Clean up audio-related utility functions to compute buffer sizes

media/audio/audio_util.cc

 // 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.
 
 // Software adjust volume of samples, allows each audio stream its own
 // volume without impacting master volume for chrome and other applications.
 
 // Implemented as templates to allow 8, 16 and 32 bit implementations.
 // 8 bit is unsigned and biased by 128.
 
@@ skipping 420 matching lines @@
       break;
     case 1:
       DoCrossfade(bytes_to_crossfade, number_of_channels, bytes_per_channel,
                   src, dest);
       break;
     default:
       NOTREACHED() << "Unsupported audio bit depth in crossfade.";
   }
 }
 
-// The minimum number of samples in a hardware packet.
-// This value is selected so that we can handle down to 5khz sample rate.
-static const int kMinSamplesPerHardwarePacket = 1024;
-
-// The maximum number of samples in a hardware packet.
-// This value is selected so that we can handle up to 192khz sample rate.
-static const int kMaxSamplesPerHardwarePacket = 64 * 1024;
-
-// This constant governs the hardware audio buffer size, this value should be
-// chosen carefully.
-// This value is selected so that we have 8192 samples for 48khz streams.
-static const int kMillisecondsPerHardwarePacket = 170;
-
-uint32 SelectSamplesPerPacket(int sample_rate) {
-  // Select the number of samples that can provide at least
-  // |kMillisecondsPerHardwarePacket| worth of audio data.
-  int samples = kMinSamplesPerHardwarePacket;
-  while (samples <= kMaxSamplesPerHardwarePacket &&
-         samples * base::Time::kMillisecondsPerSecond <
-         sample_rate * kMillisecondsPerHardwarePacket) {
-    samples *= 2;
-  }
-  return samples;
-}
-
 }  // namespace media