Simplified AudioOutputStream interface.

media/audio/audio_parameters.h

 // Copyright (c) 2010 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_AUDIO_AUDIO_PARAMETERS_H_
 #define MEDIA_AUDIO_AUDIO_PARAMETERS_H_
 
 #include "base/basictypes.h"
 
 struct AudioParameters {
   enum Format {
     AUDIO_PCM_LINEAR = 0,     // PCM is 'raw' amplitude samples.
     AUDIO_PCM_LOW_LATENCY,    // Linear PCM, low latency requested.
     AUDIO_MOCK,               // Creates a dummy AudioOutputStream object.
     AUDIO_LAST_FORMAT         // Only used for validation of format.
   };
 
   // Telephone quality sample rate, mostly for speech-only audio.
   static const uint32 kTelephoneSampleRate = 8000;
   // CD sampling rate is 44.1 KHz or conveniently 2x2x3x3x5x5x7x7.
   static const uint32 kAudioCDSampleRate = 44100;
   // Digital Audio Tape sample rate.
   static const uint32 kAudioDATSampleRate = 48000;
 
   AudioParameters();
 
-  AudioParameters(Format format, int channels,
-                  int sample_rate, int bits_per_sample);
+  AudioParameters(Format format, int channels, int sample_rate,
+                  int bits_per_sample, int samples_per_packet);
 
+  // Checks that all values are in the expected range. All limits are specified
+  // in media::Limits.
   bool IsValid() const;
 
-  Format format;        // Format of the stream.
-  int channels;         // Number of channels.
-  int sample_rate;      // Sampling frequency/rate.
-  int bits_per_sample;  // Number of bits per sample.
+  // Returns size of audio packets in bytes.
+  int GetPacketSize() const;
+
+  Format format;           // Format of the stream.
+  int channels;            // Number of channels.
+  int sample_rate;         // Sampling frequency/rate.
+  int bits_per_sample;     // Number of bits per sample.
+  int samples_per_packet;  // Size of a packet in frames.
 };
 
 #endif  // MEDIA_AUDIO_AUDIO_PARAMETERS_H_