Den 02.05.2025 21:42, skrev Andrew Randrianasulu:
пт, 2 мая 2025 г., 22:37 Terje J. Hanssen <[email protected]>:
https://www.mail-archive.com/[email protected]/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!
-------------------------------
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?
Ok, as this old post by my mistake already has been forwarded to the
list and replied, I will follow it up later today, but need to rig rig
up my camcorder and devices :)
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