[Cuis-dev] Writing a SoundBuffer to a WAV or AIFF file is broken

[Juan Vuletich]

Hi David,

While your code runs without error, the file produced has wrong byte 
ordering and sounds wrong, at least on my Mac. I preferred simplifying 
the method a bit. Just pushed the updated package to GitHub.

Thanks,

On 2026-03-02 11:30 AM, David Gouge via Cuis-dev wrote:
>
> It seems that I just found a small bug when playing around with the 
> Sound package.
>
> From a Workspace do:
>
> Feature require: 'Sound'.
> (PluckedSound default) storeWAVOnFileNamed: '/tmp/foo.wav'.
>
>
> Exception raised.. Here's the offending stack:
>
> SoundBuffer(Object)>>doesNotUnderstand: #asUtfBytes
>
> UniFileStream>>nextPutAll:: aStringOrBytes
>     "Argument can be String, UnicodeString or ByteArray.
>     Write to this file. Both kinds of Strings are UTF-8 encoded."
>
>     | bytes |
>     aStringOrBytes isEmpty ifTrue: [ ^self ].
>     bytes := aStringOrBytes.
>     (aStringOrBytes is: #ByteArray) ifFalse: [
>         bytes := aStringOrBytes asUtf8Bytes].   <--- Exception raised 
> here.
>
>
> My naive newbie fix is as follows:
>
> AbstractSound>>storeSampleCount: samplesToStore bigEndian: 
> bigEndianFlag on: aBinaryStream
>
> .. Clipped ..
>
>     'Storing audio...' displayProgressAt: Sensor mousePoint
>         from: 0 to: samplesToStore during: [:barBlock | | remaining out |
>             remaining := samplesToStore.
>             [remaining > 0] whileTrue: [
>                 barBlock value: samplesToStore - remaining.
>                 stereoBuffer primFill: 0.  "clear the buffer"
>                 self playSampleCount: (bufSize min: remaining) into: 
> stereoBuffer startingAt: 1.
>                 self isStereo
>                     ifTrue: [out := stereoBuffer asByteArray] "<-- 
> answer ByteArray instead of SoundBuffer"
>                     ifFalse: [out := stereoBuffer extractLeftChannel 
> asByteArray]. "<--- and here"
>
> ... Clipped ..
>
> This has let me work around the bug but I'm a complete Cuis noob so 
> take it FWIW.
>
>
> Best Regards,
>
> -Dave
>
>
>
> Sent with Proton Mail <https://proton.me/mail/home> secure email.
>
-- 
Juan Vuletich
www.cuis.st
github.com/jvuletich
researchgate.net/profile/Juan-Vuletich
independent.academia.edu/JuanVuletich
patents.justia.com/inventor/juan-manuel-vuletich
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