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