FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --disable-debug --enable-memalign-hack --enable-shared --enable-pp --extra-cflags=-O3 -ffast-math -fomit-frame-pointer -msse --enable-gpl --enable-pthreads --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libx264 --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-static --enable-shared --cc=x86_64-pc-linux-gnu-gcc --disable-altivec --disable-debug --disable-audio-oss --disable-dv1394 --disable-network --disable-ffplay --disable-opts --enable-libmp3lame --enable-libvorbis --enable-libogg --enable-libtheora --enable-libogg --enable-liba52 --enable-pthreads --enable-libxvid --enable-x11grab --enable-libogg --enable-libx264 --enable-libfaad --enable-libfaac --enable-gpl --enable-pp --enable-swscaler --disable-strip
  libavutil version: 49.4.0
  libavcodec version: 51.40.4
  libavformat version: 51.12.1
  built on Sep 24 2007 16:35:10, gcc: 4.1.1 (Gentoo 4.1.1-r3)
[matroska @ 0x2b4e7034e040]Ignoring seekhead entry for ID=0x1549a966
[matroska @ 0x2b4e7034e040]Ignoring seekhead entry for ID=0x1654ae6b
[matroska @ 0x2b4e7034e040]Ignoring seekhead entry for ID=0x114d9b74
[matroska @ 0x2b4e7034e040]Unknown entry 0x73a4 in info header
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x55aa - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x23314f - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x55ee - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0xaa - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x55aa - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x23314f - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0x55ee - ignoring
[matroska @ 0x2b4e7034e040]Unknown track header entry 0xaa - ignoring
Input #0, matroska, from 'Heroes S01E23 720p.mkv':
  Duration: 00:44:06.6, start: 0.000000, bitrate: N/A
  Stream #0.0: Audio: liba52, 48000 Hz, 5:1
  Stream #0.1: Video: h264, yuv420p, 1280x720, 24.39 fps(r)
Output #0, mp4, to 'Heroes S01E23 720p.mkv.mp4':
  Stream #0.0: Video: libx264, yuv420p, 1280x720, q=2-31, 1000.00 fps(c)
  Stream #0.1: Audio: ac3, 48000 Hz, 5:1
Stream mapping:
  Stream #0.1 -> #0.0
  Stream #0.0 -> #0.1
WARNING codec timebase is very high. If duration is too long,
file may not be playable by quicktime. Specify a shorter timebase
or choose different container.
[mp4 @ 0x2b4e7034e040]track 1: codec frame size is not set
Could not write header for output file #0 (incorrect codec parameters ?)