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 #include "webrtc/modules/video_coding/codec_timer.h" 12 13 #include <assert.h> 14 15 namespace webrtc { 16 17 // The first kIgnoredSampleCount samples will be ignored. 18 static const int32_t kIgnoredSampleCount = 5; 19 VCMCodecTimer()20VCMCodecTimer::VCMCodecTimer() 21 : _filteredMax(0), _ignoredSampleCount(0), _shortMax(0), _history() { 22 Reset(); 23 } 24 Reset()25void VCMCodecTimer::Reset() { 26 _filteredMax = 0; 27 _ignoredSampleCount = 0; 28 _shortMax = 0; 29 for (int i = 0; i < MAX_HISTORY_SIZE; i++) { 30 _history[i].shortMax = 0; 31 _history[i].timeMs = -1; 32 } 33 } 34 35 // Update the max-value filter MaxFilter(int32_t decodeTime,int64_t nowMs)36void VCMCodecTimer::MaxFilter(int32_t decodeTime, int64_t nowMs) { 37 if (_ignoredSampleCount >= kIgnoredSampleCount) { 38 UpdateMaxHistory(decodeTime, nowMs); 39 ProcessHistory(nowMs); 40 } else { 41 _ignoredSampleCount++; 42 } 43 } 44 UpdateMaxHistory(int32_t decodeTime,int64_t now)45void VCMCodecTimer::UpdateMaxHistory(int32_t decodeTime, int64_t now) { 46 if (_history[0].timeMs >= 0 && now - _history[0].timeMs < SHORT_FILTER_MS) { 47 if (decodeTime > _shortMax) { 48 _shortMax = decodeTime; 49 } 50 } else { 51 // Only add a new value to the history once a second 52 if (_history[0].timeMs == -1) { 53 // First, no shift 54 _shortMax = decodeTime; 55 } else { 56 // Shift 57 for (int i = (MAX_HISTORY_SIZE - 2); i >= 0; i--) { 58 _history[i + 1].shortMax = _history[i].shortMax; 59 _history[i + 1].timeMs = _history[i].timeMs; 60 } 61 } 62 if (_shortMax == 0) { 63 _shortMax = decodeTime; 64 } 65 66 _history[0].shortMax = _shortMax; 67 _history[0].timeMs = now; 68 _shortMax = 0; 69 } 70 } 71 ProcessHistory(int64_t nowMs)72void VCMCodecTimer::ProcessHistory(int64_t nowMs) { 73 _filteredMax = _shortMax; 74 if (_history[0].timeMs == -1) { 75 return; 76 } 77 for (int i = 0; i < MAX_HISTORY_SIZE; i++) { 78 if (_history[i].timeMs == -1) { 79 break; 80 } 81 if (nowMs - _history[i].timeMs > MAX_HISTORY_SIZE * SHORT_FILTER_MS) { 82 // This sample (and all samples after this) is too old 83 break; 84 } 85 if (_history[i].shortMax > _filteredMax) { 86 // This sample is the largest one this far into the history 87 _filteredMax = _history[i].shortMax; 88 } 89 } 90 } 91 92 // Get the maximum observed time within a time window RequiredDecodeTimeMs(FrameType) const93int32_t VCMCodecTimer::RequiredDecodeTimeMs(FrameType /*frameType*/) const { 94 return _filteredMax; 95 } 96 } // namespace webrtc 97