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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"
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
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