Конвертировать mp3 в flv

Я хочу конвертировать mp3 файлы в flv

почему это не сработает?

$ ffmpeg -y -i 1.mp3 -f flv -acodec libmp3 -ab 64 -ac 1 myfile.flv
ffmpeg version 0.7-rc1, Copyright (c) 2000-2011 the FFmpeg developers
  built on May 25 2011 02:37:46 with gcc 4.4.3
  configuration: 
  libavutil    50. 40. 1 / 50. 40. 1
  libavcodec   52.120. 0 / 52.120. 0
  libavformat  52.108. 0 / 52.108. 0
  libavdevice  52.  4. 0 / 52.  4. 0
  libavfilter   1. 77. 0 /  1. 77. 0
  libswscale    0. 13. 0 /  0. 13. 0
[NULL @ 0xa1c7600] Format mp3 detected only with low score of 1, misdetection possible!
[mp3 @ 0xa1c7600] Could not find codec parameters (Audio: mp3, 0 channels, s16)
[mp3 @ 0xa1c7600] Estimating duration from bitrate, this may be inaccurate
1.mp3: could not find codec parameters