| // 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 "media/base/wall_clock_time_source.h" |
| |
| #include "base/logging.h" |
| |
| namespace media { |
| |
| WallClockTimeSource::WallClockTimeSource() |
| : tick_clock_(&default_tick_clock_), ticking_(false), playback_rate_(1.0) { |
| } |
| |
| WallClockTimeSource::~WallClockTimeSource() { |
| } |
| |
| void WallClockTimeSource::StartTicking() { |
| DVLOG(1) << __FUNCTION__; |
| base::AutoLock auto_lock(lock_); |
| DCHECK(!ticking_); |
| ticking_ = true; |
| reference_wall_ticks_ = tick_clock_->NowTicks(); |
| } |
| |
| void WallClockTimeSource::StopTicking() { |
| DVLOG(1) << __FUNCTION__; |
| base::AutoLock auto_lock(lock_); |
| DCHECK(ticking_); |
| base_time_ = CurrentMediaTime_Locked(); |
| ticking_ = false; |
| reference_wall_ticks_ = tick_clock_->NowTicks(); |
| } |
| |
| void WallClockTimeSource::SetPlaybackRate(double playback_rate) { |
| DVLOG(1) << __FUNCTION__ << "(" << playback_rate << ")"; |
| base::AutoLock auto_lock(lock_); |
| // Estimate current media time using old rate to use as a new base time for |
| // the new rate. |
| if (ticking_) { |
| base_time_ = CurrentMediaTime_Locked(); |
| reference_wall_ticks_ = tick_clock_->NowTicks(); |
| } |
| |
| playback_rate_ = playback_rate; |
| } |
| |
| void WallClockTimeSource::SetMediaTime(base::TimeDelta time) { |
| DVLOG(1) << __FUNCTION__ << "(" << time.InMicroseconds() << ")"; |
| base::AutoLock auto_lock(lock_); |
| CHECK(!ticking_); |
| base_time_ = time; |
| } |
| |
| base::TimeDelta WallClockTimeSource::CurrentMediaTime() { |
| base::AutoLock auto_lock(lock_); |
| return CurrentMediaTime_Locked(); |
| } |
| |
| bool WallClockTimeSource::GetWallClockTimes( |
| const std::vector<base::TimeDelta>& media_timestamps, |
| std::vector<base::TimeTicks>* wall_clock_times) { |
| base::AutoLock auto_lock(lock_); |
| if (!ticking_ || !playback_rate_) |
| return false; |
| |
| DCHECK(wall_clock_times->empty()); |
| wall_clock_times->reserve(media_timestamps.size()); |
| for (const auto& media_timestamp : media_timestamps) { |
| wall_clock_times->push_back( |
| reference_wall_ticks_ + |
| base::TimeDelta::FromMicroseconds( |
| (media_timestamp - base_time_).InMicroseconds() / playback_rate_)); |
| } |
| return true; |
| } |
| |
| base::TimeDelta WallClockTimeSource::CurrentMediaTime_Locked() { |
| lock_.AssertAcquired(); |
| if (!ticking_ || !playback_rate_) |
| return base_time_; |
| |
| base::TimeTicks now = tick_clock_->NowTicks(); |
| return base_time_ + |
| base::TimeDelta::FromMicroseconds( |
| (now - reference_wall_ticks_).InMicroseconds() * playback_rate_); |
| } |
| |
| } // namespace media |