Varispeed support for SincResampler.

media/base/multi_channel_resampler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_MULTI_CHANNEL_RESAMPLER_H_
 #define MEDIA_BASE_MULTI_CHANNEL_RESAMPLER_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 17 matching lines @@
   // Constructs a MultiChannelResampler with the specified |read_cb|, which is
   // used to acquire audio data for resampling.  |io_sample_rate_ratio| is the
   // ratio of input / output sample rates.
   MultiChannelResampler(int channels, double io_sample_rate_ratio,
                         const ReadCB& read_cb);
   virtual ~MultiChannelResampler();
 
   // Resamples |frames| of data from |read_cb_| into AudioBus.
   void Resample(AudioBus* audio_bus, int frames);
 
-  // Flush all buffered data and reset internal indices.
+  // Flush all buffered data and reset internal indices.  Not thread safe, do
+  // not call while Resample() is in progress.
   void Flush();
 
+  // Update ratio for all SincResamplers.  SetRatio() will cause reconstruction
+  // of the kernels used for resampling.  Not thread safe, do not call while
+  // Resample() is in progress.
+  void SetRatio(double io_sample_rate_ratio);
+
  private:
   // SincResampler::ReadCB implementation.  ProvideInput() will be called for
   // each channel (in channel order) as SincResampler needs more data.
   void ProvideInput(int channel, float* destination, int frames);
 
   // Sanity check to ensure that ProvideInput() retrieves the same number of
   // frames for every channel.
   int last_frame_count_;
 
   // Source of data for resampling.
@@ skipping 10 matching lines @@
   // The number of output frames that have successfully been processed during
   // the current Resample() call.
   int output_frames_ready_;
 
   DISALLOW_COPY_AND_ASSIGN(MultiChannelResampler);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MULTI_CHANNEL_RESAMPLER_H_