<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<br>
<br>
<div class="moz-cite-prefix">Den 10.03.2023 02:46, skrev Andrew
Randrianasulu:<br>
</div>
<blockquote type="cite"
cite="mid:CA+rFky6ikNgRHoVVS4CEPDaN5jyZNb2sQvQSAqtLSoANDqH=yA@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="auto">
<div><br>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">пт, 10 мар. 2023 г., 02:43
Terje J. Hanssen <<a
href="mailto:terjejhanssen@gmail.com"
moz-do-not-send="true" class="moz-txt-link-freetext">terjejhanssen@gmail.com</a>>:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div> I contine this new thread with an short extract from
the long growing<br>
[Cin] ms2130 HDMI-USB3 UHD capture card - not quite as
expected?<br>
<br>
But shouldn't a 422 and not a 420 output format be
created?<br>
<br>
<blockquote>>> it seems in some cases ffmpeg not
geared towards preserving most information, just picks
up most commonly defined/first pixel format. <br>
>> Try mpeg2video as output codec, and/or
specify pixel format (pix_fmt) more explicitly before
output's filename?<br>
<br>
>>> Could you possibly examplify the latter?<br>
<br>
>>>> 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!<br>
</blockquote>
-------------------------------<br>
<br>
Instead of 50i (pal interlaced fields), I try 50 fps
(progressive) that at least is a pal frequence.<br>
<br>
And yes, it seems from the output that ffmpeg uses
mpeg1video as default output codec.<br>
<br>
Furter I try to combine the current line<br>
<blockquote>ffmpeg -hide_banner -f v4l2 -input_format
yuyv422 -video_size 720x576 -framerate 25 -t 20 -i
/dev/video2 out-720x576_ms2130.mpeg<br>
</blockquote>
<br>
with and utilize the syntax developed 2021 for "Blu-ray
compliant MPEG-2 SD video with LPCM audio"<br>
<blockquote>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 <br>
</blockquote>
and for the current ongoing "DVD compliant MPEG-2 Video
and PCM Audio"<br>
<blockquote>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<br>
</blockquote>
to first<br>
<blockquote>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 <br>
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.<br>
Error parsing options for input file /dev/video2.<br>
Error opening input files: Invalid argument<br>
</blockquote>
<br>
and next revised with no output. That is I need help to
debug the syntax error: <br>
<blockquote>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<br>
[video4linux2,v4l2 @ 0x55db770ef9c0] Dequeued v4l2
buffer contains corrupted data (0 bytes).<br>
Input #0, video4linux2,v4l2, from '/dev/video2':<br>
Duration: N/A, start: 0.000000, bitrate: 331776 kb/s<br>
Stream #0:0: Video: rawvideo (YUY2 / 0x32595559),
yuyv422, 720x576, 331776 kb/s, 50 fps, 50 tbr, 1000k
tbn<br>
Stream mapping:<br>
Stream #0:0 -> #0:0 (rawvideo (native) ->
mpeg2video (native))<br>
Press [q] to stop, [?] for help<br>
[video4linux2,v4l2 @ 0x55db770ef9c0] Dequeued v4l2
buffer contains corrupted data (0 bytes).<br>
Last message repeated 30 times<br>
[mpeg2video @ 0x55db77114f00] Warning vbv_delay will
be set to 0xFFFF (=VBR) as the specified vbv buffer is
too large for the given bitrate!<br>
Output #0, vob, to '720x576_50p_ms2130.mpg':<br>
Metadata:<br>
encoder : Lavf59.27.100<br>
Stream #0:0: Video: mpeg2video (4:2:2), yuv422p(tv,
progressive), 720x576, q=2-31, 8000 kb/s, 50 fps, 90k
tbn<br>
Metadata:<br>
encoder : Lavc59.37.100 mpeg2video<br>
Side data:<br>
cpb: bitrate max/min/avg:
8000000/8000000/8000000 buffer size: 20000000
vbv_delay: N/A<br>
frame= 0 fps=0.0 q=0.0 Lsize= 0kB
time=00:00:00.00 bitrate=N/A speed= 0x <br>
video:0kB audio:0kB subtitle:0kB other streams:0kB
global headers:0kB muxing overhead: unknown<br>
Output file is empty, nothing was encoded (check -ss /
-t / -frames parameters if used)<br>
</blockquote>
</div>
</blockquote>
</div>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">I am afraid you probably need help from
ffmpeg-users mail list here .... Last line looks correct, yet
not encoding??</div>
</div>
</blockquote>
<br>
My fault. I didn't remember I had to reboot to Tumbleweed to get
pcm_dvd encoder available.<br>
Then it run as above and created the output file:<br>
<br>
<blockquote>ffprobe -hide_banner 720x576_50p_ms2130.mpg<br>
Input #0, mpeg, from '720x576_50p_ms2130.mpg':<br>
Duration: 00:00:14.44, start: 0.520000, bitrate: 7749 kb/s<br>
Stream #0:0[0x1e0]: Video: mpeg2video (4:2:2), yuv422p(tv,
progressive), 720x576 [SAR 1:1 DAR 5:4], 50 fps, 50 tbr, 90k tbn<br>
Side data:<br>
cpb: bitrate max/min/avg: 8000000/0/0 buffer size: 20004864
vbv_delay: N/A<br>
<br>
</blockquote>
Color subsampling;<br>
I think we used -input_format "yuyv422" to correspond with the
capture card YUY2 to grab as much quality as possible.<br>
However, DVD-Video does only support 4:2:0 chroma subsampling (not
4:2:2).<br>
I tried to add "-pix_fmt yuv420p" on the output side after -c:v
mpeg2video but it didn't work.?<br>
<br>
Interlacing:<br>
DVDs are based on MPEG-2 encoding, which allows for either
progressive or interlaced sequences. However, very few discs use
progressive sequences, because the players are specifically designed
for interlaced output.<br>
I tried to add the previous "-flags +ilme+ildct" but then again
Empty output file?<br>
<br>
<br>
<br>
<br>
<br>
<br>
<blockquote type="cite"
cite="mid:CA+rFky6ikNgRHoVVS4CEPDaN5jyZNb2sQvQSAqtLSoANDqH=yA@mail.gmail.com">
<div dir="auto">
<div dir="auto"><br>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><br>
<br>
<br>
<br>
<br>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
<br>
</body>
</html>