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

[Sergei S. <ser...@ya...>]

>________________________________
> From: Ulrich Klauer <ul...@ch...>
>To: sox...@li... 
>Sent: Monday, December 3, 2012 5:40 AM
>Subject: Re: [SoX-users] Converting a wav file to 20-bit depth
> 
>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
>
>


Is there at all sense in supporting 20 (rather than 24) bits ?

I mean, say, does USB audio protocol allow 20 bits, thus saving some bandwidth ?

Regards,
  Sergei.