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Classes common for multiple Ant Media projects
/*
* Copyright (c) 2015 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.
*/
package org.webrtc.audio;
/**
* This class contains static functions to query sample rate and input/output audio buffer sizes.
*/
class WebRtcAudioManager {
private static final String TAG = "WebRtcAudioManagerExternal";
//TODO: We may use different sample rate?
private static final int DEFAULT_SAMPLE_RATE_HZ = 16000;
// Default audio data format is PCM 16 bit per sample.
// Guaranteed to be supported by all devices.
private static final int BITS_PER_SAMPLE = 16;
private static final int DEFAULT_FRAME_PER_BUFFER = 256;
//@CalledByNative
static Object getAudioManager(Object context) {
//return (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
return null;
}
//@CalledByNative
static int getOutputBufferSize(
Object context, Object audioManager, int sampleRate, int numberOfOutputChannels) {
// return isLowLatencyOutputSupported(context)
// ? getLowLatencyFramesPerBuffer(audioManager)
// : getMinOutputFrameSize(sampleRate, numberOfOutputChannels);
return DEFAULT_FRAME_PER_BUFFER;
}
//@CalledByNative
static int getInputBufferSize(
Object context, Object audioManager, int sampleRate, int numberOfInputChannels) {
// return isLowLatencyInputSupported(context)
// ? getLowLatencyFramesPerBuffer(audioManager)
// : getMinInputFrameSize(sampleRate, numberOfInputChannels);
return DEFAULT_FRAME_PER_BUFFER;
}
// private static boolean isLowLatencyOutputSupported(Context context) {
// return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_AUDIO_LOW_LATENCY);
// }
// private static boolean isLowLatencyInputSupported(Context context) {
// // TODO(henrika): investigate if some sort of device list is needed here
// // as well. The NDK doc states that: "As of API level 21, lower latency
// // audio input is supported on select devices. To take advantage of this
// // feature, first confirm that lower latency output is available".
// return Build.VERSION.SDK_INT >= 21 && isLowLatencyOutputSupported(context);
// }
/**
* Returns the native input/output sample rate for this device's output stream.
*/
//@CalledByNative
static int getSampleRate(Object audioManager) {
// Override this if we're running on an old emulator image which only
// supports 8 kHz and doesn't support PROPERTY_OUTPUT_SAMPLE_RATE.
// if (WebRtcAudioUtils.runningOnEmulator()) {
// Logging.d(TAG, "Running emulator, overriding sample rate to 8 kHz.");
// return 8000;
// }
// // Deliver best possible estimate based on default Android AudioManager APIs.
// final int sampleRateHz = getSampleRateForApiLevel(audioManager);
// Logging.d(TAG, "Sample rate is set to " + sampleRateHz + " Hz");
// return sampleRateHz;
return DEFAULT_SAMPLE_RATE_HZ;
}
// private static int getSampleRateForApiLevel(AudioManager audioManager) {
// if (Build.VERSION.SDK_INT < 17) {
// return DEFAULT_SAMPLE_RATE_HZ;
// }
// String sampleRateString = audioManager.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE);
// return (sampleRateString == null) ? DEFAULT_SAMPLE_RATE_HZ : Integer.parseInt(sampleRateString);
// }
//
// // Returns the native output buffer size for low-latency output streams.
// private static int getLowLatencyFramesPerBuffer(AudioManager audioManager) {
// if (Build.VERSION.SDK_INT < 17) {
// return DEFAULT_FRAME_PER_BUFFER;
// }
// String framesPerBuffer =
// audioManager.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER);
// return framesPerBuffer == null ? DEFAULT_FRAME_PER_BUFFER : Integer.parseInt(framesPerBuffer);
// }
//
// // Returns the minimum output buffer size for Java based audio (AudioTrack).
// // This size can also be used for OpenSL ES implementations on devices that
// // lacks support of low-latency output.
// private static int getMinOutputFrameSize(int sampleRateInHz, int numChannels) {
// final int bytesPerFrame = numChannels * (BITS_PER_SAMPLE / 8);
// final int channelConfig =
// (numChannels == 1 ? AudioFormat.CHANNEL_OUT_MONO : AudioFormat.CHANNEL_OUT_STEREO);
// return AudioTrack.getMinBufferSize(
// sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT)
// / bytesPerFrame;
// }
//
// // Returns the minimum input buffer size for Java based audio (AudioRecord).
// // This size can calso be used for OpenSL ES implementations on devices that
// // lacks support of low-latency input.
// private static int getMinInputFrameSize(int sampleRateInHz, int numChannels) {
// final int bytesPerFrame = numChannels * (BITS_PER_SAMPLE / 8);
// final int channelConfig =
// (numChannels == 1 ? AudioFormat.CHANNEL_IN_MONO : AudioFormat.CHANNEL_IN_STEREO);
// return AudioRecord.getMinBufferSize(
// sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT)
// / bytesPerFrame;
// }
}