15f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)// Copyright 2014 The Chromium Authors. All rights reserved. 25f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)// found in the LICENSE file. 45f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 55f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#ifndef MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ 65f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#define MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ 75f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 85f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#include "base/memory/scoped_ptr.h" 91320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci#include "base/synchronization/lock.h" 105f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#include "media/base/media_export.h" 115f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#include "media/base/time_source.h" 125f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 135f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)namespace base { 145f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)class TickClock; 155f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)} 165f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 175f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)namespace media { 185f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 195f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)// A time source that uses interpolation based on the system clock. 205f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)class MEDIA_EXPORT WallClockTimeSource : public TimeSource { 215f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) public: 225f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) WallClockTimeSource(); 235f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual ~WallClockTimeSource(); 245f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 255f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) // TimeSource implementation. 265f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual void StartTicking() OVERRIDE; 275f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual void StopTicking() OVERRIDE; 285f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual void SetPlaybackRate(float playback_rate) OVERRIDE; 295f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual void SetMediaTime(base::TimeDelta time) OVERRIDE; 305f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) virtual base::TimeDelta CurrentMediaTime() OVERRIDE; 311320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci virtual base::TimeDelta CurrentMediaTimeForSyncingVideo() OVERRIDE; 325f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 335f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) void SetTickClockForTesting(scoped_ptr<base::TickClock> tick_clock); 345f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 355f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) private: 361320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci base::TimeDelta CurrentMediaTime_Locked(); 371320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 385f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) scoped_ptr<base::TickClock> tick_clock_; 395f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) bool ticking_; 405f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 415f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) // While ticking we can interpolate the current media time by measuring the 425f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) // delta between our reference ticks and the current system ticks and scaling 435f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) // that time by the playback rate. 445f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) float playback_rate_; 455f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) base::TimeDelta base_time_; 465f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) base::TimeTicks reference_wall_ticks_; 475f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 481320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // TODO(scherkus): Remove internal locking from this class after access to 491320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // Renderer::CurrentMediaTime() is single threaded http://crbug.com/370634 501320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci base::Lock lock_; 511320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 525f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(WallClockTimeSource); 535f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)}; 545f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 555f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)} // namespace media 565f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles) 575f1c94371a64b3196d4be9466099bb892df9b88eTorne (Richard Coles)#endif // MEDIA_BASE_WALL_CLOCK_TIME_SOURCE_H_ 58