On Mon, Jul 20, 2020 at 10:22:49PM +0100, Neil Bothwick wrote:
> On Mon, 20 Jul 2020 19:10:17 +0100, Ashley Dixon wrote:
>
> > Unfortunately, as per [3], Logitech C-series cameras (among others)
> > utilise a proprietary extension to the Motion-JPEG format, in which
> > H.264 data is attached to the various JPEG key and delta frames in the
> > APP0 field [4], as shown when inspecting the data of any frame
> > ("AVI1" [5]):
> >
> > $ ffmpeg -i video.mp4 -vcodec copy %02d.jpg
>
> What command are you using to record this file in the first place?`ffmpeg -f v4l2 -r 30 -s hd720 -c:v mjpeg -i /dev/video0 -c:v h264 output.mp4` When recording, ffmpeg litters stderr with the error: "unable to decode APP fields: Invalid data found when processing input". This is from the mjpeg module. VLC (and mpv, among others) will play the resulting video without any complaints, due to the `-c:v h264` option invoking the x264 encoder, although it is played at about 4x its original speed for some reason. The integrated Firefox player now refuses to play the file entirely: "Video can't be played because the file is corrupt.". -- Ashley Dixon suugaku.co.uk 2A9A 4117 DA96 D18A 8A7B B0D2 A30E BF25 F290 A8AA
signature.asc
Description: PGP signature
