| // 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. |
| |
| #ifndef COBALT_MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ |
| #define COBALT_MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ |
| |
| #include <vector> |
| |
| #include "base/basictypes.h" |
| #include "base/default_tick_clock.h" |
| #include "base/synchronization/lock.h" |
| #include "cobalt/media/base/media_export.h" |
| #include "cobalt/media/base/time_source.h" |
| |
| namespace cobalt { |
| namespace media { |
| |
| // A time source that uses interpolation based on the system clock. |
| class MEDIA_EXPORT WallClockTimeSource : public TimeSource { |
| public: |
| WallClockTimeSource(); |
| ~WallClockTimeSource() override; |
| |
| // TimeSource implementation. |
| void StartTicking() override; |
| void StopTicking() override; |
| void SetPlaybackRate(double playback_rate) override; |
| void SetMediaTime(base::TimeDelta time) override; |
| base::TimeDelta CurrentMediaTime() override; |
| bool GetWallClockTimes( |
| const std::vector<base::TimeDelta>& media_timestamps, |
| std::vector<base::TimeTicks>* wall_clock_times) override; |
| |
| void set_tick_clock_for_testing(base::TickClock* tick_clock) { |
| tick_clock_ = tick_clock; |
| } |
| |
| private: |
| base::TimeDelta CurrentMediaTime_Locked(); |
| |
| // Allow for an injectable tick clock for testing. |
| base::DefaultTickClock default_tick_clock_; |
| |
| // If specified, used instead of |default_tick_clock_|. |
| base::TickClock* tick_clock_; |
| |
| bool ticking_; |
| |
| // While ticking we can interpolate the current media time by measuring the |
| // delta between our reference ticks and the current system ticks and scaling |
| // that time by the playback rate. |
| double playback_rate_; |
| base::TimeDelta base_timestamp_; |
| base::TimeTicks reference_time_; |
| |
| // TODO(scherkus): Remove internal locking from this class after access to |
| // Renderer::CurrentMediaTime() is single threaded http://crbug.com/370634 |
| base::Lock lock_; |
| |
| DISALLOW_COPY_AND_ASSIGN(WallClockTimeSource); |
| }; |
| |
| } // namespace media |
| } // namespace cobalt |
| |
| #endif // COBALT_MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ |