[flac-dev] warning that legacy WAVE file has format type 1 but bits-per-sample is 24

[Mark H. David]

Hello,

I've tried encoding a FLAC file from a WAVE file saved with
24-bits-per-sample, using the flac executable. I get this warning:

  WARNING: legacy WAVE file has format type 1 but bits-per-sample=24

The code is currently here on line 373:

  src/flac/encode.c

where the comment says

  let these slide with a warning since they're unambiguous

I do not really understand the warning when I try to break it
down. First,

  *legacy* WAVE file -- what makes this a "legacy" WAVE file?

Second,

  format type 1

What is that exactly?  In the source code I see "format type" is
referred to as "format tag", since the variable name is "wFormatTag".
Is this what's referred to in this reference

  http://soundfile.sapp.org/doc/WaveFormat/

as

  AudioFormat

There it says

  1 for PCM

Is there something about PCM format that implies either 8- or
16-bits-per-second?

I'm new at this and trying to understand it. Can someone explain?

Also, a related but more practical question: is there *any* way to
create a 24- or 32-bits-per-sample WAVE file without getting this
warning when flac tries to encode it?

Thanks,

Mark