I would like recode wav files from stereo to 4 channels - front channels with low frequencies and back channels with high frequencies only; to store wav files on DLNA server and play on receiver in bi-amp mode - stereo channels on front and high frequencies on back. Speakers stand side by side. Receivers have option split subwoofer frequency. So, I think there is command split audio frequencies in ffmpeg, sox or other command line.
In short, I would like create 4 channels wav audio. Front stereo sound channels with low frequency and back channels with high frequency of sound. So, left channel splited on 3kHz to front and back. And right channel splited to front and back too.
Can and how I do split wav stereo, for example on 3,000 Hz, to 4 channels wav?
Microsoft Windows [Version 10.0.19044.1466] (c) Microsoft Corporation. All rights reserved. C:\Users\Public\Downloads\ffmpeg\bin>ffmpeg -i in.wav -af "lowpass=f=3200" out-.wav C:\Users\Public\Downloads\ffmpeg\bin>ffmpeg -i in.wav -af "highpass=f=3200" out+.wav
Strange, output file size equal to input file size,
And one more option,
C:\Users\Public\Downloads\ffmpeg\bin>ffmpeg -i in.wav -filter_complex 'acrossover=split=1500:order=8th[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav ffmpeg version n5.0-4-g911d7f167c-20220206 Copyright (c) 2000-2022 the FFmpeg developers ... skiped ... Guessed Channel Layout for Input Stream #0.0 : stereo Input #0, wav, from 'in.wav': Duration: 00:01:42.23, bitrate: 1411 kb/s Stream #0:0: Audio: pcm_s16le ( / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s [AVFilterGraph @ 000001c5bc017300] No such filter: 'acrossover=split=1500:order=8th[LOW][HIGH]' Error initializing complex filters. Invalid argument
Then will use amerge to join the result to 4 channels. Then DAC outputs analog audio to 4 channels. Low to one amp and high frequencies to other amp.