[MEncoder-users] DVD compliant MPEG2 encoding

[Lauri Myllari]

On Mon, Sep 12, 2005 at 12:26:13PM -0400, Giacomo Comes wrote:
> > 2) telecine
> > 
> > 3:2 pulldown was still causing stutter on NTSC playback. It seems
> > -mpegopts flag "telecine" doesn't work 100%. MPlayer recognizes this
> > pulldown and switches to 24000/1001fps, but the Pioneer was skipping
> > all the time.
> 
> Do you have this problem with or without B-frames (or both)?
> I have observed this only with B-frames.

Both. Here's how to reproduce (using the same source as the beginning
of thread):

% mencoder kingdom_of_heaven_m720p.mov -o video_me256_0bf.mpg -nosound -noskip -ofps 24000/1001 \
-ovc lavc -of mpeg -mpegopts format=dvd:vaspect=16/9:telecine -vf expand=1280:720,scale=720:480 \
-lavcopts vcodec=mpeg2video:keyint=15:vbitrate=1800:vrc_buf_size=1835:vrc_maxrate=9000:aspect=16/9:me_range=256:vmax_b_frames=0
% mencoder kingdom_of_heaven_m720p.mov -o video_me256_1bf.mpg -nosound -noskip -ofps 24000/1001 \
-ovc lavc -of mpeg -mpegopts format=dvd:vaspect=16/9:telecine -vf expand=1280:720,scale=720:480 \
-lavcopts vcodec=mpeg2video:keyint=15:vbitrate=1800:vrc_buf_size=1835:vrc_maxrate=9000:aspect=16/9:me_range=256:vmax_b_frames=1

I had to use -nosound, otherwise I get a lot of errors like "ERROR: SCR:
228288961, APTS: 204226560, DELTA=-0.261 secs, COMPENSATE=7310, BR:
28000, lens: 2016/2016, frames: 2".

The resulting files are accepted by dvdauthor without any warnings.
Playback starts ok, then starts skipping a bit, then almost jumping and
the first stream hangs before end. Second one actually finishes, but
the video has nasty jumps.

Curiously, if I multiplex audio into these clips, it doesn't stutter
during playback (maybe the audio stutter was because of wrong me_range).
Video is still the same and the first clip hangs.

The only way I can make good NTSC streams is using mencoder for video,
DGpulldown.exe or pulldown.exe for 3:2 pulldown, mplex for multiplexing
with audio and then dvdauthor.

Does anybody have an analyzer that could peek into differences between
pulldown by mencoder and pulldown.exe? Perhaps the video problems are
related to the APTS-SCR errors when trying to encode both video and
audio? (Or have these been solved already and I've just missed some
documentation?)

--rez