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// Copyright 2014 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.
#include <algorithm>
#include "media/base/audio_block_fifo.h"
#include "base/logging.h"
namespace media {
AudioBlockFifo::AudioBlockFifo(int channels, int frames, int blocks)
: channels_(channels),
block_frames_(frames),
write_block_(0),
read_block_(0),
available_blocks_(0),
write_pos_(0) {
IncreaseCapacity(blocks);
}
AudioBlockFifo::~AudioBlockFifo() {}
void AudioBlockFifo::Push(const void* source,
int frames,
int bytes_per_sample) {
DCHECK(source);
DCHECK_GT(frames, 0);
DCHECK_GT(bytes_per_sample, 0);
DCHECK_LT(available_blocks_, static_cast<int>(audio_blocks_.size()));
CHECK_LE(frames, GetUnfilledFrames());
const uint8* source_ptr = static_cast<const uint8*>(source);
int frames_to_push = frames;
while (frames_to_push) {
// Get the current write block.
AudioBus* current_block = audio_blocks_[write_block_];
// Figure out what segment sizes we need when adding the new content to
// the FIFO.
const int push_frames =
std::min(block_frames_ - write_pos_, frames_to_push);
// Deinterleave the content to the FIFO and update the |write_pos_|.
current_block->FromInterleavedPartial(
source_ptr, write_pos_, push_frames, bytes_per_sample);
write_pos_ = (write_pos_ + push_frames) % block_frames_;
if (!write_pos_) {
// The current block is completely filled, increment |write_block_| and
// |available_blocks_|.
write_block_ = (write_block_ + 1) % audio_blocks_.size();
++available_blocks_;
}
source_ptr += push_frames * bytes_per_sample * channels_;
frames_to_push -= push_frames;
DCHECK_GE(frames_to_push, 0);
}
}
const AudioBus* AudioBlockFifo::Consume() {
DCHECK(available_blocks_);
AudioBus* audio_bus = audio_blocks_[read_block_];
read_block_ = (read_block_ + 1) % audio_blocks_.size();
--available_blocks_;
return audio_bus;
}
void AudioBlockFifo::Clear() {
write_pos_ = 0;
write_block_ = 0;
read_block_ = 0;
available_blocks_ = 0;
}
int AudioBlockFifo::GetAvailableFrames() const {
return available_blocks_ * block_frames_ + write_pos_;
}
int AudioBlockFifo::GetUnfilledFrames() const {
const int unfilled_frames =
(audio_blocks_.size() - available_blocks_) * block_frames_ - write_pos_;
DCHECK_GE(unfilled_frames, 0);
return unfilled_frames;
}
void AudioBlockFifo::IncreaseCapacity(int blocks) {
DCHECK_GT(blocks, 0);
// Create |blocks| of audio buses and insert them to the containers.
audio_blocks_.reserve(audio_blocks_.size() + blocks);
const int original_size = audio_blocks_.size();
for (int i = 0; i < blocks; ++i) {
audio_blocks_.push_back(
AudioBus::Create(channels_, block_frames_).release());
}
if (!original_size)
return;
std::rotate(audio_blocks_.begin() + read_block_,
audio_blocks_.begin() + original_size,
audio_blocks_.end());
// Update the write pointer if it is on top of the new inserted blocks.
if (write_block_ >= read_block_)
write_block_ += blocks;
// Update the read pointers correspondingly.
read_block_ += blocks;
DCHECK_LT(read_block_, static_cast<int>(audio_blocks_.size()));
DCHECK_LT(write_block_, static_cast<int>(audio_blocks_.size()));
}
} // namespace media
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