webrtc/modules/audio_device/android/audio_common.h

/*
 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_COMMON_H_
#define WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_COMMON_H_

namespace webrtc {

enum {
  kDefaultSampleRate = 44100,
  kNumChannels = 1,
  // Number of bytes per audio frame.
  // Example: 16-bit PCM in mono => 1*(16/8)=2 [bytes/frame]
  kBytesPerFrame = kNumChannels * (16 / 8),
  // Delay estimates for the two different supported modes. These values
  // are based on real-time round-trip delay estimates on a large set of
  // devices and they are lower bounds since the filter length is 128 ms,
  // so the AEC works for delays in the range [50, ~170] ms and [150, ~270] ms.
  // Note that, in most cases, the lowest delay estimate will not be utilized
  // since devices that support low-latency output audio often supports
  // HW AEC as well.
  kLowLatencyModeDelayEstimateInMilliseconds = 50,
  kHighLatencyModeDelayEstimateInMilliseconds = 150,
};

}  // namespace webrtc

#endif  // WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_COMMON_H_