usbloadergx/source/SoundOperations/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 "WavDecoder.hpp"
#include "utils/uncompress.h"

WavDecoder::WavDecoder(const char * filepath)
    : SoundDecoder(filepath)
{
    SoundType = SOUND_WAV;
    SampleRate = 48000;
    Format = VOICE_STEREO_16BIT;

    if(!file_fd)
        return;

    OpenFile();
}

WavDecoder::WavDecoder(const u8 * snd, int len)
    : SoundDecoder(snd, len)
{
    SoundType = SOUND_WAV;
    SampleRate = 48000;
    Format = VOICE_STEREO_16BIT;

    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((u8 *) &Header, sizeof(SWaveHdr));
    file_fd->read((u8 *) &FmtChunk, sizeof(SWaveFmtChunk));

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

    DataOffset = sizeof(SWaveHdr)+le32(FmtChunk.size)+8;
    file_fd->seek(DataOffset, SEEK_SET);
    SWaveChunk DataChunk;
    file_fd->read((u8 *) &DataChunk, sizeof(SWaveChunk));

    if(DataChunk.magicDATA == 'fact')
    {
        DataOffset += 8+le32(DataChunk.size);
        file_fd->seek(DataOffset, SEEK_SET);
        file_fd->read((u8 *) &DataChunk, sizeof(SWaveChunk));
    }
    if(DataChunk.magicDATA != 'data')
    {
		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 = VOICE_MONO_8BIT;
	else if (le16(FmtChunk.channels) == 1 && le16(FmtChunk.bps) == 16 && le16(FmtChunk.alignment) <= 2)
		Format = VOICE_MONO_16BIT;
	else if (le16(FmtChunk.channels) == 2 && le16(FmtChunk.bps) == 8 && le16(FmtChunk.alignment) <= 2)
		Format = VOICE_STEREO_8BIT;
	else if (le16(FmtChunk.channels) == 2 && le16(FmtChunk.bps) == 16 && le16(FmtChunk.alignment) <= 4)
		Format = VOICE_STEREO_16BIT;

    Decode();
}

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

    file_fd = NULL;
}

int WavDecoder::Read(u8 * buffer, int buffer_size, int pos)
{
    if(!file_fd)
        return -1;

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

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

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

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

            for (u32 i = 0; i < (u32) (read / sizeof (u16)); ++i)
                ((u16 *) buffer)[i] = le16(((u16 *) buffer)[i]);
        }
        CurPos += read;
    }

    return read;
}