[squeak-dev] 24-bit sound -- how??

Herbert König herbertkoenig at gmx.net
Mon Feb 4 20:59:08 UTC 2019


Hi Jim,


that seems like a big can of worms. If you only want to write and read 
soundfiles, AbstractSound>>storeWavSamplesOn: manually creates a 16 Bit 
wav file. Wav is quite well documented so you could change that. Similar 
with SampledSound class>>fromWaveStream.


But then most Sound classes use SoundBuffer which is 16 Bit which would 
make it a huge effort to actually work with the higher resolutions. This 
is especially true for SoundRecorder. And skimming the classes in 
Sound-Synthesis I see some primitives are used.


I did (technical) Audio in Squeak 3.8 and now I know why I stuck with 16 
Bit.


But to be clear, even then 48 kHz worked and that is better than CD 
quality. What processing do you want to do on the sound?


Cheers,


Herbert



Am 04.02.2019 um 08:47 schrieb Jim Rosenberg:
> After several years of doing artistic work in Squeak (interactive 
> poetry), I'm now working on a project where I need to integrate sound. 
> I can load a 16-bit .wav file, play it, and everything just works. 
> When I try to do the same thing with a 24-bit .wav file, I get a 
> convincing example of white noise -- not exactly what I was after ... 
> :-) Is this a codec problem?
>
> Details: I'm developing on Linux, have been working in Squeak 4.3 but 
> just now tried a vanilla 5.2 image and get the same results. (Requires 
> the padsp / libpulsedsp.so wrapper trick to get sound at all.) The 
> 16-bit sound that works shows in the VLC codec display as:
>
> Type: Audio
> Codec: PCM S16 LE (s16l)
> Sample rate: 44100 Hz
> Bits per sample: 16
> Bitrate: 1411 kb/s
>
> and the 24-bit sound that doesn't work shows as:
>
> Type: Audio
> Codec: PCM S24 LE (s24l)
> Sample rate: 44100 Hz
> Bits per sample: 32
>
> (Sounds are being exported from Audacity, and play just fine with no 
> "tricks" in VLC.)
>
> I'm a total newbie to Squeak sound, so any hints would be highly 
> appreciated. I suppose I can live with 16-bit sound if I have to, but 
> I'd rather have the option of the highest resolution I can get.
>
> -Thanks, Jim
>


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