Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <c6d5be4c-42c9-b8fa-fbd7-108c5da694bc@chromium.org>
Date:   Tue, 11 Apr 2023 16:31:15 +0900
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.7.1
Subject: Re: [PATCH v1] media: vivid: Add webcam parameter for (un)limited
 bandwidth
Content-Language: en-US
To:     Hans Verkuil <hverkuil@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Ricardo Ribalda <ribalda@chromium.org>,
        Yunke Cao <yunkec@chromium.org>,
        Tomasz Figa <tfiga@chromium.org>
References: <20230410063356.3894767-1-mstaudt@chromium.org>
 <20230410102350.382f7d02@sal.lan>
 <6aafad18-13a2-ef45-48a1-1f094554af31@chromium.org>
 <6ee01cf1-5a8b-081f-e218-8c7da39343bc@xs4all.nl>
From:   Max Staudt <mstaudt@chromium.org>
In-Reply-To: <6ee01cf1-5a8b-081f-e218-8c7da39343bc@xs4all.nl>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 4/11/23 16:26, Hans Verkuil wrote:
> I think we either use this bandwidth option and calculate the max fps based on
> that (basically the bandwidth divided by (image_size + some blanking factor)),
> or we keep it simple and instead of going down two steps in fps we allow up to
> 60 fps up to 720p, then 30 fps for 1080p and 15 fps for 4k.
> 
> The fps values currently used are a bit outdated w.r.t. modern webcams, so
> upgrading it wouldn't hurt. And this is a lot simpler than doing bandwidth
> calculations.

Do I understand you correctly, are you suggesting to simply update the 
FPS limits to a new fixed schema, and not have an option at all?

I'm happy to prepare an alternative patch for that, too.


Max