annotate data/fileio/MP3FileReader.cpp @ 1310:aa1b1fc2d018 mp3-gapless

Stop reporting sync errors only when we really are at eof, i.e. after the input callback has been called again (previously we just tested whether we'd buffered up all the input, which of course we do in one go at the start)

/* -*- 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 "base/ProgressReporter.h"

#include "system/System.h"

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

#include <iostream>

#include <cstdlib>

#ifdef HAVE_ID3TAG
#include <id3tag.h>
#endif

#include <QFileInfo>

#ifdef _MSC_VER
#include <io.h>
#define open _open
#endif

using std::string;

static sv_frame_t DEFAULT_DECODER_DELAY = 529;

MP3FileReader::MP3FileReader(FileSource source, DecodeMode decodeMode, 
                             CacheMode mode, GaplessMode gaplessMode,
                             sv_samplerate_t targetRate,
                             bool normalised,
                             ProgressReporter *reporter) :
    CodedAudioFileReader(mode, targetRate, normalised),
    m_source(source),
    m_path(source.getLocalFilename()),
    m_gaplessMode(gaplessMode),
    m_decodeErrorShown(false),
    m_decodeThread(0)
{
    SVDEBUG << "MP3FileReader: local path: \"" << m_path
            << "\", decode mode: " << decodeMode << " ("
            << (decodeMode == DecodeAtOnce ? "DecodeAtOnce" : "DecodeThreaded")
            << ")" << endl;
    
    m_channelCount = 0;
    m_fileRate = 0;
    m_fileSize = 0;
    m_bitrateNum = 0;
    m_bitrateDenom = 0;
    m_cancelled = false;
    m_mp3FrameCount = 0;
    m_completion = 0;
    m_done = false;
    m_reporter = reporter;

    if (m_gaplessMode == Gapless) {
        CodedAudioFileReader::setFramesToTrim(DEFAULT_DECODER_DELAY, 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;

    m_fileBuffer = 0;
    m_fileBufferSize = 0;

    m_sampleBuffer = 0;
    m_sampleBufferSize = 0;

    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;
    }	

    try {
        // We need a mysterious MAD_BUFFER_GUARD (== 8) zero bytes at
        // end of input, to ensure libmad decodes the last frame
        // correctly. Otherwise the decoded audio is truncated.
        m_fileBufferSize = m_fileSize + MAD_BUFFER_GUARD;
        m_fileBuffer = new unsigned char[m_fileBufferSize];
        memset(m_fileBuffer + m_fileSize, 0, MAD_BUFFER_GUARD);
    } catch (...) {
        m_error = QString("Out of memory");
        ::close(fd);
	return;
    }
    
    ssize_t sz = 0;
    ssize_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) {
            SVCERR << QString("MP3FileReader::MP3FileReader: Warning: reached EOF after only %1 of %2 bytes")
                .arg(offset).arg(m_fileSize) << endl;
            m_fileSize = offset;
            m_fileBufferSize = m_fileSize + MAD_BUFFER_GUARD;
            memset(m_fileBuffer + m_fileSize, 0, MAD_BUFFER_GUARD);
            break;
        }
        offset += sz;
    }

    ::close(fd);

    loadTags();

    if (decodeMode == DecodeAtOnce) {

        if (m_reporter) {
            connect(m_reporter, SIGNAL(cancelled()), this, SLOT(cancelled()));
            m_reporter->setMessage
                (tr("Decoding %1...").arg(QFileInfo(m_path).fileName()));
        }

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

        if (isDecodeCacheInitialised()) finishDecodeCache();
        endSerialised();

    } else {

        if (m_reporter) m_reporter->setProgress(100);

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

        while ((m_channelCount == 0 || m_fileRate == 0 || m_sampleRate == 0)
               && !m_done) {
            usleep(10);
        }
        
        SVDEBUG << "MP3FileReader: decoding startup complete, file rate = " << m_fileRate << endl;
    }

    if (m_error != "") {
        SVDEBUG << "MP3FileReader::MP3FileReader(\"" << m_path << "\"): ERROR: " << m_error << endl;
    }
}

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

void
MP3FileReader::cancelled()
{
    m_cancelled = true;
}

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) {
        SVDEBUG << "MP3FileReader::loadTags: No ID3 tag found" << endl;
        id3_file_close(file);
        return;
    }

    m_title = loadTag(tag, "TIT2"); // work title
    if (m_title == "") m_title = loadTag(tag, "TIT1");
    if (m_title == "") SVDEBUG << "MP3FileReader::loadTags: No title found" << endl;

    m_maker = loadTag(tag, "TPE1"); // "lead artist"
    if (m_maker == "") m_maker = loadTag(tag, "TPE2");
    if (m_maker == "") SVDEBUG << "MP3FileReader::loadTags: No artist/maker found" << endl;

    for (unsigned int i = 0; i < tag->nframes; ++i) {
        if (tag->frames[i]) {
            QString value = loadTag(tag, tag->frames[i]->id);
            if (value != "") {
                m_tags[tag->frames[i]->id] = value;
            }
        }
    }

    id3_file_close(file);

#else
    SVDEBUG << "MP3FileReader::loadTags: ID3 tag support not compiled in" << endl;
#endif
}

QString
MP3FileReader::loadTag(void *vtag, const char *name)
{
#ifdef HAVE_ID3TAG
    id3_tag *tag = (id3_tag *)vtag;

    id3_frame *frame = id3_tag_findframe(tag, name, 0);
    if (!frame) {
        SVDEBUG << "MP3FileReader::loadTag: No \"" << name << "\" frame found in ID3 tag" << endl;
        return "";
    }
        
    if (frame->nfields < 2) {
        cerr << "MP3FileReader::loadTag: WARNING: Not enough fields (" << frame->nfields << ") for \"" << name << "\" in ID3 tag" << endl;
        return "";
    }

    unsigned int nstrings = id3_field_getnstrings(&frame->fields[1]);
    if (nstrings == 0) {
        SVDEBUG << "MP3FileReader::loadTag: No strings for \"" << name << "\" in ID3 tag" << endl;
        return "";
    }

    id3_ucs4_t const *ustr = id3_field_getstrings(&frame->fields[1], 0);
    if (!ustr) {
        SVDEBUG << "MP3FileReader::loadTag: Invalid or absent data for \"" << name << "\" in ID3 tag" << endl;
        return "";
    }
        
    id3_utf8_t *u8str = id3_ucs4_utf8duplicate(ustr);
    if (!u8str) {
        SVDEBUG << "MP3FileReader::loadTag: ERROR: Internal error: Failed to convert UCS4 to UTF8 in ID3 tag" << endl;
        return "";
    }
        
    QString rv = QString::fromUtf8((const char *)u8str);
    free(u8str);

    SVDEBUG << "MP3FileReader::loadTag: Tag \"" << name << "\" -> \""
            << rv << "\"" << endl;

    return rv;

#else
    return "";
#endif
}

void
MP3FileReader::DecodeThread::run()
{
    if (!m_reader->decode(m_reader->m_fileBuffer, m_reader->m_fileBufferSize)) {
        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 (int 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, sv_frame_t sz)
{
    DecoderData data;
    struct mad_decoder decoder;

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

    mad_decoder_init(&decoder,          // decoder to initialise
                     &data,             // our own data block for callbacks
                     input_callback,    // provides (entire) input to mad
                     0,                 // checks header
                     filter_callback,   // filters frame before decoding
                     output_callback,   // receives decoded output
                     error_callback,    // handles decode errors
                     0);                // "message_func"

    mad_decoder_run(&decoder, MAD_DECODER_MODE_SYNC);
    mad_decoder_finish(&decoder);

    SVDEBUG << "MP3FileReader: Decoding complete, decoded " << m_mp3FrameCount
            << " mp3 frames" << endl;
    
    m_done = true;
    return true;
}

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

    if (!data->length) {
        data->finished = true;
        return MAD_FLOW_STOP;
    }

    unsigned char const *start = data->start;
    sv_frame_t length = data->length;

#ifdef HAVE_ID3TAG
    while (length > ID3_TAG_QUERYSIZE) {
        ssize_t taglen = id3_tag_query(start, ID3_TAG_QUERYSIZE);
        if (taglen <= 0) {
            break;
        }
        SVDEBUG << "MP3FileReader: ID3 tag length to skip: " << taglen << endl;
        start += taglen;
        length -= taglen;
    }
#endif

    mad_stream_buffer(stream, start, length);
    data->length = 0;

    return MAD_FLOW_CONTINUE;
}

enum mad_flow
MP3FileReader::filter_callback(void *dp,
                               struct mad_stream const *stream,
                               struct mad_frame *frame)
{
    DecoderData *data = (DecoderData *)dp;
    return data->reader->filter(stream, frame);
}

static string toMagic(unsigned long fourcc)
{
    string magic("....");
    for (int i = 0; i < 4; ++i) {
        magic[3-i] = char((fourcc >> (8*i)) & 0xff);
    }
    return magic;
}

enum mad_flow
MP3FileReader::filter(struct mad_stream const *stream,
                      struct mad_frame *)
{
    if (m_mp3FrameCount > 0) {
        // only handle info frame if it appears as first mp3 frame
        return MAD_FLOW_CONTINUE;
    }

    if (m_gaplessMode == Gappy) {
        // Our non-gapless mode does not even filter out the Xing/LAME
        // frame. That's because the main reason non-gapless mode
        // exists is for backward compatibility with MP3FileReader
        // behaviour before the gapless support was added, so we even
        // need to keep the spurious 1152 samples resulting from
        // feeding Xing/LAME frame to the decoder as otherwise we'd
        // have different output from before.
        SVDEBUG << "MP3FileReader: Not gapless mode, not checking Xing/LAME frame"
                << endl;
        return MAD_FLOW_CONTINUE;
    }
    
    struct mad_bitptr ptr = stream->anc_ptr;
    string magic = toMagic(mad_bit_read(&ptr, 32));

    if (magic == "Xing" || magic == "Info") {

        SVDEBUG << "MP3FileReader: Found Xing/LAME metadata frame (magic = \""
                << magic << "\")" << endl;

        // All we want at this point is the LAME encoder delay and
        // padding values. We expect to see the Xing/Info magic (which
        // we've already read), then 116 bytes of Xing data, then LAME
        // magic, 5 byte version string, 12 bytes of LAME data that we
        // aren't currently interested in, then the delays encoded as
        // two 12-bit numbers into three bytes.
        //
        // (See gabriel.mp3-tech.org/mp3infotag.html)
        
        for (int skip = 0; skip < 116; ++skip) {
            (void)mad_bit_read(&ptr, 8);
        }

        magic = toMagic(mad_bit_read(&ptr, 32));

        if (magic == "LAME") {

            SVDEBUG << "MP3FileReader: Found LAME-specific metadata" << endl;

            for (int skip = 0; skip < 5 + 12; ++skip) {
                (void)mad_bit_read(&ptr, 8);
            }

            auto delay = mad_bit_read(&ptr, 12);
            auto padding = mad_bit_read(&ptr, 12);

            sv_frame_t delayToDrop = DEFAULT_DECODER_DELAY + delay;
            sv_frame_t paddingToDrop = padding - DEFAULT_DECODER_DELAY;
            if (paddingToDrop < 0) paddingToDrop = 0;

            SVDEBUG << "MP3FileReader: LAME encoder delay = " << delay
                    << ", padding = " << padding << endl;

            SVDEBUG << "MP3FileReader: Will be trimming " << delayToDrop
                    << " samples from start and " << paddingToDrop
                    << " from end" << endl;

            CodedAudioFileReader::setFramesToTrim(delayToDrop, paddingToDrop);
            
        } else {
            SVDEBUG << "MP3FileReader: Xing frame has no LAME metadata" << endl;
        }
            
        return MAD_FLOW_IGNORE;
        
    } else {
        return MAD_FLOW_CONTINUE;
    }
}

enum mad_flow
MP3FileReader::output_callback(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 = m_bitrateNum + double(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) {
//            SVDEBUG << "MP3FileReader::accept: channel count " << m_channelCount << ", file rate " << m_fileRate << ", about to start serialised section" << 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 = 100;
        if (duration > 0.0) percent = ((elapsed * 100.0) / duration);
        int p = int(percent);
        if (p < 1) p = 1;
        if (p > 99) p = 99;
        if (m_completion != p && m_reporter) {
            m_completion = p;
            m_reporter->setProgress(m_completion);
        }
    }

    if (m_cancelled) {
        SVDEBUG << "MP3FileReader: Decoding cancelled" << endl;
        return MAD_FLOW_STOP;
    }

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

    if (m_sampleBufferSize < size_t(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);

    ++m_mp3FrameCount;

    return MAD_FLOW_CONTINUE;
}

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

    if (stream->error == MAD_ERROR_LOSTSYNC &&
        data->finished) {
        // We are at end of file, losing sync is expected behaviour,
        // don't report it
        return MAD_FLOW_CONTINUE;
    }
    
    if (!data->reader->m_decodeErrorShown) {
        char buffer[256];
        snprintf(buffer, 255,
                 "MP3 decoding error 0x%04x (%s) at byte offset %lu",
                 stream->error, mad_stream_errorstr(stream),
                 (unsigned long)(stream->this_frame - data->start));
        SVCERR << "Warning: in file \"" << data->reader->m_path << "\": "
               << buffer << " (continuing; will not report any further decode errors for this file)" << endl;
        data->reader->m_decodeErrorShown = true;
    }

    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(FileSource &source)
{
    return (supportsExtension(source.getExtension()) ||
            supportsContentType(source.getContentType()));
}


#endif