Topic: Split PolyWAV to Stereo Tracks with FFMPEG

[voltronic]

I have finally found an easy solution to splitting polyphonic WAV files to stereo tracks without having to split to mono files and then recombine those to stereo.

EDIT: This is most useful for 32-bit float PolyWAV files. For 16/24-bit fixed, WaveAgent is the easier choice (see here).

1. Install FFMPEG.

2. Copy/move the WAV to the directory containing ffmpeg.exe, or copy ffmpeg.exe to the directory containing the WAV file.

3. Open a command prompt and navigate to the directory containing your WAV and FFMPEG.

4. Enter the appropriate command based on how many channels your PolyWAV contains, replacing [inputfilename] with the name of your WAV:

Code: [Select]

*FOR 8 CHANNELS*

ffmpeg -i inputfilename.wav -filter_complex "[0]pan=stereo|c0=c0|c1=c1[a]; [0]pan=stereo|c0=c2|c1=c3[b]; [0]pan=stereo|c0=c4|c1=c5[c]; [0]pan=stereo|c0=c6|c1=c7[d]" -map "[a]" 1_2.wav -map "[b]" 3_4.wav -map "[c]" 5_6.wav -map "[d]" 7_8.wav


*FOR 6 CHANNELS*

ffmpeg -i inputfilename.wav -filter_complex "[0]pan=stereo|c0=c0|c1=c1[a]; [0]pan=stereo|c0=c2|c1=c3[b]; [0]pan=stereo|c0=c4|c1=c5[c]" -map "[a]" 1_2.wav -map "[b]" 3_4.wav -map "[c]" 5_6.wav


*FOR 4 CHANNELS*

ffmpeg -i inputfilename.wav -filter_complex "[0]pan=stereo|c0=c0|c1=c1[a]; [0]pan=stereo|c0=c2|c1=c3[b]" -map "[a]" 1_2.wav -map "[b]" 3_4.wav

You can run the 8-channel command on a file containing fewer channels without problems. Just be aware you'll be left with silent stereo files for the channels that were not recorded.

I adapted this from one of the solutions found here. The other solutions listed there all returned errors, as did the syntax found in the official documentation.

[voltronic]

Next task is to verify that this works for 32-bit float files.

[aaronji]

Why not use WaveAgent for 24-bit files?

[voltronic]

Why not use WaveAgent for 24-bit files?

I was not able to get WaveAgent to export directly to stereo tracks. Fortunately a user on GS Remote just showed me what I was doing wrong. I will likely go back to using WaveAgent now...

[aaronji]

Ha, ha! It is really simple, but not clearly documented. Another nice feature is that you can drop multiple files into WaveAgent (if there were auto-splits or different sets/bands or whatever) and do the same split on all simultaneously.

[goodcooker]

Reaper will also explode Poly files. I started with Wave Agent but kinda got used to Reaper already so I'll probably stick with it.

[Gordon]

iZotope RX makes it real easy as well!

[voltronic]

iZotope RX makes it real easy as well!

Only if you have Advanced. I have standard, and it only supports mono or stereo files.

[live2496]

ffmpeg is awesome for lots of stuff. I primarily use it to cut/extract snippets from original (long run) mp4 video files.

Really quick for repeated tasks once you get the syntax figured out.

Gordon

[kliked]

Why not use WaveAgent for 24-bit files?

I was not able to get WaveAgent to export directly to stereo tracks. Fortunately a user on GS Remote just showed me what I was doing wrong. I will likely go back to using WaveAgent now...

Care to share?

[voltronic]

In the split / combine window, clear the default selections. Then select the first two tracks in column 1, the next two tracks in column 2, etc.

[C.Clark]

If you're willing to pay, Adobe Audition makes it very easy to directly export stereo wave files from polywav, but really appreciate the alternate applications that can do this Voltronic!