ffmpeg gives buffer underflow

[zkab]

I am recording from a STB and converting the .ts-files with ProjectX to .m2v,.ac3 or .mp2, .srt files
Then I have used ffmpeg to merge video & sound and after that used spumux to get the subtitles.
At last I have used dvdauthor to create a DVD structure.
So all in all - it has worked without any problems (for years) until recently ... one satellite channel gives me buffer underflow from ffmpeg ... all other channels gives OK result
I use following ffmpeg command:

ffmpeg -i /home/raivo/movie/bild.m2v \
-i /home/raivo/movie/ljud.ac3_mp2 \
-target dvd -vcodec copy -acodec copy \
/home/raivo/movie/bild_ljud_dvd.mpg


and get a massive buffer underflow (pls check below) ... and when playing the DVD it stutters (both video & sound)
I have DEbian 5.03 AMD64 as OS
What could be wrong ?


FFmpeg version SVN-r20916, Copyright (c) 2000-2009 Fabrice Bellard, et al.
built on Dec 24 2009 09:29:43 with gcc 4.4.2
configuration: --prefix=/usr --extra-cflags='-Wall -g ' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-libfaad --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libtheora --enable-libdc1394 --enable-libspeex --enable-nonfree --disable-stripping --enable-avfilter --enable-libdirac --disable-decoder=libdirac --enable-libschroedinger --disable-encoder=libschroedinger --enable-avfilter-lavf --enable-libopenjpeg --enable-version3 --disable-altivec --disable-armv5te --disable-armv6 --disable-vis
libavutil 50. 7. 0 / 50. 7. 0
libavcodec 52.45. 0 / 52.45. 0
libavformat 52.44. 0 / 52.44. 0
libavdevice 52. 2. 0 / 52. 2. 0
libavfilter 1.12. 0 / 1.12. 0
libswscale 0. 7. 2 / 0. 7. 2
libpostproc 51. 2. 0 / 51. 2. 0
[mpegvideo @ 0x1a0c5f0]MAX_READ_SIZE:5000000 reached
[mpegvideo @ 0x1a0c5f0]Estimating duration from bitrate, this may be inaccurate

Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1)
Input #0, mpegvideo, from '/home/raivo/movie/bild.m2v':
Duration: 00:49:07.86, bitrate: 10013 kb/s
Stream #0.0: Video: mpeg2video, yuv420p, 704x576 [PAR 16:11 DAR 16:9], 10014 kb/s, 25 fps, 25 tbr, 1200k tbn, 50 tbc
[ac3 @ 0x1a15d60]max_analyze_duration reached
[ac3 @ 0x1a15d60]Estimating duration from bitrate, this may be inaccurate
Input #1, ac3, from '/home/raivo/movie/ljud.ac3_mp2':
Duration: 00:49:13.34, bitrate: 448 kb/s
Stream #1.0: Audio: ac3, 48000 Hz, stereo, s16, 448 kb/s
Assuming PAL for target.


Only a small fraction of output:

[dvd @ 0x1a20960]buffer underflow i=1 bufi=1764 size=1792
[dvd @ 0x1a20960]buffer underflow i=0 bufi=6684 size=33834
[dvd @ 0x1a20960]buffer underflow i=1 bufi=1764 size=1792
[dvd @ 0x1a20960]buffer underflow i=0 bufi=8708 size=33834
[dvd @ 0x1a20960]buffer underflow i=1 bufi=1764 size=1792
[dvd @ 0x1a20960]buffer underflow i=0 bufi=10732 size=33834

[Gotblade]

Not good with the whys & where fores of this stuff but trial & error has shown me that if I use " ffmpeg -threads 4 -i input.m2ts -deinterlace -r 29.970 -g 12 -vb 15000k -f mpegts -acodec copy output.mpg" I don't see buffer underflows any more.

For you that could translate as " ffmpeg -i /home/raivo/movie/bild.m2v \
-i /home/raivo/movie/ljud.ac3_mp2 \ -f mpegts
-target dvd -vb 6000k -acodec copy \
/home/raivo/movie/bild_ljud_dvd.mpg

notice I omitted the vcodec specification & included a video bitrate that is within dvd specs.

[zkab]

Thanks - I will try it next time