| // 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 "cobalt/media/base/audio_push_fifo.h" |
| |
| #include <algorithm> |
| |
| #include "base/logging.h" |
| |
| namespace cobalt { |
| namespace media { |
| |
| AudioPushFifo::AudioPushFifo(const OutputCallback& callback) |
| : callback_(callback), frames_per_buffer_(0) { |
| DCHECK(!callback_.is_null()); |
| } |
| |
| AudioPushFifo::~AudioPushFifo() {} |
| |
| 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) { |
| 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 |
| } // namespace cobalt |