Re: [Osalp-dev] aflibConverter question

[Bruce F. <for...@tn...>]

Akos Maroy wrote:
> 
> Hi,
> 
> I'm trying to use the class aflibConverter from OSALP to do some raw
> audio data resampling. And I can't get it to work. I read through the
> documentation for the class at
> http://osalp.sourceforge.net/doc/html/class_aflibConverter.html
> but could someone please elaborate more on the parameters to the
> aflibConverter::resample() function? In particular:
> 
> - is inCount an output only parameter, or is it in/out?
> - in inArray, should I supply a 2 channel input with channels interleaved?
> - will the outArray contain them interleaved?
> - for inCount / outCount and the return value: a value of n means:
>      - n * channels values in the actual array?
>      - n values in the actual array?
> 
> For example:
> 
> aflibConverter    * converter = new aflibConverter( true, true, false);
> 
> converter->initialize( 0.5, 2);
> 
> short      inArray[2048];
> short      outArray[1024];
> int        inCount = 2048;
> int        outCount = 1024;
> 
> // suppose inArray contains two channel interleaved raw audio data of
> // 1024 samples
> 
> int converted = converter->resample( inCount,
>                                       outCount,
>                                       inArray,
>                                       outArray);
> 
> after this call I get 2048 for inCount and 1024 for the return value.
> But the data in outArray[0 ... 1024] is no good, if I save it to a file,
> it's not proper .wav data:
> 
> $ file result.wav
> result.wav: data
> $ play result.wav
> sox: WAVE: RIFF header not found
> 
> I'm trying to get it work, but so far only resampling with a factor of 1
> gives me any useful results (which is of course quite useless :). Any
> help would be appreciated.
> 

This class is not really designed to be used by itself. It is certainly
difficult to understand. It has also been awhile. The best that I can
recommend
is to look at the aflibAudioSampleRateCvt class. I would also use an
audio
chain using this class. This will simplify the task for you. This is
the way it was intended to be used.

Bruce Forsberg