Re: [SoX-users] Converting a wav file to 20-bit depth

[Ulrich K. <ul...@ch...>]

R R <el...@li...>:

> I thought 20-bit depth format was simply 24-bit data with the LSBs  
> padded to 0. Is this correct?

Essentially, yes. There is also a wValidBitsPerSample header entry  
that says "20" instead of "24". Unfortunately, the SoX WAVE format  
driver is restricted to 8/16/24/32 bit.

> Or sox doesn't support 20-bit conversion? Or the wav format itself  
> doesn't support 20-bit?
> If not, suggestions on any other methods/tools are welcome.

If it is sufficient for you to have 20-bit values in the file, but  
still a header saying "24", then you can use the -p option to dither:
   sox input.wav -b 24 output.wav dither -p 20

If you need a correct header, probably the easiest way to achieve this  
is changing the generated file afterwards with a hex editor or similar  
(change the byte at position 38/0x26 from 24/0x18 into 20/0x14).

Ulrich