如何在Windows命令行中使用ffmpeg将MP3转换为AMR

Question

使用基于Windows的ffmpeg将MP3转换为AMR。 由于某种原因，它失败并显示以下错误。

不知道如何为AMR指定正确的参数。

C:\Program Files (x86)\AMR to MP3 Converter>ffmpeg -i mfile.mp3 -ar 8000 -ab 12.2k audio.amr
FFmpeg version SVN-r26400, Copyright (c) 2000-2011 the FFmpeg developers
  built on Jan 18 2011 04:07:05 with gcc 4.4.2
  configuration: --enable-gpl --enable-version3 --enable-libgsm --enable-libvorb
is --enable-libtheora --enable-libspeex --enable-libmp3lame --enable-libopenjpeg
 --enable-libschroedinger --enable-libopencore_amrwb --enable-libopencore_amrnb
--enable-libvpx --disable-decoder=libvpx --arch=x86 --enable-runtime-cpudetect -
-enable-libxvid --enable-libx264 --enable-librtmp --extra-libs='-lrtmp -lpolarss
l -lws2_32 -lwinmm' --target-os=mingw32 --enable-avisynth --enable-w32threads --
cross-prefix=i686-mingw32- --cc='ccache i686-mingw32-gcc' --enable-memalign-hack

  libavutil     50.36. 0 / 50.36. 0
  libavcore      0.16. 1 /  0.16. 1
  libavcodec    52.108. 0 / 52.108. 0
  libavformat   52.93. 0 / 52.93. 0
  libavdevice   52. 2. 3 / 52. 2. 3
  libavfilter    1.74. 0 /  1.74. 0
  libswscale     0.12. 0 /  0.12. 0
[mp3 @ 003abeb0] max_analyze_duration reached
[mp3 @ 003abeb0] Estimating duration from bitrate, this may be inaccurate
Input #0, mp3, from 'mfile.mp3':
  Metadata:
    title           : SPL_TRACK
    artist          : Krishnan
    album           : Lord
    genre           : Lord
    track           : 5
  Duration: 00:30:06.00, start: 0.000000, bitrate: 127 kb/s
    Stream #0.0: Audio: mp3, 44100 Hz, 2 channels, s16, 128 kb/s
[libopencore_amrnb @ 017e0d20] Only mono supported
Output #0, amr, to 'audio.amr':
    Stream #0.0: Audio: libopencore_amrnb, 8000 Hz, 2 channels, s16, 12 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
Error while opening encoder for output stream #0.0 - maybe incorrect parameters
such as bit_rate, rate, width or height

Answer 1

如错误消息msg所示， Only mono supported ，因此请添加-ac 1 。

无论如何，您的ffmpeg是史前的。 从https://ffmpeg.zeranoe.com/builds/获取新的二进制文件