libgui/source/sounds/WavDecoder.cpp

/***************************************************************************
 * Copyright (C) 2010
 * by Dimok
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any
 * damages arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any
 * purpose, including commercial applications, and to alter it and
 * redistribute it freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you
 * must not claim that you wrote the original software. If you use
 * this software in a product, an acknowledgment in the product
 * documentation would be appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and
 * must not be misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source
 * distribution.
 *
 * for WiiXplorer 2010
 ***************************************************************************/
#include <string.h>
#include <utils/utils.h>
#include <sounds/WavDecoder.hpp>

WavDecoder::WavDecoder(const char * filepath)
    : SoundDecoder(filepath) {
    SoundType = SOUND_WAV;
    SampleRate = 48000;
    Format = CHANNELS_STEREO | FORMAT_PCM_16_BIT;

    if(!file_fd)
        return;

    OpenFile();
}

WavDecoder::WavDecoder(const uint8_t * snd, int32_t len)
    : SoundDecoder(snd, len) {
    SoundType = SOUND_WAV;
    SampleRate = 48000;
    Format = CHANNELS_STEREO | FORMAT_PCM_16_BIT;

    if(!file_fd)
        return;

    OpenFile();
}

WavDecoder::~WavDecoder() {
}


void WavDecoder::OpenFile() {
    SWaveHdr Header;
    SWaveFmtChunk FmtChunk;
    memset(&Header, 0, sizeof(SWaveHdr));
    memset(&FmtChunk, 0, sizeof(SWaveFmtChunk));

    file_fd->read((uint8_t *) &Header, sizeof(SWaveHdr));
    file_fd->read((uint8_t *) &FmtChunk, sizeof(SWaveFmtChunk));

    if (Header.magicRIFF != 0x52494646) { // 'RIFF'
        CloseFile();
        return;
    } else if(Header.magicWAVE != 0x57415645) { // 'WAVE'
        CloseFile();
        return;
    } else if(FmtChunk.magicFMT != 0x666d7420) { // 'fmt '
        CloseFile();
        return;
    }

    DataOffset = sizeof(SWaveHdr)+le32(FmtChunk.size)+8;
    file_fd->seek(DataOffset, SEEK_SET);
    SWaveChunk DataChunk;
    file_fd->read((uint8_t *) &DataChunk, sizeof(SWaveChunk));

    while(DataChunk.magicDATA != 0x64617461) { // 'data'
        DataOffset += 8+le32(DataChunk.size);
        file_fd->seek(DataOffset, SEEK_SET);
        int32_t ret = file_fd->read((uint8_t *) &DataChunk, sizeof(SWaveChunk));
        if(ret <= 0) {
            CloseFile();
            return;
        }
    }

    DataOffset += 8;
    DataSize = le32(DataChunk.size);
    Is16Bit = (le16(FmtChunk.bps) == 16);
    SampleRate = le32(FmtChunk.freq);

    if (le16(FmtChunk.channels) == 1 && le16(FmtChunk.bps) == 8 && le16(FmtChunk.alignment) <= 1)
        Format = CHANNELS_MONO | FORMAT_PCM_8_BIT;
    else if (le16(FmtChunk.channels) == 1 && le16(FmtChunk.bps) == 16 && le16(FmtChunk.alignment) <= 2)
        Format = CHANNELS_MONO | FORMAT_PCM_16_BIT;
    else if (le16(FmtChunk.channels) == 2 && le16(FmtChunk.bps) == 8 && le16(FmtChunk.alignment) <= 2)
        Format = CHANNELS_STEREO | FORMAT_PCM_8_BIT;
    else if (le16(FmtChunk.channels) == 2 && le16(FmtChunk.bps) == 16 && le16(FmtChunk.alignment) <= 4)
        Format = CHANNELS_STEREO | FORMAT_PCM_16_BIT;
}

void WavDecoder::CloseFile() {
    if(file_fd)
        delete file_fd;

    file_fd = NULL;
}

int32_t WavDecoder::Read(uint8_t * buffer, int32_t buffer_size, int32_t pos) {
    if(!file_fd)
        return -1;

    if(CurPos >= (int32_t) DataSize)
        return 0;

    file_fd->seek(DataOffset+CurPos, SEEK_SET);

    if(buffer_size > (int32_t) DataSize-CurPos)
        buffer_size = DataSize-CurPos;

    int32_t read = file_fd->read(buffer, buffer_size);
    if(read > 0) {
        if (Is16Bit) {
            read &= ~0x0001;

            for (uint32_t i = 0; i < (uint32_t) (read / sizeof (uint16_t)); ++i)
                ((uint16_t *) buffer)[i] = le16(((uint16_t *) buffer)[i]);
        }
        CurPos += read;
    }

    return read;
}