1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_TIMING_H_ 12 #define WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_TIMING_H_ 13 14 #include "webrtc/modules/video_coding/main/source/codec_timer.h" 15 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h" 16 #include "webrtc/typedefs.h" 17 18 namespace webrtc { 19 20 class Clock; 21 class TimestampExtrapolator; 22 23 class VCMTiming { 24 public: 25 // The primary timing component should be passed 26 // if this is the dual timing component. 27 VCMTiming(Clock* clock, 28 VCMTiming* master_timing = NULL); 29 ~VCMTiming(); 30 31 // Resets the timing to the initial state. 32 void Reset(); 33 void ResetDecodeTime(); 34 35 // Set the amount of time needed to render an image. Defaults to 10 ms. 36 void set_render_delay(uint32_t render_delay_ms); 37 38 // Set the minimum time the video must be delayed on the receiver to 39 // get the desired jitter buffer level. 40 void SetJitterDelay(uint32_t required_delay_ms); 41 42 // Set the minimum playout delay required to sync video with audio. 43 void set_min_playout_delay(uint32_t min_playout_delay); 44 45 // Increases or decreases the current delay to get closer to the target delay. 46 // Calculates how long it has been since the previous call to this function, 47 // and increases/decreases the delay in proportion to the time difference. 48 void UpdateCurrentDelay(uint32_t frame_timestamp); 49 50 // Increases or decreases the current delay to get closer to the target delay. 51 // Given the actual decode time in ms and the render time in ms for a frame, 52 // this function calculates how late the frame is and increases the delay 53 // accordingly. 54 void UpdateCurrentDelay(int64_t render_time_ms, 55 int64_t actual_decode_time_ms); 56 57 // Stops the decoder timer, should be called when the decoder returns a frame 58 // or when the decoded frame callback is called. 59 int32_t StopDecodeTimer(uint32_t time_stamp, 60 int64_t start_time_ms, 61 int64_t now_ms); 62 63 // Used to report that a frame is passed to decoding. Updates the timestamp 64 // filter which is used to map between timestamps and receiver system time. 65 void IncomingTimestamp(uint32_t time_stamp, int64_t last_packet_time_ms); 66 // Returns the receiver system time when the frame with timestamp 67 // frame_timestamp should be rendered, assuming that the system time currently 68 // is now_ms. 69 int64_t RenderTimeMs(uint32_t frame_timestamp, int64_t now_ms) const; 70 71 // Returns the maximum time in ms that we can wait for a frame to become 72 // complete before we must pass it to the decoder. 73 uint32_t MaxWaitingTime(int64_t render_time_ms, int64_t now_ms) const; 74 75 // Returns the current target delay which is required delay + decode time + 76 // render delay. 77 uint32_t TargetVideoDelay() const; 78 79 // Calculates whether or not there is enough time to decode a frame given a 80 // certain amount of processing time. 81 bool EnoughTimeToDecode(uint32_t available_processing_time_ms) const; 82 83 // Return current timing information. 84 void GetTimings(int* decode_ms, 85 int* max_decode_ms, 86 int* current_delay_ms, 87 int* target_delay_ms, 88 int* jitter_buffer_ms, 89 int* min_playout_delay_ms, 90 int* render_delay_ms) const; 91 92 enum { kDefaultRenderDelayMs = 10 }; 93 enum { kDelayMaxChangeMsPerS = 100 }; 94 95 protected: 96 int32_t MaxDecodeTimeMs(FrameType frame_type = kVideoFrameDelta) const; 97 int64_t RenderTimeMsInternal(uint32_t frame_timestamp, int64_t now_ms) const; 98 uint32_t TargetDelayInternal() const; 99 100 private: 101 CriticalSectionWrapper* crit_sect_; 102 Clock* clock_; 103 bool master_; 104 TimestampExtrapolator* ts_extrapolator_; 105 VCMCodecTimer codec_timer_; 106 uint32_t render_delay_ms_; 107 uint32_t min_playout_delay_ms_; 108 uint32_t jitter_delay_ms_; 109 uint32_t current_delay_ms_; 110 int last_decode_ms_; 111 uint32_t prev_frame_timestamp_; 112 }; 113 } // namespace webrtc 114 115 #endif // WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_TIMING_H_ 116