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Diffstat (limited to 'media/libmediaplayerservice/VideoFrameScheduler.h')
-rw-r--r-- | media/libmediaplayerservice/VideoFrameScheduler.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/media/libmediaplayerservice/VideoFrameScheduler.h b/media/libmediaplayerservice/VideoFrameScheduler.h new file mode 100644 index 0000000..84b27b4 --- /dev/null +++ b/media/libmediaplayerservice/VideoFrameScheduler.h @@ -0,0 +1,99 @@ +/* + * Copyright 2014, The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef VIDEO_FRAME_SCHEDULER_H_ +#define VIDEO_FRAME_SCHEDULER_H_ + +#include <utils/RefBase.h> +#include <utils/Timers.h> + +#include <media/stagefright/foundation/ABase.h> + +namespace android { + +struct ISurfaceComposer; + +struct VideoFrameScheduler : public RefBase { + VideoFrameScheduler(); + + // (re)initialize scheduler + void init(float videoFps = -1); + // use in case of video render-time discontinuity, e.g. seek + void restart(); + // get adjusted nanotime for a video frame render at renderTime + nsecs_t schedule(nsecs_t renderTime); + + // returns the vsync period for the main display + nsecs_t getVsyncPeriod(); + + void release(); + + static const size_t kHistorySize = 8; + +protected: + virtual ~VideoFrameScheduler(); + +private: + struct PLL { + PLL(); + + // reset PLL to new PLL + void reset(float fps = -1); + // keep current estimate, but restart phase + void restart(); + // returns period + nsecs_t addSample(nsecs_t time); + + private: + nsecs_t mPeriod; + nsecs_t mPhase; + + bool mPrimed; // have an estimate for the period + size_t mSamplesUsedForPriming; + + nsecs_t mLastTime; // last input time + nsecs_t mRefitAt; // next input time to fit at + + size_t mNumSamples; // can go past kHistorySize + nsecs_t mTimes[kHistorySize]; + + void test(); + // returns whether fit was successful + bool fit(nsecs_t phase, nsecs_t period, size_t numSamples, + int64_t *a, int64_t *b, int64_t *err); + void prime(size_t numSamples); + }; + + void updateVsync(); + + nsecs_t mVsyncTime; // vsync timing from display + nsecs_t mVsyncPeriod; + nsecs_t mVsyncRefreshAt; // next time to refresh timing info + + nsecs_t mLastVsyncTime; // estimated vsync time for last frame + nsecs_t mTimeCorrection; // running adjustment + + PLL mPll; // PLL for video frame rate based on render time + + sp<ISurfaceComposer> mComposer; + + DISALLOW_EVIL_CONSTRUCTORS(VideoFrameScheduler); +}; + +} // namespace android + +#endif // VIDEO_FRAME_SCHEDULER_H_ + |