view data/fileio/CodedAudioFileReader.h @ 1196:c7b9c902642f spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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.
*/

#ifndef _CODED_AUDIO_FILE_READER_H_
#define _CODED_AUDIO_FILE_READER_H_

#include "AudioFileReader.h"

#include <sndfile.h>
#include <QMutex>
#include <QReadWriteLock>

class WavFileReader;
class Serialiser;
class Resampler;

class CodedAudioFileReader : public AudioFileReader
{
    Q_OBJECT

public:
    virtual ~CodedAudioFileReader();

    enum CacheMode {
        CacheInTemporaryFile,
        CacheInMemory
    };

    enum DecodeMode {
        DecodeAtOnce, // decode the file on construction, with progress 
        DecodeThreaded // decode in a background thread after construction
    };

    virtual std::vector<float> getInterleavedFrames(sv_frame_t start, sv_frame_t count) const;

    virtual sv_samplerate_t getNativeRate() const { return m_fileRate; }

    virtual QString getLocalFilename() const { return m_cacheFileName; }
    
    /// Intermediate cache means all CodedAudioFileReaders are quickly seekable
    virtual bool isQuicklySeekable() const { return true; }

signals:
    void progress(int);

protected:
    CodedAudioFileReader(CacheMode cacheMode, 
                         sv_samplerate_t targetRate,
                         bool normalised);

    void initialiseDecodeCache(); // samplerate, channels must have been set

    // may throw InsufficientDiscSpace:
    void addSamplesToDecodeCache(float **samples, sv_frame_t nframes);
    void addSamplesToDecodeCache(float *samplesInterleaved, sv_frame_t nframes);
    void addSamplesToDecodeCache(const std::vector<float> &interleaved);

    // may throw InsufficientDiscSpace:
    void finishDecodeCache();

    bool isDecodeCacheInitialised() const { return m_initialised; }

    void startSerialised(QString id);
    void endSerialised();

private:
    void pushBuffer(float *interleaved, sv_frame_t sz, bool final);
    void pushBufferResampling(float *interleaved, sv_frame_t sz, double ratio, bool final);
    void pushBufferNonResampling(float *interleaved, sv_frame_t sz);

protected:
    QMutex m_cacheMutex;
    CacheMode m_cacheMode;
    std::vector<float> m_data;
    mutable QMutex m_dataLock;
    bool m_initialised;
    Serialiser *m_serialiser;
    sv_samplerate_t m_fileRate;

    QString m_cacheFileName;
    SNDFILE *m_cacheFileWritePtr;
    WavFileReader *m_cacheFileReader;
    float *m_cacheWriteBuffer;
    sv_frame_t m_cacheWriteBufferIndex;
    sv_frame_t m_cacheWriteBufferSize; // frames

    Resampler *m_resampler;
    float *m_resampleBuffer;
    sv_frame_t m_fileFrameCount;

    bool m_normalised;
    float m_max;
    float m_gain;
};

#endif