82f014aa0b
BUG=1669 R=andrew@webrtc.org, fischman@webrtc.org, niklas.enbom@webrtc.org Review URL: https://webrtc-codereview.appspot.com/2032004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@4719 4adac7df-926f-26a2-2b94-8c16560cd09d
89 lines
3.4 KiB
C++
89 lines
3.4 KiB
C++
/*
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* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/modules/audio_device/android/fine_audio_buffer.h"
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#include <memory.h>
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#include <stdio.h>
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#include <algorithm>
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#include "webrtc/modules/audio_device/audio_device_buffer.h"
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namespace webrtc {
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FineAudioBuffer::FineAudioBuffer(AudioDeviceBuffer* device_buffer,
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int desired_frame_size_bytes,
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int sample_rate)
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: device_buffer_(device_buffer),
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desired_frame_size_bytes_(desired_frame_size_bytes),
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sample_rate_(sample_rate),
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samples_per_10_ms_(sample_rate_ * 10 / 1000),
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bytes_per_10_ms_(samples_per_10_ms_ * sizeof(int16_t)),
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cached_buffer_start_(0),
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cached_bytes_(0) {
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cache_buffer_.reset(new int8_t[bytes_per_10_ms_]);
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}
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FineAudioBuffer::~FineAudioBuffer() {
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}
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int FineAudioBuffer::RequiredBufferSizeBytes() {
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// It is possible that we store the desired frame size - 1 samples. Since new
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// audio frames are pulled in chunks of 10ms we will need a buffer that can
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// hold desired_frame_size - 1 + 10ms of data. We omit the - 1.
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return desired_frame_size_bytes_ + bytes_per_10_ms_;
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}
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void FineAudioBuffer::GetBufferData(int8_t* buffer) {
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if (desired_frame_size_bytes_ <= cached_bytes_) {
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memcpy(buffer, &cache_buffer_.get()[cached_buffer_start_],
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desired_frame_size_bytes_);
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cached_buffer_start_ += desired_frame_size_bytes_;
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cached_bytes_ -= desired_frame_size_bytes_;
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assert(cached_buffer_start_ + cached_bytes_ < bytes_per_10_ms_);
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return;
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}
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memcpy(buffer, &cache_buffer_.get()[cached_buffer_start_], cached_bytes_);
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// Push another n*10ms of audio to |buffer|. n > 1 if
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// |desired_frame_size_bytes_| is greater than 10ms of audio. Note that we
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// write the audio after the cached bytes copied earlier.
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int8_t* unwritten_buffer = &buffer[cached_bytes_];
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int bytes_left = desired_frame_size_bytes_ - cached_bytes_;
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// Ceiling of integer division: 1 + ((x - 1) / y)
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int number_of_requests = 1 + (bytes_left - 1) / (bytes_per_10_ms_);
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for (int i = 0; i < number_of_requests; ++i) {
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device_buffer_->RequestPlayoutData(samples_per_10_ms_);
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int num_out = device_buffer_->GetPlayoutData(unwritten_buffer);
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if (num_out != samples_per_10_ms_) {
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assert(num_out == 0);
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cached_bytes_ = 0;
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return;
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}
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unwritten_buffer += bytes_per_10_ms_;
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assert(bytes_left >= 0);
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bytes_left -= bytes_per_10_ms_;
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}
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assert(bytes_left <= 0);
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// Put the samples that were written to |buffer| but are not used in the
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// cache.
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int cache_location = desired_frame_size_bytes_;
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int8_t* cache_ptr = &buffer[cache_location];
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cached_bytes_ = number_of_requests * bytes_per_10_ms_ -
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(desired_frame_size_bytes_ - cached_bytes_);
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// If cached_bytes_ is larger than the cache buffer, uninitialized memory
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// will be read.
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assert(cached_bytes_ <= bytes_per_10_ms_);
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assert(-bytes_left == cached_bytes_);
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cached_buffer_start_ = 0;
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memcpy(cache_buffer_.get(), cache_ptr, cached_bytes_);
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}
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} // namespace webrtc
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