пт, 2 мая 2025 г., 22:37 Terje J. Hanssen <terjejhanssen@gmail.com>:

https://www.mail-archive.com/cin@lists.cinelerra-gg.org/msg05748.html

I contine this new thread with an short extract from the long growing
[Cin] ms2130 HDMI-USB3 UHD capture card - not quite as expected?

But shouldn't a 422 and not a 420 output format be created?

>> it seems in some cases ffmpeg not geared towards preserving most information, just picks up most commonly defined/first pixel format.
>> Try mpeg2video as output codec, and/or specify pixel format (pix_fmt) more explicitly before output's filename?

>>> Could you possibly examplify the latter?

>>>> I think I just theorized ffmpeg may try to get some info from alsa device file directly, as it tries with /dev/video. But I never >>>> tried this way, so I can be totally wrong!

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Instead of 50i (pal interlaced fields), I try 50 fps (progressive) that at least is a pal frequence.

And yes, it seems from the output that ffmpeg uses mpeg1video as default output codec.

Furter I try to combine the current line

ffmpeg -hide_banner -f v4l2 -input_format yuyv422 -video_size 720x576 -framerate 25 -t 20 -i /dev/video2 out-720x576_ms2130.mpeg

with and utilize the syntax developed 2021 for "Blu-ray compliant MPEG-2 SD video with LPCM audio"

ffmpeg -i dv28.dv -c:v mpeg2video -refs 1 -bf 2 -b:v 25M -maxrate 25M -minrate 25M -bufsize 45M -muxrate 45M -dc 10 -c:a pcm_s16be -f vob dv28.mpg

and for the current ongoing "DVD compliant MPEG-2 Video and PCM Audio"

ffmpeg -hide_banner -i dv01.dv -c:v mpeg2video -refs 1 -bf 2 -b:v 8M -maxrate 8M -minrate 8M -bufsize 20M -muxrate 11M -dc 10 -c:a pcm_dvd -f vob -flags +ilme+ildct dv01.mpg

to first

ffmpeg -hide_banner -f v4l2 -input_format yuyv422 -video_size 720x576 -framerate 50 -c:v mpeg2video -refs 1 -bf 2 -b:v 8M -maxrate 8M -minrate 8M -bufsize 20M -muxrate 11M -dc 10 -c:a pcm_dvd -f vob -t 20 -i /dev/video2 720x576_50p_ms2130.mpg
Option b:v (video bitrate (please use -b:v)) cannot be applied to input url /dev/video2 -- you are trying to apply an input option to an output file or vice versa. Move this option before the file it belongs to.
Error parsing options for input file /dev/video2.
Error opening input files: Invalid argument

and next revised with no output. That is I need help to debug the syntax error:

ffmpeg -hide_banner -f v4l2 -input_format yuyv422 -video_size 720x576 -framerate 50 -i /dev/video2 -c:v mpeg2video -refs 1 -bf 2 -b:v 8M -maxrate 8M -minrate 8M -bufsize 20M -muxrate 11M -dc 10 -c:a pcm_dvd -f vob -t 20 720x576_50p_ms2130.mpg
[video4linux2,v4l2 @ 0x55db770ef9c0] Dequeued v4l2 buffer contains corrupted data (0 bytes).
Input #0, video4linux2,v4l2, from '/dev/video2':
Duration: N/A, start: 0.000000, bitrate: 331776 kb/s
Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 720x576, 331776 kb/s, 50 fps, 50 tbr, 1000k tbn
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg2video (native))
Press [q] to stop, [?] for help
[video4linux2,v4l2 @ 0x55db770ef9c0] Dequeued v4l2 buffer contains corrupted data (0 bytes).
    Last message repeated 30 times
[mpeg2video @ 0x55db77114f00] Warning vbv_delay will be set to 0xFFFF (=VBR) as the specified vbv buffer is too large for the given bitrate!
Output #0, vob, to '720x576_50p_ms2130.mpg':
Metadata:
    encoder         : Lavf59.27.100
Stream #0:0: Video: mpeg2video (4:2:2), yuv422p(tv, progressive), 720x576, q=2-31, 8000 kb/s, 50 fps, 90k tbn
    Metadata:
      encoder         : Lavc59.37.100 mpeg2video
    Side data:
      cpb: bitrate max/min/avg: 8000000/8000000/8000000 buffer size: 20000000 vbv_delay: N/A
frame=    0 fps=0.0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=N/A speed=   0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)

well, I think framerate still 25 for 50i stream ....

can you re-check last line with framerate parameter removed or changed back to 25?