1 /*
2  *  Copyright (c) 2012 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 "modules/video_coding/generic_decoder.h"
12 
13 #include <stddef.h>
14 
15 #include <algorithm>
16 
17 #include "api/video/video_timing.h"
18 #include "modules/video_coding/include/video_error_codes.h"
19 #include "rtc_base/checks.h"
20 #include "rtc_base/logging.h"
21 #include "rtc_base/thread.h"
22 #include "rtc_base/time_utils.h"
23 #include "rtc_base/trace_event.h"
24 #include "system_wrappers/include/clock.h"
25 #include "system_wrappers/include/field_trial.h"
26 
27 namespace webrtc {
28 
VCMDecodedFrameCallback(VCMTiming * timing,Clock * clock)29 VCMDecodedFrameCallback::VCMDecodedFrameCallback(VCMTiming* timing,
30                                                  Clock* clock)
31     : _clock(clock),
32       _timing(timing),
33       _timestampMap(kDecoderFrameMemoryLength),
34       _extra_decode_time("t", absl::nullopt) {
35   ntp_offset_ =
36       _clock->CurrentNtpInMilliseconds() - _clock->TimeInMilliseconds();
37 
38   ParseFieldTrial({&_extra_decode_time},
39                   field_trial::FindFullName("WebRTC-SlowDownDecoder"));
40 }
41 
~VCMDecodedFrameCallback()42 VCMDecodedFrameCallback::~VCMDecodedFrameCallback() {}
43 
SetUserReceiveCallback(VCMReceiveCallback * receiveCallback)44 void VCMDecodedFrameCallback::SetUserReceiveCallback(
45     VCMReceiveCallback* receiveCallback) {
46   RTC_DCHECK(construction_thread_.IsCurrent());
47   RTC_DCHECK((!_receiveCallback && receiveCallback) ||
48              (_receiveCallback && !receiveCallback));
49   _receiveCallback = receiveCallback;
50 }
51 
UserReceiveCallback()52 VCMReceiveCallback* VCMDecodedFrameCallback::UserReceiveCallback() {
53   // Called on the decode thread via VCMCodecDataBase::GetDecoder.
54   // The callback must always have been set before this happens.
55   RTC_DCHECK(_receiveCallback);
56   return _receiveCallback;
57 }
58 
Decoded(VideoFrame & decodedImage)59 int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage) {
60   // This function may be called on the decode TaskQueue, but may also be called
61   // on an OS provided queue such as on iOS (see e.g. b/153465112).
62   return Decoded(decodedImage, -1);
63 }
64 
Decoded(VideoFrame & decodedImage,int64_t decode_time_ms)65 int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
66                                          int64_t decode_time_ms) {
67   Decoded(decodedImage,
68           decode_time_ms >= 0 ? absl::optional<int32_t>(decode_time_ms)
69                               : absl::nullopt,
70           absl::nullopt);
71   return WEBRTC_VIDEO_CODEC_OK;
72 }
73 
Decoded(VideoFrame & decodedImage,absl::optional<int32_t> decode_time_ms,absl::optional<uint8_t> qp)74 void VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
75                                       absl::optional<int32_t> decode_time_ms,
76                                       absl::optional<uint8_t> qp) {
77   // Wait some extra time to simulate a slow decoder.
78   if (_extra_decode_time) {
79     rtc::Thread::SleepMs(_extra_decode_time->ms());
80   }
81 
82   RTC_DCHECK(_receiveCallback) << "Callback must not be null at this point";
83   TRACE_EVENT_INSTANT1("webrtc", "VCMDecodedFrameCallback::Decoded",
84                        "timestamp", decodedImage.timestamp());
85   // TODO(holmer): We should improve this so that we can handle multiple
86   // callbacks from one call to Decode().
87   VCMFrameInformation* frameInfo;
88   {
89     MutexLock lock(&lock_);
90     frameInfo = _timestampMap.Pop(decodedImage.timestamp());
91   }
92 
93   if (frameInfo == NULL) {
94     RTC_LOG(LS_WARNING) << "Too many frames backed up in the decoder, dropping "
95                            "this one.";
96     _receiveCallback->OnDroppedFrames(1);
97     return;
98   }
99 
100   decodedImage.set_ntp_time_ms(frameInfo->ntp_time_ms);
101   decodedImage.set_packet_infos(frameInfo->packet_infos);
102   decodedImage.set_rotation(frameInfo->rotation);
103 
104   const Timestamp now = _clock->CurrentTime();
105   RTC_DCHECK(frameInfo->decodeStart);
106   if (!decode_time_ms) {
107     decode_time_ms = (now - *frameInfo->decodeStart).ms();
108   }
109   _timing->StopDecodeTimer(*decode_time_ms, now.ms());
110   decodedImage.set_processing_time({*frameInfo->decodeStart, now});
111 
112   // Report timing information.
113   TimingFrameInfo timing_frame_info;
114   if (frameInfo->timing.flags != VideoSendTiming::kInvalid) {
115     int64_t capture_time_ms = decodedImage.ntp_time_ms() - ntp_offset_;
116     // Convert remote timestamps to local time from ntp timestamps.
117     frameInfo->timing.encode_start_ms -= ntp_offset_;
118     frameInfo->timing.encode_finish_ms -= ntp_offset_;
119     frameInfo->timing.packetization_finish_ms -= ntp_offset_;
120     frameInfo->timing.pacer_exit_ms -= ntp_offset_;
121     frameInfo->timing.network_timestamp_ms -= ntp_offset_;
122     frameInfo->timing.network2_timestamp_ms -= ntp_offset_;
123 
124     int64_t sender_delta_ms = 0;
125     if (decodedImage.ntp_time_ms() < 0) {
126       // Sender clock is not estimated yet. Make sure that sender times are all
127       // negative to indicate that. Yet they still should be relatively correct.
128       sender_delta_ms =
129           std::max({capture_time_ms, frameInfo->timing.encode_start_ms,
130                     frameInfo->timing.encode_finish_ms,
131                     frameInfo->timing.packetization_finish_ms,
132                     frameInfo->timing.pacer_exit_ms,
133                     frameInfo->timing.network_timestamp_ms,
134                     frameInfo->timing.network2_timestamp_ms}) +
135           1;
136     }
137 
138     timing_frame_info.capture_time_ms = capture_time_ms - sender_delta_ms;
139     timing_frame_info.encode_start_ms =
140         frameInfo->timing.encode_start_ms - sender_delta_ms;
141     timing_frame_info.encode_finish_ms =
142         frameInfo->timing.encode_finish_ms - sender_delta_ms;
143     timing_frame_info.packetization_finish_ms =
144         frameInfo->timing.packetization_finish_ms - sender_delta_ms;
145     timing_frame_info.pacer_exit_ms =
146         frameInfo->timing.pacer_exit_ms - sender_delta_ms;
147     timing_frame_info.network_timestamp_ms =
148         frameInfo->timing.network_timestamp_ms - sender_delta_ms;
149     timing_frame_info.network2_timestamp_ms =
150         frameInfo->timing.network2_timestamp_ms - sender_delta_ms;
151   }
152 
153   timing_frame_info.flags = frameInfo->timing.flags;
154   timing_frame_info.decode_start_ms = frameInfo->decodeStart->ms();
155   timing_frame_info.decode_finish_ms = now.ms();
156   timing_frame_info.render_time_ms = frameInfo->renderTimeMs;
157   timing_frame_info.rtp_timestamp = decodedImage.timestamp();
158   timing_frame_info.receive_start_ms = frameInfo->timing.receive_start_ms;
159   timing_frame_info.receive_finish_ms = frameInfo->timing.receive_finish_ms;
160   _timing->SetTimingFrameInfo(timing_frame_info);
161 
162   decodedImage.set_timestamp_us(frameInfo->renderTimeMs *
163                                 rtc::kNumMicrosecsPerMillisec);
164   _receiveCallback->FrameToRender(decodedImage, qp, *decode_time_ms,
165                                   frameInfo->content_type);
166 }
167 
OnDecoderImplementationName(const char * implementation_name)168 void VCMDecodedFrameCallback::OnDecoderImplementationName(
169     const char* implementation_name) {
170   _receiveCallback->OnDecoderImplementationName(implementation_name);
171 }
172 
Map(uint32_t timestamp,VCMFrameInformation * frameInfo)173 void VCMDecodedFrameCallback::Map(uint32_t timestamp,
174                                   VCMFrameInformation* frameInfo) {
175   MutexLock lock(&lock_);
176   _timestampMap.Add(timestamp, frameInfo);
177 }
178 
Pop(uint32_t timestamp)179 int32_t VCMDecodedFrameCallback::Pop(uint32_t timestamp) {
180   MutexLock lock(&lock_);
181   if (_timestampMap.Pop(timestamp) == NULL) {
182     return VCM_GENERAL_ERROR;
183   }
184   _receiveCallback->OnDroppedFrames(1);
185   return VCM_OK;
186 }
187 
VCMGenericDecoder(std::unique_ptr<VideoDecoder> decoder)188 VCMGenericDecoder::VCMGenericDecoder(std::unique_ptr<VideoDecoder> decoder)
189     : VCMGenericDecoder(decoder.release(), false /* isExternal */) {}
190 
VCMGenericDecoder(VideoDecoder * decoder,bool isExternal)191 VCMGenericDecoder::VCMGenericDecoder(VideoDecoder* decoder, bool isExternal)
192     : _callback(NULL),
193       _frameInfos(),
194       _nextFrameInfoIdx(0),
195       decoder_(decoder),
196       _codecType(kVideoCodecGeneric),
197       _isExternal(isExternal),
198       _last_keyframe_content_type(VideoContentType::UNSPECIFIED) {
199   RTC_DCHECK(decoder_);
200 }
201 
~VCMGenericDecoder()202 VCMGenericDecoder::~VCMGenericDecoder() {
203   decoder_->Release();
204   if (_isExternal)
205     decoder_.release();
206   RTC_DCHECK(_isExternal || decoder_);
207 }
208 
InitDecode(const VideoCodec * settings,int32_t numberOfCores)209 int32_t VCMGenericDecoder::InitDecode(const VideoCodec* settings,
210                                       int32_t numberOfCores) {
211   TRACE_EVENT0("webrtc", "VCMGenericDecoder::InitDecode");
212   _codecType = settings->codecType;
213 
214   int err = decoder_->InitDecode(settings, numberOfCores);
215   implementation_name_ = decoder_->ImplementationName();
216   RTC_LOG(LS_INFO) << "Decoder implementation: " << implementation_name_;
217   return err;
218 }
219 
Decode(const VCMEncodedFrame & frame,Timestamp now)220 int32_t VCMGenericDecoder::Decode(const VCMEncodedFrame& frame, Timestamp now) {
221   TRACE_EVENT1("webrtc", "VCMGenericDecoder::Decode", "timestamp",
222                frame.Timestamp());
223   _frameInfos[_nextFrameInfoIdx].decodeStart = now;
224   _frameInfos[_nextFrameInfoIdx].renderTimeMs = frame.RenderTimeMs();
225   _frameInfos[_nextFrameInfoIdx].rotation = frame.rotation();
226   _frameInfos[_nextFrameInfoIdx].timing = frame.video_timing();
227   _frameInfos[_nextFrameInfoIdx].ntp_time_ms =
228       frame.EncodedImage().ntp_time_ms_;
229   _frameInfos[_nextFrameInfoIdx].packet_infos = frame.PacketInfos();
230 
231   // Set correctly only for key frames. Thus, use latest key frame
232   // content type. If the corresponding key frame was lost, decode will fail
233   // and content type will be ignored.
234   if (frame.FrameType() == VideoFrameType::kVideoFrameKey) {
235     _frameInfos[_nextFrameInfoIdx].content_type = frame.contentType();
236     _last_keyframe_content_type = frame.contentType();
237   } else {
238     _frameInfos[_nextFrameInfoIdx].content_type = _last_keyframe_content_type;
239   }
240   _callback->Map(frame.Timestamp(), &_frameInfos[_nextFrameInfoIdx]);
241 
242   _nextFrameInfoIdx = (_nextFrameInfoIdx + 1) % kDecoderFrameMemoryLength;
243   int32_t ret = decoder_->Decode(frame.EncodedImage(), frame.MissingFrame(),
244                                  frame.RenderTimeMs());
245   const char* new_implementation_name = decoder_->ImplementationName();
246   if (new_implementation_name != implementation_name_) {
247     implementation_name_ = new_implementation_name;
248     RTC_LOG(LS_INFO) << "Changed decoder implementation to: "
249                      << new_implementation_name;
250   }
251   _callback->OnDecoderImplementationName(implementation_name_.c_str());
252   if (ret < WEBRTC_VIDEO_CODEC_OK) {
253     RTC_LOG(LS_WARNING) << "Failed to decode frame with timestamp "
254                         << frame.Timestamp() << ", error code: " << ret;
255     _callback->Pop(frame.Timestamp());
256     return ret;
257   } else if (ret == WEBRTC_VIDEO_CODEC_NO_OUTPUT) {
258     // No output
259     _callback->Pop(frame.Timestamp());
260   }
261   return ret;
262 }
263 
RegisterDecodeCompleteCallback(VCMDecodedFrameCallback * callback)264 int32_t VCMGenericDecoder::RegisterDecodeCompleteCallback(
265     VCMDecodedFrameCallback* callback) {
266   _callback = callback;
267   return decoder_->RegisterDecodeCompleteCallback(callback);
268 }
269 
PrefersLateDecoding() const270 bool VCMGenericDecoder::PrefersLateDecoding() const {
271   return decoder_->PrefersLateDecoding();
272 }
273 
274 }  // namespace webrtc
275