使用openal播放WAV音频

本文转载自博客：http://blog.csdn.net/u011417605/article/details/49666465

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下载openal sdk,alut源文件：

http://download.csdn.net/detail/u011417605/9244991

不使用alut，只使用openal播放WAV文件：

#include
#include

struct WAVE_Data {
    char subChunkID[4]; //should contain the word data
    long subChunk2Size; //Stores the size of the data block
};

struct WAVE_Format {
    char subChunkID[4];
    long subChunkSize;
    short audioFormat;
    short numChannels;
    long sampleRate;
    long byteRate;
    short blockAlign;
    short bitsPerSample;
};

struct RIFF_Header {
    char chunkID[4];
    long chunkSize;//size not including chunkSize or chunkID
    char format[4];
};

bool loadWavFile(const std::string filename, ALuint* buffer,
    ALsizei* size, ALsizei* frequency,
    ALenum* format) {
    //Local Declarations
    FILE* soundFile = NULL;
    WAVE_Format wave_format;
    RIFF_Header riff_header;
    WAVE_Data wave_data;
    unsigned char* data;

    try {
        soundFile = fopen(filename.c_str(), "rb");
        if (!soundFile)
            throw (filename);

        // Read in the first chunk into the struct
        fread(&riff_header, sizeof(RIFF_Header), 1, soundFile);

        //check for RIFF and WAVE tag in memeory
        if ((riff_header.chunkID[0] != 'R' ||
            riff_header.chunkID[1] != 'I' ||
            riff_header.chunkID[2] != 'F' ||
            riff_header.chunkID[3] != 'F') ||
            (riff_header.format[0] != 'W' ||
            riff_header.format[1] != 'A' ||
            riff_header.format[2] != 'V' ||
            riff_header.format[3] != 'E'))
            throw ("Invalid RIFF or WAVE Header");

        //Read in the 2nd chunk for the wave info
        fread(&wave_format, sizeof(WAVE_Format), 1, soundFile);
        //check for fmt tag in memory
        if (wave_format.subChunkID[0] != 'f' ||
            wave_format.subChunkID[1] != 'm' ||
            wave_format.subChunkID[2] != 't' ||
            wave_format.subChunkID[3] != ' ')
            throw ("Invalid Wave Format");

        //check for extra parameters;
        if (wave_format.subChunkSize > 16)
            fseek(soundFile, sizeof(short), SEEK_CUR);

        //Read in the the last byte of data before the sound file
        fread(&wave_data, sizeof(WAVE_Data), 1, soundFile);
        //check for data tag in memory
        if (wave_data.subChunkID[0] != 'd' ||
            wave_data.subChunkID[1] != 'a' ||
            wave_data.subChunkID[2] != 't' ||
            wave_data.subChunkID[3] != 'a')
            throw ("Invalid data header");

        //Allocate memory for data
        data = new unsigned char[wave_data.subChunk2Size];

        // Read in the sound data into the soundData variable
        if (!fread(data, wave_data.subChunk2Size, 1, soundFile))
            throw ("error loading WAVE data into struct!");

        //Now we set the variables that we passed in with the
        //data from the structs
        *size = wave_data.subChunk2Size;
        *frequency = wave_format.sampleRate;
        //The format is worked out by looking at the number of
        //channels and the bits per sample.
        if (wave_format.numChannels == 1) {
            if (wave_format.bitsPerSample == 8)
                *format = AL_FORMAT_MONO8;
            else if (wave_format.bitsPerSample == 16)
                *format = AL_FORMAT_MONO16;
        }
        else if (wave_format.numChannels == 2) {
            if (wave_format.bitsPerSample == 8)
                *format = AL_FORMAT_STEREO8;
            else if (wave_format.bitsPerSample == 16)
                *format = AL_FORMAT_STEREO16;
        }
        //create our openAL buffer and check for success
        alGenBuffers(1, buffer);
        //errorCheck();
        //now we put our data into the openAL buffer and
        //check for success
        alBufferData(*buffer, *format, (void*)data,
            *size, *frequency);
        //errorCheck();
        //clean up and return true if successful
        fclose(soundFile);
        return true;
    }
    catch (std::string error) {
        //our catch statement for if we throw a string
        std::cerr << error << " : trying to load "
            << filename << std::endl;
        //clean up memory if wave loading fails
        if (soundFile != NULL)
            fclose(soundFile);
        //return false to indicate the failure to load wave
        return false;
    }
}

ALuint alSource;
ALuint source;
ALsizei size2;
ALsizei frequent;
ALenum format;

void main()
{
    alcMakeContextCurrent(alcCreateContext(alcOpenDevice(NULL), NULL));

    //openal播放音频1
    loadWavFile("shengdao.wav", &alSource, &size2, &frequent, &format);
    alGenSources(1, &source);
    alSourcei(source, AL_BUFFER, alSource);
    alSourcePlay(source);
}