[Chromecast] Complete PostProcessingPipeline changes

chromecast/public/media/audio_post_processor_shlib.h

 // Copyright 2017 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 CHROMECAST_PUBLIC_MEDIA_AUDIO_POST_PROCESSOR_SHLIB_H_
 #define CHROMECAST_PUBLIC_MEDIA_AUDIO_POST_PROCESSOR_SHLIB_H_
 
 #include <string>
 
 #include "chromecast_export.h"
@@ skipping 27 matching lines @@
   // Returns |false| if the processor cannot support |sample_rate|
   // Returning false will result in crashing cast_shell.
   virtual bool SetSampleRate(int sample_rate) = 0;
 
   // Processes audio frames from |data|, overwriting contents.
   // |data| will always be 32-bit planar float.
   // |frames| is the number of audio frames in data and is
   // always non-zero and less than or equal to 20ms of audio.
   // AudioPostProcessor must always provide |frames| frames of data back
   // (may output 0’s)
-  // |volume| is the attenuation level (multiplier) of the stream.
-  // |volume| is between 0 and 1 inclusive.
+  // |volume| is the Cast Volume applied to the stream (normalized to 0-1)
   // AudioPostProcessor should assume that it has already been applied.
-  // TODO(bshaya): Change |volume| to Cast System Volume.
   // Returns the current rendering delay of the filter in frames,
   // or negative if an error occurred during processing.
   // If an error occurred during processing, |data| should be unchanged.
   virtual int ProcessFrames(const std::vector<float*>& data,
                             int frames,
                             float volume) = 0;
 
   // Returns the number of frames of silence it will take for the
   // processor to come to rest.
   // This may be the actual number of frames stored,
   // or may be calculated from internal resonators or similar.
   // When inputs are paused, at least this |GetRingingTimeInFrames()| of
   // silence will be passed through the processor.
   // This is not expected to be real-time;
   // It should only change when SetSampleRate is called.
   virtual int GetRingingTimeInFrames() = 0;
 
   virtual ~AudioPostProcessor() = default;
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_PUBLIC_MEDIA_AUDIO_POST_PROCESSOR_SHLIB_H_