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_TIMING_H_ 12 #define WEBRTC_MODULES_VIDEO_CODING_TIMING_H_ 13 14 #include "webrtc/base/thread_annotations.h" 15 #include "webrtc/modules/video_coding/codec_timer.h" 16 #include "webrtc/system_wrappers/include/critical_section_wrapper.h" 17 #include "webrtc/typedefs.h" 18 19 namespace webrtc { 20 21 class Clock; 22 class TimestampExtrapolator; 23 24 class VCMTiming { 25 public: 26 // The primary timing component should be passed 27 // if this is the dual timing component. 28 explicit VCMTiming(Clock* clock, 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 int32_t decode_time_ms, 61 int64_t now_ms, 62 int64_t render_time_ms); 63 64 // Used to report that a frame is passed to decoding. Updates the timestamp 65 // filter which is used to map between timestamps and receiver system time. 66 void IncomingTimestamp(uint32_t time_stamp, int64_t last_packet_time_ms); 67 // Returns the receiver system time when the frame with timestamp 68 // frame_timestamp should be rendered, assuming that the system time currently 69 // is now_ms. 70 int64_t RenderTimeMs(uint32_t frame_timestamp, int64_t now_ms) const; 71 72 // Returns the maximum time in ms that we can wait for a frame to become 73 // complete before we must pass it to the decoder. 74 uint32_t MaxWaitingTime(int64_t render_time_ms, int64_t now_ms) const; 75 76 // Returns the current target delay which is required delay + decode time + 77 // render delay. 78 uint32_t TargetVideoDelay() const; 79 80 // Calculates whether or not there is enough time to decode a frame given a 81 // certain amount of processing time. 82 bool EnoughTimeToDecode(uint32_t available_processing_time_ms) const; 83 84 // Return current timing information. 85 void GetTimings(int* decode_ms, 86 int* max_decode_ms, 87 int* current_delay_ms, 88 int* target_delay_ms, 89 int* jitter_buffer_ms, 90 int* min_playout_delay_ms, 91 int* render_delay_ms) const; 92 93 enum { kDefaultRenderDelayMs = 10 }; 94 enum { kDelayMaxChangeMsPerS = 100 }; 95 96 protected: 97 int32_t MaxDecodeTimeMs(FrameType frame_type = kVideoFrameDelta) const 98 EXCLUSIVE_LOCKS_REQUIRED(crit_sect_); 99 int64_t RenderTimeMsInternal(uint32_t frame_timestamp, int64_t now_ms) const 100 EXCLUSIVE_LOCKS_REQUIRED(crit_sect_); 101 uint32_t TargetDelayInternal() const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_); 102 103 private: 104 void UpdateHistograms() const; 105 106 CriticalSectionWrapper* crit_sect_; 107 Clock* const clock_; 108 bool master_ GUARDED_BY(crit_sect_); 109 TimestampExtrapolator* ts_extrapolator_ GUARDED_BY(crit_sect_); 110 VCMCodecTimer codec_timer_ GUARDED_BY(crit_sect_); 111 uint32_t render_delay_ms_ GUARDED_BY(crit_sect_); 112 uint32_t min_playout_delay_ms_ GUARDED_BY(crit_sect_); 113 uint32_t jitter_delay_ms_ GUARDED_BY(crit_sect_); 114 uint32_t current_delay_ms_ GUARDED_BY(crit_sect_); 115 int last_decode_ms_ GUARDED_BY(crit_sect_); 116 uint32_t prev_frame_timestamp_ GUARDED_BY(crit_sect_); 117 118 // Statistics. 119 size_t num_decoded_frames_ GUARDED_BY(crit_sect_); 120 size_t num_delayed_decoded_frames_ GUARDED_BY(crit_sect_); 121 int64_t first_decoded_frame_ms_ GUARDED_BY(crit_sect_); 122 uint64_t sum_missed_render_deadline_ms_ GUARDED_BY(crit_sect_); 123 }; 124 } // namespace webrtc 125 126 #endif // WEBRTC_MODULES_VIDEO_CODING_TIMING_H_ 127
