webrtc/modules/video_coding/main/source/timing.h

111 lines
4.5 KiB
C++

/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_MODULES_VIDEO_CODING_TIMING_H_
#define WEBRTC_MODULES_VIDEO_CODING_TIMING_H_
#include "typedefs.h"
#include "critical_section_wrapper.h"
#include "codec_timer.h"
namespace webrtc
{
class VCMTimestampExtrapolator;
class VCMTiming
{
public:
// The primary timing component should be passed
// if this is the dual timing component.
VCMTiming(WebRtc_Word32 vcmId = 0,
WebRtc_Word32 timingId = 0,
VCMTiming* masterTiming = NULL);
~VCMTiming();
// Resets the timing to the initial state.
void Reset(WebRtc_Word64 nowMs = -1);
void ResetDecodeTime();
// The amount of time needed to render an image. Defaults to 10 ms.
void SetRenderDelay(WebRtc_UWord32 renderDelayMs);
// The minimum time the video must be delayed on the receiver to
// get the desired jitter buffer level.
void SetRequiredDelay(WebRtc_UWord32 requiredDelayMs);
// Minimum total delay required to sync video with audio.
void SetMinimumTotalDelay(WebRtc_UWord32 minTotalDelayMs);
// Increases or decreases the current delay to get closer to the target delay.
// Calculates how long it has been since the previous call to this function,
// and increases/decreases the delay in proportion to the time difference.
void UpdateCurrentDelay(WebRtc_UWord32 frameTimestamp);
// Increases or decreases the current delay to get closer to the target delay.
// Given the actual decode time in ms and the render time in ms for a frame, this
// function calculates how late the frame is and increases the delay accordingly.
void UpdateCurrentDelay(WebRtc_Word64 renderTimeMs, WebRtc_Word64 actualDecodeTimeMs);
// Stops the decoder timer, should be called when the decoder returns a frame
// or when the decoded frame callback is called.
WebRtc_Word32 StopDecodeTimer(WebRtc_UWord32 timeStamp,
WebRtc_Word64 startTimeMs,
WebRtc_Word64 nowMs);
// Used to report that a frame is passed to decoding. Updates the timestamp filter
// which is used to map between timestamps and receiver system time.
void IncomingTimestamp(WebRtc_UWord32 timeStamp, WebRtc_Word64 lastPacketTimeMs);
// Returns the receiver system time when the frame with timestamp frameTimestamp
// should be rendered, assuming that the system time currently is nowMs.
WebRtc_Word64 RenderTimeMs(WebRtc_UWord32 frameTimestamp, WebRtc_Word64 nowMs) const;
// Returns the maximum time in ms that we can wait for a frame to become complete
// before we must pass it to the decoder.
WebRtc_UWord32 MaxWaitingTime(WebRtc_Word64 renderTimeMs, WebRtc_Word64 nowMs) const;
// Returns the current target delay which is required delay + decode time + render
// delay.
WebRtc_UWord32 TargetVideoDelay() const;
// Calculates whether or not there is enough time to decode a frame given a
// certain amount of processing time.
bool EnoughTimeToDecode(WebRtc_UWord32 availableProcessingTimeMs) const;
enum { kDefaultRenderDelayMs = 10 };
enum { kDelayMaxChangeMsPerS = 100 };
protected:
WebRtc_Word32 MaxDecodeTimeMs(FrameType frameType = kVideoFrameDelta) const;
WebRtc_Word64 RenderTimeMsInternal(WebRtc_UWord32 frameTimestamp,
WebRtc_Word64 nowMs) const;
WebRtc_UWord32 TargetDelayInternal() const;
private:
CriticalSectionWrapper& _critSect;
WebRtc_Word32 _vcmId;
WebRtc_Word32 _timingId;
bool _master;
VCMTimestampExtrapolator* _tsExtrapolator;
VCMCodecTimer _codecTimer;
WebRtc_UWord32 _renderDelayMs;
WebRtc_UWord32 _minTotalDelayMs;
WebRtc_UWord32 _requiredDelayMs;
WebRtc_UWord32 _currentDelayMs;
WebRtc_UWord32 _prevFrameTimestamp;
WebRtc_Word64 _startStoragePlaybackMs;
WebRtc_Word64 _firstStoredRenderTimeMs;
};
} // namespace webrtc
#endif // WEBRTC_MODULES_VIDEO_CODING_TIMING_H_