On Tuesday, November 30, 2021, Terje J. Hanssen <terjejhanssen@gmail.com> wrote:
Tested the original sample script with minimal changes. A lot of buffer underflow messages, but the PCM audio stream was muxed and worked in VLC:
ffmpeg -i dv28.dv -c:v mpeg2video -pix_fmt yuv422p -refs 1 -bf 2 -b:v 25M -maxrate 25M -minrate 25M -s 720x576 -aspect 4:3 -c:a pcm_s16be -f vob dv28.mpg
[vob @ 0x562322bbb6c0] packet too large, ignoring buffer limits to mux it
[vob @ 0x562322bbb6c0] buffer underflow st=1 bufi=6876 size=7680
frame= 3416 fps=374 q=2.2 Lsize= 448010kB time=00:02:16.60 bitrate=26867.5kbits/s speed= 15x
video:416900kB audio:25620kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.240520%
ffmpeg -i dv28.mpg 2>&1 >/dev/null | egrep "Video|Audio"
Stream #0:0[0x1e0]: Video: mpeg2video (4:2:2), yuv422p(tv, progressive), 720x576 [SAR 16:15 DAR 4:3], 25000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0:1[0xa0]: Audio: pcm_dvd, 48000 Hz, stereo, s16, 1536 kb/s
mediainfo dv28.mpg | grep Format
Format : MPEG-PS
Format : MPEG Video
Format version : Version 2
Format profile : 4:2:2@Main
Format settings : BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=12
Format : PCM
Format settings : Big / Signed
there is also -muxrate and -bufsize options..
try bufsize = muxrate = much bigger (1.8x?) than min/maxrate...
ffmpeg exposes a lot of knobs...
you also can try '-dc 9' 10 or 11 for higher-precision in some mpeg2 math..
for minimising disk loss you probably can prep. few samples with different encoding/muxing params and burn them all on one disk and see how well/bad your hw player plays (and seeks) them..
Terje J. H