# HG changeset patch
# User Chris Cannam
# Date 1440000211 -3600
# Node ID b9faee02afa5fccf2984789303801cf1dcd79ea6
# Parent  020277bfafcb99d636a13830dc72c237cf072b0c
Make WritableWaveFileModel a true WaveFileModel (and ReadOnlyWaveFileModel the other sort of it). Enable recording from an empty session using that.

diff -r 020277bfafcb -r b9faee02afa5 data/model/ReadOnlyWaveFileModel.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data/model/ReadOnlyWaveFileModel.cpp	Wed Aug 19 17:03:31 2015 +0100
@@ -0,0 +1,752 @@
+/* -*- 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 and 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 "ReadOnlyWaveFileModel.h"
+
+#include "fileio/AudioFileReader.h"
+#include "fileio/AudioFileReaderFactory.h"
+
+#include "system/System.h"
+
+#include "base/Preferences.h"
+
+#include <QFileInfo>
+#include <QTextStream>
+
+#include <iostream>
+#include <unistd.h>
+#include <cmath>
+#include <sndfile.h>
+
+#include <cassert>
+
+//#define DEBUG_WAVE_FILE_MODEL 1
+
+PowerOfSqrtTwoZoomConstraint
+ReadOnlyWaveFileModel::m_zoomConstraint;
+
+ReadOnlyWaveFileModel::ReadOnlyWaveFileModel(FileSource source, sv_samplerate_t targetRate) :
+    m_source(source),
+    m_path(source.getLocation()),
+    m_reader(0),
+    m_myReader(true),
+    m_startFrame(0),
+    m_fillThread(0),
+    m_updateTimer(0),
+    m_lastFillExtent(0),
+    m_exiting(false),
+    m_lastDirectReadStart(0),
+    m_lastDirectReadCount(0)
+{
+    m_source.waitForData();
+    if (m_source.isOK()) {
+        bool normalise = Preferences::getInstance()->getNormaliseAudio();
+        m_reader = AudioFileReaderFactory::createThreadingReader
+            (m_source, targetRate, normalise);
+        if (m_reader) {
+            SVDEBUG << "ReadOnlyWaveFileModel::ReadOnlyWaveFileModel: reader rate: "
+                      << m_reader->getSampleRate() << endl;
+        }
+    }
+    if (m_reader) setObjectName(m_reader->getTitle());
+    if (objectName() == "") setObjectName(QFileInfo(m_path).fileName());
+    if (isOK()) fillCache();
+}
+
+ReadOnlyWaveFileModel::ReadOnlyWaveFileModel(FileSource source, AudioFileReader *reader) :
+    m_source(source),
+    m_path(source.getLocation()),
+    m_reader(0),
+    m_myReader(false),
+    m_startFrame(0),
+    m_fillThread(0),
+    m_updateTimer(0),
+    m_lastFillExtent(0),
+    m_exiting(false)
+{
+    m_reader = reader;
+    if (m_reader) setObjectName(m_reader->getTitle());
+    if (objectName() == "") setObjectName(QFileInfo(m_path).fileName());
+    fillCache();
+}
+
+ReadOnlyWaveFileModel::~ReadOnlyWaveFileModel()
+{
+    m_exiting = true;
+    if (m_fillThread) m_fillThread->wait();
+    if (m_myReader) delete m_reader;
+    m_reader = 0;
+}
+
+bool
+ReadOnlyWaveFileModel::isOK() const
+{
+    return m_reader && m_reader->isOK();
+}
+
+bool
+ReadOnlyWaveFileModel::isReady(int *completion) const
+{
+    bool ready = (isOK() && (m_fillThread == 0));
+    double c = double(m_lastFillExtent) / double(getEndFrame() - getStartFrame());
+    static int prevCompletion = 0;
+    if (completion) {
+        *completion = int(c * 100.0 + 0.01);
+        if (m_reader) {
+            int decodeCompletion = m_reader->getDecodeCompletion();
+            if (decodeCompletion < 90) *completion = decodeCompletion;
+            else *completion = std::min(*completion, decodeCompletion);
+        }
+        if (*completion != 0 &&
+            *completion != 100 &&
+            prevCompletion != 0 &&
+            prevCompletion > *completion) {
+            // just to avoid completion going backwards
+            *completion = prevCompletion;
+        }
+        prevCompletion = *completion;
+    }
+#ifdef DEBUG_WAVE_FILE_MODEL
+    SVDEBUG << "ReadOnlyWaveFileModel::isReady(): ready = " << ready << ", completion = " << (completion ? *completion : -1) << endl;
+#endif
+    return ready;
+}
+
+sv_frame_t
+ReadOnlyWaveFileModel::getFrameCount() const
+{
+    if (!m_reader) return 0;
+    return m_reader->getFrameCount();
+}
+
+int
+ReadOnlyWaveFileModel::getChannelCount() const
+{
+    if (!m_reader) return 0;
+    return m_reader->getChannelCount();
+}
+
+sv_samplerate_t
+ReadOnlyWaveFileModel::getSampleRate() const 
+{
+    if (!m_reader) return 0;
+    return m_reader->getSampleRate();
+}
+
+sv_samplerate_t
+ReadOnlyWaveFileModel::getNativeRate() const 
+{
+    if (!m_reader) return 0;
+    sv_samplerate_t rate = m_reader->getNativeRate();
+    if (rate == 0) rate = getSampleRate();
+    return rate;
+}
+
+QString
+ReadOnlyWaveFileModel::getTitle() const
+{
+    QString title;
+    if (m_reader) title = m_reader->getTitle();
+    if (title == "") title = objectName();
+    return title;
+}
+
+QString
+ReadOnlyWaveFileModel::getMaker() const
+{
+    if (m_reader) return m_reader->getMaker();
+    return "";
+}
+
+QString
+ReadOnlyWaveFileModel::getLocation() const
+{
+    if (m_reader) return m_reader->getLocation();
+    return "";
+}
+
+QString
+ReadOnlyWaveFileModel::getLocalFilename() const
+{
+    if (m_reader) return m_reader->getLocalFilename();
+    return "";
+}
+    
+sv_frame_t
+ReadOnlyWaveFileModel::getData(int channel, sv_frame_t start, sv_frame_t count,
+                       float *buffer) const
+{
+    // Always read these directly from the file. 
+    // This is used for e.g. audio playback.
+    // Could be much more efficient (although compiler optimisation will help)
+
+#ifdef DEBUG_WAVE_FILE_MODEL
+    cout << "ReadOnlyWaveFileModel::getData[" << this << "]: " << channel << ", " << start << ", " << count << ", " << buffer << endl;
+#endif
+
+    if (start >= m_startFrame) {
+        start -= m_startFrame;
+    } else {
+        for (sv_frame_t i = 0; i < count; ++i) {
+            buffer[i] = 0.f;
+        }
+        if (count <= m_startFrame - start) {
+            return 0;
+        } else {
+            count -= (m_startFrame - start);
+            start = 0;
+        }
+    }
+
+    if (!m_reader || !m_reader->isOK() || count == 0) {
+        for (sv_frame_t i = 0; i < count; ++i) buffer[i] = 0.f;
+        return 0;
+    }
+
+#ifdef DEBUG_WAVE_FILE_MODEL
+//    SVDEBUG << "ReadOnlyWaveFileModel::getValues(" << channel << ", "
+//              << start << ", " << end << "): calling reader" << endl;
+#endif
+
+    int channels = getChannelCount();
+
+    SampleBlock frames = m_reader->getInterleavedFrames(start, count);
+
+    sv_frame_t i = 0;
+
+    int ch0 = channel, ch1 = channel;
+    if (channel == -1) {
+	ch0 = 0;
+	ch1 = channels - 1;
+    }
+    
+    while (i < count) {
+
+	buffer[i] = 0.0;
+
+	for (int ch = ch0; ch <= ch1; ++ch) {
+
+	    sv_frame_t index = i * channels + ch;
+	    if (index >= (sv_frame_t)frames.size()) break;
+            
+	    float sample = frames[index];
+	    buffer[i] += sample;
+	}
+
+	++i;
+    }
+
+    return i;
+}
+
+sv_frame_t
+ReadOnlyWaveFileModel::getMultiChannelData(int fromchannel, int tochannel,
+                                   sv_frame_t start, sv_frame_t count,
+                                   float **buffer) const
+{
+#ifdef DEBUG_WAVE_FILE_MODEL
+    cout << "ReadOnlyWaveFileModel::getData[" << this << "]: " << fromchannel << "," << tochannel << ", " << start << ", " << count << ", " << buffer << endl;
+#endif
+
+    int channels = getChannelCount();
+
+    if (fromchannel > tochannel) {
+        cerr << "ERROR: ReadOnlyWaveFileModel::getData: fromchannel ("
+                  << fromchannel << ") > tochannel (" << tochannel << ")"
+                  << endl;
+        return 0;
+    }
+
+    if (tochannel >= channels) {
+        cerr << "ERROR: ReadOnlyWaveFileModel::getData: tochannel ("
+                  << tochannel << ") >= channel count (" << channels << ")"
+                  << endl;
+        return 0;
+    }
+
+    if (fromchannel == tochannel) {
+        return getData(fromchannel, start, count, buffer[0]);
+    }
+
+    int reqchannels = (tochannel - fromchannel) + 1;
+
+    // Always read these directly from the file. 
+    // This is used for e.g. audio playback.
+    // Could be much more efficient (although compiler optimisation will help)
+
+    if (start >= m_startFrame) {
+        start -= m_startFrame;
+    } else {
+        for (int c = 0; c < reqchannels; ++c) {
+            for (sv_frame_t i = 0; i < count; ++i) buffer[c][i] = 0.f;
+        }
+        if (count <= m_startFrame - start) {
+            return 0;
+        } else {
+            count -= (m_startFrame - start);
+            start = 0;
+        }
+    }
+
+    if (!m_reader || !m_reader->isOK() || count == 0) {
+        for (int c = 0; c < reqchannels; ++c) {
+            for (sv_frame_t i = 0; i < count; ++i) buffer[c][i] = 0.f;
+        }
+        return 0;
+    }
+
+    SampleBlock frames = m_reader->getInterleavedFrames(start, count);
+
+    sv_frame_t i = 0;
+
+    sv_frame_t index = 0, available = frames.size();
+
+    while (i < count) {
+
+        if (index >= available) break;
+
+        int destc = 0;
+
+        for (int c = 0; c < channels; ++c) {
+            
+            if (c >= fromchannel && c <= tochannel) {
+                buffer[destc][i] = frames[index];
+                ++destc;
+            }
+
+            ++index;
+        }
+
+        ++i;
+    }
+
+    return i;
+}
+
+int
+ReadOnlyWaveFileModel::getSummaryBlockSize(int desired) const
+{
+    int cacheType = 0;
+    int power = m_zoomConstraint.getMinCachePower();
+    int roundedBlockSize = m_zoomConstraint.getNearestBlockSize
+        (desired, cacheType, power, ZoomConstraint::RoundDown);
+    if (cacheType != 0 && cacheType != 1) {
+        // We will be reading directly from file, so can satisfy any
+        // blocksize requirement
+        return desired;
+    } else {
+        return roundedBlockSize;
+    }
+}    
+
+void
+ReadOnlyWaveFileModel::getSummaries(int channel, sv_frame_t start, sv_frame_t count,
+                            RangeBlock &ranges, int &blockSize) const
+{
+    ranges.clear();
+    if (!isOK()) return;
+    ranges.reserve((count / blockSize) + 1);
+
+    if (start > m_startFrame) start -= m_startFrame;
+    else if (count <= m_startFrame - start) return;
+    else {
+        count -= (m_startFrame - start);
+        start = 0;
+    }
+
+    int cacheType = 0;
+    int power = m_zoomConstraint.getMinCachePower();
+    int roundedBlockSize = m_zoomConstraint.getNearestBlockSize
+        (blockSize, cacheType, power, ZoomConstraint::RoundDown);
+
+    int channels = getChannelCount();
+
+    if (cacheType != 0 && cacheType != 1) {
+
+	// We need to read directly from the file.  We haven't got
+	// this cached.  Hope the requested area is small.  This is
+	// not optimal -- we'll end up reading the same frames twice
+	// for stereo files, in two separate calls to this method.
+	// We could fairly trivially handle this for most cases that
+	// matter by putting a single cache in getInterleavedFrames
+	// for short queries.
+
+        m_directReadMutex.lock();
+
+        if (m_lastDirectReadStart != start ||
+            m_lastDirectReadCount != count ||
+            m_directRead.empty()) {
+
+            m_directRead = m_reader->getInterleavedFrames(start, count);
+            m_lastDirectReadStart = start;
+            m_lastDirectReadCount = count;
+        }
+
+	float max = 0.0, min = 0.0, total = 0.0;
+	sv_frame_t i = 0, got = 0;
+
+	while (i < count) {
+
+	    sv_frame_t index = i * channels + channel;
+	    if (index >= (sv_frame_t)m_directRead.size()) break;
+            
+	    float sample = m_directRead[index];
+            if (sample > max || got == 0) max = sample;
+	    if (sample < min || got == 0) min = sample;
+            total += fabsf(sample);
+
+	    ++i;
+            ++got;
+            
+            if (got == blockSize) {
+                ranges.push_back(Range(min, max, total / float(got)));
+                min = max = total = 0.0f;
+                got = 0;
+	    }
+	}
+
+        m_directReadMutex.unlock();
+
+	if (got > 0) {
+            ranges.push_back(Range(min, max, total / float(got)));
+	}
+
+	return;
+
+    } else {
+
+	QMutexLocker locker(&m_mutex);
+    
+	const RangeBlock &cache = m_cache[cacheType];
+
+        blockSize = roundedBlockSize;
+
+	sv_frame_t cacheBlock, div;
+        
+	if (cacheType == 0) {
+	    cacheBlock = (1 << m_zoomConstraint.getMinCachePower());
+            div = (1 << power) / cacheBlock;
+	} else {
+	    cacheBlock = sv_frame_t((1 << m_zoomConstraint.getMinCachePower()) * sqrt(2.) + 0.01);
+            div = sv_frame_t(((1 << power) * sqrt(2.) + 0.01) / double(cacheBlock));
+	}
+
+	sv_frame_t startIndex = start / cacheBlock;
+	sv_frame_t endIndex = (start + count) / cacheBlock;
+
+	float max = 0.0, min = 0.0, total = 0.0;
+	sv_frame_t i = 0, got = 0;
+
+#ifdef DEBUG_WAVE_FILE_MODEL
+	cerr << "blockSize is " << blockSize << ", cacheBlock " << cacheBlock << ", start " << start << ", count " << count << " (frame count " << getFrameCount() << "), power is " << power << ", div is " << div << ", startIndex " << startIndex << ", endIndex " << endIndex << endl;
+#endif
+
+	for (i = 0; i <= endIndex - startIndex; ) {
+        
+	    sv_frame_t index = (i + startIndex) * channels + channel;
+	    if (index >= (sv_frame_t)cache.size()) break;
+            
+            const Range &range = cache[index];
+            if (range.max() > max || got == 0) max = range.max();
+            if (range.min() < min || got == 0) min = range.min();
+            total += range.absmean();
+            
+	    ++i;
+            ++got;
+            
+	    if (got == div) {
+		ranges.push_back(Range(min, max, total / float(got)));
+                min = max = total = 0.0f;
+                got = 0;
+	    }
+	}
+		
+	if (got > 0) {
+            ranges.push_back(Range(min, max, total / float(got)));
+	}
+    }
+
+#ifdef DEBUG_WAVE_FILE_MODEL
+    SVDEBUG << "returning " << ranges.size() << " ranges" << endl;
+#endif
+    return;
+}
+
+ReadOnlyWaveFileModel::Range
+ReadOnlyWaveFileModel::getSummary(int channel, sv_frame_t start, sv_frame_t count) const
+{
+    Range range;
+    if (!isOK()) return range;
+
+    if (start > m_startFrame) start -= m_startFrame;
+    else if (count <= m_startFrame - start) return range;
+    else {
+        count -= (m_startFrame - start);
+        start = 0;
+    }
+
+    int blockSize;
+    for (blockSize = 1; blockSize <= count; blockSize *= 2);
+    if (blockSize > 1) blockSize /= 2;
+
+    bool first = false;
+
+    sv_frame_t blockStart = (start / blockSize) * blockSize;
+    sv_frame_t blockEnd = ((start + count) / blockSize) * blockSize;
+
+    if (blockStart < start) blockStart += blockSize;
+        
+    if (blockEnd > blockStart) {
+        RangeBlock ranges;
+        getSummaries(channel, blockStart, blockEnd - blockStart, ranges, blockSize);
+        for (int i = 0; i < (int)ranges.size(); ++i) {
+            if (first || ranges[i].min() < range.min()) range.setMin(ranges[i].min());
+            if (first || ranges[i].max() > range.max()) range.setMax(ranges[i].max());
+            if (first || ranges[i].absmean() < range.absmean()) range.setAbsmean(ranges[i].absmean());
+            first = false;
+        }
+    }
+
+    if (blockStart > start) {
+        Range startRange = getSummary(channel, start, blockStart - start);
+        range.setMin(std::min(range.min(), startRange.min()));
+        range.setMax(std::max(range.max(), startRange.max()));
+        range.setAbsmean(std::min(range.absmean(), startRange.absmean()));
+    }
+
+    if (blockEnd < start + count) {
+        Range endRange = getSummary(channel, blockEnd, start + count - blockEnd);
+        range.setMin(std::min(range.min(), endRange.min()));
+        range.setMax(std::max(range.max(), endRange.max()));
+        range.setAbsmean(std::min(range.absmean(), endRange.absmean()));
+    }
+
+    return range;
+}
+
+void
+ReadOnlyWaveFileModel::fillCache()
+{
+    m_mutex.lock();
+
+    m_updateTimer = new QTimer(this);
+    connect(m_updateTimer, SIGNAL(timeout()), this, SLOT(fillTimerTimedOut()));
+    m_updateTimer->start(100);
+
+    m_fillThread = new RangeCacheFillThread(*this);
+    connect(m_fillThread, SIGNAL(finished()), this, SLOT(cacheFilled()));
+
+    m_mutex.unlock();
+    m_fillThread->start();
+
+#ifdef DEBUG_WAVE_FILE_MODEL
+    SVDEBUG << "ReadOnlyWaveFileModel::fillCache: started fill thread" << endl;
+#endif
+}   
+
+void
+ReadOnlyWaveFileModel::fillTimerTimedOut()
+{
+    if (m_fillThread) {
+	sv_frame_t fillExtent = m_fillThread->getFillExtent();
+#ifdef DEBUG_WAVE_FILE_MODEL
+        SVDEBUG << "ReadOnlyWaveFileModel::fillTimerTimedOut: extent = " << fillExtent << endl;
+#endif
+	if (fillExtent > m_lastFillExtent) {
+	    emit modelChangedWithin(m_lastFillExtent, fillExtent);
+	    m_lastFillExtent = fillExtent;
+	}
+    } else {
+#ifdef DEBUG_WAVE_FILE_MODEL
+        SVDEBUG << "ReadOnlyWaveFileModel::fillTimerTimedOut: no thread" << endl;
+#endif
+	emit modelChanged();
+    }
+}
+
+void
+ReadOnlyWaveFileModel::cacheFilled()
+{
+    m_mutex.lock();
+    delete m_fillThread;
+    m_fillThread = 0;
+    delete m_updateTimer;
+    m_updateTimer = 0;
+    m_mutex.unlock();
+    if (getEndFrame() > m_lastFillExtent) {
+        emit modelChangedWithin(m_lastFillExtent, getEndFrame());
+    }
+    emit modelChanged();
+    emit ready();
+#ifdef DEBUG_WAVE_FILE_MODEL
+    SVDEBUG << "ReadOnlyWaveFileModel::cacheFilled" << endl;
+#endif
+}
+
+void
+ReadOnlyWaveFileModel::RangeCacheFillThread::run()
+{
+    int cacheBlockSize[2];
+    cacheBlockSize[0] = (1 << m_model.m_zoomConstraint.getMinCachePower());
+    cacheBlockSize[1] = (int((1 << m_model.m_zoomConstraint.getMinCachePower()) *
+                                        sqrt(2.) + 0.01));
+    
+    sv_frame_t frame = 0;
+    const sv_frame_t readBlockSize = 16384;
+    SampleBlock block;
+
+    if (!m_model.isOK()) return;
+    
+    int channels = m_model.getChannelCount();
+    bool updating = m_model.m_reader->isUpdating();
+
+    if (updating) {
+        while (channels == 0 && !m_model.m_exiting) {
+//            SVDEBUG << "ReadOnlyWaveFileModel::fill: Waiting for channels..." << endl;
+            sleep(1);
+            channels = m_model.getChannelCount();
+        }
+    }
+
+    Range *range = new Range[2 * channels];
+    float *means = new float[2 * channels];
+    int count[2];
+    count[0] = count[1] = 0;
+    for (int i = 0; i < 2 * channels; ++i) {
+        means[i] = 0.f;
+    }
+
+    bool first = true;
+
+    while (first || updating) {
+
+        updating = m_model.m_reader->isUpdating();
+        m_frameCount = m_model.getFrameCount();
+
+//        SVDEBUG << "ReadOnlyWaveFileModel::fill: frame = " << frame << ", count = " << m_frameCount << endl;
+
+        while (frame < m_frameCount) {
+
+//            SVDEBUG << "ReadOnlyWaveFileModel::fill inner loop: frame = " << frame << ", count = " << m_frameCount << ", blocksize " << readBlockSize << endl;
+
+            if (updating && (frame + readBlockSize > m_frameCount)) break;
+
+            block = m_model.m_reader->getInterleavedFrames(frame, readBlockSize);
+
+//            cerr << "block is " << block.size() << endl;
+
+            for (sv_frame_t i = 0; i < readBlockSize; ++i) {
+		
+                if (channels * i + channels > (int)block.size()) break;
+
+                for (int ch = 0; ch < channels; ++ch) {
+
+                    sv_frame_t index = channels * i + ch;
+                    float sample = block[index];
+                    
+                    for (int cacheType = 0; cacheType < 2; ++cacheType) { // cache type
+                        
+                        sv_frame_t rangeIndex = ch * 2 + cacheType;
+                        range[rangeIndex].sample(sample);
+                        means[rangeIndex] += fabsf(sample);
+                    }
+                }
+
+                //!!! this looks like a ludicrous way to do synchronisation
+                QMutexLocker locker(&m_model.m_mutex);
+
+                for (int cacheType = 0; cacheType < 2; ++cacheType) {
+
+                    if (++count[cacheType] == cacheBlockSize[cacheType]) {
+                        
+                        for (int ch = 0; ch < int(channels); ++ch) {
+                            int rangeIndex = ch * 2 + cacheType;
+                            means[rangeIndex] = means[rangeIndex] / float(count[cacheType]);
+                            range[rangeIndex].setAbsmean(means[rangeIndex]);
+                            m_model.m_cache[cacheType].push_back(range[rangeIndex]);
+                            range[rangeIndex] = Range();
+                            means[rangeIndex] = 0.f;
+                        }
+
+                        count[cacheType] = 0;
+                    }
+                }
+                
+                ++frame;
+            }
+            
+            if (m_model.m_exiting) break;
+            
+            m_fillExtent = frame;
+        }
+
+//        cerr << "ReadOnlyWaveFileModel: inner loop ended" << endl;
+
+        first = false;
+        if (m_model.m_exiting) break;
+        if (updating) {
+//            cerr << "sleeping..." << endl;
+            sleep(1);
+        }
+    }
+
+    if (!m_model.m_exiting) {
+
+        QMutexLocker locker(&m_model.m_mutex);
+
+        for (int cacheType = 0; cacheType < 2; ++cacheType) {
+
+            if (count[cacheType] > 0) {
+
+                for (int ch = 0; ch < int(channels); ++ch) {
+                    int rangeIndex = ch * 2 + cacheType;
+                    means[rangeIndex] = means[rangeIndex] / float(count[cacheType]);
+                    range[rangeIndex].setAbsmean(means[rangeIndex]);
+                    m_model.m_cache[cacheType].push_back(range[rangeIndex]);
+                    range[rangeIndex] = Range();
+                    means[rangeIndex] = 0.f;
+                }
+
+                count[cacheType] = 0;
+            }
+            
+            const Range &rr = *m_model.m_cache[cacheType].begin();
+            MUNLOCK(&rr, m_model.m_cache[cacheType].capacity() * sizeof(Range));
+        }
+    }
+    
+    delete[] means;
+    delete[] range;
+
+    m_fillExtent = m_frameCount;
+
+#ifdef DEBUG_WAVE_FILE_MODEL        
+    for (int cacheType = 0; cacheType < 2; ++cacheType) {
+        cerr << "Cache type " << cacheType << " now contains " << m_model.m_cache[cacheType].size() << " ranges" << endl;
+    }
+#endif
+}
+
+void
+ReadOnlyWaveFileModel::toXml(QTextStream &out,
+                     QString indent,
+                     QString extraAttributes) const
+{
+    Model::toXml(out, indent,
+                 QString("type=\"wavefile\" file=\"%1\" %2")
+                 .arg(encodeEntities(m_path)).arg(extraAttributes));
+}
+
+    
diff -r 020277bfafcb -r b9faee02afa5 data/model/ReadOnlyWaveFileModel.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data/model/ReadOnlyWaveFileModel.h	Wed Aug 19 17:03:31 2015 +0100
@@ -0,0 +1,134 @@
+/* -*- 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 and 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 READ_ONLY_WAVE_FILE_MODEL_H
+#define READ_ONLY_WAVE_FILE_MODEL_H
+
+#include "WaveFileModel.h"
+
+#include "base/Thread.h"
+#include <QMutex>
+#include <QTimer>
+
+#include "data/fileio/FileSource.h"
+
+#include "RangeSummarisableTimeValueModel.h"
+#include "PowerOfSqrtTwoZoomConstraint.h"
+
+#include <stdlib.h>
+
+class AudioFileReader;
+
+class ReadOnlyWaveFileModel : public WaveFileModel
+{
+    Q_OBJECT
+
+public:
+    ReadOnlyWaveFileModel(FileSource source, sv_samplerate_t targetRate = 0);
+    ReadOnlyWaveFileModel(FileSource source, AudioFileReader *reader);
+    ~ReadOnlyWaveFileModel();
+
+    bool isOK() const;
+    bool isReady(int *) const;
+
+    const ZoomConstraint *getZoomConstraint() const { return &m_zoomConstraint; }
+
+    sv_frame_t getFrameCount() const;
+    int getChannelCount() const;
+    sv_samplerate_t getSampleRate() const;
+    sv_samplerate_t getNativeRate() const;
+
+    QString getTitle() const;
+    QString getMaker() const;
+    QString getLocation() const;
+
+    QString getLocalFilename() const;
+
+    float getValueMinimum() const { return -1.0f; }
+    float getValueMaximum() const { return  1.0f; }
+
+    virtual sv_frame_t getStartFrame() const { return m_startFrame; }
+    virtual sv_frame_t getEndFrame() const { return m_startFrame + getFrameCount(); }
+
+    void setStartFrame(sv_frame_t startFrame) { m_startFrame = startFrame; }
+
+    virtual sv_frame_t getData(int channel, sv_frame_t start, sv_frame_t count,
+                               float *buffer) const;
+
+    virtual sv_frame_t getMultiChannelData(int fromchannel, int tochannel,
+                                           sv_frame_t start, sv_frame_t count,
+                                           float **buffers) const;
+
+    virtual int getSummaryBlockSize(int desired) const;
+
+    virtual void getSummaries(int channel, sv_frame_t start, sv_frame_t count,
+                              RangeBlock &ranges,
+                              int &blockSize) const;
+
+    virtual Range getSummary(int channel, sv_frame_t start, sv_frame_t count) const;
+
+    QString getTypeName() const { return tr("Wave File"); }
+
+    virtual void toXml(QTextStream &out,
+                       QString indent = "",
+                       QString extraAttributes = "") const;
+
+protected slots:
+    void fillTimerTimedOut();
+    void cacheFilled();
+    
+protected:
+    void initialize();
+
+    class RangeCacheFillThread : public Thread
+    {
+    public:
+        RangeCacheFillThread(ReadOnlyWaveFileModel &model) :
+	    m_model(model), m_fillExtent(0),
+            m_frameCount(model.getFrameCount()) { }
+    
+	sv_frame_t getFillExtent() const { return m_fillExtent; }
+        virtual void run();
+
+    protected:
+        ReadOnlyWaveFileModel &m_model;
+	sv_frame_t m_fillExtent;
+        sv_frame_t m_frameCount;
+    };
+         
+    void fillCache();
+
+    FileSource m_source;
+    QString m_path;
+    AudioFileReader *m_reader;
+    bool m_myReader;
+
+    sv_frame_t m_startFrame;
+
+    RangeBlock m_cache[2]; // interleaved at two base resolutions
+    mutable QMutex m_mutex;
+    RangeCacheFillThread *m_fillThread;
+    QTimer *m_updateTimer;
+    sv_frame_t m_lastFillExtent;
+    bool m_exiting;
+    static PowerOfSqrtTwoZoomConstraint m_zoomConstraint;
+
+    mutable SampleBlock m_directRead;
+    mutable sv_frame_t m_lastDirectReadStart;
+    mutable sv_frame_t m_lastDirectReadCount;
+    mutable QMutex m_directReadMutex;
+};    
+
+#endif
diff -r 020277bfafcb -r b9faee02afa5 data/model/WaveFileModel.cpp
--- a/data/model/WaveFileModel.cpp	Tue Aug 04 13:27:42 2015 +0100
+++ b/data/model/WaveFileModel.cpp	Wed Aug 19 17:03:31 2015 +0100
@@ -15,738 +15,7 @@
 
 #include "WaveFileModel.h"
 
-#include "fileio/AudioFileReader.h"
-#include "fileio/AudioFileReaderFactory.h"
-
-#include "system/System.h"
-
-#include "base/Preferences.h"
-
-#include <QFileInfo>
-#include <QTextStream>
-
-#include <iostream>
-#include <unistd.h>
-#include <cmath>
-#include <sndfile.h>
-
-#include <cassert>
-
-//#define DEBUG_WAVE_FILE_MODEL 1
-
-PowerOfSqrtTwoZoomConstraint
-WaveFileModel::m_zoomConstraint;
-
-WaveFileModel::WaveFileModel(FileSource source, sv_samplerate_t targetRate) :
-    m_source(source),
-    m_path(source.getLocation()),
-    m_reader(0),
-    m_myReader(true),
-    m_startFrame(0),
-    m_fillThread(0),
-    m_updateTimer(0),
-    m_lastFillExtent(0),
-    m_exiting(false),
-    m_lastDirectReadStart(0),
-    m_lastDirectReadCount(0)
+WaveFileModel::~WaveFileModel()
 {
-    m_source.waitForData();
-    if (m_source.isOK()) {
-        bool normalise = Preferences::getInstance()->getNormaliseAudio();
-        m_reader = AudioFileReaderFactory::createThreadingReader
-            (m_source, targetRate, normalise);
-        if (m_reader) {
-            SVDEBUG << "WaveFileModel::WaveFileModel: reader rate: "
-                      << m_reader->getSampleRate() << endl;
-        }
-    }
-    if (m_reader) setObjectName(m_reader->getTitle());
-    if (objectName() == "") setObjectName(QFileInfo(m_path).fileName());
-    if (isOK()) fillCache();
 }
 
-WaveFileModel::WaveFileModel(FileSource source, AudioFileReader *reader) :
-    m_source(source),
-    m_path(source.getLocation()),
-    m_reader(0),
-    m_myReader(false),
-    m_startFrame(0),
-    m_fillThread(0),
-    m_updateTimer(0),
-    m_lastFillExtent(0),
-    m_exiting(false)
-{
-    m_reader = reader;
-    if (m_reader) setObjectName(m_reader->getTitle());
-    if (objectName() == "") setObjectName(QFileInfo(m_path).fileName());
-    fillCache();
-}
-
-WaveFileModel::~WaveFileModel()
-{
-    m_exiting = true;
-    if (m_fillThread) m_fillThread->wait();
-    if (m_myReader) delete m_reader;
-    m_reader = 0;
-}
-
-bool
-WaveFileModel::isOK() const
-{
-    return m_reader && m_reader->isOK();
-}
-
-bool
-WaveFileModel::isReady(int *completion) const
-{
-    bool ready = (isOK() && (m_fillThread == 0));
-    double c = double(m_lastFillExtent) / double(getEndFrame() - getStartFrame());
-    static int prevCompletion = 0;
-    if (completion) {
-        *completion = int(c * 100.0 + 0.01);
-        if (m_reader) {
-            int decodeCompletion = m_reader->getDecodeCompletion();
-            if (decodeCompletion < 90) *completion = decodeCompletion;
-            else *completion = std::min(*completion, decodeCompletion);
-        }
-        if (*completion != 0 &&
-            *completion != 100 &&
-            prevCompletion != 0 &&
-            prevCompletion > *completion) {
-            // just to avoid completion going backwards
-            *completion = prevCompletion;
-        }
-        prevCompletion = *completion;
-    }
-#ifdef DEBUG_WAVE_FILE_MODEL
-    SVDEBUG << "WaveFileModel::isReady(): ready = " << ready << ", completion = " << (completion ? *completion : -1) << endl;
-#endif
-    return ready;
-}
-
-sv_frame_t
-WaveFileModel::getFrameCount() const
-{
-    if (!m_reader) return 0;
-    return m_reader->getFrameCount();
-}
-
-int
-WaveFileModel::getChannelCount() const
-{
-    if (!m_reader) return 0;
-    return m_reader->getChannelCount();
-}
-
-sv_samplerate_t
-WaveFileModel::getSampleRate() const 
-{
-    if (!m_reader) return 0;
-    return m_reader->getSampleRate();
-}
-
-sv_samplerate_t
-WaveFileModel::getNativeRate() const 
-{
-    if (!m_reader) return 0;
-    sv_samplerate_t rate = m_reader->getNativeRate();
-    if (rate == 0) rate = getSampleRate();
-    return rate;
-}
-
-QString
-WaveFileModel::getTitle() const
-{
-    QString title;
-    if (m_reader) title = m_reader->getTitle();
-    if (title == "") title = objectName();
-    return title;
-}
-
-QString
-WaveFileModel::getMaker() const
-{
-    if (m_reader) return m_reader->getMaker();
-    return "";
-}
-
-QString
-WaveFileModel::getLocation() const
-{
-    if (m_reader) return m_reader->getLocation();
-    return "";
-}
-
-QString
-WaveFileModel::getLocalFilename() const
-{
-    if (m_reader) return m_reader->getLocalFilename();
-    return "";
-}
-    
-sv_frame_t
-WaveFileModel::getData(int channel, sv_frame_t start, sv_frame_t count,
-                       float *buffer) const
-{
-    // Always read these directly from the file. 
-    // This is used for e.g. audio playback.
-    // Could be much more efficient (although compiler optimisation will help)
-
-#ifdef DEBUG_WAVE_FILE_MODEL
-    cout << "WaveFileModel::getData[" << this << "]: " << channel << ", " << start << ", " << count << ", " << buffer << endl;
-#endif
-
-    if (start >= m_startFrame) {
-        start -= m_startFrame;
-    } else {
-        for (sv_frame_t i = 0; i < count; ++i) {
-            buffer[i] = 0.f;
-        }
-        if (count <= m_startFrame - start) {
-            return 0;
-        } else {
-            count -= (m_startFrame - start);
-            start = 0;
-        }
-    }
-
-    if (!m_reader || !m_reader->isOK() || count == 0) {
-        for (sv_frame_t i = 0; i < count; ++i) buffer[i] = 0.f;
-        return 0;
-    }
-
-#ifdef DEBUG_WAVE_FILE_MODEL
-//    SVDEBUG << "WaveFileModel::getValues(" << channel << ", "
-//              << start << ", " << end << "): calling reader" << endl;
-#endif
-
-    int channels = getChannelCount();
-
-    SampleBlock frames = m_reader->getInterleavedFrames(start, count);
-
-    sv_frame_t i = 0;
-
-    int ch0 = channel, ch1 = channel;
-    if (channel == -1) {
-	ch0 = 0;
-	ch1 = channels - 1;
-    }
-    
-    while (i < count) {
-
-	buffer[i] = 0.0;
-
-	for (int ch = ch0; ch <= ch1; ++ch) {
-
-	    sv_frame_t index = i * channels + ch;
-	    if (index >= (sv_frame_t)frames.size()) break;
-            
-	    float sample = frames[index];
-	    buffer[i] += sample;
-	}
-
-	++i;
-    }
-
-    return i;
-}
-
-sv_frame_t
-WaveFileModel::getMultiChannelData(int fromchannel, int tochannel,
-                                   sv_frame_t start, sv_frame_t count,
-                                   float **buffer) const
-{
-#ifdef DEBUG_WAVE_FILE_MODEL
-    cout << "WaveFileModel::getData[" << this << "]: " << fromchannel << "," << tochannel << ", " << start << ", " << count << ", " << buffer << endl;
-#endif
-
-    int channels = getChannelCount();
-
-    if (fromchannel > tochannel) {
-        cerr << "ERROR: WaveFileModel::getData: fromchannel ("
-                  << fromchannel << ") > tochannel (" << tochannel << ")"
-                  << endl;
-        return 0;
-    }
-
-    if (tochannel >= channels) {
-        cerr << "ERROR: WaveFileModel::getData: tochannel ("
-                  << tochannel << ") >= channel count (" << channels << ")"
-                  << endl;
-        return 0;
-    }
-
-    if (fromchannel == tochannel) {
-        return getData(fromchannel, start, count, buffer[0]);
-    }
-
-    int reqchannels = (tochannel - fromchannel) + 1;
-
-    // Always read these directly from the file. 
-    // This is used for e.g. audio playback.
-    // Could be much more efficient (although compiler optimisation will help)
-
-    if (start >= m_startFrame) {
-        start -= m_startFrame;
-    } else {
-        for (int c = 0; c < reqchannels; ++c) {
-            for (sv_frame_t i = 0; i < count; ++i) buffer[c][i] = 0.f;
-        }
-        if (count <= m_startFrame - start) {
-            return 0;
-        } else {
-            count -= (m_startFrame - start);
-            start = 0;
-        }
-    }
-
-    if (!m_reader || !m_reader->isOK() || count == 0) {
-        for (int c = 0; c < reqchannels; ++c) {
-            for (sv_frame_t i = 0; i < count; ++i) buffer[c][i] = 0.f;
-        }
-        return 0;
-    }
-
-    SampleBlock frames = m_reader->getInterleavedFrames(start, count);
-
-    sv_frame_t i = 0;
-
-    sv_frame_t index = 0, available = frames.size();
-
-    while (i < count) {
-
-        if (index >= available) break;
-
-        int destc = 0;
-
-        for (int c = 0; c < channels; ++c) {
-            
-            if (c >= fromchannel && c <= tochannel) {
-                buffer[destc][i] = frames[index];
-                ++destc;
-            }
-
-            ++index;
-        }
-
-        ++i;
-    }
-
-    return i;
-}
-
-int
-WaveFileModel::getSummaryBlockSize(int desired) const
-{
-    int cacheType = 0;
-    int power = m_zoomConstraint.getMinCachePower();
-    int roundedBlockSize = m_zoomConstraint.getNearestBlockSize
-        (desired, cacheType, power, ZoomConstraint::RoundDown);
-    if (cacheType != 0 && cacheType != 1) {
-        // We will be reading directly from file, so can satisfy any
-        // blocksize requirement
-        return desired;
-    } else {
-        return roundedBlockSize;
-    }
-}    
-
-void
-WaveFileModel::getSummaries(int channel, sv_frame_t start, sv_frame_t count,
-                            RangeBlock &ranges, int &blockSize) const
-{
-    ranges.clear();
-    if (!isOK()) return;
-    ranges.reserve((count / blockSize) + 1);
-
-    if (start > m_startFrame) start -= m_startFrame;
-    else if (count <= m_startFrame - start) return;
-    else {
-        count -= (m_startFrame - start);
-        start = 0;
-    }
-
-    int cacheType = 0;
-    int power = m_zoomConstraint.getMinCachePower();
-    int roundedBlockSize = m_zoomConstraint.getNearestBlockSize
-        (blockSize, cacheType, power, ZoomConstraint::RoundDown);
-
-    int channels = getChannelCount();
-
-    if (cacheType != 0 && cacheType != 1) {
-
-	// We need to read directly from the file.  We haven't got
-	// this cached.  Hope the requested area is small.  This is
-	// not optimal -- we'll end up reading the same frames twice
-	// for stereo files, in two separate calls to this method.
-	// We could fairly trivially handle this for most cases that
-	// matter by putting a single cache in getInterleavedFrames
-	// for short queries.
-
-        m_directReadMutex.lock();
-
-        if (m_lastDirectReadStart != start ||
-            m_lastDirectReadCount != count ||
-            m_directRead.empty()) {
-
-            m_directRead = m_reader->getInterleavedFrames(start, count);
-            m_lastDirectReadStart = start;
-            m_lastDirectReadCount = count;
-        }
-
-	float max = 0.0, min = 0.0, total = 0.0;
-	sv_frame_t i = 0, got = 0;
-
-	while (i < count) {
-
-	    sv_frame_t index = i * channels + channel;
-	    if (index >= (sv_frame_t)m_directRead.size()) break;
-            
-	    float sample = m_directRead[index];
-            if (sample > max || got == 0) max = sample;
-	    if (sample < min || got == 0) min = sample;
-            total += fabsf(sample);
-
-	    ++i;
-            ++got;
-            
-            if (got == blockSize) {
-                ranges.push_back(Range(min, max, total / float(got)));
-                min = max = total = 0.0f;
-                got = 0;
-	    }
-	}
-
-        m_directReadMutex.unlock();
-
-	if (got > 0) {
-            ranges.push_back(Range(min, max, total / float(got)));
-	}
-
-	return;
-
-    } else {
-
-	QMutexLocker locker(&m_mutex);
-    
-	const RangeBlock &cache = m_cache[cacheType];
-
-        blockSize = roundedBlockSize;
-
-	sv_frame_t cacheBlock, div;
-        
-	if (cacheType == 0) {
-	    cacheBlock = (1 << m_zoomConstraint.getMinCachePower());
-            div = (1 << power) / cacheBlock;
-	} else {
-	    cacheBlock = sv_frame_t((1 << m_zoomConstraint.getMinCachePower()) * sqrt(2.) + 0.01);
-            div = sv_frame_t(((1 << power) * sqrt(2.) + 0.01) / double(cacheBlock));
-	}
-
-	sv_frame_t startIndex = start / cacheBlock;
-	sv_frame_t endIndex = (start + count) / cacheBlock;
-
-	float max = 0.0, min = 0.0, total = 0.0;
-	sv_frame_t i = 0, got = 0;
-
-#ifdef DEBUG_WAVE_FILE_MODEL
-	cerr << "blockSize is " << blockSize << ", cacheBlock " << cacheBlock << ", start " << start << ", count " << count << " (frame count " << getFrameCount() << "), power is " << power << ", div is " << div << ", startIndex " << startIndex << ", endIndex " << endIndex << endl;
-#endif
-
-	for (i = 0; i <= endIndex - startIndex; ) {
-        
-	    sv_frame_t index = (i + startIndex) * channels + channel;
-	    if (index >= (sv_frame_t)cache.size()) break;
-            
-            const Range &range = cache[index];
-            if (range.max() > max || got == 0) max = range.max();
-            if (range.min() < min || got == 0) min = range.min();
-            total += range.absmean();
-            
-	    ++i;
-            ++got;
-            
-	    if (got == div) {
-		ranges.push_back(Range(min, max, total / float(got)));
-                min = max = total = 0.0f;
-                got = 0;
-	    }
-	}
-		
-	if (got > 0) {
-            ranges.push_back(Range(min, max, total / float(got)));
-	}
-    }
-
-#ifdef DEBUG_WAVE_FILE_MODEL
-    SVDEBUG << "returning " << ranges.size() << " ranges" << endl;
-#endif
-    return;
-}
-
-WaveFileModel::Range
-WaveFileModel::getSummary(int channel, sv_frame_t start, sv_frame_t count) const
-{
-    Range range;
-    if (!isOK()) return range;
-
-    if (start > m_startFrame) start -= m_startFrame;
-    else if (count <= m_startFrame - start) return range;
-    else {
-        count -= (m_startFrame - start);
-        start = 0;
-    }
-
-    int blockSize;
-    for (blockSize = 1; blockSize <= count; blockSize *= 2);
-    if (blockSize > 1) blockSize /= 2;
-
-    bool first = false;
-
-    sv_frame_t blockStart = (start / blockSize) * blockSize;
-    sv_frame_t blockEnd = ((start + count) / blockSize) * blockSize;
-
-    if (blockStart < start) blockStart += blockSize;
-        
-    if (blockEnd > blockStart) {
-        RangeBlock ranges;
-        getSummaries(channel, blockStart, blockEnd - blockStart, ranges, blockSize);
-        for (int i = 0; i < (int)ranges.size(); ++i) {
-            if (first || ranges[i].min() < range.min()) range.setMin(ranges[i].min());
-            if (first || ranges[i].max() > range.max()) range.setMax(ranges[i].max());
-            if (first || ranges[i].absmean() < range.absmean()) range.setAbsmean(ranges[i].absmean());
-            first = false;
-        }
-    }
-
-    if (blockStart > start) {
-        Range startRange = getSummary(channel, start, blockStart - start);
-        range.setMin(std::min(range.min(), startRange.min()));
-        range.setMax(std::max(range.max(), startRange.max()));
-        range.setAbsmean(std::min(range.absmean(), startRange.absmean()));
-    }
-
-    if (blockEnd < start + count) {
-        Range endRange = getSummary(channel, blockEnd, start + count - blockEnd);
-        range.setMin(std::min(range.min(), endRange.min()));
-        range.setMax(std::max(range.max(), endRange.max()));
-        range.setAbsmean(std::min(range.absmean(), endRange.absmean()));
-    }
-
-    return range;
-}
-
-void
-WaveFileModel::fillCache()
-{
-    m_mutex.lock();
-
-    m_updateTimer = new QTimer(this);
-    connect(m_updateTimer, SIGNAL(timeout()), this, SLOT(fillTimerTimedOut()));
-    m_updateTimer->start(100);
-
-    m_fillThread = new RangeCacheFillThread(*this);
-    connect(m_fillThread, SIGNAL(finished()), this, SLOT(cacheFilled()));
-
-    m_mutex.unlock();
-    m_fillThread->start();
-
-#ifdef DEBUG_WAVE_FILE_MODEL
-    SVDEBUG << "WaveFileModel::fillCache: started fill thread" << endl;
-#endif
-}   
-
-void
-WaveFileModel::fillTimerTimedOut()
-{
-    if (m_fillThread) {
-	sv_frame_t fillExtent = m_fillThread->getFillExtent();
-#ifdef DEBUG_WAVE_FILE_MODEL
-        SVDEBUG << "WaveFileModel::fillTimerTimedOut: extent = " << fillExtent << endl;
-#endif
-	if (fillExtent > m_lastFillExtent) {
-	    emit modelChangedWithin(m_lastFillExtent, fillExtent);
-	    m_lastFillExtent = fillExtent;
-	}
-    } else {
-#ifdef DEBUG_WAVE_FILE_MODEL
-        SVDEBUG << "WaveFileModel::fillTimerTimedOut: no thread" << endl;
-#endif
-	emit modelChanged();
-    }
-}
-
-void
-WaveFileModel::cacheFilled()
-{
-    m_mutex.lock();
-    delete m_fillThread;
-    m_fillThread = 0;
-    delete m_updateTimer;
-    m_updateTimer = 0;
-    m_mutex.unlock();
-    if (getEndFrame() > m_lastFillExtent) {
-        emit modelChangedWithin(m_lastFillExtent, getEndFrame());
-    }
-    emit modelChanged();
-    emit ready();
-#ifdef DEBUG_WAVE_FILE_MODEL
-    SVDEBUG << "WaveFileModel::cacheFilled" << endl;
-#endif
-}
-
-void
-WaveFileModel::RangeCacheFillThread::run()
-{
-    int cacheBlockSize[2];
-    cacheBlockSize[0] = (1 << m_model.m_zoomConstraint.getMinCachePower());
-    cacheBlockSize[1] = (int((1 << m_model.m_zoomConstraint.getMinCachePower()) *
-                                        sqrt(2.) + 0.01));
-    
-    sv_frame_t frame = 0;
-    const sv_frame_t readBlockSize = 16384;
-    SampleBlock block;
-
-    if (!m_model.isOK()) return;
-    
-    int channels = m_model.getChannelCount();
-    bool updating = m_model.m_reader->isUpdating();
-
-    if (updating) {
-        while (channels == 0 && !m_model.m_exiting) {
-//            SVDEBUG << "WaveFileModel::fill: Waiting for channels..." << endl;
-            sleep(1);
-            channels = m_model.getChannelCount();
-        }
-    }
-
-    Range *range = new Range[2 * channels];
-    float *means = new float[2 * channels];
-    int count[2];
-    count[0] = count[1] = 0;
-    for (int i = 0; i < 2 * channels; ++i) {
-        means[i] = 0.f;
-    }
-
-    bool first = true;
-
-    while (first || updating) {
-
-        updating = m_model.m_reader->isUpdating();
-        m_frameCount = m_model.getFrameCount();
-
-//        SVDEBUG << "WaveFileModel::fill: frame = " << frame << ", count = " << m_frameCount << endl;
-
-        while (frame < m_frameCount) {
-
-//            SVDEBUG << "WaveFileModel::fill inner loop: frame = " << frame << ", count = " << m_frameCount << ", blocksize " << readBlockSize << endl;
-
-            if (updating && (frame + readBlockSize > m_frameCount)) break;
-
-            block = m_model.m_reader->getInterleavedFrames(frame, readBlockSize);
-
-//            cerr << "block is " << block.size() << endl;
-
-            for (sv_frame_t i = 0; i < readBlockSize; ++i) {
-		
-                if (channels * i + channels > (int)block.size()) break;
-
-                for (int ch = 0; ch < channels; ++ch) {
-
-                    sv_frame_t index = channels * i + ch;
-                    float sample = block[index];
-                    
-                    for (int cacheType = 0; cacheType < 2; ++cacheType) { // cache type
-                        
-                        sv_frame_t rangeIndex = ch * 2 + cacheType;
-                        range[rangeIndex].sample(sample);
-                        means[rangeIndex] += fabsf(sample);
-                    }
-                }
-
-                //!!! this looks like a ludicrous way to do synchronisation
-                QMutexLocker locker(&m_model.m_mutex);
-
-                for (int cacheType = 0; cacheType < 2; ++cacheType) {
-
-                    if (++count[cacheType] == cacheBlockSize[cacheType]) {
-                        
-                        for (int ch = 0; ch < int(channels); ++ch) {
-                            int rangeIndex = ch * 2 + cacheType;
-                            means[rangeIndex] = means[rangeIndex] / float(count[cacheType]);
-                            range[rangeIndex].setAbsmean(means[rangeIndex]);
-                            m_model.m_cache[cacheType].push_back(range[rangeIndex]);
-                            range[rangeIndex] = Range();
-                            means[rangeIndex] = 0.f;
-                        }
-
-                        count[cacheType] = 0;
-                    }
-                }
-                
-                ++frame;
-            }
-            
-            if (m_model.m_exiting) break;
-            
-            m_fillExtent = frame;
-        }
-
-//        cerr << "WaveFileModel: inner loop ended" << endl;
-
-        first = false;
-        if (m_model.m_exiting) break;
-        if (updating) {
-//            cerr << "sleeping..." << endl;
-            sleep(1);
-        }
-    }
-
-    if (!m_model.m_exiting) {
-
-        QMutexLocker locker(&m_model.m_mutex);
-
-        for (int cacheType = 0; cacheType < 2; ++cacheType) {
-
-            if (count[cacheType] > 0) {
-
-                for (int ch = 0; ch < int(channels); ++ch) {
-                    int rangeIndex = ch * 2 + cacheType;
-                    means[rangeIndex] = means[rangeIndex] / float(count[cacheType]);
-                    range[rangeIndex].setAbsmean(means[rangeIndex]);
-                    m_model.m_cache[cacheType].push_back(range[rangeIndex]);
-                    range[rangeIndex] = Range();
-                    means[rangeIndex] = 0.f;
-                }
-
-                count[cacheType] = 0;
-            }
-            
-            const Range &rr = *m_model.m_cache[cacheType].begin();
-            MUNLOCK(&rr, m_model.m_cache[cacheType].capacity() * sizeof(Range));
-        }
-    }
-    
-    delete[] means;
-    delete[] range;
-
-    m_fillExtent = m_frameCount;
-
-#ifdef DEBUG_WAVE_FILE_MODEL        
-    for (int cacheType = 0; cacheType < 2; ++cacheType) {
-        cerr << "Cache type " << cacheType << " now contains " << m_model.m_cache[cacheType].size() << " ranges" << endl;
-    }
-#endif
-}
-
-void
-WaveFileModel::toXml(QTextStream &out,
-                     QString indent,
-                     QString extraAttributes) const
-{
-    Model::toXml(out, indent,
-                 QString("type=\"wavefile\" file=\"%1\" %2")
-                 .arg(encodeEntities(m_path)).arg(extraAttributes));
-}
-
-    
diff -r 020277bfafcb -r b9faee02afa5 data/model/WaveFileModel.h
--- a/data/model/WaveFileModel.h	Tue Aug 04 13:27:42 2015 +0100
+++ b/data/model/WaveFileModel.h	Wed Aug 19 17:03:31 2015 +0100
@@ -13,120 +13,36 @@
     COPYING included with this distribution for more information.
 */
 
-#ifndef _WAVE_FILE_MODEL_H_
-#define _WAVE_FILE_MODEL_H_
-
-#include "base/Thread.h"
-#include <QMutex>
-#include <QTimer>
-
-#include "data/fileio/FileSource.h"
+#ifndef WAVE_FILE_MODEL_H
+#define WAVE_FILE_MODEL_H
 
 #include "RangeSummarisableTimeValueModel.h"
-#include "PowerOfSqrtTwoZoomConstraint.h"
 
 #include <stdlib.h>
 
-class AudioFileReader;
-
 class WaveFileModel : public RangeSummarisableTimeValueModel
 {
     Q_OBJECT
 
 public:
-    WaveFileModel(FileSource source, sv_samplerate_t targetRate = 0);
-    WaveFileModel(FileSource source, AudioFileReader *reader);
-    ~WaveFileModel();
+    virtual ~WaveFileModel();
 
-    bool isOK() const;
-    bool isReady(int *) const;
+    virtual sv_frame_t getFrameCount() const = 0;
+    virtual int getChannelCount() const = 0;
+    virtual sv_samplerate_t getSampleRate() const = 0;
+    virtual sv_samplerate_t getNativeRate() const = 0;
 
-    const ZoomConstraint *getZoomConstraint() const { return &m_zoomConstraint; }
+    virtual QString getTitle() const = 0;
+    virtual QString getMaker() const = 0;
+    virtual QString getLocation() const = 0;
 
-    sv_frame_t getFrameCount() const;
-    int getChannelCount() const;
-    sv_samplerate_t getSampleRate() const;
-    sv_samplerate_t getNativeRate() const;
+    virtual sv_frame_t getStartFrame() const = 0;
+    virtual sv_frame_t getEndFrame() const = 0;
 
-    QString getTitle() const;
-    QString getMaker() const;
-    QString getLocation() const;
+    virtual void setStartFrame(sv_frame_t startFrame) = 0;
 
-    QString getLocalFilename() const;
-
-    float getValueMinimum() const { return -1.0f; }
-    float getValueMaximum() const { return  1.0f; }
-
-    virtual sv_frame_t getStartFrame() const { return m_startFrame; }
-    virtual sv_frame_t getEndFrame() const { return m_startFrame + getFrameCount(); }
-
-    void setStartFrame(sv_frame_t startFrame) { m_startFrame = startFrame; }
-
-    virtual sv_frame_t getData(int channel, sv_frame_t start, sv_frame_t count,
-                               float *buffer) const;
-
-    virtual sv_frame_t getMultiChannelData(int fromchannel, int tochannel,
-                                           sv_frame_t start, sv_frame_t count,
-                                           float **buffers) const;
-
-    virtual int getSummaryBlockSize(int desired) const;
-
-    virtual void getSummaries(int channel, sv_frame_t start, sv_frame_t count,
-                              RangeBlock &ranges,
-                              int &blockSize) const;
-
-    virtual Range getSummary(int channel, sv_frame_t start, sv_frame_t count) const;
-
-    QString getTypeName() const { return tr("Wave File"); }
-
-    virtual void toXml(QTextStream &out,
-                       QString indent = "",
-                       QString extraAttributes = "") const;
-
-protected slots:
-    void fillTimerTimedOut();
-    void cacheFilled();
-    
 protected:
-    void initialize();
-
-    class RangeCacheFillThread : public Thread
-    {
-    public:
-        RangeCacheFillThread(WaveFileModel &model) :
-	    m_model(model), m_fillExtent(0),
-            m_frameCount(model.getFrameCount()) { }
-    
-	sv_frame_t getFillExtent() const { return m_fillExtent; }
-        virtual void run();
-
-    protected:
-        WaveFileModel &m_model;
-	sv_frame_t m_fillExtent;
-        sv_frame_t m_frameCount;
-    };
-         
-    void fillCache();
-
-    FileSource m_source;
-    QString m_path;
-    AudioFileReader *m_reader;
-    bool m_myReader;
-
-    sv_frame_t m_startFrame;
-
-    RangeBlock m_cache[2]; // interleaved at two base resolutions
-    mutable QMutex m_mutex;
-    RangeCacheFillThread *m_fillThread;
-    QTimer *m_updateTimer;
-    sv_frame_t m_lastFillExtent;
-    bool m_exiting;
-    static PowerOfSqrtTwoZoomConstraint m_zoomConstraint;
-
-    mutable SampleBlock m_directRead;
-    mutable sv_frame_t m_lastDirectReadStart;
-    mutable sv_frame_t m_lastDirectReadCount;
-    mutable QMutex m_directReadMutex;
+    WaveFileModel() { } // only accessible from subclasses
 };    
 
 #endif
diff -r 020277bfafcb -r b9faee02afa5 data/model/WritableWaveFileModel.cpp
--- a/data/model/WritableWaveFileModel.cpp	Tue Aug 04 13:27:42 2015 +0100
+++ b/data/model/WritableWaveFileModel.cpp	Wed Aug 19 17:03:31 2015 +0100
@@ -15,6 +15,8 @@
 
 #include "WritableWaveFileModel.h"
 
+#include "ReadOnlyWaveFileModel.h"
+
 #include "base/TempDirectory.h"
 #include "base/Exceptions.h"
 
@@ -74,7 +76,7 @@
         return;
     }
     
-    m_model = new WaveFileModel(source, m_reader);
+    m_model = new ReadOnlyWaveFileModel(source, m_reader);
     if (!m_model->isOK()) {
         cerr << "WritableWaveFileModel: Error in creating wave file model" << endl;
         delete m_model;
diff -r 020277bfafcb -r b9faee02afa5 data/model/WritableWaveFileModel.h
--- a/data/model/WritableWaveFileModel.h	Tue Aug 04 13:27:42 2015 +0100
+++ b/data/model/WritableWaveFileModel.h	Wed Aug 19 17:03:31 2015 +0100
@@ -13,15 +13,17 @@
     COPYING included with this distribution for more information.
 */
 
-#ifndef _WRITABLE_WAVE_FILE_MODEL_H_
-#define _WRITABLE_WAVE_FILE_MODEL_H_
+#ifndef WRITABLE_WAVE_FILE_MODEL_H
+#define WRITABLE_WAVE_FILE_MODEL_H
 
 #include "WaveFileModel.h"
+#include "ReadOnlyWaveFileModel.h"
+#include "PowerOfSqrtTwoZoomConstraint.h"
 
 class WavFileWriter;
 class WavFileReader;
 
-class WritableWaveFileModel : public RangeSummarisableTimeValueModel
+class WritableWaveFileModel : public WaveFileModel
 {
     Q_OBJECT
 
@@ -51,6 +53,20 @@
     sv_frame_t getFrameCount() const;
     int getChannelCount() const { return m_channels; }
     sv_samplerate_t getSampleRate() const { return m_sampleRate; }
+    sv_samplerate_t getNativeRate() const { return m_sampleRate; }
+
+    QString getTitle() const {
+        if (m_model) return m_model->getTitle();
+        else return "";
+    } 
+    QString getMaker() const {
+        if (m_model) return m_model->getMaker();
+        else return "";
+    }
+    QString getLocation() const {
+        if (m_model) return m_model->getLocation();
+        else return "";
+    }
 
     float getValueMinimum() const { return -1.0f; }
     float getValueMaximum() const { return  1.0f; }
@@ -81,7 +97,7 @@
                        QString extraAttributes = "") const;
 
 protected:
-    WaveFileModel *m_model;
+    ReadOnlyWaveFileModel *m_model;
     WavFileWriter *m_writer;
     WavFileReader *m_reader;
     sv_samplerate_t m_sampleRate;
diff -r 020277bfafcb -r b9faee02afa5 rdf/RDFImporter.cpp
--- a/rdf/RDFImporter.cpp	Tue Aug 04 13:27:42 2015 +0100
+++ b/rdf/RDFImporter.cpp	Wed Aug 19 17:03:31 2015 +0100
@@ -30,7 +30,7 @@
 #include "data/model/NoteModel.h"
 #include "data/model/TextModel.h"
 #include "data/model/RegionModel.h"
-#include "data/model/WaveFileModel.h"
+#include "data/model/ReadOnlyWaveFileModel.h"
 
 #include "data/fileio/FileSource.h"
 #include "data/fileio/CachedFile.h"
@@ -270,7 +270,7 @@
             reporter->setMessage(RDFImporter::tr("Importing audio referenced in RDF..."));
         }
         fs->waitForData();
-        WaveFileModel *newModel = new WaveFileModel(*fs, m_sampleRate);
+        ReadOnlyWaveFileModel *newModel = new ReadOnlyWaveFileModel(*fs, m_sampleRate);
         if (newModel->isOK()) {
             cerr << "Successfully created wave file model from source at \"" << source << "\"" << endl;
             models.push_back(newModel);
diff -r 020277bfafcb -r b9faee02afa5 svcore.pro
--- a/svcore.pro	Tue Aug 04 13:27:42 2015 +0100
+++ b/svcore.pro	Wed Aug 19 17:03:31 2015 +0100
@@ -180,6 +180,7 @@
            data/model/TabularModel.h \
            data/model/TextModel.h \
            data/model/WaveFileModel.h \
+           data/model/ReadOnlyWaveFileModel.h \
            data/model/WritableWaveFileModel.h \
            data/osc/OSCMessage.h \
            data/osc/OSCQueue.h 
@@ -224,6 +225,7 @@
            data/model/PowerOfTwoZoomConstraint.cpp \
            data/model/RangeSummarisableTimeValueModel.cpp \
            data/model/WaveFileModel.cpp \
+           data/model/ReadOnlyWaveFileModel.cpp \
            data/model/WritableWaveFileModel.cpp \
            data/osc/OSCMessage.cpp \
            data/osc/OSCQueue.cpp