我正在尝试将“mcompand”音频过滤器与 FFMPEG 一起使用： https://ffmpeg.org/ffmpeg-filters.html#mcompand
但看起来过滤器不存在，我不明白为什么或如何安装它。
我正在运行以下命令：
ffmpeg -i input.wav -af "mcompand=0 0:1 1:-90/-900 -70/-70 -30/-9 0/-3:6:0:0:0" out.wav
输出如下：
ffmpeg version 2.8.11-0ubuntu0.16.04.1 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609 configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv libavutil 54. 31.100 / 54. 31.100 libavcodec 56. 60.100 / 56. 60.100 libavformat 56. 40.101 / 56. 40.101 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 40.101 / 5. 40.101 libavresample 2. 1. 0 / 2. 1. 0 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.101 / 1. 2.101 libpostproc 53. 3.100 / 53. 3.100 Guessed Channel Layout for Input Stream #0.0 : mono Input #0, wav, from 'input.wav': Metadata: encoded_by : Pro Tools originator_reference: 8hQM2ATxHVjaaaGk date : 2017-12-19 creation_time : 10:32:43 time_reference : 2724864 Duration: 00:00:46.22, bitrate: 1066 kb/s Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 44100 Hz, 1 channels, s32 (24 bit), 1058 kb/s File 'out.wav' already exists. Overwrite ? [y/N] y [AVFilterGraph @ 0x14260a0] No such filter: 'mcompand' Error opening filters!
有人知道我该怎么办吗？谢谢。