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- // Copyright 2016 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 "media/base/audio_push_fifo.h"
- #include <algorithm>
- #include "base/logging.h"
- #include "base/trace_event/trace_event.h"
- namespace media {
- AudioPushFifo::AudioPushFifo(const OutputCallback& callback)
- : callback_(callback), frames_per_buffer_(0) {
- DCHECK(!callback_.is_null());
- }
- AudioPushFifo::~AudioPushFifo() = default;
- void AudioPushFifo::Reset(int frames_per_buffer) {
- DCHECK_GT(frames_per_buffer, 0);
- audio_queue_.reset();
- queued_frames_ = 0;
- frames_per_buffer_ = frames_per_buffer;
- }
- void AudioPushFifo::Push(const AudioBus& input_bus) {
- TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("audio"), "AudioPushFifo::Push");
- DCHECK_GT(frames_per_buffer_, 0);
- // Fast path: No buffering required.
- if ((queued_frames_ == 0) && (input_bus.frames() == frames_per_buffer_)) {
- callback_.Run(input_bus, 0);
- return;
- }
- // Lazy-create the |audio_queue_| if needed.
- if (!audio_queue_ || audio_queue_->channels() != input_bus.channels())
- audio_queue_ = AudioBus::Create(input_bus.channels(), frames_per_buffer_);
- // Start with a frame offset that refers to the position of the first sample
- // in |audio_queue_| relative to the first sample in |input_bus|.
- int frame_delay = -queued_frames_;
- // Repeatedly fill up |audio_queue_| with more sample frames from |input_bus|
- // and deliver batches until all sample frames in |input_bus| have been
- // consumed.
- int input_offset = 0;
- do {
- // Attempt to fill |audio_queue_| completely.
- const int frames_to_enqueue =
- std::min(static_cast<int>(input_bus.frames() - input_offset),
- frames_per_buffer_ - queued_frames_);
- if (frames_to_enqueue > 0) {
- DVLOG(2) << "Enqueuing " << frames_to_enqueue << " frames.";
- input_bus.CopyPartialFramesTo(input_offset, frames_to_enqueue,
- queued_frames_, audio_queue_.get());
- queued_frames_ += frames_to_enqueue;
- input_offset += frames_to_enqueue;
- }
- // If |audio_queue_| has been filled completely, deliver the re-buffered
- // audio to the consumer.
- if (queued_frames_ == frames_per_buffer_) {
- DVLOG(2) << "Delivering another " << queued_frames_ << " frames.";
- callback_.Run(*audio_queue_, frame_delay);
- frame_delay += frames_per_buffer_;
- queued_frames_ = 0;
- } else {
- // Not enough frames queued-up yet to deliver more frames.
- }
- } while (input_offset < input_bus.frames());
- }
- void AudioPushFifo::Flush() {
- if (queued_frames_ == 0)
- return;
- audio_queue_->ZeroFramesPartial(queued_frames_,
- audio_queue_->frames() - queued_frames_);
- callback_.Run(*audio_queue_, -queued_frames_);
- queued_frames_ = 0;
- }
- } // namespace media
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