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