Given your application field, SoundBuffer should be fine.

- Bert -

Am 19.07.2006 um 13:40 schrieb Eugene Beschastnov:

> I'm not very good in C, but as I understand - yes, it is typedef for
> 'short*', but it's standard typedef.
>
> Anyway, what kind of data should I use to call FFI function that
> expects 'short*'?
>
> To be more specific, C function is
> __declspec(dllexport) BE_ERR    beEncodeChunk(HBE_STREAM hbeStream,
> DWORD nSamples, PSHORT pSamples, PBYTE pOutput, PDWORD pdwOutput);
> ========================================================
> For this function I made this apicall construction:
> apiBeEncodeChunkHbeStream: hbeStream nSamples: nSamples pSamples:
> pSamples pOutput: pOutput pdwOutput: pdwOutput
>    <apicall: ulong 'beEncodeChunk' ( ulong long short* byte* long* )
> module: 'lame_enc.dll'>
>    ^self externalCallFailed
> ========================================================
> And I'm trying to call it in following way:
> 	pMp3Buffer := ByteArray new: dwMp3Buffer.
> 	samples := (SampledSound fromWaveFileNamed: 'Message.wav')  
> asSampledSound
> 				samples asWordArray.
> 	startOfChunk := 1.
> 	mp3Output := ByteArray new: 0.
> 	[startOfChunk <= samples size] whileTrue:
> 			[endOfChunk := startOfChunk + dwSamples - 1 min: samples size.
> 			buf := samples copyFrom: startOfChunk to: endOfChunk.
> 			startOfChunk := endOfChunk + 1.
> 			pDwWrite := WordArray new: 1.
> 			errCode := self
> 						apiBeEncodeChunkHbeStream: hbeStream
> 						nSamples: buf size
> 						pSamples: buf
> 						pOutput: pMp3Buffer
> 						pdwOutput: pDwWrite.
> 			errCode ~= self beErrSuccessful
> 				ifTrue:
> 					[self apiBeCloseStreamHbeStream: hbeStream.
> 					Exception signal: 'beEncodeChunk() failed (' , errCode  
> asString , ')'].
> 			mp3Output addAll: (pMp3Buffer copyFrom: 1 to: pDwWrite first)].
> 	(FileStream fileNamed: 'Message.mp3') binary
> 		next: mp3Output size
> 		putAll: mp3Output
> 		startingAt: 1
>
> hbeStream, dwSamples and dwMp3Buffer are got from FFI function
> 'beInitStream', which is called earlier and executed correctly.
>
> 2006/7/19, Bert Freudenberg <bert at impara.de>:
>> Am 19.07.2006 um 12:33 schrieb Eugene Beschastnov:
>>
>> > Another question - what construction in Squeak corresponds to
>> > PSHORT in C?
>>
>> There is no type PSHORT in C. It probably is a typedef (could be a
>> macro too) which you need to lookup in the headers.
>>
>> I'd guess it's a 'short*'.
>>
>> - Bert -
>>
>>
>>
>
>
> -- 
> Eugene