comparison data/fileio/MP3FileReader.cpp @ 148:1a42221a1522

* Reorganising code base.  This revision will not compile.

+
+/* -*- 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/System.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <iostream>
+
+#include <QApplication>
+#include <QProgressDialog>
+
+MP3FileReader::MP3FileReader(QString path, bool showProgress, CacheMode mode) :
+    CodedAudioFileReader(mode),
+    m_path(path)
+{
+    m_frameCount = 0;
+    m_channelCount = 0;
+    m_sampleRate = 0;
+    m_fileSize = 0;
+    m_bitrateNum = 0;
+    m_bitrateDenom = 0;
+    m_frameCount = 0;
+    m_cancelled = false;
+
+    struct stat stat;
+    if (::stat(path.toLocal8Bit().data(), &stat) == -1 || stat.st_size == 0) {
+	m_error = QString("File %1 does not exist.").arg(path);
+	return;
+    }
+
+    m_fileSize = stat.st_size;
+
+    int fd;
+    if ((fd = ::open(path.toLocal8Bit().data(), O_RDONLY, 0)) < 0) {
+	m_error = QString("Failed to open file %1 for reading.").arg(path);
+	return;
+    }	
+
+    unsigned char *filebuffer = 0;
+
+    try {
+        filebuffer = new unsigned char[stat.st_size];
+    } catch (...) {
+        m_error = QString("Out of memory");
+        ::close(fd);
+	return;
+    }
+    
+    if (::read(fd, filebuffer, stat.st_size) < stat.st_size) {
+	m_error = QString("Failed to read file %1.").arg(path);
+        delete[] filebuffer;
+        ::close(fd);
+	return;
+    }
+
+    ::close(fd);
+
+    if (showProgress) {
+	m_progress = new QProgressDialog
+	    (QObject::tr("Decoding MP3 file..."),
+	     QObject::tr("Stop"), 0, 100);
+	m_progress->hide();
+    }
+
+    if (!decode(filebuffer, stat.st_size)) {
+	m_error = QString("Failed to decode file %1.").arg(path);
+        delete[] filebuffer;
+	return;
+    }
+    
+    if (isDecodeCacheInitialised()) finishDecodeCache();
+
+    if (showProgress) {
+	delete m_progress;
+	m_progress = 0;
+    }
+
+    delete[] filebuffer;
+}
+
+MP3FileReader::~MP3FileReader()
+{
+}
+
+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);
+
+    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_channelCount = channels;
+        m_sampleRate = pcm->samplerate;
+    }
+    
+    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;
+        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;
+
+    m_frameCount += frames;
+
+    if (!isDecodeCacheInitialised()) {
+        initialiseDecodeCache();
+    }
+
+    for (int i = 0; i < frames; ++i) {
+
+	for (int ch = 0; ch < channels; ++ch) {
+	    mad_fixed_t sample = 0;
+	    if (ch < int(sizeof(pcm->samples) / sizeof(pcm->samples[0]))) {
+		sample = pcm->samples[ch][i];
+	    }
+	    float fsample = float(sample) / float(MAD_F_ONE);
+            addSampleToDecodeCache(fsample);
+	}
+
+	if (! (i & 0xffff)) {
+	    // periodically munlock to ensure we don't exhaust real memory
+	    // if running with memory locked down
+	    MUNLOCK_SAMPLEBLOCK(m_data);
+	}
+    }
+
+    if (frames > 0) {
+	MUNLOCK_SAMPLEBLOCK(m_data);
+    }
+
+    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;
+}
+
+#endif