remoting/host/audio_silence_detector.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef REMOTING_HOST_AUDIO_SILENCE_DETECTOR_H_
   6 #define REMOTING_HOST_AUDIO_SILENCE_DETECTOR_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/logging.h"
  10
  11 namespace remoting {
  12
  13 // Helper used in audio capturers to detect and drop silent audio packets.
  14 class AudioSilenceDetector {
  15  public:
  16   // |threshold| is used to specify maximum absolute sample value that should
  17   // still be considered as silence.
  18   explicit AudioSilenceDetector(int threshold);
  19   ~AudioSilenceDetector();
  20
  21   void Reset(int sampling_rate, int channels);
  22
  23   // Must be called for each new chunk of data. Return true the given packet
  24   // is silence should be dropped.
  25   bool IsSilence(const int16* samples, size_t samples_count);
  26
  27  private:
  28   // Maximum absolute sample value that should still be considered as silence.
  29   int threshold_;
  30
  31   // Silence period threshold in samples. Silence intervals shorter than this
  32   // value are still encoded and sent to the client, so that we don't disrupt
  33   // playback by dropping them.
  34   int silence_length_max_;
  35
  36   // Lengths of the current silence period in samples.
  37   int silence_length_;
  38 };
  39
  40 }  // namespace remoting
  41
  42 #endif  // REMOTING_HOST_AUDIO_SILENCE_DETECTOR_H_