[MEncoder-users] DVD compliant MPEG2 encoding

[Giacomo Comes]

On Mon, Sep 12, 2005 at 08:40:03PM +0300, Lauri Myllari wrote:
> 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 errors are due to the fact that you do not use the harddup filter.
Use -vf expand=1280:720,scale=720:480,harddup
(or -vf scale=720:362,expand=720:480,harddup)
and add you favorite dvd audio stream. 
The missing harddup could also be related to the DVD player skipping.

Can you try again with your Pioneer? Add harddup and the audio channel,
and test telecine with and without B-frames.

> 
> The resulting files are accepted by dvdauthor without any warnings.

Are you using dvdauthor 0.6.11? This version is more strict than older
ones and may shows more errors.

Giacomo

> 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