OpenAL?

hylke · 05-21-2005, 06:05 AM

Hello
I've got the following code to play FancyPants.wav:

Code:

	ALuint num = 1;
	soundinfo = new SoundInfo[num];
	alGenBuffers(num, &BufferIndices);
	alGenSources(num, &SourceIndices);
	int error;
	int index = 0;
	soundinfo[index].buffer = BufferIndices;
	soundinfo[index].source = SourceIndices;
	alutLoadWAVFile((ALbyte*)"FancyPants.wav", &soundinfo[index].format, &soundinfo[index].data, &soundinfo[index].size, &soundinfo[index].freq, &soundinfo[index].loop);
	alBufferData(soundinfo[index].buffer, soundinfo[index].format, soundinfo[index].data, soundinfo[index].size, soundinfo[index].freq);
	alutUnloadWAV(soundinfo[index].format, soundinfo[index].data, soundinfo[index].size, soundinfo[index].freq);
	alSourcei(soundinfo[index].source, AL_BUFFER, soundinfo[index].buffer);
	alSourcef(soundinfo[index].source, AL_PITCH, 1.0);
	alSourcef(soundinfo[index].source, AL_GAIN, 1.0);
	float sourcepos[3] = { 0.0, 0.0, 0.0 };
	float listenerpos[3] = { 0.0, 0.0, 0.0 };
	float velocitysource[3] = { 0.0, 0.0, 0.0 };
	float velocitylistener[3] = { 0.0, 0.0, 0.0 };
	float orientation[6] = { 0.0, 0.0, -1.0, 0.0, 1.0, 0.0};
	alSourcefv(soundinfo[index].source, AL_POSITION, sourcepos);
	alSourcefv(soundinfo[index].source, AL_VELOCITY, velocitysource);
	alSourcei(soundinfo[index].source, AL_LOOPING, false);
	alListenerfv(AL_POSITION, listenerpos);
	alListenerfv(AL_VELOCITY, velocitylistener);
	alListenerfv(AL_ORIENTATION, orientation);
	while(true)
		alSourcePlay(soundinfo[index].source);

But my problem is that it doesn't work.
Can anyone see what's wrong with the code?
Sorry for being sucha noob.
Greetz Hylke

deiussum · 05-21-2005, 10:49 AM

I'm still a newb when it comes to OpenAL, but here are a couple of things I noticed off the top of my head:

I don't see a call to alutInit anywhere. Maybe that is in another portion of code you didn't include, though.
I don't think you need to put the alSourcePlay into an infinite loop like that. You are just going to start playing it again and again and again...

Other than that, it looks pretty similar to some of the test code I did when first trying to get OpenAL to play, though it's arranged a bit differently.

hylke · 05-21-2005, 12:06 PM

Ok, thanx.
That did the trick.
Hylke
EDIT:
btw, which tutorial are you following?

deiussum · 05-21-2005, 02:37 PM

I don't remember to be honest. I wrote my OpenAL code to play wav files awhile ago and haven't had to do much with it since. I think I just used the OpenAL docs, though.

hylke · 05-22-2005, 03:14 AM

Oh ok.

krock923 · 07-24-2005, 11:42 PM

can anyone post some openAL code that would allow me to just play a sound. I couldn't even edit out the little switch in the tutorial that I found online. This is quite confusing. . .

AngryLlama · 07-25-2005, 10:32 AM

OpenAngryLlama?? no I know, just kidding.

deiussum · 07-25-2005, 10:37 AM

Here's some sample code I threw together as an example. I'm not at home right now so I can't test to make sure it actually works, but it compiles with:

g++ soundtest.cpp -o soundtest -lopenal

Code:

#include <string>
#include <vector>
#include <AL/al.h>
#include <AL/alut.h>

unsigned int LoadWav(const std::string &sFilename);
void PlayWav(unsigned int nWavID,
    const std::vector<float> &vecListenerPosition,
    const std::vector<float> &vecListenerVelocity,
    const std::vector<float> &vecListenerOrientation,
    const std::vector<float> &vecSoundPosition,
    const std::vector<float> &vecSoundVelocity);

int main(int argc, char** argv)
{
    unsigned int nWavID;
    std::vector<float> vecListenerPosition(3);
    std::vector<float> vecListenerVelocity(3);
    std::vector<float> vecListenerOrientation(3);
    std::vector<float> vecSoundPosition(3);
    std::vector<float> vecSoundVelocity(3);

    alutInit(&argc, argv);

    nWavID = LoadWav("somewavefile.wav");

    // Initialize vectors to 0, maybe not necessary, but safe
    for (int c=0;c<3;c++)
    {
        vecListenerPosition[c] = 0;
        vecListenerVelocity[c] = 0;
        vecListenerOrientation[c] = 0;
        vecSoundPosition[c] = 0;
        vecSoundVelocity[c] = 0;
    }

    // set orientation to face down z axis
    vecListenerOrientation[2] = 1;

    PlayWav(nWavID, vecListenerPosition, vecListenerVelocity,
            vecListenerOrientation, vecSoundPosition, vecSoundVelocity);

    return 0;
}

void PlayWav(unsigned int nWavID,
    const std::vector<float> &vecListenerPosition,
    const std::vector<float> &vecListenerVelocity,
    const std::vector<float> &vecListenerOrientation,
    const std::vector<float> &vecSoundPosition,
    const std::vector<float> &vecSoundVelocity)
{
    unsigned int nSource;

    alListenerfv(AL_POSITION, &vecListenerPosition[0]);
    alListenerfv(AL_VELOCITY, &vecListenerVelocity[0]);
    alListenerfv(AL_ORIENTATION, &vecListenerOrientation[0]);

    alGenSources(1, &nSource);
    alSourcef(nSource, AL_PITCH, 1.0f);
    alSourcef(nSource, AL_GAIN, 1.0f);
    alSourcefv(nSource, AL_POSITION, &vecSoundPosition[0]);
    alSourcefv(nSource, AL_VELOCITY, &vecSoundVelocity[0]);
    alSourcei(nSource, AL_BUFFER, nWavID);
    alSourcei(nSource, AL_LOOPING, AL_FALSE);

    alSourcePlay(nSource);
}

unsigned int LoadWav(const std::string &sFilename)
{
    unsigned int nID;
    ALenum eFormat;
    ALvoid *pData;
    ALboolean b;
    ALsizei nSize;
    ALsizei nFreq;

    alGenBuffers(1, &nID);

    alutLoadWAVFile(const_cast<ALbyte*>(reinterpret_cast<const ALbyte*>(
                    sFilename.c_str())), &eFormat, &pData, &nSize, &nFreq, &b);
    alBufferData(nID, eFormat, pData, nSize, nFreq);
    alutUnloadWAV(eFormat, pData, nSize, nFreq);

    return nID;
}

krock923 · 07-25-2005, 05:31 PM

thank you very much, however that wouldn't compile for some reason.

Code:

sound.C: In function `void PlayWav(unsigned int, const std::vector<float,
   std::allocator<float> >&, const std::vector<float, std::allocator<float> >&,
   const std::vector<float, std::allocator<float> >&, const std::vector<float,
   std::allocator<float> >&, const std::vector<float, std::allocator<float>
   >&)':
sound.C:55: invalid conversion from `const float*' to `ALfloat*'
sound.C:56: invalid conversion from `const float*' to `ALfloat*'
sound.C:57: invalid conversion from `const float*' to `ALfloat*'
sound.C:62: invalid conversion from `const float*' to `ALfloat*'
sound.C:63: invalid conversion from `const float*' to `ALfloat*'

Maybe I just don't understand the API well enough. I could only find minimal documentation.

deiussum · 07-25-2005, 05:49 PM

Interesting. I wonder if you have a different version of OpenAL than I do with the parameter of the fv version of functions not delcared const... You can try a few things.

1. Do a const_cast to get rid of the "constness" of the vector. Not usually the best thing to do, but in this case those functions SHOULDN'T be modifying the contents.

e.g.
alListenerfv(AL_POSITION, &vecListenerPosition[0]);
becomes:
alListenerfv(AL_POSITION, const_cast<ALfloat*>(&vecListenerPosition[0]));

2. Just do a C-style cast to ALfloat*
e.g.
alListenerfv(AL_POSITION, &vecListenerPosition[0]);
becomes:
alListenerfv(AL_POSITION, (ALfloat*)&vecListenerPosition[0]);

3. Switch to the 3f version
e.g.
alListenerfv(AL_POSITION, &vecListenerPosition[0]);
becomes:
alListener3f(AL_POSITION, vecListenerPosition[0], vecListenerPosition[1], vecListenerPosition[2]);

4. Just change my functions to take in ALfloat pointers and pass them directly to the function.