diff data/model/WritableWaveFileModel.h @ 1527:710e6250a401 zoom

Merge from default branch

--- a/data/model/WritableWaveFileModel.h	Mon Dec 12 15:18:52 2016 +0000
+++ b/data/model/WritableWaveFileModel.h	Mon Sep 17 13:51:14 2018 +0100
@@ -28,18 +28,88 @@
     Q_OBJECT
 
 public:
-    WritableWaveFileModel(sv_samplerate_t sampleRate, int channels, QString path = "");
+    enum class Normalisation { None, Peak };
+
+    /**
+     * Create a WritableWaveFileModel of the given sample rate and
+     * channel count, storing data in a new float-type extended WAV
+     * file with the given path. If path is the empty string, the data
+     * will be stored in a newly-created temporary file.
+     *
+     * If normalisation == None, sample values will be written
+     * verbatim, and will be ready to read as soon as they have been
+     * written. Otherwise samples will be normalised on writing; this
+     * will require an additional pass and temporary file, and no
+     * samples will be available to read until after writeComplete()
+     * has returned.
+     */
+    WritableWaveFileModel(QString path,
+                          sv_samplerate_t sampleRate,
+                          int channels,
+                          Normalisation normalisation);
+    
+    /**
+     * Create a WritableWaveFileModel of the given sample rate and
+     * channel count, storing data in a new float-type extended WAV
+     * file in a temporary location. This is equivalent to passing an
+     * empty path to the constructor above.
+     *
+     * If normalisation == None, sample values will be written
+     * verbatim, and will be ready to read as soon as they have been
+     * written. Otherwise samples will be normalised on writing; this
+     * will require an additional pass and temporary file, and no
+     * samples will be available to read until after writeComplete()
+     * has returned.
+     */
+    WritableWaveFileModel(sv_samplerate_t sampleRate,
+                          int channels,
+                          Normalisation normalisation);
+
+    /**
+     * Create a WritableWaveFileModel of the given sample rate and
+     * channel count, storing data in a new float-type extended WAV
+     * file in a temporary location, and applying no normalisation.
+     *
+     * This is equivalent to passing an empty path and
+     * Normalisation::None to the first constructor above.
+     */
+    WritableWaveFileModel(sv_samplerate_t sampleRate,
+                          int channels);
+
     ~WritableWaveFileModel();
 
     /**
      * Call addSamples to append a block of samples to the end of the
-     * file.  Caller should also call setWriteProportion() to update
-     * the progress of this file, if it has a known end point, and
-     * should call writeComplete() when the file has been written.
+     * file.
+     *
+     * This function only appends the samples to the file being
+     * written; it does not update the model's view of the samples in
+     * that file. That is, it updates the file on disc but the model
+     * itself does not change its content. This is because re-reading
+     * the file to update the model may be more expensive than adding
+     * the samples in the first place. If you are writing small
+     * numbers of samples repeatedly, you probably only want the model
+     * to update periodically rather than after every write.
+     *
+     * Call updateModel() periodically to tell the model to update its
+     * own view of the samples in the file being written.
+     *
+     * Call setWriteProportion() periodically if the file being
+     * written has known duration and you want the model to be able to
+     * report the write progress as a percentage.
+     *
+     * Call writeComplete() when the file has been completely written.
      */
-    virtual bool addSamples(float **samples, sv_frame_t count);
+    virtual bool addSamples(const float *const *samples, sv_frame_t count);
 
     /**
+     * Tell the model to update its own (read) view of the (written)
+     * file. May cause modelChanged() and modelChangedWithin() to be
+     * emitted. See the comment to addSamples above for rationale.
+     */
+    void updateModel();
+    
+    /**
      * Set the proportion of the file which has been written so far,
      * as a percentage. This may be used to indicate progress.
      *
@@ -56,7 +126,7 @@
 
     /**
      * Indicate that writing is complete. You should call this even if
-     * you have never called setWriteProportion().
+     * you have never called setWriteProportion() or updateModel().
      */
     void writeComplete();
 
@@ -110,9 +180,9 @@
 
     void setStartFrame(sv_frame_t startFrame);
 
-    virtual std::vector<float> getData(int channel, sv_frame_t start, sv_frame_t count) const;
+    virtual floatvec_t getData(int channel, sv_frame_t start, sv_frame_t count) const;
 
-    virtual std::vector<std::vector<float>> getMultiChannelData(int fromchannel, int tochannel, sv_frame_t start, sv_frame_t count) const;
+    virtual std::vector<floatvec_t> getMultiChannelData(int fromchannel, int tochannel, sv_frame_t start, sv_frame_t count) const;
 
     virtual int getSummaryBlockSize(int desired) const;
 
@@ -129,13 +199,35 @@
 
 protected:
     ReadOnlyWaveFileModel *m_model;
-    WavFileWriter *m_writer;
+
+    /** When normalising, this writer is used to write verbatim
+     *  samples to the temporary file prior to
+     *  normalisation. Otherwise it's null
+     */
+    WavFileWriter *m_temporaryWriter;
+    QString m_temporaryPath;
+
+    /** When not normalising, this writer is used to write verbatim
+     *  samples direct to the target file. When normalising, it is
+     *  used to write normalised samples to the target after the
+     *  temporary file has been completed. But it is still created on
+     *  initialisation, so that there is a file header ready for the
+     *  reader to address.
+     */
+    WavFileWriter *m_targetWriter;
+    QString m_targetPath;
+
     WavFileReader *m_reader;
+    Normalisation m_normalisation;
     sv_samplerate_t m_sampleRate;
     int m_channels;
     sv_frame_t m_frameCount;
     sv_frame_t m_startFrame;
     int m_proportion;
+
+private:
+    void init(QString path = "");
+    void normaliseToTarget();
 };
 
 #endif