1 /* 2 * Copyright (c) 2013 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_REMOTE_BITRATE_ESTIMATOR_INTER_ARRIVAL_H_ 12 #define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INTER_ARRIVAL_H_ 13 14 #include <cstddef> 15 16 #include "webrtc/base/constructormagic.h" 17 #include "webrtc/typedefs.h" 18 19 namespace webrtc { 20 21 // Helper class to compute the inter-arrival time delta and the size delta 22 // between two timestamp groups. A timestamp is a 32 bit unsigned number with 23 // a client defined rate. 24 class InterArrival { 25 public: 26 // A timestamp group is defined as all packets with a timestamp which are at 27 // most timestamp_group_length_ticks older than the first timestamp in that 28 // group. 29 InterArrival(uint32_t timestamp_group_length_ticks, 30 double timestamp_to_ms_coeff, 31 bool enable_burst_grouping); 32 33 // This function returns true if a delta was computed, or false if the current 34 // group is still incomplete or if only one group has been completed. 35 // |timestamp| is the timestamp. 36 // |arrival_time_ms| is the local time at which the packet arrived. 37 // |packet_size| is the size of the packet. 38 // |timestamp_delta| (output) is the computed timestamp delta. 39 // |arrival_time_delta_ms| (output) is the computed arrival-time delta. 40 // |packet_size_delta| (output) is the computed size delta. 41 bool ComputeDeltas(uint32_t timestamp, 42 int64_t arrival_time_ms, 43 size_t packet_size, 44 uint32_t* timestamp_delta, 45 int64_t* arrival_time_delta_ms, 46 int* packet_size_delta); 47 48 private: 49 struct TimestampGroup { TimestampGroupTimestampGroup50 TimestampGroup() 51 : size(0), 52 first_timestamp(0), 53 timestamp(0), 54 complete_time_ms(-1) {} 55 IsFirstPacketTimestampGroup56 bool IsFirstPacket() const { 57 return complete_time_ms == -1; 58 } 59 60 size_t size; 61 uint32_t first_timestamp; 62 uint32_t timestamp; 63 int64_t complete_time_ms; 64 }; 65 66 // Returns true if the packet with timestamp |timestamp| arrived in order. 67 bool PacketInOrder(uint32_t timestamp); 68 69 // Returns true if the last packet was the end of the current batch and the 70 // packet with |timestamp| is the first of a new batch. 71 bool NewTimestampGroup(int64_t arrival_time_ms, uint32_t timestamp) const; 72 73 bool BelongsToBurst(int64_t arrival_time_ms, uint32_t timestamp) const; 74 75 const uint32_t kTimestampGroupLengthTicks; 76 TimestampGroup current_timestamp_group_; 77 TimestampGroup prev_timestamp_group_; 78 double timestamp_to_ms_coeff_; 79 bool burst_grouping_; 80 81 RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(InterArrival); 82 }; 83 } // namespace webrtc 84 85 #endif // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INTER_ARRIVAL_H_ 86