Re: 64bit audio read and write

[Eric Wong <normalperson@yhbt.net>]

Matt Flax <flatmax@flatmax.org> wrote:
> Hi there,
> 
> I currently use libsox to load and save audio data. I was wanting to 
> write and read 64bit data, however the generic sox sample type is 32 bit 

Correct, sox does some calculations internally in 64-bit double,
but data which flows in between the effects is all 32-bit int.

> (from sox.h) :
> typedef sox_int32_t sox_sample_t;
> 
> The basic format of the read (and write) functions are :
> size_t sox_read(
>      sox_format_t * ft,
>      sox_sample_t *buf,
>      size_t len
>      );
> 
> Can anyone tell me the basic methodology for reading/writing 64bit audio ?

It would probably reworking a lot of sox internals and would
require increased memory bandwidth, hurting performance for
common <= 32-bit processing.

But, where and how are you working with 64-bit audio
and what 64-bit audio formats are there?

I'm not up-to-date with the latest technology, but even 32-bit
is far beyond the range of human hearing; and last I checked;
available ADC/DACs can't even make full use of 24-bit (nor
our ears).


On the other hand, moving to 32-bit float would make sense for
compatibility with 3rd-party plugins (LADSPA for sure, maybe
LV2?).  Right now, we're constantly converting between
float/integer in effects chains which hurts performance.

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