Multitrack recordings during rehearsal - how to quickly play them back?

21

Just been playing around with this with sox-14-4-2 and it seems to cope with Cantabile’s wave files. Perhaps they’ve fixed sox?

I was running this command: sox MultiChannel.wav out.wav remix 3 4 on a 5 channel recording from Cantabile and it worked just fine.

@torsten - were you using an older build of sox?

22

Nope, I was using sox-14-4-2 as well.

23

Just went back to @a6325435’s file that he sent me and tried pretty much the same command that @brad used:

sox Piano_2017-05-24_21-37-13.wav out.wav remix 1

Result with sox-14-4-2 was:

sox FAIL formats: can't open input file `Piano_2017-05-24_21-37-13.wav': WAVE file fmt with padded samples is not supported yet

@brad: did you create a 24 bit recording like Al did? Seems the problem only occurs with 24 bit recordings…

I did a quick test now: created a simple song with just a Synth1 plugin, sending audio to two stereo outputs.

  • Recorded only one stereo output @ 24 bit → file was OK and good to process with sox
  • Recorded both stereo outputs plus Metronome Output @ 24 bit → file looks strange from a codec perspective; not good with sox
  • Recorded one stereo output @ 16 bit → file OK and good to process with sox
  • Recorded both stereo outputs plus metronome @ 16 bit → file looks strange but processes OK with sox

What do I mean with “looks strange”: here’s some MediaInfo output for an “OK” file:

snip.JPG696×463 44.9 KB

And here’s a “strange” one:

The codec ID looks kinda fishy for the multi-channel files - same happens at 16 bit: Codec 1 for stereo, but the strange one for multichannel. But since sox can deal with the strange Codec ID for 16 bit files, this doesn’t seem to be the cause of the issues.

@brad: maybe with this info, you can reproduce (and hopefully correct) the issue?

Cheers,

Torsten

24

Hi @torsten,

I thought I had it set to 24-bit but I’ll double check today.

Brad

25

Yep, my bad. 24-bit fails here too.

So I think I know what’s going on now… the junk chunk was a red herring and it’s related to the sample format.

Cantabile’s 24-bit record format writes the samples packed as 32-bit (mainly for performance reasons) and that’s what sox is complaining about - it wants the sample data tightly packed (reference)

I’ll look into providing support for this, but in the meantime you might as well use 32-bit integer - the file will be exactly the same size as 24-bit anyway.

Ugh. I obviously need a holiday. Turns out Cantabile does write 24-bit data tightly packed (forgotten that I changed that) but there was a problem with what it was writing in the header. Fixed for next build.

Brad

26

Fixed in build 3255 (available now).