ffmpeg将多个mp3文件合并为1个m4b文件

根据如何将MP3系列批量转换为M4B的建议，我选择了ffmpeg作为工具。

我从http://ffmpeg.zeranoe.com/builds/下载了Windows的静态版本。

当我尝试将4个mp3文件合并为1个m4b文件时，发生了以下错误。我该怎么办？通过正确的ffmpeg支持m4b文件。

我跑了：

C:\EBC>ffmpeg -i "concat:65.mp3|airbus.mp3|alcoholabuse.mp3|allergies.mp3" -c libfdk_aac -b:a 64k EBC.m4b 

错误：

ffmpeg version N-66564-gc29d999 Copyright (c) 2000-2014 the FFmpeg developers   built on Oct  2 2014 00:53:44 with gcc 4.9.1 (GCC)   configuration: --enable-gpl --enable-version3
--disable-w32threads --enable-av isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca -- enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-lib modplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrw b --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinge r --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --en able-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc
--enable-libvorbis  --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable- libx265 --enable-libxavs --enable-libxvid --enable-zlib   libavutil      54.  7.101 / 54.  7.101   libavcodec     56.  1.102 / 56.  1.102   libavformat    56.  7.102 / 56.  7.102   libavdevice    56.  1.100 / 56.  1.100   libavfilter     5.  1.102 /  5.  1.102   libswscale      3.  1.100 / 
3.  1.100   libswresample   1.  1.100 /  1.  1.100   libpostproc    53.  1.100 / 53.  1.100 [mp3 @ 02dca020] Estimating duration from bitrate, this may be inaccurate Input #0, mp3, from 'concat:65.mp3|airbus.mp3|alcoholabuse.mp3|allergies.mp3':   Metadata:
    album_artist    : British Council
    title           : When I'm 65
    artist          : British Council
    album           : British Council
    encoded_by      : MPH
    genre           : Podcast
    copyright       : British Council
    date            : 2006   Duration: 00:10:42.98, start: 0.000000, bitrate: 160 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 160 kb/s
    Stream #0:1: Video: mjpeg, yuvj444p(pc, bt470bg), 250x250 [SAR 100:100 DAR 1 :1], 90k tbr, 90k tbn, 90k tbc
    Metadata:
      title           :
      comment         : Cover (front) [NULL @ 02dc7480] Unable to find a suitable output format for 'EBC.m4b' EBC.m4b: Invalid argument