On 10/23/17, Frank @ Taapo <info@taapo.com> wrote:

I have been trying to get sidechaining to work with FFMPEG, but my complex filter skills are lacking.

I'm running two aif files into ffmpeg, hoping the voice would "duck" the background music when the voice-over is speaking. But I get an error with this command-line (on Windows, with latest FFMPEG binary):

ffmpeg.exe -i temp_music.aif -i temp_voice.aif -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress=threshold=0.1:ratio=5[bg]; [bg][mix]amerge[fin**al]" -map [final] final.mp3

Everything decodes fine:

ffmpeg version N-87353-g183fd30 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib libavutil 55. 76.100 / 55. 76.100 libavcodec 57.106.101 / 57.106.101 libavformat 57. 82.101 / 57. 82.101 libavdevice 57. 8.101 / 57. 8.101 libavfilter 6.105.100 / 6.105.100 libswscale 4. 7.103 / 4. 7.103 libswresample 2. 8.100 / 2. 8.100 libpostproc 54. 6.100 / 54. 6.100 Guessed Channel Layout for Input Stream #0.0 : stereo Input #0, aiff, from 'temp_music.aif': Duration: 00:01:26.68, start: 0.000000, bitrate: 1536 kb/s Stream #0:0: Audio: pcm_s16be, 48000 Hz, stereo, s16, 1536 kb/s Guessed Channel Layout for Input Stream #1.0 : stereo Input #1, aiff, from 'temp_voice.aif': Duration: 00:01:26.68, start: 0.000000, bitrate: 1536 kb/s Stream #1:0: Audio: pcm_s16be, 48000 Hz, stereo, s16, 1536 kb/s Output with label 'final' does not exist in any defined filter graph, or was already used elsewhere.

But then I receive an error:

Output with label 'final' does not exist in any defined filter graph, or was already used elsewhere.

Anybody knows why?

outputs pads names apparently can not have more than 2 chars.