1, 0xe271, 0xe1f0, 0xe16e, 0xe0eb, 0xe068, 0xdfe3, 0xdf5d,
+	0xded7, 0xde4f, 0xddc7, 0xdd3d, 0xdcb3, 0xdc28, 0xdb9c, 0xdb0f,
+	0xda82, 0xd9f3, 0xd964, 0xd8d3, 0xd842, 0xd7b0, 0xd71d, 0xd689,
+	0xd5f5, 0xd55f, 0xd4c9, 0xd432, 0xd39a, 0xd302, 0xd268, 0xd1ce,
+	0xd133, 0xd097, 0xcffb, 0xcf5d, 0xcebf, 0xce20, 0xcd81, 0xcce0,
+	0xcc3f, 0xcb9d, 0xcafb, 0xca57, 0xc9b3, 0xc90f, 0xc869, 0xc7c3,
+	0xc71c, 0xc675, 0xc5cc, 0xc524, 0xc47a, 0xc3d0, 0xc325, 0xc279,
+	0xc1cd, 0xc121, 0xc073, 0xbfc5, 0xbf17, 0xbe67, 0xbdb7, 0xbd07,
+	0xbc56, 0xbba4, 0xbaf2, 0xba3f, 0xb98c, 0xb8d8, 0xb824, 0xb76f,
+	0xb6b9, 0xb603, 0xb54d, 0xb496, 0xb3de, 0xb326, 0xb26e, 0xb1b5,
+	0xb0fb, 0xb041, 0xaf87, 0xaecc, 0xae10, 0xad55, 0xac98, 0xabdc,
+	0xab1f, 0xaa61, 0xa9a3, 0xa8e5, 0xa826, 0xa767, 0xa6a7, 0xa5e8,
+	0xa527, 0xa467, 0xa3a6, 0xa2e5, 0xa223, 0xa161, 0xa09f, 0x9fdc,
+	0x9f19, 0x9e56, 0x9d93, 0x9ccf, 0x9c0b, 0x9b47, 0x9a82, 0x99bd,
+	0x98f8, 0x9833, 0x976d, 0x96a7, 0x95e1, 0x951b, 0x9455, 0x938e,
+	0x92c7, 0x9201, 0x9139, 0x9072, 0x8fab, 0x8ee3, 0x8e1b, 0x8d53,
+	0x8c8b, 0x8bc3, 0x8afb, 0x8a32, 0x896a, 0x88a1, 0x87d9, 0x8710,
+	0x8647, 0x857e, 0x84b6, 0x83ed, 0x8324, 0x825b, 0x8192, 0x80c9,
+	0x8000, 0x7f36, 0x7e6d, 0x7da4, 0x7cdb, 0x7c12, 0x7b49, 0x7a81,
+	0x79b8, 0x78ef, 0x7826, 0x775e, 0x7695, 0x75cd, 0x7504, 0x743c,
+	0x7374, 0x72ac, 0x71e4, 0x711c, 0x7054, 0x6f8d, 0x6ec6, 0x6dfe,
+	0x6d38, 0x6c71, 0x6baa, 0x6ae4, 0x6a1e, 0x6958, 0x6892, 0x67cc,
+	0x6707, 0x6642, 0x657d, 0x64b8, 0x63f4, 0x6330, 0x626c, 0x61a9,
+	0x60e6, 0x6023, 0x5f60, 0x5e9e, 0x5ddc, 0x5d1a, 0x5c59, 0x5b98,
+	0x5ad8, 0x5a17, 0x5958, 0x5898, 0x57d9, 0x571a, 0x565c, 0x559e,
+	0x54e0, 0x5423, 0x5367, 0x52aa, 0x51ef, 0x5133, 0x5078, 0x4fbe,
+	0x4f04, 0x4e4a, 0x4d91, 0x4cd9, 0x4c21, 0x4b69, 0x4ab2, 0x49fc,
+	0x4946, 0x4890, 0x47db, 0x4727, 0x4673, 0x45c0, 0x450d, 0x445b,
+	0x43a9, 0x42f8, 0x4248, 0x4198, 0x40e8, 0x403a, 0x3f8c, 0x3ede,
+	0x3e32, 0x3d86, 0x3cda, 0x3c2f, 0x3b85, 0x3adb, 0x3a33, 0x398a,
+	0x38e3, 0x383c, 0x3796, 0x36f0, 0x364c, 0x35a8, 0x3504, 0x3462,
+	0x33c0, 0x331f, 0x327e, 0x31df, 0x3140, 0x30a2, 0x3004, 0x2f68,
+	0x2ecc, 0x2e31, 0x2d97, 0x2cfd, 0x2c65, 0x2bcd, 0x2b36, 0x2aa0,
+	0x2a0a, 0x2976, 0x28e2, 0x284f, 0x27bd, 0x272c, 0x269b, 0x260c,
+	0x257d, 0x24f0, 0x2463, 0x23d7, 0x234c, 0x22c2, 0x2238, 0x21b0,
+	0x2128, 0x20a2, 0x201c, 0x1f97, 0x1f14, 0x1e91, 0x1e0f, 0x1d8e,
+	0x1d0e, 0x1c8f, 0x1c11, 0x1b94, 0x1b17, 0x1a9c, 0x1a22, 0x19a9,
+	0x1930, 0x18b9, 0x1843, 0x17ce, 0x1759, 0x16e6, 0x1674, 0x1603,
+	0x1592, 0x1523, 0x14b5, 0x1448, 0x13dc, 0x1371, 0x1307, 0x129e,
+	0x1236, 0x11cf, 0x1169, 0x1105, 0x10a1, 0x103e, 0xfdd, 0xf7c,
+	0xf1d, 0xebf, 0xe62, 0xe06, 0xdab, 0xd51, 0xcf8, 0xca1,
+	0xc4a, 0xbf5, 0xba0, 0xb4d, 0xafb, 0xaaa, 0xa5a, 0xa0c,
+	0x9be, 0x972, 0x927, 0x8dd, 0x894, 0x84c, 0x805, 0x7c0,
+	0x77b, 0x738, 0x6f6, 0x6b5, 0x676, 0x637, 0x5fa, 0x5be,
+	0x583, 0x549, 0x511, 0x4d9, 0x4a3, 0x46e, 0x43a, 0x407,
+	0x3d6, 0x3a6, 0x377, 0x349, 0x31c, 0x2f1, 0x2c6, 0x29d,
+	0x276, 0x24f, 0x22a, 0x205, 0x1e2, 0x1c1, 0x1a0, 0x181,
+	0x163, 0x146, 0x12a, 0x110, 0xf6, 0xde, 0xc8, 0xb2,
+	0x9e, 0x8b, 0x79, 0x68, 0x59, 0x4b, 0x3e, 0x32,
+	0x27, 0x1e, 0x16, 0xf, 0xa, 0x6, 0x2, 0x1,
+	0x0, 0x1, 0x2, 0x6, 0xa, 0xf, 0x16, 0x1e,
+	0x27, 0x32, 0x3e, 0x4b, 0x59, 0x68, 0x79, 0x8b,
+	0x9e, 0xb2, 0xc8, 0xde, 0xf6, 0x110, 0x12a, 0x146,
+	0x163, 0x181, 0x1a0, 0x1c1, 0x1e2, 0x205, 0x22a, 0x24f,
+	0x276, 0x29d, 0x2c6, 0x2f1, 0x31c, 0x349, 0x377, 0x3a6,
+	0x3d6, 0x407, 0x43a, 0x46e, 0x4a3, 0x4d9, 0x511, 0x549,
+	0x583, 0x5be, 0x5fa, 0x637, 0x676, 0x6b5, 0x6f6, 0x738,
+	0x77b, 0x7c0, 0x805, 0x84c, 0x894, 0x8dd, 0x927, 0x972,
+	0x9be, 0xa0c, 0xa5a, 0xaaa, 0xafb, 0xb4d, 0xba0, 0xbf5,
+	0xc4a, 0xca1, 0xcf8, 0xd51, 0xdab, 0xe06, 0xe62, 0xebf,
+	0xf1d, 0xf7c, 0xfdd, 0x103e, 0x10a1, 0x1105, 0x1169, 0x11cf,
+	0x1236, 0x129e, 0x1307, 0x1371, 0x13dc, 0x1448, 0x14b5, 0x1523,
+	0x1592, 0x1603, 0x1674, 0x16e6, 0x1759, 0x17ce, 0x1843, 0x18b9,
+	0x1930, 0x19a9, 0x1a22, 0x1a9c, 0x1b17, 0x1b94, 0x1c11, 0x1c8f,
+	0x1d0e, 0x1d8e, 0x1e0f, 0x1e91, 0x1f14, 0x1f97, 0x201c, 0x20a2,
+	0x2128, 0x21b0, 0x2238, 0x22c2, 0x234c, 0x23d7, 0x2463, 0x24f0,
+	0x257d, 0x260c, 0x269b, 0x272c, 0x27bd, 0x284f, 0x28e2, 0x2976,
+	0x2a0a, 0x2aa0, 0x2b36, 0x2bcd, 0x2c65, 0x2cfd, 0x2d97, 0x2e31,
+	0x2ecc, 0x2f68, 0x3004, 0x30a2, 0x3140, 0x31df, 0x327e, 0x331f,
+	0x33c0, 0x3462, 0x3504, 0x35a8, 0x364c, 0x36f0, 0x3796, 0x383c,
+	0x38e3, 0x398a, 0x3a33, 0x3adb, 0x3b85, 0x3c2f, 0x3cda, 0x3d86,
+	0x3e32, 0x3ede, 0x3f8c, 0x403a, 0x40e8, 0x4198, 0x4248, 0x42f8,
+	0x43a9, 0x445b, 0x450d, 0x45c0, 0x4673, 0x4727, 0x47db, 0x4890,
+	0x4946, 0x49fc, 0x4ab2, 0x4b69, 0x4c21, 0x4cd9, 0x4d91, 0x4e4a,
+	0x4f04, 0x4fbe, 0x5078, 0x5133, 0x51ef, 0x52aa, 0x5367, 0x5423,
+	0x54e0, 0x559e, 0x565c, 0x571a, 0x57d9, 0x5898, 0x5958, 0x5a17,
+	0x5ad8, 0x5b98, 0x5c59, 0x5d1a, 0x5ddc, 0x5e9e, 0x5f60, 0x6023,
+	0x60e6, 0x61a9, 0x626c, 0x6330, 0x63f4, 0x64b8, 0x657d, 0x6642,
+	0x6707, 0x67cc, 0x6892, 0x6958, 0x6a1e, 0x6ae4, 0x6baa, 0x6c71,
+	0x6d38, 0x6dfe, 0x6ec6, 0x6f8d, 0x7054, 0x711c, 0x71e4, 0x72ac,
+	0x7374, 0x743c, 0x7504, 0x75cd, 0x7695, 0x775e, 0x7826, 0x78ef,
+	0x79b8, 0x7a81, 0x7b49, 0x7c12, 0x7cdb, 0x7da4, 0x7e6d, 0x7f36
+};
+
+static void vidtv_s302m_compute_nunits(struct vidtv_encoder *e)
+{
+	/*
+	 * match the amount of video units if we are trying to sync with a video
+	 * encoder
+	 */
+	if (e->sync && e->sync->video) {
+		e->nunits = e->sync->nunits;
+		return;
+	}
+
+	/* otherwise return enough samples for the timedelta in one AU */
+	e->nunits = 1;
+}
+
+static void
+vidtv_s302m_compute_sample_count_v(struct vidtv_encoder *e)
+{
+	/* compute sample count for VAU[i] in 'sync' */
+	u32 vau_duration_usecs;
+	u32 sample_duration_usecs;
+	u32 i;
+	u32 sample_count;
+	u32 s;
+
+	vau_duration_usecs    = USEC_PER_SEC / e->sync->sampling_rate_hz;
+	sample_duration_usecs = USEC_PER_SEC / e->sampling_rate_hz;
+
+	for (i = 0; i < e->sync->nunits; ++i) {
+		sample_count = e->samples_per_unit[i];
+		s = DIV_ROUND_UP(vau_duration_usecs, sample_duration_usecs);
+		e->samples_per_unit[i] = s;
+	}
+}
+
+static void
+vidtv_s302m_compute_sample_count(struct vidtv_encoder *e,
+				 u64 elapsed_time_usecs)
+{
+	/* compute sample count for 'elapsed_time_usecs' */
+	u32 sample_duration_usecs = USEC_PER_SEC / e->sampling_rate_hz;
+
+	e->samples_per_unit[0] = elapsed_time_usecs / sample_duration_usecs;
+}
+
+static void vidtv_s302m_compute_pts(struct vidtv_encoder *e)
+{
+	u32 count = e->previous_sample_count;
+	u32 i;
+
+	for (i = 0; i < e->nunits; ++i) {
+		count += e->samples_per_unit[i];
+
+		e->pts[i] = count *
+			    CLOCK_UNIT_90KHZ / e->sampling_rate_hz;
+	}
+}
+
+static void vidtv_s302m_compute_pts_v(struct vidtv_encoder *e)
+{
+	u32 i;
+
+	/* use the same pts for video */
+	for (i = 0; i < e->sync->nunits; ++i)
+		e->pts[i] = e->sync->pts[i];
+}
+
+static bool vidtv_s302m_get_c_bit(struct vidtv_encoder *e)
+{
+	/*
+	 * see EBU Tech 3250 2004 clause 5.2.1: minimal implementation of
+	 * channel status
+	 */
+	struct vidtv_s302m_ctx *ctx = e->ctx;
+	bool   start_was_z;
+
+	start_was_z = ctx->last_start_preamble == PREAMBLE_Z_F0 ||
+		      ctx->last_start_preamble == PREAMBLE_Z_F1;
+
+	if (!start_was_z)
+		return false;
+
+	++ctx->current_c_bit;
+
+	/* set the bit only if it is the first C bit after a Z preamble */
+	return !(ctx->current_c_bit % CHANNEL_STATUS_BIT_LEN);
+}
+
+static s16 vidtv_s302m_get_sample(struct vidtv_encoder *e)
+{
+	s16 ret;
+
+	/* bug somewhere */
+	WARN_ON(e->src_buf_offset > e->src_buf_sz);
+
+	if (e->src_buf_offset >= e->src_buf_sz) {
+		/* let the source know we are out of data */
+		if (e->last_sample_cb)
+			e->last_sample_cb(e->sample_count);
+
+		e->src_buf_offset = 0;
+	}
+
+	ret = *(s16 *)(e->src_buf + e->src_buf_offset);
+
+	e->sample_count++;
+	e->src_buf_offset += sizeof(s16);
+
+	return ret;
+}
+
+static void vidtv_s302m_toggle_subframe(struct vidtv_encoder *e)
+{
+	struct vidtv_s302m_ctx *ctx = e->ctx;
+
+	ctx->is_subframe_a = !ctx->is_subframe_a;
+}
+
+static bool vidtv_s302m_is_block_start(const struct vidtv_encoder *e)
+{
+	return e->sample_count % S302M_BLOCK_SZ;
+}
+
+static bool vidtv_s302m_get_f_bit(const struct vidtv_encoder *e)
+{
+	const struct vidtv_s302m_ctx *ctx = e->ctx;
+
+	return vidtv_s302m_is_block_start(e) && ctx->is_subframe_a;
+}
+
+static u8 vidtv_s302m_get_preamble(struct vidtv_encoder *e)
+{
+	/*
+	 * some codecs might disregard the preambles (e.g. ffmpeg s302m), but
+	 * we implement them according to the specs anyway, because some other
+	 * codecs might rely on them.
+	 */
+
+	struct vidtv_s302m_ctx *ctx = e->ctx;
+
+	bool start_was_x = ctx->last_start_preamble == PREAMBLE_X_F0 ||
+			   ctx->last_start_preamble == PREAMBLE_X_F1;
+
+	bool start_was_z = ctx->last_start_preamble == PREAMBLE_Z_F0 ||
+			   ctx->last_start_preamble == PREAMBLE_Z_F1;
+
+	bool is_block_start = vidtv_s302m_is_block_start(e);
+
+	/* bug somewhere: a block always starts with an A subframe */
+	WARN_ON(!ctx->is_subframe_a && is_block_start);
+
+	if (!ctx->is_subframe_a)
+		return (ctx->last_f) ? PREAMBLE_Y_F1 : PREAMBLE_Y_F0;
+
+	if (start_was_x && is_block_start) {
+		if (ctx->last_f) {
+			ctx->last_start_preamble = PREAMBLE_Z_F0;
+			return PREAMBLE_Z_F0;
+		}
+
+		ctx->last_start_preamble = PREAMBLE_Z_F1;
+		return PREAMBLE_Z_F1;
+	}
+
+	if (start_was_z && is_block_start) {
+		if (ctx->last_f) {
+			ctx->last_start_preamble = PREAMBLE_X_F0;
+			return PREAMBLE_X_F0;
+		}
+
+		ctx->last_start_preamble = PREAMBLE_X_F1;
+		return PREAMBLE_X_F1;
+	}
+
+	return PREAMBLE_X_F0;
+}
+
+static u32 vidtv_s302m_write_subframe(struct vidtv_encoder *e,
+				      struct vidtv_s302m_subframe_16 *f)
+{
+	u32 nbytes = 0;
+
+	nbytes += vidtv_memcpy(e->encoder_buf + e->encoder_buf_offset,
+			       f,
+			       sizeof(*f),
+			       e->encoder_buf_offset,
+			       VIDTV_S302M_BUF_SZ);
+
+	e->encoder_buf_offset += nbytes;
+
+	return nbytes;
+}
+
+static void vidtv_s302m_write_h(struct vidtv_encoder *e, u32 p_sz)
+{
+	struct vidtv_smpte_s302m_es h = {0};
+	u32    nbytes                 = 0;
+
+	h.bits_per_sample        = S302M_BITS_PER_SAMPLE_16;
+	h.channel_identification = 0;
+	h.num_channels           = S302M_2CHANNELS;
+	h.audio_packet_size      = p_sz;
+
+	cpu_to_be32s(&h.bitfield);
+
+	nbytes += vidtv_memcpy(e->encoder_buf + e->encoder_buf_offset,
+			       &h,
+			       sizeof(h),
+			       e->encoder_buf_offset,
+			       e->encoder_buf_sz);
+
+	be32_to_cpus(&h.bitfield);
+
+	e->encoder_buf_offset += nbytes;
+}
+
+static void vidtv_s302m_write_frames(struct vidtv_encoder *e)
+{
+	u32    nbytes                    = 0;
+	u32    nbytes_per_unit           = 0;
+	u32    preamble_bit_num          = 0;
+	const  u8 preamble_bit_count     = 4;
+	u32    au_sz                     = 0;
+	struct vidtv_s302m_ctx *ctx      = e->ctx;
+	struct vidtv_s302m_subframe_16 a = {0};
+	struct vidtv_s302m_subframe_16 b = {0};
+	u8     preamble_a                = 0;
+	u8     preamble_b                = 0;
+	u8     aux                       = 0;
+	s16    sample                    = 0;
+	bool   v                         = true;
+	bool   u                         = false;
+	bool   c;
+	bool   f;
+
+	u32    i;
+	u32    j;
+
+	ctx->is_subframe_a = true;
+
+	for (i = 0; i < e->nunits; ++i) {
+		/* stereo: each sample will generate two subframes */
+		au_sz = e->samples_per_unit[i] *
+			sizeof(struct vidtv_s302m_subframe_16) *
+			2;
+
+		vidtv_s302m_write_h(e, au_sz);
+
+		for (j = 0; j < e->samples_per_unit[i]; ++j) {
+			/* keep this in this order */
+			preamble_a = vidtv_s302m_get_preamble(e);
+			sample     = cpu_to_le16(vidtv_s302m_get_sample(e));
+			c          = vidtv_s302m_get_c_bit(e);
+			f          = vidtv_s302m_get_f_bit(e);
+
+			a.preamble = vidtv_extract_bits(preamble_a,
+							preamble_bit_num % 8,
+							preamble_bit_count);
+			a.aux       = aux;
+			a.data_word = sample;
+			a.v         = v;
+			a.u         = u;
+			a.c         = c;
+			a.f         = f;
+
+			vidtv_s302m_toggle_subframe(e);
+
+			preamble_b = vidtv_s302m_get_preamble(e);
+			c          = vidtv_s302m_get_c_bit(e);
+			f          = vidtv_s302m_get_f_bit(e);
+
+			b.preamble = vidtv_extract_bits(preamble_b,
+							preamble_bit_num % 8,
+							preamble_bit_count);
+			b.aux       = aux;
+			b.data_word = sample;
+			b.v         = v;
+			b.u         = u;
+			b.c         = c;
+			b.f         = f;
+
+			preamble_bit_num += preamble_bit_count;
+
+			nbytes_per_unit += vidtv_s302m_write_subframe(e, &a);
+			nbytes_per_unit += vidtv_s302m_write_subframe(e, &b);
+
+			nbytes += nbytes_per_unit;
+
+			vidtv_s302m_toggle_subframe(e);
+		}
+
+		e->nbytes[i] = nbytes;
+
+		/* did we write more bytes than we initially computed? */
+		WARN_ON(au_sz != nbytes_per_unit);
+
+		e->offsets[i] = nbytes_per_unit;
+		nbytes_per_unit = 0;
+	}
+}
+
+static void *vidtv_s302m_encode(struct vidtv_encoder *e, u64 elapsed_time)
+{
+	/*
+	 * According to SMPTE 302M, an audio access unit is specified as those
+	 * AES3 words that are associated with a corresponding video frame.
+	 * Therefore we should write one AAU for every VAU in the corresponding
+	 * video encoder ('sync'), using the same values for PTS as used by the
+	 * video encoder.
+	 *
+	 * I assume that it is also possible to send audio without any
+	 * associated video, as in a radio-like service. If this is the case,
+	 * we are sending only _one_ AAU with enough audio data for
+	 * 'elapsed_time' instead, computing the value for PTS manually.
+	 */
+
+	vidtv_s302m_compute_nunits(e);
+
+	if (e->sync && e->sync->video) {
+		vidtv_s302m_compute_sample_count_v(e);
+		vidtv_s302m_compute_pts_v(e);
+	} else {
+		vidtv_s302m_compute_sample_count(e, elapsed_time);
+		vidtv_s302m_compute_pts(e);
+	}
+
+	vidtv_s302m_write_frames(e);
+
+	return e->encoder_buf;
+}
+
+static u8 vidtv_s302m_clear(struct vidtv_encoder *e)
+{
+	u8 ret = e->nunits;
+
+	e->nunits = 0;
+	memset(e->samples_per_unit, 0, e->access_unit_capacity);
+	memset(e->nbytes, 0, e->access_unit_capacity);
+	memset(e->offsets, 0, e->access_unit_capacity);
+	memset(e->pts, 0, e->access_unit_capacity);
+	memset(e->dts, 0, e->access_unit_capacity);
+
+	return ret;
+}
+
+struct vidtv_encoder
+*vidtv_s302m_encoder_init(struct vidtv_s302m_encoder_init_args args)
+{
+	struct vidtv_encoder *e = kzalloc(sizeof(e), GFP_KERNEL);
+	u32    priv_sz          = sizeof(struct vidtv_s302m_ctx);
+
+	if (args.sync)
+		args.access_unit_capacity = args.sync->access_unit_capacity;
+
+	e->id = S302M;
+
+	e->name = kzalloc(strlen(args.name), GFP_KERNEL);
+	strncpy(e->name, args.name, strlen(e->name));
+
+	e->encoder_buf        = vzalloc(VIDTV_S302M_BUF_SZ);
+	e->encoder_buf_sz     = VIDTV_S302M_BUF_SZ;
+	e->encoder_buf_offset = 0;
+
+	e->sample_count          = 0;
+	e->previous_sample_count = 0;
+	e->nunits                = 0;
+
+	e->samples_per_unit = kcalloc(args.access_unit_capacity,
+				      sizeof(u32),
+				      GFP_KERNEL);
+
+	e->pts = kcalloc(args.access_unit_capacity, sizeof(u64), GFP_KERNEL);
+	e->dts = kcalloc(args.access_unit_capacity, sizeof(u64), GFP_KERNEL);
+
+	e->nbytes  = kcalloc(args.access_unit_capacity,
+			     sizeof(u32),
+			     GFP_KERNEL);
+
+	e->offsets = kcalloc(args.access_unit_capacity,
+			     sizeof(u32),
+			     GFP_KERNEL);
+
+	e->src_buf        = (args.src_buf) ? args.src_buf : &s302m_sin_lut;
+	e->src_buf_sz     = (args.src_buf) ? args.src_buf_sz : S302M_SIN_LUT_SZ;
+	e->src_buf_offset = 0;
+
+	e->video = false;
+	e->ctx   = kzalloc(priv_sz, GFP_KERNEL);
+
+	e->encode = vidtv_s302m_encode;
+	e->clear  = vidtv_s302m_clear;
+
+	e->es_pid = args.es_pid;
+
+	e->sync                 = args.sync;
+	e->sampling_rate_hz     = S302M_SAMPLING_RATE_HZ;
+	e->access_unit_capacity = args.access_unit_capacity;
+
+	/* we will wrap around 'src' if this is NULL */
+	e->last_sample_cb = args.last_sample_cb;
+
+	e->destroy = vidtv_s302m_encoder_destroy;
+
+	if (args.head) {
+		while (args.head->next)
+			args.head = args.head->next;
+
+		args.head->next = e;
+	}
+
+	e->next = NULL;
+
+	return e;
+}
+
+void vidtv_s302m_encoder_destroy(struct vidtv_encoder *e)
+{
+	WARN_ON(e->id != S302M);
+	kfree(e->name);
+	kfree(e->encoder_buf);
+	kfree(e->samples_per_unit);
+	kfree(e->pts);
+	kfree(e->dts);
+	kfree(e->nbytes);
+	kfree(e->offsets);
+	kfree(e->ctx);
+	kfree(e);
+}
diff --git a/drivers/media/test-drivers/vidtv/vidtv_s302m.h b/drivers/media/test-drivers/vidtv/vidtv_s302m.h
new file mode 100644
index 0000000000000..bfb8b0c80eddf
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_s302m.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Vidtv serves as a reference DVB driver and helps validate the existing APIs
+ * in the media subsystem. It can also aid developers working on userspace
+ * applications.
+ *
+ * This file contains the code for an AES3 (also known as AES/EBU) encoder.
+ * It is based on EBU Tech 3250 and SMPTE 302M technical documents.
+ *
+ * This encoder currently supports 16bit AES3 subframes using 16bit signed
+ * integers.
+ *
+ * Note: AU stands for Access Unit, and AAU stands for Audio Access Unit
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#ifndef VIDTV_S302M_H
+#define VIDTV_S302M_H
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+#include "vidtv_encoder.h"
+
+/* see SMPTE 302M 2007 clause 7.3 */
+#define VIDTV_S302M_BUF_SZ 65024
+
+/* see ETSI TS 102 154 v.1.2.1 clause 7.3.5 */
+#define VIDTV_S302M_FORMAT_IDENTIFIER 0x42535344
+
+struct vidtv_s302m_ctx {
+	struct vidtv_encoder *enc;
+
+	/* whether the F bit was set for the last sub-frame */
+	bool last_f;
+	/* either X or Z */
+	u8 last_start_preamble;
+	/* are we writing an A subframe now? */
+	bool is_subframe_a;
+	/* we send a bit per subframe */
+	u8 current_c_bit;
+};
+
+struct vidtv_smpte_s302m_es {
+	union {
+		u32 bitfield;
+		struct {
+			u16 audio_packet_size:16;
+			u16 num_channels:2;
+			u16 channel_identification:8;
+			u16 bits_per_sample:2; /* 0x0 for 16bits */
+			u16 zero:4;
+		} __packed;
+	} __packed;
+} __packed;
+
+struct vidtv_s302m_subframe_16 {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	u8 f:1;
+	u8 c:1;
+	u8 u:1;
+	u8 v:1;
+	u16 data_word:16; /* little endian, use cpu_to_le before writing */
+	u8 zero:4;
+	u8 aux:4;
+	u8 preamble:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	u8 preamble:4;
+	u8 aux:4;
+	u8 zero:4;
+	u16 data_word:16; /* little endian */
+	u8 v:1;
+	u8 u:1;
+	u8 c:1;
+	u8 f:1;
+#else
+#error  "Please fix <asm/byteorder.h>"
+#endif
+}__packed;
+
+struct vidtv_s302m_encoder_init_args {
+	char *name;
+	void *src_buf;
+	u32 src_buf_sz;
+	u16 es_pid;
+	struct vidtv_encoder *sync;
+	u8 access_unit_capacity;
+	void (*last_sample_cb)(u32 sample_no);
+
+	/* optionally chain to this encoder */
+	struct vidtv_encoder *head;
+};
+
+struct vidtv_encoder
+*vidtv_s302m_encoder_init(struct vidtv_s302m_encoder_init_args args);
+
+void vidtv_s302m_encoder_destroy(struct vidtv_encoder *encoder);
+
+#endif /* VIDTV_S302M_H */
-- 
2.26.2