Re: [Jack-Devel] S24_3LE

Hi Paul, thanks for your rapid answer!

Ok I see. Float if I want the jack api.

The wordlengths we operate with today may make the discussion less
relevant, but I don't understand the benefit of adding resolution to
something which was not converted correspondingly.

Say you have a low- and a high-frequency tone added together. Say the lf
tone amplitude is 1000 times that of the hf tone. I happen to be only
interested in the low-amplitude hf tone but the lf tone "steals" the
resolution to represent it. And that resolution changes with the level of
the lf tone! Am I right?

With integers I know what resolution I have, no more, no less.

Best, Anders
Den 11/08/2013 16.03 skrev "Paul Davis" <[hidden]>:

>
>
>
> On Sun, Aug 11, 2013 at 7:11 AM, Anders Tornvig <[hidden]>wrote:
>
>> Dear list,
>>
>> I'm writing a full-duplex program (2in/2out) which will output something,
>> record it as a block of data (1024-3268 samples), analyze it and decide
>> what to output next. I'm on Ubuntu, at the moment with a UA-25ex USB audio
>> interface, speaking S24_3LE.
>>
>> The Jack API looks fantastic except for one thing: I prefer working with
>> integers and not float. In ALSA I can set the sample format to
>> SND_PCM_FORMAT_S24_3LE and then I can give it data in that format directly,
>> 3 bytes per sample per channel. On the capture side, I receive nice 24-bit
>> integers.
>>
>
> You should know that almost all audio software on almost every platform
> these days using floating point. Even platforms that used to use fixed
> point (e.g. protools DSP boxes) now use floating point.
>
> Adding a new data type to JACK is not particularly hard if it is intended
> only for client-to-client communication. Adding a new data type to JACK
> that involves the backends is a major undertaking.
>
> You really should try to get over your attachment to integers - they are
> fundamentally inappropriate for working with audio, something it has taken
> the industry 10-20 years to realize but is now accepted by almost everyone.
>
> --p
>
>
>

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