libgui/source/sounds/Mp3Decoder.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 "fs/CFile.hpp"
#include <coreinit/thread.h>
#include <coreinit/time.h>
#include <gui/sounds/Mp3Decoder.hpp>
#include <limits.h>
#include <malloc.h>
#include <math.h>
#include <string.h>
#include <string>
#include <unistd.h>

Mp3Decoder::Mp3Decoder(const char *filepath)
    : SoundDecoder(filepath) {
    SoundType  = SOUND_MP3;
    ReadBuffer = NULL;
    mad_timer_reset(&Timer);
    mad_stream_init(&Stream);
    mad_frame_init(&Frame);
    mad_synth_init(&Synth);

    if (!file_fd) {
        return;
    }

    OpenFile();
}

Mp3Decoder::Mp3Decoder(const uint8_t *snd, int32_t len)
    : SoundDecoder(snd, len) {
    SoundType  = SOUND_MP3;
    ReadBuffer = NULL;
    mad_timer_reset(&Timer);
    mad_stream_init(&Stream);
    mad_frame_init(&Frame);
    mad_synth_init(&Synth);

    if (!file_fd) {
        return;
    }

    OpenFile();
}

Mp3Decoder::~Mp3Decoder() {
    ExitRequested = true;
    while (Decoding)
        OSSleepTicks(OSMicrosecondsToTicks(100));

    mad_synth_finish(&Synth);
    mad_frame_finish(&Frame);
    mad_stream_finish(&Stream);

    if (ReadBuffer) {
        free(ReadBuffer);
    }
    ReadBuffer = NULL;
}

void Mp3Decoder::OpenFile() {
    GuardPtr   = NULL;
    ReadBuffer = (uint8_t *) memalign(32, SoundBlockSize * SoundBlocks);
    if (!ReadBuffer) {
        if (file_fd) {
            delete file_fd;
        }
        file_fd = NULL;
        return;
    }

    uint8_t dummybuff[4096];
    int32_t ret = Read(dummybuff, 4096, 0);
    if (ret <= 0) {
        if (file_fd) {
            delete file_fd;
        }
        file_fd = NULL;
        return;
    }

    SampleRate = (uint32_t) Frame.header.samplerate;
    Format     = ((MAD_NCHANNELS(&Frame.header) == 2) ? (FORMAT_PCM_16_BIT | CHANNELS_STEREO) : (FORMAT_PCM_16_BIT | CHANNELS_MONO));
    Rewind();
}

int32_t Mp3Decoder::Rewind() {
    mad_synth_finish(&Synth);
    mad_frame_finish(&Frame);
    mad_stream_finish(&Stream);
    mad_timer_reset(&Timer);
    mad_stream_init(&Stream);
    mad_frame_init(&Frame);
    mad_synth_init(&Synth);
    SynthPos = 0;
    GuardPtr = NULL;

    if (!file_fd) {
        return -1;
    }

    return SoundDecoder::Rewind();
}

static inline int16_t FixedToShort(mad_fixed_t Fixed) {
    /* Clipping */
    if (Fixed >= MAD_F_ONE) {
        return (SHRT_MAX);
    }
    if (Fixed <= -MAD_F_ONE) {
        return (-SHRT_MAX);
    }

    Fixed = Fixed >> (MAD_F_FRACBITS - 15);
    return ((int16_t) Fixed);
}

int32_t Mp3Decoder::Read(uint8_t *buffer, int32_t buffer_size, int32_t pos) {
    if (!file_fd) {
        return -1;
    }

    if (Format == (FORMAT_PCM_16_BIT | CHANNELS_STEREO)) {
        buffer_size &= ~0x0003;
    } else {
        buffer_size &= ~0x0001;
    }

    uint8_t *write_pos = buffer;
    uint8_t *write_end = buffer + buffer_size;

    while (1) {
        while (SynthPos < Synth.pcm.length) {
            if (write_pos >= write_end) {
                return write_pos - buffer;
            }

            *((int16_t *) write_pos) = FixedToShort(Synth.pcm.samples[0][SynthPos]);
            write_pos += 2;

            if (MAD_NCHANNELS(&Frame.header) == 2) {
                *((int16_t *) write_pos) = FixedToShort(Synth.pcm.samples[1][SynthPos]);
                write_pos += 2;
            }
            SynthPos++;
        }

        if (Stream.buffer == NULL || Stream.error == MAD_ERROR_BUFLEN) {
            uint8_t *ReadStart = ReadBuffer;
            int32_t ReadSize   = SoundBlockSize * SoundBlocks;
            int32_t Remaining  = 0;

            if (Stream.next_frame != NULL) {
                Remaining = Stream.bufend - Stream.next_frame;
                memmove(ReadBuffer, Stream.next_frame, Remaining);
                ReadStart += Remaining;
                ReadSize -= Remaining;
            }

            ReadSize = file_fd->read(ReadStart, ReadSize);
            if (ReadSize <= 0) {
                GuardPtr = ReadStart;
                memset(GuardPtr, 0, MAD_BUFFER_GUARD);
                ReadSize = MAD_BUFFER_GUARD;
            }

            CurPos += ReadSize;
            mad_stream_buffer(&Stream, ReadBuffer, Remaining + ReadSize);
        }

        if (mad_frame_decode(&Frame, &Stream)) {
            if (MAD_RECOVERABLE(Stream.error)) {
                if (Stream.error != MAD_ERROR_LOSTSYNC || !GuardPtr) {
                    continue;
                }
            } else {
                if (Stream.error != MAD_ERROR_BUFLEN) {
                    return -1;
                } else if (Stream.error == MAD_ERROR_BUFLEN && GuardPtr) {
                    return -1;
                }
            }
        }

        mad_timer_add(&Timer, Frame.header.duration);
        mad_synth_frame(&Synth, &Frame);
        SynthPos = 0;
    }
    return 0;
}