view data/fileio/MP3FileReader.cpp @ 316:3a6725f285d6

* Make RemoteFile far more pervasive, and use it for local files as well
  so that we can handle both transparently.  Make it shallow copy with
  reference counting, so it can be used by value without having to worry
  about the cache file lifetime.  Use RemoteFile for MainWindow file-open
  functions, etc

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifdef HAVE_MAD

#include "MP3FileReader.h"
#include "system/System.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <iostream>

#ifdef HAVE_ID3TAG
#include <id3tag.h>
#endif
#define DEBUG_ID3TAG 1

#include <QApplication>
#include <QFileInfo>
#include <QProgressDialog>

MP3FileReader::MP3FileReader(RemoteFile source, DecodeMode decodeMode, 
                             CacheMode mode, size_t targetRate) :
    CodedAudioFileReader(mode, targetRate),
    m_source(source),
    m_path(source.getLocalFilename()),
    m_decodeThread(0)
{
    m_channelCount = 0;
    m_fileRate = 0;
    m_fileSize = 0;
    m_bitrateNum = 0;
    m_bitrateDenom = 0;
    m_cancelled = false;
    m_completion = 0;
    m_done = false;
    m_progress = 0;

    struct stat stat;
    if (::stat(m_path.toLocal8Bit().data(), &stat) == -1 || stat.st_size == 0) {
	m_error = QString("File %1 does not exist.").arg(m_path);
	return;
    }

    m_fileSize = stat.st_size;

    int fd = -1;
    if ((fd = ::open(m_path.toLocal8Bit().data(), O_RDONLY
#ifdef _WIN32
                     | O_BINARY
#endif
                     , 0)) < 0) {
	m_error = QString("Failed to open file %1 for reading.").arg(m_path);
	return;
    }	

    m_filebuffer = 0;
    m_samplebuffer = 0;
    m_samplebuffersize = 0;

    try {
        m_filebuffer = new unsigned char[m_fileSize];
    } catch (...) {
        m_error = QString("Out of memory");
        ::close(fd);
	return;
    }
    
    ssize_t sz = 0;
    size_t offset = 0;
    while (offset < m_fileSize) {
        sz = ::read(fd, m_filebuffer + offset, m_fileSize - offset);
        if (sz < 0) {
            m_error = QString("Read error for file %1 (after %2 bytes)")
                .arg(m_path).arg(offset);
            delete[] m_filebuffer;
            ::close(fd);
            return;
        } else if (sz == 0) {
            std::cerr << QString("MP3FileReader::MP3FileReader: Warning: reached EOF after only %1 of %2 bytes")
                .arg(offset).arg(m_fileSize).toStdString() << std::endl;
            m_fileSize = offset;
            break;
        }
        offset += sz;
    }

    ::close(fd);

    loadTags();

    if (decodeMode == DecodeAtOnce) {

	m_progress = new QProgressDialog
	    (QObject::tr("Decoding %1...").arg(QFileInfo(m_path).fileName()),
	     QObject::tr("Stop"), 0, 100);
	m_progress->hide();

        if (!decode(m_filebuffer, m_fileSize)) {
            m_error = QString("Failed to decode file %1.").arg(m_path);
        }
        
        delete[] m_filebuffer;
        m_filebuffer = 0;

        if (isDecodeCacheInitialised()) finishDecodeCache();

	delete m_progress;
	m_progress = 0;

    } else {

        m_decodeThread = new DecodeThread(this);
        m_decodeThread->start();

        while (m_channelCount == 0 && !m_done) {
            usleep(10);
        }
    }
}

MP3FileReader::~MP3FileReader()
{
    if (m_decodeThread) {
        m_cancelled = true;
        m_decodeThread->wait();
        delete m_decodeThread;
    }
}

void
MP3FileReader::loadTags()
{
    m_title = "";

#ifdef HAVE_ID3TAG

    id3_file *file = id3_file_open(m_path.toLocal8Bit().data(),
                                   ID3_FILE_MODE_READONLY);
    if (!file) return;

    // We can do this a lot more elegantly, but we'll leave that for
    // when we implement support for more than just the one tag!
    
    id3_tag *tag = id3_file_tag(file);
    if (!tag) {
#ifdef DEBUG_ID3TAG
        std::cerr << "MP3FileReader::loadTags: No ID3 tag found" << std::endl;
#endif
        id3_file_close(file);
        return;
    }

    id3_frame *frame = id3_tag_findframe(tag, "TIT2", 0); // work title
    if (!frame) {
#ifdef DEBUG_ID3TAG
        std::cerr << "MP3FileReader::loadTags: No work title in ID3 tag" << std::endl;
#endif
        id3_file_close(file);
        return;
    }
        
    if (frame->nfields < 2) {
        std::cerr << "MP3FileReader::loadTags: WARNING: Not enough fields (" << frame->nfields << ") for work title in ID3 tag" << std::endl;
        id3_file_close(file);
        return;
    }

    unsigned int nstrings = id3_field_getnstrings(&frame->fields[1]);
    if (nstrings == 0) {
#ifdef DEBUG_ID3TAG
        std::cerr << "MP3FileReader::loadTags: No data for work title in ID3 tag" << std::endl;
#endif
        id3_file_close(file);
        return;
    }

    id3_ucs4_t const *ustr = id3_field_getstrings(&frame->fields[1], 0);
    if (!ustr) {
#ifdef DEBUG_ID3TAG
        std::cerr << "MP3FileReader::loadTags: Invalid or absent data for work title in ID3 tag" << std::endl;
#endif
        id3_file_close(file);
        return;
    }
        
    id3_utf8_t *u8str = id3_ucs4_utf8duplicate(ustr);
    if (!u8str) {
        std::cerr << "MP3FileReader::loadTags: ERROR: Internal error: Failed to convert UCS4 to UTF8 in ID3 title" << std::endl;
        id3_file_close(file);
        return;
    }
        
    m_title = QString::fromUtf8((const char *)u8str);
    free(u8str);
    id3_file_close(file);

#else
#ifdef DEBUG_ID3TAG
    std::cerr << "MP3FileReader::loadTags: ID3 tag support not compiled in"
              << std::endl;
#endif
#endif

}

void
MP3FileReader::DecodeThread::run()
{
    if (!m_reader->decode(m_reader->m_filebuffer, m_reader->m_fileSize)) {
        m_reader->m_error = QString("Failed to decode file %1.").arg(m_reader->m_path);
    }

    delete[] m_reader->m_filebuffer;
    m_reader->m_filebuffer = 0;

    if (m_reader->m_samplebuffer) {
        for (size_t c = 0; c < m_reader->m_channelCount; ++c) {
            delete[] m_reader->m_samplebuffer[c];
        }
        delete[] m_reader->m_samplebuffer;
        m_reader->m_samplebuffer = 0;
    }

    if (m_reader->isDecodeCacheInitialised()) m_reader->finishDecodeCache();

    m_reader->m_done = true;
    m_reader->m_completion = 100;

    m_reader->endSerialised();
} 

bool
MP3FileReader::decode(void *mm, size_t sz)
{
    DecoderData data;
    struct mad_decoder decoder;

    data.start = (unsigned char const *)mm;
    data.length = (unsigned long)sz;
    data.reader = this;

    mad_decoder_init(&decoder, &data, input, 0, 0, output, error, 0);
    mad_decoder_run(&decoder, MAD_DECODER_MODE_SYNC);
    mad_decoder_finish(&decoder);

    m_done = true;
    return true;
}

enum mad_flow
MP3FileReader::input(void *dp, struct mad_stream *stream)
{
    DecoderData *data = (DecoderData *)dp;

    if (!data->length) return MAD_FLOW_STOP;
    mad_stream_buffer(stream, data->start, data->length);
    data->length = 0;

    return MAD_FLOW_CONTINUE;
}

enum mad_flow
MP3FileReader::output(void *dp,
		      struct mad_header const *header,
		      struct mad_pcm *pcm)
{
    DecoderData *data = (DecoderData *)dp;
    return data->reader->accept(header, pcm);
}

enum mad_flow
MP3FileReader::accept(struct mad_header const *header,
		      struct mad_pcm *pcm)
{
    int channels = pcm->channels;
    int frames = pcm->length;

    if (header) {
        m_bitrateNum += header->bitrate;
        m_bitrateDenom ++;
    }

    if (frames < 1) return MAD_FLOW_CONTINUE;

    if (m_channelCount == 0) {

        m_fileRate = pcm->samplerate;
        m_channelCount = channels;

        initialiseDecodeCache();

        if (m_cacheMode == CacheInTemporaryFile) {
            m_completion = 1;
            std::cerr << "MP3FileReader::accept: channel count " << m_channelCount << ", file rate " << m_fileRate << ", about to start serialised section" << std::endl;
            startSerialised("MP3FileReader::Decode");
        }
    }
    
    if (m_bitrateDenom > 0) {
        double bitrate = m_bitrateNum / m_bitrateDenom;
        double duration = double(m_fileSize * 8) / bitrate;
        double elapsed = double(m_frameCount) / m_sampleRate;
        double percent = ((elapsed * 100.0) / duration);
        int progress = int(percent);
        if (progress < 1) progress = 1;
        if (progress > 99) progress = 99;
        m_completion = progress;
        if (m_progress) {
            if (progress > m_progress->value()) {
                m_progress->setValue(progress);
                m_progress->show();
                m_progress->raise();
                qApp->processEvents();
                if (m_progress->wasCanceled()) {
                    m_cancelled = true;
                }
            }
        }
    }

    if (m_cancelled) return MAD_FLOW_STOP;

    if (!isDecodeCacheInitialised()) {
        initialiseDecodeCache();
    }

    if (m_samplebuffersize < frames) {
        if (!m_samplebuffer) {
            m_samplebuffer = new float *[channels];
            for (int c = 0; c < channels; ++c) {
                m_samplebuffer[c] = 0;
            }
        }
        for (int c = 0; c < channels; ++c) {
            delete[] m_samplebuffer[c];
            m_samplebuffer[c] = new float[frames];
        }
        m_samplebuffersize = frames;
    }

    int activeChannels = int(sizeof(pcm->samples) / sizeof(pcm->samples[0]));

    for (int ch = 0; ch < channels; ++ch) {

        for (int i = 0; i < frames; ++i) {

	    mad_fixed_t sample = 0;
	    if (ch < activeChannels) {
		sample = pcm->samples[ch][i];
	    }
	    float fsample = float(sample) / float(MAD_F_ONE);
            
            m_samplebuffer[ch][i] = fsample;
	}
    }

    addSamplesToDecodeCache(m_samplebuffer, frames);

    return MAD_FLOW_CONTINUE;
}

enum mad_flow
MP3FileReader::error(void *dp,
		     struct mad_stream *stream,
		     struct mad_frame *)
{
    DecoderData *data = (DecoderData *)dp;

    fprintf(stderr, "decoding error 0x%04x (%s) at byte offset %u\n",
	    stream->error, mad_stream_errorstr(stream),
	    stream->this_frame - data->start);

    return MAD_FLOW_CONTINUE;
}

void
MP3FileReader::getSupportedExtensions(std::set<QString> &extensions)
{
    extensions.insert("mp3");
}

bool
MP3FileReader::supportsExtension(QString extension)
{
    std::set<QString> extensions;
    getSupportedExtensions(extensions);
    return (extensions.find(extension.toLower()) != extensions.end());
}

bool
MP3FileReader::supportsContentType(QString type)
{
    return (type == "audio/mpeg");
}

bool
MP3FileReader::supports(RemoteFile &source)
{
    return (supportsExtension(source.getExtension()) ||
            supportsContentType(source.getContentType()));
}


#endif