Re: setup 3d audio

On Monday 03 May 2010 5:24:17 am coolbreeze wrote:
> I tested with a mono sound but it is too noisy,
> i find a tutorial but they use alut to load files and its depreciated...
> 
> maybe the problem is when i init openAL? or when i load the file ? with
> libsndfile
...
>     switch (device_type)
>     {
>     case ASS_DEFAULT_DEVICE:
>         d->device=alcOpenDevice(NULL);
>         break;
>     case ASS_PULSEAUDIO_DEVICE:
>         d->device=alcOpenDevice("PulseAudio Software");
>         break;
>         case ASS_ALSA_DEVICE:
>         d->device=alcOpenDevice("ALSA Software");
>         break;
>         case ASS_OSS_DEVICE:
>         d->device=alcOpenDevice("OSS Software");
>         break;
>         case ASS_PORTAUDIO_DEVICE:
>         d->device=alcOpenDevice("PortAudio Software");
>         break;
>         default:
>         break;
>     }
...

Not related to the problem, but you shouldn't rely on specific device strings 
like this. They are implementation-defined, and subject to change. Not that I 
have any immediate plans to change them, but just saying.

>     if (sf_read_short(file, audio->data_samples,audio->nbr_samples) <
> audio->nbr_samples) return ASS_FALSE;

IIRC, sf_read_short takes and returns the number of frames, not samples. So 
you'd want to use audio->file_info.frames instead of audio->nbr_samples.

You'll also want to be careful because not all file formats will have a known 
(or correct) frame count. In general, you'll want to read in a loop until it 
has no more to give. Eg:

ALshort *data = NULL;
ALsizei datasize = 0;
ALsizei totalsize = 0;
int todo;
do {
    todo = (totalsize-datasize) / audio->file_info.channels;
    if(todo == 0)
    {
        ALshort *temp;

        totalsize = (totalsize ? totalsize<<1 : 65536);
        temp = realloc(data, totalsize*sizeof(ALshort));
        if(!temp)
        {
            free(data);
            return false;
        }
        data = temp;
        todo = (totalsize-datasize) / audio->file_info.channels;
    }

    todo = sf_read_short(file, data+datasize, todo);
    datasize += todo;
} while(todo > 0);
data = realloc(data, datasize*sizeof(ALshort));

alBufferData(bID, format, data, datasize*sizeof(ALshort), samplerate);
free(data);
...

C++ would benefit from using std::vector<ALshort>, but that's how you'd do it 
in C.
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