gistfile1.txt

ffmpeg -y -i stream1.flv -acodec libmp3lame -ar 44100 -ac 1 -vcodec libx264 stream1.mp4;
FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers
  built on Jan 29 2012 23:56:18 with gcc 4.1.2 20080704 (Red Hat 4.1.2-51)
  configuration: --prefix=/usr --libdir=/usr/lib --shlibdir=/usr/lib --mandir=/usr/share/man --incdir=/usr/include --disable-avisynth --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables' --enable-avfilter --enable-avfilter-lavf --enable-libdirac --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-gpl --enable-nonfree --enable-postproc --enable-pthreads --enable-shared --enable-swscale --enable-vdpau --enable-version3 --enable-x11grab
  libavutil     50.15. 1 / 50.15. 1
  libavcodec    52.72. 2 / 52.72. 2
  libavformat   52.64. 2 / 52.64. 2
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    1.19. 0 /  1.19. 0
  libswscale     0.11. 0 /  0.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
[flv @ 0x9a60850]Could not find codec parameters (Audio: 0x0000, 16000 Hz, 1 channels)
[flv @ 0x9a60850]Estimating duration from bitrate, this may be inaccurate

Seems stream 0 codec frame rate differs from container frame rate: 60.00 (60/1) -> 30.00 (60/2)
Input #0, flv, from 'stream1.flv':
  Duration: 00:00:01.60, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: h264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], 30 tbr, 1k tbn, 60 tbc
    Stream #0.1: Audio: 0x0000, 16000 Hz, 1 channels
[libx264 @ 0x9a67b60]broken ffmpeg default settings detected
[libx264 @ 0x9a67b60]use an encoding preset (e.g. -vpre medium)
[libx264 @ 0x9a67b60]preset usage: -vpre <speed> -vpre <profile>
[libx264 @ 0x9a67b60]speed presets are listed in x264 --help
[libx264 @ 0x9a67b60]profile is optional; x264 defaults to high
Output #0, mp4, to 'stream1.mp4':
    Stream #0.0: Video: libx264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 90k tbn, 30 tbc
    Stream #0.1: Audio: libmp3lame, 44100 Hz, 1 channels, s16, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Error while opening encoder for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height