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// Copyright 2015 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/null_video_sink.h"
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/single_thread_task_runner.h"
namespace media {
NullVideoSink::NullVideoSink(
bool clockless,
base::TimeDelta interval,
const NewFrameCB& new_frame_cb,
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
: clockless_(clockless),
interval_(interval),
new_frame_cb_(new_frame_cb),
task_runner_(task_runner),
started_(false),
callback_(nullptr),
tick_clock_(&default_tick_clock_),
background_render_(false) {
}
NullVideoSink::~NullVideoSink() {
DCHECK(!started_);
}
void NullVideoSink::Start(RenderCallback* callback) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(!started_);
callback_ = callback;
started_ = true;
last_now_ = current_render_time_ = tick_clock_->NowTicks();
cancelable_worker_.Reset(
base::Bind(&NullVideoSink::CallRender, base::Unretained(this)));
task_runner_->PostTask(FROM_HERE, cancelable_worker_.callback());
}
void NullVideoSink::Stop() {
DCHECK(task_runner_->BelongsToCurrentThread());
cancelable_worker_.Cancel();
started_ = false;
if (!stop_cb_.is_null())
base::ResetAndReturn(&stop_cb_).Run();
}
void NullVideoSink::CallRender() {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(started_);
const base::TimeTicks end_of_interval = current_render_time_ + interval_;
scoped_refptr<VideoFrame> new_frame = callback_->Render(
current_render_time_, end_of_interval, background_render_);
const bool is_new_frame = new_frame != last_frame_;
last_frame_ = new_frame;
if (is_new_frame && !new_frame_cb_.is_null())
new_frame_cb_.Run(new_frame);
current_render_time_ += interval_;
if (clockless_) {
task_runner_->PostTask(FROM_HERE, cancelable_worker_.callback());
return;
}
const base::TimeTicks now = tick_clock_->NowTicks();
base::TimeDelta delay;
if (last_now_ == now) {
// The tick clock is frozen in this case, so don't advance deadline.
delay = interval_;
current_render_time_ = now;
} else {
// If we're behind, find the next nearest on time interval.
delay = current_render_time_ - now;
if (delay < base::TimeDelta())
delay += interval_ * (-delay / interval_ + 1);
current_render_time_ = now + delay;
last_now_ = now;
}
task_runner_->PostDelayedTask(FROM_HERE, cancelable_worker_.callback(),
delay);
}
void NullVideoSink::PaintFrameUsingOldRenderingPath(
const scoped_refptr<VideoFrame>& frame) {
new_frame_cb_.Run(frame);
}
} // namespace media
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