1 // Copyright 2020 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "cast/standalone_sender/looping_file_sender.h"
6
7 #include "util/trace_logging.h"
8
9 namespace openscreen {
10 namespace cast {
11
LoopingFileSender(TaskRunner * task_runner,const char * path,const IPEndpoint & remote_endpoint,SenderSession::ConfiguredSenders senders,int max_bitrate)12 LoopingFileSender::LoopingFileSender(TaskRunner* task_runner,
13 const char* path,
14 const IPEndpoint& remote_endpoint,
15 SenderSession::ConfiguredSenders senders,
16 int max_bitrate)
17 : env_(&Clock::now, task_runner),
18 path_(path),
19 packet_router_(&env_),
20 max_bitrate_(max_bitrate),
21 audio_encoder_(senders.audio_sender->config().channels,
22 StreamingOpusEncoder::kDefaultCastAudioFramesPerSecond,
23 senders.audio_sender),
24 video_encoder_(StreamingVp8Encoder::Parameters{},
25 env_.task_runner(),
26 senders.video_sender),
27 next_task_(env_.now_function(), env_.task_runner()),
28 console_update_task_(env_.now_function(), env_.task_runner()) {
29 env_.set_remote_endpoint(remote_endpoint);
30 // Opus and Vp8 are the default values for the config, and if these are set
31 // to a different value that means we offered a codec that we do not
32 // support, which is a developer error.
33 OSP_CHECK(senders.audio_config.codec == AudioCodec::kOpus);
34 OSP_CHECK(senders.video_config.codec == VideoCodec::kVp8);
35 OSP_LOG_INFO << "Streaming to " << remote_endpoint << "...";
36 OSP_LOG_INFO << "Max allowed media bitrate (audio + video) will be "
37 << max_bitrate_;
38 bandwidth_being_utilized_ = max_bitrate_ / 2;
39 UpdateEncoderBitrates();
40
__anonc8c487f30102null41 next_task_.Schedule([this] { SendFileAgain(); }, Alarm::kImmediately);
42 }
43
44 LoopingFileSender::~LoopingFileSender() = default;
45
UpdateEncoderBitrates()46 void LoopingFileSender::UpdateEncoderBitrates() {
47 if (bandwidth_being_utilized_ >= kHighBandwidthThreshold) {
48 audio_encoder_.UseHighQuality();
49 } else {
50 audio_encoder_.UseStandardQuality();
51 }
52 video_encoder_.SetTargetBitrate(bandwidth_being_utilized_ -
53 audio_encoder_.GetBitrate());
54 }
55
ControlForNetworkCongestion()56 void LoopingFileSender::ControlForNetworkCongestion() {
57 bandwidth_estimate_ = packet_router_.ComputeNetworkBandwidth();
58 if (bandwidth_estimate_ > 0) {
59 // Don't ever try to use *all* of the network bandwidth! However, don't go
60 // below the absolute minimum requirement either.
61 constexpr double kGoodNetworkCitizenFactor = 0.8;
62 const int usable_bandwidth = std::max<int>(
63 kGoodNetworkCitizenFactor * bandwidth_estimate_, kMinRequiredBitrate);
64
65 // See "congestion control" discussion in the class header comments for
66 // BandwidthEstimator.
67 if (usable_bandwidth > bandwidth_being_utilized_) {
68 constexpr double kConservativeIncrease = 1.1;
69 bandwidth_being_utilized_ = std::min<int>(
70 bandwidth_being_utilized_ * kConservativeIncrease, usable_bandwidth);
71 } else {
72 bandwidth_being_utilized_ = usable_bandwidth;
73 }
74
75 // Repsect the user's maximum bitrate setting.
76 bandwidth_being_utilized_ =
77 std::min(bandwidth_being_utilized_, max_bitrate_);
78
79 UpdateEncoderBitrates();
80 } else {
81 // There is no current bandwidth estimate. So, nothing should be adjusted.
82 }
83
84 next_task_.ScheduleFromNow([this] { ControlForNetworkCongestion(); },
85 kCongestionCheckInterval);
86 }
87
SendFileAgain()88 void LoopingFileSender::SendFileAgain() {
89 OSP_LOG_INFO << "Sending " << path_ << " (starts in one second)...";
90 TRACE_DEFAULT_SCOPED(TraceCategory::kStandaloneSender);
91
92 OSP_DCHECK_EQ(num_capturers_running_, 0);
93 num_capturers_running_ = 2;
94 capture_start_time_ = latest_frame_time_ = env_.now() + seconds(1);
95 audio_capturer_.emplace(&env_, path_, audio_encoder_.num_channels(),
96 audio_encoder_.sample_rate(), capture_start_time_,
97 this);
98 video_capturer_.emplace(&env_, path_, capture_start_time_, this);
99
100 next_task_.ScheduleFromNow([this] { ControlForNetworkCongestion(); },
101 kCongestionCheckInterval);
102 console_update_task_.Schedule([this] { UpdateStatusOnConsole(); },
103 capture_start_time_);
104 }
105
OnAudioData(const float * interleaved_samples,int num_samples,Clock::time_point capture_time)106 void LoopingFileSender::OnAudioData(const float* interleaved_samples,
107 int num_samples,
108 Clock::time_point capture_time) {
109 TRACE_DEFAULT_SCOPED(TraceCategory::kStandaloneSender);
110 latest_frame_time_ = std::max(capture_time, latest_frame_time_);
111 audio_encoder_.EncodeAndSend(interleaved_samples, num_samples, capture_time);
112 }
113
OnVideoFrame(const AVFrame & av_frame,Clock::time_point capture_time)114 void LoopingFileSender::OnVideoFrame(const AVFrame& av_frame,
115 Clock::time_point capture_time) {
116 TRACE_DEFAULT_SCOPED(TraceCategory::kStandaloneSender);
117 latest_frame_time_ = std::max(capture_time, latest_frame_time_);
118 StreamingVp8Encoder::VideoFrame frame{};
119 frame.width = av_frame.width - av_frame.crop_left - av_frame.crop_right;
120 frame.height = av_frame.height - av_frame.crop_top - av_frame.crop_bottom;
121 frame.yuv_planes[0] = av_frame.data[0] + av_frame.crop_left +
122 av_frame.linesize[0] * av_frame.crop_top;
123 frame.yuv_planes[1] = av_frame.data[1] + av_frame.crop_left / 2 +
124 av_frame.linesize[1] * av_frame.crop_top / 2;
125 frame.yuv_planes[2] = av_frame.data[2] + av_frame.crop_left / 2 +
126 av_frame.linesize[2] * av_frame.crop_top / 2;
127 for (int i = 0; i < 3; ++i) {
128 frame.yuv_strides[i] = av_frame.linesize[i];
129 }
130 // TODO(miu): Add performance metrics visual overlay (based on Stats
131 // callback).
132 video_encoder_.EncodeAndSend(frame, capture_time, {});
133 }
134
UpdateStatusOnConsole()135 void LoopingFileSender::UpdateStatusOnConsole() {
136 const Clock::duration elapsed = latest_frame_time_ - capture_start_time_;
137 const auto seconds_part = to_seconds(elapsed);
138 const auto millis_part = to_microseconds(elapsed - seconds_part);
139 // The control codes here attempt to erase the current line the cursor is
140 // on, and then print out the updated status text. If the terminal does not
141 // support simple ANSI escape codes, the following will still work, but
142 // there might sometimes be old status lines not getting erased (i.e., just
143 // partially overwritten).
144 fprintf(stdout,
145 "\r\x1b[2K\rLoopingFileSender: At %01" PRId64
146 ".%03ds in file (est. network bandwidth: %d kbps). \n",
147 static_cast<int64_t>(seconds_part.count()),
148 static_cast<int>(millis_part.count()), bandwidth_estimate_ / 1024);
149 fflush(stdout);
150
151 console_update_task_.ScheduleFromNow([this] { UpdateStatusOnConsole(); },
152 kConsoleUpdateInterval);
153 }
154
OnEndOfFile(SimulatedCapturer * capturer)155 void LoopingFileSender::OnEndOfFile(SimulatedCapturer* capturer) {
156 OSP_LOG_INFO << "The " << ToTrackName(capturer)
157 << " capturer has reached the end of the media stream.";
158 --num_capturers_running_;
159 if (num_capturers_running_ == 0) {
160 console_update_task_.Cancel();
161 next_task_.Schedule([this] { SendFileAgain(); }, Alarm::kImmediately);
162 }
163 }
164
OnError(SimulatedCapturer * capturer,std::string message)165 void LoopingFileSender::OnError(SimulatedCapturer* capturer,
166 std::string message) {
167 OSP_LOG_ERROR << "The " << ToTrackName(capturer)
168 << " has failed: " << message;
169 --num_capturers_running_;
170 // If both fail, the application just pauses. This accounts for things like
171 // "file not found" errors. However, if only one track fails, then keep
172 // going.
173 }
174
ToTrackName(SimulatedCapturer * capturer) const175 const char* LoopingFileSender::ToTrackName(SimulatedCapturer* capturer) const {
176 const char* which;
177 if (capturer == &*audio_capturer_) {
178 which = "audio";
179 } else if (capturer == &*video_capturer_) {
180 which = "video";
181 } else {
182 OSP_NOTREACHED();
183 which = "";
184 }
185 return which;
186 }
187
188 } // namespace cast
189 } // namespace openscreen
190