[FFmpeg-devel] [PATCH] V4L2 compliance: Make sure VIDIOC_S_INPUT is called before querying/setting any input properties
lucabe72 at email.it
Thu Jan 12 15:34:25 CET 2012
On 01/11/2012 10:28 PM, Michael Niedermayer wrote:
> On Wed, Jan 11, 2012 at 09:46:57PM +0100, Rupert Eibauer wrote:
>> Michael Niedermayer<michaelni at gmx.at> wrote on 01/11/2012 09:23:45 PM:
>>> On Wed, Jan 11, 2012 at 08:01:25PM +0100, Rupert Eibauer wrote:
>>>> This solves a problem with a V4L device which supports different
>>>> The problem is that the different inputs have different resolutions,
>>>> the device cannot do image scaling.
>>>> This is what happened:
>>>> - ffmpeg calls VIDIOC_S_FMT with the resolution we specified on the
>>>> command line.
>>>> - The driver responds with a resolution which is correct for the
>>>> - ffmpeg calls VIDIOC_S_INPUT, and the driver switches to the
>>>> supported by that input.
>>>> - Now we have a problem: ffmpegs idea about the image resolution is
>>>> The patch below fixes that problem. Please apply it.
>>> The patch looks like its linebreaks where messed up
>> Sorry, automatic line wrapping. I hope it works better this time (or the
> the attachment is ok wraping wise, luca, please review if you have time
At a first glance, it looks ok... But I am pretty sure that the code worked
fine last time I used it (1 year ago, I think).
So, I need to check what happened, and why this change is needed now (or
maybe I am simply misremembering something... :).
I'll have a look at the git history, and send a reply tomorrow.
More information about the ffmpeg-devel