[MEncoder-users] Mencoder soft telecine broken; fix included

[xiphmont at xiph.org]

On 9/30/07, John Brown <johnbrown105 at hotmail.com> wrote:

> Does this have anything to do with my post to mplayer-users entitled "Telecine
> does not seem to be working"?

The bug I fixed is encode-side only.

> I just updated to r24632 (which should include your patch, as I updated after
> reading your post), but I still have the same problem, which is that MPlayer
> cannot play MPEGs produced by MEncoder with -mpegopts format=dvd:telecine.

Really?  I have been making telecined DVDs with mencoder, testing them
with mplayer, and finding mplayer to behave nearly identically to the
output of the standalone DVD player.  I have been using 'tele_src' and
'tele_dest' to do custom pulldowns, not the 'telecine' flag, but they
should be using the same code path to do telecine.

Now, mplayer is printing some wrong output... eg, for the 25fps PAL ->
30000/1001 NTSC direct pulldown I did, mplayer reports:

demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.

...which is wrong-- the source is 25fps PAL, not NTSC film-- but the
output plays correctly.  The command line that produced this
particular mpeg is:

mencoder -oac lavc -ovc lavc -of mpeg -mpegopts
format=dvd:tsaf:vaspect=4/3:tele_src=25:tele_dest=30000/1001 -vf
softskip,scale=704:272,expand=704:480:0:104,harddup,eq2=.65,hue=0:.6
-srate 48000 -af lavcresample=48000 -lavcopts
vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vrc_minrate=4000:vbitrate=6000:keyint=30:vstrict=0:acodec=ac3:abitrate=192:aspect=4/3
-fps 25 -ofps 25 -o soft_telecine2.mpg
star_wreck_in_the_pirkinning_subtitled_xvid.avi

> There
> is continuously increasing A/V desync, with the audio running ahead of the
> video. If I play it with -demuxer lavf, the video plays faster, but the desync
> is not as great. Also, with -demuxer lavf, MPlayer does not display the usual
> warning:
>
> demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
> Warning! FPS changed 23.976 -> 29.970  (-5.994005) [4]   ??,?% 0 0

Was there an earlier message about switching to 23.976?  That's
certainly an indication mplayer is screwing up (but for the record, I
only saw that message before I fixed the soft telecine bug).

For the record, I just re-tested an earlier successful telecining
using the 'telecine' flag rather than the 'tele_src' and 'tele_dest'
flags.  Mplayer reports:

demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.

and plays the file correctly.

Hrm.  What is the command line you're using to encode your file?

Monty