comparison data/model/WritableWaveFileModel.h @ 1520:954d0cf29ca7 import-audio-data

Switch the normalisation option in WritableWaveFileModel from normalising on read to normalising on write, so that the saved file is already normalised and therefore can be read again without having to remember to normalise it

 class WritableWaveFileModel : public WaveFileModel
 {
     Q_OBJECT
 
 public:
+    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,
-                          QString path = "",
-                          bool normaliseOnRead = false);
+                          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.

                        QString indent = "",
                        QString extraAttributes = "") const;
 
 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