src/apps/mediaplayer/media_node_framework/audio/AudioResampler.h

   1 /*
   2  * Copyright 2000-2006 Ingo Weinhold <ingo_weinhold@gmx.de>
   3  * All rights reserved. Distributed under the terms of the MIT licensce.
   4  */
   5 #ifndef AUDIO_RESAMPLER_H
   6 #define AUDIO_RESAMPLER_H
   7
   8
   9 /*! This AudioReader does both resampling an audio source to a different
  10         sample rate and rescaling the time, e.g. it is possible to convert the
  11         source data from 41.1 KHz to 96 KHz played backward twice as fast
  12         (time scale = -2).
  13 */
  14
  15
  16 #include "AudioReader.h"
  17
  18
  19 class AudioResampler : public AudioReader {
  20 public:
  21                                                                 AudioResampler();
  22                                                                 AudioResampler(AudioReader* source,
  23                                                                         float frameRate, float timeScale = 1.0);
  24         virtual                                         ~AudioResampler();
  25
  26         virtual bigtime_t                       InitialLatency() const;
  27         virtual status_t                        Read(void* buffer, int64 pos, int64 frames);
  28
  29         virtual status_t                        InitCheck() const;
  30
  31                         void                            SetSource(AudioReader* source);
  32                         void                            SetFrameRate(float frameRate);
  33                         void                            SetTimeScale(float timeScale);
  34
  35                         AudioReader*            Source() const;
  36                         float                           FrameRate() const;
  37                         float                           TimeScale() const;
  38
  39                         void                            SetInOffset(int64 offset);
  40                         int64                           InOffset() const;
  41
  42                         int64                           ConvertFromSource(int64 pos) const;
  43                         int64                           ConvertToSource(int64 pos) const;
  44
  45 private:
  46                         status_t                        _ReadLinear(void* buffer, int64 pos,
  47                                                                         int64 frames);
  48
  49 private:
  50                         AudioReader*            fSource;
  51                         float                           fTimeScale;     // speed
  52                         int64                           fInOffset;
  53 };
  54
  55 #endif  // AUDIO_RESAMPLER_H