changeset 823:f0558e69a074

Rename Resampling- to DecodingWavFileReader, and use it whenever we have an audio file that is not quickly seekable using libsndfile. Avoids very slow performance when analysing ogg files.
author Chris Cannam
date Wed, 17 Jul 2013 15:40:01 +0100 (2013-07-17)
parents 06c64a1c6785
children 420ade1cb6da 69bde159744f
files data/fileio/AudioFileReader.h data/fileio/AudioFileReaderFactory.cpp data/fileio/CodedAudioFileReader.h data/fileio/DecodingWavFileReader.cpp data/fileio/DecodingWavFileReader.h data/fileio/ResamplingWavFileReader.cpp data/fileio/ResamplingWavFileReader.h data/fileio/WavFileReader.cpp data/fileio/WavFileReader.h
diffstat 9 files changed, 342 insertions(+), 299 deletions(-) [+]
line wrap: on
line diff
--- a/data/fileio/AudioFileReader.h	Mon Jul 08 14:49:28 2013 +0100
+++ b/data/fileio/AudioFileReader.h	Wed Jul 17 15:40:01 2013 +0100
@@ -65,6 +65,13 @@
     typedef std::map<QString, QString> TagMap;
     virtual TagMap getTags() const { return TagMap(); }
 
+    /**
+     * Return true if this file supports fast seek and random
+     * access. Typically this will be true for uncompressed formats
+     * and false for compressed ones.
+     */
+    virtual bool isQuicklySeekable() const = 0;
+
     /** 
      * Return interleaved samples for count frames from index start.
      * The resulting sample block will contain count *
--- a/data/fileio/AudioFileReaderFactory.cpp	Mon Jul 08 14:49:28 2013 +0100
+++ b/data/fileio/AudioFileReaderFactory.cpp	Wed Jul 17 15:40:01 2013 +0100
@@ -16,7 +16,7 @@
 #include "AudioFileReaderFactory.h"
 
 #include "WavFileReader.h"
-#include "ResamplingWavFileReader.h"
+#include "DecodingWavFileReader.h"
 #include "OggVorbisFileReader.h"
 #include "MP3FileReader.h"
 #include "QuickTimeFileReader.h"
@@ -98,20 +98,22 @@
 
         reader = new WavFileReader(source);
 
-        if (targetRate != 0 &&
-            reader->isOK() &&
-            reader->getSampleRate() != targetRate) {
+        int fileRate = reader->getSampleRate();
 
-            SVDEBUG << "AudioFileReaderFactory::createReader: WAV file rate: " << reader->getSampleRate() << ", creating resampling reader" << endl;
+        if (reader->isOK() &&
+            (!reader->isQuicklySeekable() ||
+             (targetRate != 0 && fileRate != targetRate))) {
+
+            SVDEBUG << "AudioFileReaderFactory::createReader: WAV file rate: " << reader->getSampleRate() << ", seekable " << reader->isQuicklySeekable() << ", creating decoding reader" << endl;
 
             delete reader;
-            reader = new ResamplingWavFileReader
+            reader = new DecodingWavFileReader
                 (source,
                  threading ?
-                 ResamplingWavFileReader::ResampleThreaded :
-                 ResamplingWavFileReader::ResampleAtOnce,
-                 ResamplingWavFileReader::CacheInTemporaryFile,
-                 targetRate,
+                 DecodingWavFileReader::ResampleThreaded :
+                 DecodingWavFileReader::ResampleAtOnce,
+                 DecodingWavFileReader::CacheInTemporaryFile,
+                 targetRate ? targetRate : fileRate,
                  reporter);
             if (!reader->isOK()) {
                 delete reader;
@@ -209,20 +211,22 @@
 
         reader = new WavFileReader(source);
 
-        if (targetRate != 0 &&
-            reader->isOK() &&
-            reader->getSampleRate() != targetRate) {
+        int fileRate = reader->getSampleRate();
 
-            SVDEBUG << "AudioFileReaderFactory::createReader: WAV file rate: " << reader->getSampleRate() << ", creating resampling reader" << endl;
+        if (reader->isOK() &&
+            (!reader->isQuicklySeekable() ||
+             (targetRate != 0 && fileRate != targetRate))) {
+
+            SVDEBUG << "AudioFileReaderFactory::createReader: WAV file rate: " << reader->getSampleRate() << ", seekable " << reader->isQuicklySeekable() << ", creating decoding reader" << endl;
 
             delete reader;
-            reader = new ResamplingWavFileReader
+            reader = new DecodingWavFileReader
                 (source,
                  threading ?
-                 ResamplingWavFileReader::ResampleThreaded :
-                 ResamplingWavFileReader::ResampleAtOnce,
-                 ResamplingWavFileReader::CacheInTemporaryFile,
-                 targetRate,
+                 DecodingWavFileReader::ResampleThreaded :
+                 DecodingWavFileReader::ResampleAtOnce,
+                 DecodingWavFileReader::CacheInTemporaryFile,
+                 targetRate ? targetRate : fileRate,
                  reporter);
         }
 
--- a/data/fileio/CodedAudioFileReader.h	Mon Jul 08 14:49:28 2013 +0100
+++ b/data/fileio/CodedAudioFileReader.h	Wed Jul 17 15:40:01 2013 +0100
@@ -43,6 +43,9 @@
 
     virtual size_t getNativeRate() const { return m_fileRate; }
 
+    /// Intermediate cache means all CodedAudioFileReaders are quickly seekable
+    virtual bool isQuicklySeekable() const { return true; }
+
 signals:
     void progress(int);
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data/fileio/DecodingWavFileReader.cpp	Wed Jul 17 15:40:01 2013 +0100
@@ -0,0 +1,192 @@
+/* -*- 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 2007 QMUL.
+    
+    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.
+*/
+
+#include "DecodingWavFileReader.h"
+
+#include "WavFileReader.h"
+#include "base/Profiler.h"
+#include "base/ProgressReporter.h"
+
+#include <QFileInfo>
+
+DecodingWavFileReader::DecodingWavFileReader(FileSource source,
+						 ResampleMode resampleMode,
+						 CacheMode mode,
+						 size_t targetRate,
+                                                 ProgressReporter *reporter) :
+    CodedAudioFileReader(mode, targetRate),
+    m_source(source),
+    m_path(source.getLocalFilename()),
+    m_cancelled(false),
+    m_processed(0),
+    m_completion(0),
+    m_original(0),
+    m_reporter(reporter),
+    m_decodeThread(0)
+{
+    m_channelCount = 0;
+    m_fileRate = 0;
+
+    SVDEBUG << "DecodingWavFileReader::DecodingWavFileReader(\""
+              << m_path << "\"): rate " << targetRate << endl;
+
+    Profiler profiler("DecodingWavFileReader::DecodingWavFileReader", true);
+
+    m_original = new WavFileReader(m_path);
+    if (!m_original->isOK()) {
+        m_error = m_original->getError();
+        return;
+    }
+
+    m_channelCount = m_original->getChannelCount();
+    m_fileRate = m_original->getSampleRate();
+
+    initialiseDecodeCache();
+
+    if (resampleMode == ResampleAtOnce) {
+
+        if (m_reporter) {
+            connect(m_reporter, SIGNAL(cancelled()), this, SLOT(cancelled()));
+            m_reporter->setMessage
+                (tr("Decoding %1...").arg(QFileInfo(m_path).fileName()));
+        }
+
+        size_t blockSize = 16384;
+        size_t total = m_original->getFrameCount();
+
+        SampleBlock block;
+
+        for (size_t i = 0; i < total; i += blockSize) {
+
+            size_t count = blockSize;
+            if (i + count > total) count = total - i;
+
+            m_original->getInterleavedFrames(i, count, block);
+            addBlock(block);
+
+            if (m_cancelled) break;
+        }
+
+        if (isDecodeCacheInitialised()) finishDecodeCache();
+        endSerialised();
+
+        if (m_reporter) m_reporter->setProgress(100);
+
+        delete m_original;
+        m_original = 0;
+
+    } else {
+
+        if (m_reporter) m_reporter->setProgress(100);
+
+        m_decodeThread = new DecodeThread(this);
+        m_decodeThread->start();
+    }
+}
+
+DecodingWavFileReader::~DecodingWavFileReader()
+{
+    if (m_decodeThread) {
+        m_cancelled = true;
+        m_decodeThread->wait();
+        delete m_decodeThread;
+    }
+    
+    delete m_original;
+}
+
+void
+DecodingWavFileReader::cancelled()
+{
+    m_cancelled = true;
+}
+
+void
+DecodingWavFileReader::DecodeThread::run()
+{
+    if (m_reader->m_cacheMode == CacheInTemporaryFile) {
+        m_reader->startSerialised("DecodingWavFileReader::Decode");
+    }
+
+    size_t blockSize = 16384;
+    size_t total = m_reader->m_original->getFrameCount();
+    
+    SampleBlock block;
+    
+    for (size_t i = 0; i < total; i += blockSize) {
+        
+        size_t count = blockSize;
+        if (i + count > total) count = total - i;
+        
+        m_reader->m_original->getInterleavedFrames(i, count, block);
+        m_reader->addBlock(block);
+
+        if (m_reader->m_cancelled) break;
+    }
+    
+    if (m_reader->isDecodeCacheInitialised()) m_reader->finishDecodeCache();
+    m_reader->m_completion = 100;
+
+    m_reader->endSerialised();
+
+    delete m_reader->m_original;
+    m_reader->m_original = 0;
+} 
+
+void
+DecodingWavFileReader::addBlock(const SampleBlock &frames)
+{
+    addSamplesToDecodeCache(frames);
+
+    m_processed += frames.size();
+
+    float ratio = float(m_sampleRate) / float(m_fileRate);
+
+    int progress = lrint((float(m_processed) * ratio * 100) /
+                         float(m_original->getFrameCount()));
+
+    if (progress > 99) progress = 99;
+    m_completion = progress;
+    
+    if (m_reporter) {
+        m_reporter->setProgress(progress);
+    }
+}
+
+void
+DecodingWavFileReader::getSupportedExtensions(std::set<QString> &extensions)
+{
+    WavFileReader::getSupportedExtensions(extensions);
+}
+
+bool
+DecodingWavFileReader::supportsExtension(QString extension)
+{
+    return WavFileReader::supportsExtension(extension);
+}
+
+bool
+DecodingWavFileReader::supportsContentType(QString type)
+{
+    return WavFileReader::supportsContentType(type);
+}
+
+bool
+DecodingWavFileReader::supports(FileSource &source)
+{
+    return WavFileReader::supports(source);
+}
+
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data/fileio/DecodingWavFileReader.h	Wed Jul 17 15:40:01 2013 +0100
@@ -0,0 +1,87 @@
+/* -*- 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 2007 QMUL.
+    
+    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.
+*/
+
+#ifndef _DECODING_WAV_FILE_READER_H_
+#define _DECODING_WAV_FILE_READER_H_
+
+#include "CodedAudioFileReader.h"
+
+#include "base/Thread.h"
+
+#include <set>
+
+class WavFileReader;
+class ProgressReporter;
+
+class DecodingWavFileReader : public CodedAudioFileReader
+{
+    Q_OBJECT
+public:
+    enum ResampleMode {
+        ResampleAtOnce, // resample the file on construction, with progress dialog
+        ResampleThreaded // resample in a background thread after construction
+    };
+
+    DecodingWavFileReader(FileSource source,
+                            ResampleMode resampleMode,
+                            CacheMode cacheMode,
+                            size_t targetRate = 0,
+                            ProgressReporter *reporter = 0);
+    virtual ~DecodingWavFileReader();
+
+    virtual QString getError() const { return m_error; }
+    virtual QString getLocation() const { return m_source.getLocation(); }
+    static void getSupportedExtensions(std::set<QString> &extensions);
+    static bool supportsExtension(QString ext);
+    static bool supportsContentType(QString type);
+    static bool supports(FileSource &source);
+
+    virtual int getDecodeCompletion() const { return m_completion; }
+
+    virtual bool isUpdating() const {
+        return m_decodeThread && m_decodeThread->isRunning();
+    }
+
+public slots:
+    void cancelled();
+
+protected:
+    FileSource m_source;
+    QString m_path;
+    QString m_error;
+    bool m_cancelled;
+    size_t m_processed;
+    int m_completion;
+
+    WavFileReader *m_original;
+    ProgressReporter *m_reporter;
+
+    void addBlock(const SampleBlock &frames);
+    
+    class DecodeThread : public Thread
+    {
+    public:
+        DecodeThread(DecodingWavFileReader *reader) : m_reader(reader) { }
+        virtual void run();
+
+    protected:
+        DecodingWavFileReader *m_reader;
+    };
+
+    DecodeThread *m_decodeThread;
+};
+
+#endif
+
--- a/data/fileio/ResamplingWavFileReader.cpp	Mon Jul 08 14:49:28 2013 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,192 +0,0 @@
-/* -*- 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 2007 QMUL.
-    
-    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.
-*/
-
-#include "ResamplingWavFileReader.h"
-
-#include "WavFileReader.h"
-#include "base/Profiler.h"
-#include "base/ProgressReporter.h"
-
-#include <QFileInfo>
-
-ResamplingWavFileReader::ResamplingWavFileReader(FileSource source,
-						 ResampleMode resampleMode,
-						 CacheMode mode,
-						 size_t targetRate,
-                                                 ProgressReporter *reporter) :
-    CodedAudioFileReader(mode, targetRate),
-    m_source(source),
-    m_path(source.getLocalFilename()),
-    m_cancelled(false),
-    m_processed(0),
-    m_completion(0),
-    m_original(0),
-    m_reporter(reporter),
-    m_decodeThread(0)
-{
-    m_channelCount = 0;
-    m_fileRate = 0;
-
-    SVDEBUG << "ResamplingWavFileReader::ResamplingWavFileReader(\""
-              << m_path << "\"): rate " << targetRate << endl;
-
-    Profiler profiler("ResamplingWavFileReader::ResamplingWavFileReader", true);
-
-    m_original = new WavFileReader(m_path);
-    if (!m_original->isOK()) {
-        m_error = m_original->getError();
-        return;
-    }
-
-    m_channelCount = m_original->getChannelCount();
-    m_fileRate = m_original->getSampleRate();
-
-    initialiseDecodeCache();
-
-    if (resampleMode == ResampleAtOnce) {
-
-        if (m_reporter) {
-            connect(m_reporter, SIGNAL(cancelled()), this, SLOT(cancelled()));
-            m_reporter->setMessage
-                (tr("Resampling %1...").arg(QFileInfo(m_path).fileName()));
-        }
-
-        size_t blockSize = 16384;
-        size_t total = m_original->getFrameCount();
-
-        SampleBlock block;
-
-        for (size_t i = 0; i < total; i += blockSize) {
-
-            size_t count = blockSize;
-            if (i + count > total) count = total - i;
-
-            m_original->getInterleavedFrames(i, count, block);
-            addBlock(block);
-
-            if (m_cancelled) break;
-        }
-
-        if (isDecodeCacheInitialised()) finishDecodeCache();
-        endSerialised();
-
-        if (m_reporter) m_reporter->setProgress(100);
-
-        delete m_original;
-        m_original = 0;
-
-    } else {
-
-        if (m_reporter) m_reporter->setProgress(100);
-
-        m_decodeThread = new DecodeThread(this);
-        m_decodeThread->start();
-    }
-}
-
-ResamplingWavFileReader::~ResamplingWavFileReader()
-{
-    if (m_decodeThread) {
-        m_cancelled = true;
-        m_decodeThread->wait();
-        delete m_decodeThread;
-    }
-    
-    delete m_original;
-}
-
-void
-ResamplingWavFileReader::cancelled()
-{
-    m_cancelled = true;
-}
-
-void
-ResamplingWavFileReader::DecodeThread::run()
-{
-    if (m_reader->m_cacheMode == CacheInTemporaryFile) {
-        m_reader->startSerialised("ResamplingWavFileReader::Decode");
-    }
-
-    size_t blockSize = 16384;
-    size_t total = m_reader->m_original->getFrameCount();
-    
-    SampleBlock block;
-    
-    for (size_t i = 0; i < total; i += blockSize) {
-        
-        size_t count = blockSize;
-        if (i + count > total) count = total - i;
-        
-        m_reader->m_original->getInterleavedFrames(i, count, block);
-        m_reader->addBlock(block);
-
-        if (m_reader->m_cancelled) break;
-    }
-    
-    if (m_reader->isDecodeCacheInitialised()) m_reader->finishDecodeCache();
-    m_reader->m_completion = 100;
-
-    m_reader->endSerialised();
-
-    delete m_reader->m_original;
-    m_reader->m_original = 0;
-} 
-
-void
-ResamplingWavFileReader::addBlock(const SampleBlock &frames)
-{
-    addSamplesToDecodeCache(frames);
-
-    m_processed += frames.size();
-
-    float ratio = float(m_sampleRate) / float(m_fileRate);
-
-    int progress = lrint((float(m_processed) * ratio * 100) /
-                         float(m_original->getFrameCount()));
-
-    if (progress > 99) progress = 99;
-    m_completion = progress;
-    
-    if (m_reporter) {
-        m_reporter->setProgress(progress);
-    }
-}
-
-void
-ResamplingWavFileReader::getSupportedExtensions(std::set<QString> &extensions)
-{
-    WavFileReader::getSupportedExtensions(extensions);
-}
-
-bool
-ResamplingWavFileReader::supportsExtension(QString extension)
-{
-    return WavFileReader::supportsExtension(extension);
-}
-
-bool
-ResamplingWavFileReader::supportsContentType(QString type)
-{
-    return WavFileReader::supportsContentType(type);
-}
-
-bool
-ResamplingWavFileReader::supports(FileSource &source)
-{
-    return WavFileReader::supports(source);
-}
-
-
--- a/data/fileio/ResamplingWavFileReader.h	Mon Jul 08 14:49:28 2013 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,87 +0,0 @@
-/* -*- 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 2007 QMUL.
-    
-    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.
-*/
-
-#ifndef _RESAMPLING_WAV_FILE_READER_H_
-#define _RESAMPLING_WAV_FILE_READER_H_
-
-#include "CodedAudioFileReader.h"
-
-#include "base/Thread.h"
-
-#include <set>
-
-class WavFileReader;
-class ProgressReporter;
-
-class ResamplingWavFileReader : public CodedAudioFileReader
-{
-    Q_OBJECT
-public:
-    enum ResampleMode {
-        ResampleAtOnce, // resample the file on construction, with progress dialog
-        ResampleThreaded // resample in a background thread after construction
-    };
-
-    ResamplingWavFileReader(FileSource source,
-                            ResampleMode resampleMode,
-                            CacheMode cacheMode,
-                            size_t targetRate = 0,
-                            ProgressReporter *reporter = 0);
-    virtual ~ResamplingWavFileReader();
-
-    virtual QString getError() const { return m_error; }
-    virtual QString getLocation() const { return m_source.getLocation(); }
-    static void getSupportedExtensions(std::set<QString> &extensions);
-    static bool supportsExtension(QString ext);
-    static bool supportsContentType(QString type);
-    static bool supports(FileSource &source);
-
-    virtual int getDecodeCompletion() const { return m_completion; }
-
-    virtual bool isUpdating() const {
-        return m_decodeThread && m_decodeThread->isRunning();
-    }
-
-public slots:
-    void cancelled();
-
-protected:
-    FileSource m_source;
-    QString m_path;
-    QString m_error;
-    bool m_cancelled;
-    size_t m_processed;
-    int m_completion;
-
-    WavFileReader *m_original;
-    ProgressReporter *m_reporter;
-
-    void addBlock(const SampleBlock &frames);
-    
-    class DecodeThread : public Thread
-    {
-    public:
-        DecodeThread(ResamplingWavFileReader *reader) : m_reader(reader) { }
-        virtual void run();
-
-    protected:
-        ResamplingWavFileReader *m_reader;
-    };
-
-    DecodeThread *m_decodeThread;
-};
-
-#endif
-
--- a/data/fileio/WavFileReader.cpp	Mon Jul 08 14:49:28 2013 +0100
+++ b/data/fileio/WavFileReader.cpp	Wed Jul 17 15:40:01 2013 +0100
@@ -24,6 +24,7 @@
     m_file(0),
     m_source(source),
     m_path(source.getLocalFilename()),
+    m_seekable(false),
     m_buffer(0),
     m_bufsiz(0),
     m_lastStart(0),
@@ -54,12 +55,26 @@
     }
 
     if (m_fileInfo.channels > 0) {
+
         m_frameCount = m_fileInfo.frames;
         m_channelCount = m_fileInfo.channels;
         m_sampleRate = m_fileInfo.samplerate;
+
+        m_seekable = (m_fileInfo.seekable != 0);
+
+        // Our m_seekable reports whether a file is rapidly seekable,
+        // so things like Ogg don't qualify. We cautiously report
+        // every file type of "at least" the historical period of Ogg
+        // or FLAC as non-seekable.
+        int type = m_fileInfo.format & SF_FORMAT_TYPEMASK;
+//        std::cerr << "WavFileReader: format type is " << type << " (flac, ogg are " << SF_FORMAT_FLAC << ", " << SF_FORMAT_OGG << ")" << std::endl;
+        if (type >= SF_FORMAT_FLAC || type >= SF_FORMAT_OGG) {
+//            std::cerr << "WavFileReader: Recording as non-seekable" << std::endl;
+            m_seekable = false;
+        }
     }
 
-//    std::cerr << "WavFileReader: Frame count " << m_frameCount << ", channel count " << m_channelCount << ", sample rate " << m_sampleRate << std::endl;
+//    std::cerr << "WavFileReader: Frame count " << m_frameCount << ", channel count " << m_channelCount << ", sample rate " << m_sampleRate << ", seekable " << m_seekable << std::endl;
 
 }
 
--- a/data/fileio/WavFileReader.h	Mon Jul 08 14:49:28 2013 +0100
+++ b/data/fileio/WavFileReader.h	Wed Jul 17 15:40:01 2013 +0100
@@ -23,6 +23,16 @@
 
 #include <set>
 
+/**
+ * Reader for audio files using libsndfile.
+ *
+ * This is typically intended for seekable file types that can be read
+ * directly (e.g. WAV, AIFF etc).
+ *
+ * Compressed files supported by libsndfile (e.g. Ogg, FLAC) should
+ * normally be read using DecodingWavFileReader instead (which decodes
+ * to an intermediate cached file).
+ */
 class WavFileReader : public AudioFileReader
 {
 public:
@@ -32,6 +42,8 @@
     virtual QString getLocation() const { return m_source.getLocation(); }
     virtual QString getError() const { return m_error; }
 
+    virtual bool isQuicklySeekable() const { return m_seekable; }
+    
     /** 
      * Must be safe to call from multiple threads with different
      * arguments on the same object at the same time.
@@ -59,6 +71,8 @@
     QString m_path;
     QString m_error;
 
+    bool m_seekable;
+
     mutable QMutex m_mutex;
     mutable float *m_buffer;
     mutable size_t m_bufsiz;