c – 为OpenAL加载.WAV文件

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

/*
 * Struct to hold fmt subchunk data for WAVE files.
 */
struct WAVE_Format {
    char subChunkID[4];
    long subChunkSize;
    short audioFormat;
    short numChannels;
    long sampleRate;
    long byteRate;
    short blockAlign;
    short bitsPerSample;
};

/*
* Struct to hold the data of the wave file
*/
struct WAVE_Data {
    char subChunkID[4]; //should contain the word data
    long subChunk2Size; //Stores the size of the data block
};

bool loadWavFile(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;

    *size = wave_data.subChunk2Size;
    *frequency = wave_format.sampleRate;
    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;
    }

    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),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),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,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(2,buffer);
        if(alGetError() != AL_NO_ERROR) {
            std::cerr << alGetError() << std::endl;
        }
        //now we put our data into the openAL buffer and
        //check for success
        alBufferData(*buffer,*format,(void*)data,*size,*frequency);
        if(alGetError() != AL_NO_ERROR) {
            std::cerr << alGetError() << std::endl;
        }
        //clean up and return true if successful
        fclose(soundFile);
        delete data;
        return true;
    } catch(const char* 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
        delete data;
        return false;
    }
}

int main() {
    ALuint buffer,source;
    ALint state;
    ALsizei size;
    ALsizei frequency;
    ALenum format;

    ALCcontext *context;
    ALCdevice *device;

    device = alcOpenDevice(nullptr);
    if (device == NULL)
    {
        cerr << "Error finding default Audio Output Device" << endl;
    }

    context = alcCreateContext(device,NULL);

    alcMakeContextCurrent(context);

    alGetError();

    loadWavFile("test.wav",&buffer,&size,&frequency,&format);

    alGenSources(1,&source);
    alSourcei(source,AL_BUFFER,buffer);

    // Play
    alSourcePlay(source);

    // Wait for the song to complete
    do {
        alGetSourcei(source,AL_SOURCE_STATE,&state);
    } while (state == AL_PLAYING);

    // Clean up sources and buffers
    alDeleteSources(1,&source);
    alDeleteBuffers(1,&buffer);
    return 0;
}

我有几个大约50kb的WAV文件.他们加载和播放就好了.但是,当我尝试加载整首歌曲(是的,我验证文件使用VLC Media Player和MusicBee正确格式化)时,它会返回“无效数据标题：尝试加载test.wav”,这是由此块引起的：

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");

我怀疑这是与尺寸相关的东西正在抛弃那个标题,因为看起来只有不到1000kb的工作(还没有完全测试过,很难找到在我的电脑和互联网上漂浮的完美尺寸的声音文件).这只是猜测,我真的不知道发生了什么.感谢帮助！