Line data Source code
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/timing.h"
12 :
13 : #include <algorithm>
14 :
15 : #include "webrtc/modules/video_coding/internal_defines.h"
16 : #include "webrtc/modules/video_coding/jitter_buffer_common.h"
17 : #include "webrtc/system_wrappers/include/clock.h"
18 : #include "webrtc/system_wrappers/include/metrics.h"
19 : #include "webrtc/system_wrappers/include/timestamp_extrapolator.h"
20 :
21 : namespace webrtc {
22 :
23 0 : VCMTiming::VCMTiming(Clock* clock, VCMTiming* master_timing)
24 0 : : crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
25 : clock_(clock),
26 : master_(false),
27 : ts_extrapolator_(),
28 0 : codec_timer_(new VCMCodecTimer()),
29 : render_delay_ms_(kDefaultRenderDelayMs),
30 : min_playout_delay_ms_(0),
31 : max_playout_delay_ms_(10000),
32 : jitter_delay_ms_(0),
33 : current_delay_ms_(0),
34 : last_decode_ms_(0),
35 : prev_frame_timestamp_(0),
36 : num_decoded_frames_(0),
37 : num_delayed_decoded_frames_(0),
38 : first_decoded_frame_ms_(-1),
39 0 : sum_missed_render_deadline_ms_(0) {
40 0 : if (master_timing == NULL) {
41 0 : master_ = true;
42 0 : ts_extrapolator_ = new TimestampExtrapolator(clock_->TimeInMilliseconds());
43 : } else {
44 0 : ts_extrapolator_ = master_timing->ts_extrapolator_;
45 : }
46 0 : }
47 :
48 0 : VCMTiming::~VCMTiming() {
49 0 : UpdateHistograms();
50 0 : if (master_) {
51 0 : delete ts_extrapolator_;
52 : }
53 0 : delete crit_sect_;
54 0 : }
55 :
56 0 : void VCMTiming::UpdateHistograms() const {
57 0 : CriticalSectionScoped cs(crit_sect_);
58 0 : if (num_decoded_frames_ == 0) {
59 0 : return;
60 : }
61 : int64_t elapsed_sec =
62 0 : (clock_->TimeInMilliseconds() - first_decoded_frame_ms_) / 1000;
63 0 : if (elapsed_sec < metrics::kMinRunTimeInSeconds) {
64 0 : return;
65 : }
66 0 : RTC_HISTOGRAM_COUNTS_100(
67 : "WebRTC.Video.DecodedFramesPerSecond",
68 : static_cast<int>((num_decoded_frames_ / elapsed_sec) + 0.5f));
69 0 : RTC_HISTOGRAM_PERCENTAGE(
70 : "WebRTC.Video.DelayedFramesToRenderer",
71 : num_delayed_decoded_frames_ * 100 / num_decoded_frames_);
72 0 : if (num_delayed_decoded_frames_ > 0) {
73 0 : RTC_HISTOGRAM_COUNTS_1000(
74 : "WebRTC.Video.DelayedFramesToRenderer_AvgDelayInMs",
75 : sum_missed_render_deadline_ms_ / num_delayed_decoded_frames_);
76 : }
77 : }
78 :
79 0 : void VCMTiming::Reset() {
80 0 : CriticalSectionScoped cs(crit_sect_);
81 0 : ts_extrapolator_->Reset(clock_->TimeInMilliseconds());
82 0 : codec_timer_.reset(new VCMCodecTimer());
83 0 : render_delay_ms_ = kDefaultRenderDelayMs;
84 0 : min_playout_delay_ms_ = 0;
85 0 : jitter_delay_ms_ = 0;
86 0 : current_delay_ms_ = 0;
87 0 : prev_frame_timestamp_ = 0;
88 0 : }
89 :
90 0 : void VCMTiming::ResetDecodeTime() {
91 0 : CriticalSectionScoped lock(crit_sect_);
92 0 : codec_timer_.reset(new VCMCodecTimer());
93 0 : }
94 :
95 0 : void VCMTiming::set_render_delay(int render_delay_ms) {
96 0 : CriticalSectionScoped cs(crit_sect_);
97 0 : render_delay_ms_ = render_delay_ms;
98 0 : }
99 :
100 0 : void VCMTiming::set_min_playout_delay(int min_playout_delay_ms) {
101 0 : CriticalSectionScoped cs(crit_sect_);
102 0 : min_playout_delay_ms_ = min_playout_delay_ms;
103 0 : }
104 :
105 0 : int VCMTiming::min_playout_delay() {
106 0 : CriticalSectionScoped cs(crit_sect_);
107 0 : return min_playout_delay_ms_;
108 : }
109 :
110 0 : void VCMTiming::set_max_playout_delay(int max_playout_delay_ms) {
111 0 : CriticalSectionScoped cs(crit_sect_);
112 0 : max_playout_delay_ms_ = max_playout_delay_ms;
113 0 : }
114 :
115 0 : int VCMTiming::max_playout_delay() {
116 0 : CriticalSectionScoped cs(crit_sect_);
117 0 : return max_playout_delay_ms_;
118 : }
119 :
120 0 : void VCMTiming::SetJitterDelay(int jitter_delay_ms) {
121 0 : CriticalSectionScoped cs(crit_sect_);
122 0 : if (jitter_delay_ms != jitter_delay_ms_) {
123 0 : jitter_delay_ms_ = jitter_delay_ms;
124 : // When in initial state, set current delay to minimum delay.
125 0 : if (current_delay_ms_ == 0) {
126 0 : current_delay_ms_ = jitter_delay_ms_;
127 : }
128 : }
129 0 : }
130 :
131 0 : void VCMTiming::UpdateCurrentDelay(uint32_t frame_timestamp) {
132 0 : CriticalSectionScoped cs(crit_sect_);
133 0 : int target_delay_ms = TargetDelayInternal();
134 :
135 0 : if (current_delay_ms_ == 0) {
136 : // Not initialized, set current delay to target.
137 0 : current_delay_ms_ = target_delay_ms;
138 0 : } else if (target_delay_ms != current_delay_ms_) {
139 : int64_t delay_diff_ms =
140 0 : static_cast<int64_t>(target_delay_ms) - current_delay_ms_;
141 : // Never change the delay with more than 100 ms every second. If we're
142 : // changing the delay in too large steps we will get noticeable freezes. By
143 : // limiting the change we can increase the delay in smaller steps, which
144 : // will be experienced as the video is played in slow motion. When lowering
145 : // the delay the video will be played at a faster pace.
146 0 : int64_t max_change_ms = 0;
147 0 : if (frame_timestamp < 0x0000ffff && prev_frame_timestamp_ > 0xffff0000) {
148 : // wrap
149 0 : max_change_ms = kDelayMaxChangeMsPerS *
150 0 : (frame_timestamp + (static_cast<int64_t>(1) << 32) -
151 0 : prev_frame_timestamp_) /
152 0 : 90000;
153 : } else {
154 0 : max_change_ms = kDelayMaxChangeMsPerS *
155 0 : (frame_timestamp - prev_frame_timestamp_) / 90000;
156 : }
157 :
158 0 : if (max_change_ms <= 0) {
159 : // Any changes less than 1 ms are truncated and
160 : // will be postponed. Negative change will be due
161 : // to reordering and should be ignored.
162 0 : return;
163 : }
164 0 : delay_diff_ms = std::max(delay_diff_ms, -max_change_ms);
165 0 : delay_diff_ms = std::min(delay_diff_ms, max_change_ms);
166 :
167 0 : current_delay_ms_ = current_delay_ms_ + delay_diff_ms;
168 : }
169 0 : prev_frame_timestamp_ = frame_timestamp;
170 : }
171 :
172 0 : void VCMTiming::UpdateCurrentDelay(int64_t render_time_ms,
173 : int64_t actual_decode_time_ms) {
174 0 : CriticalSectionScoped cs(crit_sect_);
175 0 : uint32_t target_delay_ms = TargetDelayInternal();
176 : int64_t delayed_ms =
177 : actual_decode_time_ms -
178 0 : (render_time_ms - RequiredDecodeTimeMs() - render_delay_ms_);
179 0 : if (delayed_ms < 0) {
180 0 : return;
181 : }
182 0 : if (current_delay_ms_ + delayed_ms <= target_delay_ms) {
183 0 : current_delay_ms_ += delayed_ms;
184 : } else {
185 0 : current_delay_ms_ = target_delay_ms;
186 : }
187 : }
188 :
189 0 : int32_t VCMTiming::StopDecodeTimer(uint32_t time_stamp,
190 : int32_t decode_time_ms,
191 : int64_t now_ms,
192 : int64_t render_time_ms) {
193 0 : CriticalSectionScoped cs(crit_sect_);
194 0 : codec_timer_->AddTiming(decode_time_ms, now_ms);
195 0 : assert(decode_time_ms >= 0);
196 0 : last_decode_ms_ = decode_time_ms;
197 :
198 : // Update stats.
199 0 : ++num_decoded_frames_;
200 0 : if (num_decoded_frames_ == 1) {
201 0 : first_decoded_frame_ms_ = now_ms;
202 : }
203 0 : int time_until_rendering_ms = render_time_ms - render_delay_ms_ - now_ms;
204 0 : if (time_until_rendering_ms < 0) {
205 0 : sum_missed_render_deadline_ms_ += -time_until_rendering_ms;
206 0 : ++num_delayed_decoded_frames_;
207 : }
208 0 : return 0;
209 : }
210 :
211 0 : void VCMTiming::IncomingTimestamp(uint32_t time_stamp, int64_t now_ms) {
212 0 : CriticalSectionScoped cs(crit_sect_);
213 0 : ts_extrapolator_->Update(now_ms, time_stamp);
214 0 : }
215 :
216 0 : int64_t VCMTiming::RenderTimeMs(uint32_t frame_timestamp,
217 : int64_t now_ms) const {
218 0 : CriticalSectionScoped cs(crit_sect_);
219 0 : const int64_t render_time_ms = RenderTimeMsInternal(frame_timestamp, now_ms);
220 0 : return render_time_ms;
221 : }
222 :
223 0 : int64_t VCMTiming::RenderTimeMsInternal(uint32_t frame_timestamp,
224 : int64_t now_ms) const {
225 : int64_t estimated_complete_time_ms =
226 0 : ts_extrapolator_->ExtrapolateLocalTime(frame_timestamp);
227 0 : if (estimated_complete_time_ms == -1) {
228 0 : estimated_complete_time_ms = now_ms;
229 : }
230 :
231 0 : if (min_playout_delay_ms_ == 0 && max_playout_delay_ms_ == 0) {
232 : // Render as soon as possible
233 0 : return now_ms;
234 : }
235 :
236 : // Make sure the actual delay stays in the range of |min_playout_delay_ms_|
237 : // and |max_playout_delay_ms_|.
238 0 : int actual_delay = std::max(current_delay_ms_, min_playout_delay_ms_);
239 0 : actual_delay = std::min(actual_delay, max_playout_delay_ms_);
240 0 : return estimated_complete_time_ms + actual_delay;
241 : }
242 :
243 : // Must be called from inside a critical section.
244 0 : int VCMTiming::RequiredDecodeTimeMs() const {
245 0 : const int decode_time_ms = codec_timer_->RequiredDecodeTimeMs();
246 0 : assert(decode_time_ms >= 0);
247 0 : return decode_time_ms;
248 : }
249 :
250 0 : uint32_t VCMTiming::MaxWaitingTime(int64_t render_time_ms,
251 : int64_t now_ms) const {
252 0 : CriticalSectionScoped cs(crit_sect_);
253 :
254 : const int64_t max_wait_time_ms =
255 0 : render_time_ms - now_ms - RequiredDecodeTimeMs() - render_delay_ms_;
256 :
257 0 : if (max_wait_time_ms < 0) {
258 0 : return 0;
259 : }
260 0 : return static_cast<uint32_t>(max_wait_time_ms);
261 : }
262 :
263 0 : bool VCMTiming::EnoughTimeToDecode(
264 : uint32_t available_processing_time_ms) const {
265 0 : CriticalSectionScoped cs(crit_sect_);
266 0 : int64_t required_decode_time_ms = RequiredDecodeTimeMs();
267 0 : if (required_decode_time_ms < 0) {
268 : // Haven't decoded any frames yet, try decoding one to get an estimate
269 : // of the decode time.
270 0 : return true;
271 0 : } else if (required_decode_time_ms == 0) {
272 : // Decode time is less than 1, set to 1 for now since
273 : // we don't have any better precision. Count ticks later?
274 0 : required_decode_time_ms = 1;
275 : }
276 0 : return static_cast<int64_t>(available_processing_time_ms) -
277 : required_decode_time_ms >
278 0 : 0;
279 : }
280 :
281 0 : int VCMTiming::TargetVideoDelay() const {
282 0 : CriticalSectionScoped cs(crit_sect_);
283 0 : return TargetDelayInternal();
284 : }
285 :
286 0 : int VCMTiming::TargetDelayInternal() const {
287 : return std::max(min_playout_delay_ms_,
288 0 : jitter_delay_ms_ + RequiredDecodeTimeMs() + render_delay_ms_);
289 : }
290 :
291 0 : bool VCMTiming::GetTimings(int* decode_ms,
292 : int* max_decode_ms,
293 : int* current_delay_ms,
294 : int* target_delay_ms,
295 : int* jitter_buffer_ms,
296 : int* min_playout_delay_ms,
297 : int* render_delay_ms) const {
298 0 : CriticalSectionScoped cs(crit_sect_);
299 0 : *decode_ms = last_decode_ms_;
300 0 : *max_decode_ms = RequiredDecodeTimeMs();
301 0 : *current_delay_ms = current_delay_ms_;
302 0 : *target_delay_ms = TargetDelayInternal();
303 0 : *jitter_buffer_ms = jitter_delay_ms_;
304 0 : *min_playout_delay_ms = min_playout_delay_ms_;
305 0 : *render_delay_ms = render_delay_ms_;
306 0 : return (num_decoded_frames_ > 0);
307 : }
308 :
309 : } // namespace webrtc
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