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On Mon, Jul 20, 2020 at 09:18:19PM +0100, Michael wrote: |
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> I don't have this webcam so I don't know if it will or won't play nicely with |
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> Linux, but at least ffmpeg seems to contain the requisite mjpeg codec: |
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> |
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> $ ffmpeg -hide_banner -codecs | grep mjpeg |
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> DEVIL. mjpeg Motion JPEG (encoders: mjpeg mjpeg_vaapi ) |
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> D.VIL. mjpegb Apple MJPEG-B |
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> D.A.L. adpcm_ima_smjpeg ADPCM IMA Loki SDL MJPEG |
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MJPEG seems fully supported in FFmpeg; it is the Logitech H.264 "internal" |
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streams in the key and delta frames (APP0 field) that are causing the trouble. |
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FFmpeg has no idea how to interpret them, and thus throws loads of warnings. |
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> Again, I don't know what VLC can do with this. :-/ |
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I have a feeling that the VLC issue is different. As mentioned in my original |
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e-mail, it almost crashes (infinite UI-blocking loop) when trying to load these |
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bloody files. When I record a video with OBS (Open Broadcaster Software) using |
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the separate x264 encoding module, the video is obviously no longer MJPEG, and |
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VLC plays it fine. (Nonetheless, I would like to play native Logi MJPEG files.) |
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VLC is supposed to have an MJPEG-demultiplexing module [1, 2], and it seems to |
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be able to find it: |
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$ vlc --list | grep mjpeg |
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VLC media player 3.0.10 Vetinari (revision 3.0.10-0-g7f145afa84) |
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mjpeg M-JPEG camera demuxer |
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... But when I specify `--demux=mjpeg` on the command-line, it cannot be found: |
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$ vlc --demux=mjpeg mjpeg-test.mp4 |
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main demux debug: looking for demux module matching "mjpeg": 46 candidates |
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main demux debug: no demux modules matched |
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[1] https://git.videolan.org/?p=vlc.git;a=blob;f=modules/demux/mjpeg.c#l49 |
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[2] https://wiki.videolan.org/Documentation:Modules/mjpeg/#Demux |
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-- |
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|
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Ashley Dixon |
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suugaku.co.uk |
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2A9A 4117 |
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DA96 D18A |
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8A7B B0D2 |
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A30E BF25 |
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F290 A8AA |
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