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_INTER_FRAME_DELAY_H_ 12 #define WEBRTC_MODULES_VIDEO_CODING_INTER_FRAME_DELAY_H_ 13 14 #include "webrtc/typedefs.h" 15 16 namespace webrtc 17 { 18 19 class VCMInterFrameDelay 20 { 21 public: 22 VCMInterFrameDelay(int64_t currentWallClock); 23 24 // Resets the estimate. Zeros are given as parameters. 25 void Reset(int64_t currentWallClock); 26 27 // Calculates the delay of a frame with the given timestamp. 28 // This method is called when the frame is complete. 29 // 30 // Input: 31 // - timestamp : RTP timestamp of a received frame 32 // - *delay : Pointer to memory where the result should be stored 33 // - currentWallClock : The current time in milliseconds. 34 // Should be -1 for normal operation, only used for testing. 35 // Return value : true if OK, false when reordered timestamps 36 bool CalculateDelay(uint32_t timestamp, 37 int64_t *delay, 38 int64_t currentWallClock); 39 40 // Returns the current difference between incoming timestamps 41 // 42 // Return value : Wrap-around compensated difference between incoming 43 // timestamps. 44 uint32_t CurrentTimeStampDiffMs() const; 45 46 private: 47 // Controls if the RTP timestamp counter has had a wrap around 48 // between the current and the previously received frame. 49 // 50 // Input: 51 // - timestmap : RTP timestamp of the current frame. 52 void CheckForWrapArounds(uint32_t timestamp); 53 54 int64_t _zeroWallClock; // Local timestamp of the first video packet received 55 int32_t _wrapArounds; // Number of wrapArounds detected 56 // The previous timestamp passed to the delay estimate 57 uint32_t _prevTimestamp; 58 // The previous wall clock timestamp used by the delay estimate 59 int64_t _prevWallClock; 60 // Wrap-around compensated difference between incoming timestamps 61 int64_t _dTS; 62 }; 63 64 } // namespace webrtc 65 66 #endif // WEBRTC_MODULES_VIDEO_CODING_INTER_FRAME_DELAY_H_ 67
