[Ffmpeg-devel] Bug when encoding NTSC

Penny Wise penny_it
Thu Jun 30 11:56:10 CEST 2005

I uploaded a couple of sample files to /MPlayer/incoming/PennyWis so that 
you can see this yourself.
Okay; first the tech details:

'-y -hq  -deinterlace -target dvd -async 1 -vsync 0 -pass 1 -passlogfile 
'.$passlog.' -acodec mp2 -ab 224';
'-y -hq  -deinterlace -target dvd -async 1 -vsync 0 -pass 2 -passlogfile 
'.$passlog.' -acodec mp2 -ab 224';

ffmpeg version 0.4.9-pre1, build 4757, Copyright (c) 2000-2004 Fabrice 
  configuration:  --prefix=/usr --enable-mp3lame  --enable-vorbis 
--enable-a52 --enable-pp  --enable-shared --enable-gpl --enable-pthreads  
--enable-xvid --enable-shared-pp  --enable-libogg  --enable-theora 
--enable-faad  --enable-faac
  built on Jun 29 2005 15:21:12, gcc: 3.4.2 20041017 (Red Hat 3.4.2-6.fc3)

And the input was:
Input #0, mpegvideo, from 
  Duration: 00:01:01.9, start: 0.000000, bitrate: 8000 kb/s
  Stream #0.0: Video: mpeg2video, yuv420p, 720x480, 29.97 fps, 8000 kb/s
Input #1, wav, from 
  Duration: 00:01:05.4, start: 0.000000, bitrate: 1535 kb/s
  Stream #1.0: Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s
Assuming NTSC for target.
Output #0, dvd, to '/domains/lulop.com/titles/3/3_broadcast04.mpg':
  Stream #0.0: Video: mpeg2video (hq), yuv420p, 720x480, 29.97 fps, q=2-31, 
pass 1, 6000 kb/s
  Stream #0.1: Audio: mp2, 48000 Hz, stereo, 224 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #1.0 -> #0.1

First of all, the input duration looks weird ?cause I?m positively sure the 
both clips duration is 1 min 5 secs. Anyhow, the result is weird. Outputfile 
duration is 1 min 18 sec and the audio stops and 1 in 5 secs, as it should. 
Something odd happens with framerate, could it be that ffmpeg takes 25 
frames and "stretches" to 29,97 and that?s why the result is ~20% longer? 
(29,97>25 ~20%)
With PAL the enconding goes perfectly.

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