FFmpeg merge files into single multichannel file
FFmpeg can merge several files each containing one audio channel into a single file with multiple channels. For example, a multichannel data collection might save each sensor channel into individual files. For data analysis and for practicality to avoid mixing channels from different experiments, it can be useful to combine the individual channel files into a single multichannel file. The amerge filter can merge multiple files into a single multichannel file. . The amerge filter requires all input files to have the same sample rate and format.