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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/libwebrtc/modules/video_coding/timing/timing.cc | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/modules/video_coding/timing/timing.cc')
-rw-r--r-- | third_party/libwebrtc/modules/video_coding/timing/timing.cc | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/timing/timing.cc b/third_party/libwebrtc/modules/video_coding/timing/timing.cc new file mode 100644 index 0000000000..0b61d5a35e --- /dev/null +++ b/third_party/libwebrtc/modules/video_coding/timing/timing.cc @@ -0,0 +1,297 @@ +/* + * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "modules/video_coding/timing/timing.h" + +#include <algorithm> + +#include "api/units/time_delta.h" +#include "modules/video_coding/timing/timestamp_extrapolator.h" +#include "rtc_base/experiments/field_trial_parser.h" +#include "rtc_base/logging.h" +#include "system_wrappers/include/clock.h" + +namespace webrtc { +namespace { + +// Default pacing that is used for the low-latency renderer path. +constexpr TimeDelta kZeroPlayoutDelayDefaultMinPacing = TimeDelta::Millis(8); +constexpr TimeDelta kLowLatencyStreamMaxPlayoutDelayThreshold = + TimeDelta::Millis(500); + +void CheckDelaysValid(TimeDelta min_delay, TimeDelta max_delay) { + if (min_delay > max_delay) { + RTC_LOG(LS_ERROR) + << "Playout delays set incorrectly: min playout delay (" << min_delay + << ") > max playout delay (" << max_delay + << "). This is undefined behaviour. Application writers should " + "ensure that the min delay is always less than or equals max " + "delay. If trying to use the playout delay header extensions " + "described in " + "https://webrtc.googlesource.com/src/+/refs/heads/main/docs/" + "native-code/rtp-hdrext/playout-delay/, be careful that a playout " + "delay hint or A/V sync settings may have caused this conflict."; + } +} + +} // namespace + +VCMTiming::VCMTiming(Clock* clock, const FieldTrialsView& field_trials) + : clock_(clock), + ts_extrapolator_( + std::make_unique<TimestampExtrapolator>(clock_->CurrentTime())), + codec_timer_(std::make_unique<CodecTimer>()), + render_delay_(kDefaultRenderDelay), + min_playout_delay_(TimeDelta::Zero()), + max_playout_delay_(TimeDelta::Seconds(10)), + jitter_delay_(TimeDelta::Zero()), + current_delay_(TimeDelta::Zero()), + prev_frame_timestamp_(0), + num_decoded_frames_(0), + zero_playout_delay_min_pacing_("min_pacing", + kZeroPlayoutDelayDefaultMinPacing), + last_decode_scheduled_(Timestamp::Zero()) { + ParseFieldTrial({&zero_playout_delay_min_pacing_}, + field_trials.Lookup("WebRTC-ZeroPlayoutDelay")); +} + +void VCMTiming::Reset() { + MutexLock lock(&mutex_); + ts_extrapolator_->Reset(clock_->CurrentTime()); + codec_timer_ = std::make_unique<CodecTimer>(); + render_delay_ = kDefaultRenderDelay; + min_playout_delay_ = TimeDelta::Zero(); + jitter_delay_ = TimeDelta::Zero(); + current_delay_ = TimeDelta::Zero(); + prev_frame_timestamp_ = 0; +} + +void VCMTiming::set_render_delay(TimeDelta render_delay) { + MutexLock lock(&mutex_); + render_delay_ = render_delay; +} + +TimeDelta VCMTiming::min_playout_delay() const { + MutexLock lock(&mutex_); + return min_playout_delay_; +} + +void VCMTiming::set_min_playout_delay(TimeDelta min_playout_delay) { + MutexLock lock(&mutex_); + if (min_playout_delay_ != min_playout_delay) { + CheckDelaysValid(min_playout_delay, max_playout_delay_); + min_playout_delay_ = min_playout_delay; + } +} + +void VCMTiming::set_max_playout_delay(TimeDelta max_playout_delay) { + MutexLock lock(&mutex_); + if (max_playout_delay_ != max_playout_delay) { + CheckDelaysValid(min_playout_delay_, max_playout_delay); + max_playout_delay_ = max_playout_delay; + } +} + +void VCMTiming::SetJitterDelay(TimeDelta jitter_delay) { + MutexLock lock(&mutex_); + if (jitter_delay != jitter_delay_) { + jitter_delay_ = jitter_delay; + // When in initial state, set current delay to minimum delay. + if (current_delay_.IsZero()) { + current_delay_ = jitter_delay_; + } + } +} + +void VCMTiming::UpdateCurrentDelay(uint32_t frame_timestamp) { + MutexLock lock(&mutex_); + TimeDelta target_delay = TargetDelayInternal(); + + if (current_delay_.IsZero()) { + // Not initialized, set current delay to target. + current_delay_ = target_delay; + } else if (target_delay != current_delay_) { + TimeDelta delay_diff = target_delay - current_delay_; + // Never change the delay with more than 100 ms every second. If we're + // changing the delay in too large steps we will get noticeable freezes. By + // limiting the change we can increase the delay in smaller steps, which + // will be experienced as the video is played in slow motion. When lowering + // the delay the video will be played at a faster pace. + TimeDelta max_change = TimeDelta::Zero(); + if (frame_timestamp < 0x0000ffff && prev_frame_timestamp_ > 0xffff0000) { + // wrap + max_change = + TimeDelta::Millis(kDelayMaxChangeMsPerS * + (frame_timestamp + (static_cast<int64_t>(1) << 32) - + prev_frame_timestamp_) / + 90000); + } else { + max_change = + TimeDelta::Millis(kDelayMaxChangeMsPerS * + (frame_timestamp - prev_frame_timestamp_) / 90000); + } + + if (max_change <= TimeDelta::Zero()) { + // Any changes less than 1 ms are truncated and will be postponed. + // Negative change will be due to reordering and should be ignored. + return; + } + delay_diff = std::max(delay_diff, -max_change); + delay_diff = std::min(delay_diff, max_change); + + current_delay_ = current_delay_ + delay_diff; + } + prev_frame_timestamp_ = frame_timestamp; +} + +void VCMTiming::UpdateCurrentDelay(Timestamp render_time, + Timestamp actual_decode_time) { + MutexLock lock(&mutex_); + TimeDelta target_delay = TargetDelayInternal(); + TimeDelta delayed = + (actual_decode_time - render_time) + RequiredDecodeTime() + render_delay_; + + // Only consider `delayed` as negative by more than a few microseconds. + if (delayed.ms() < 0) { + return; + } + if (current_delay_ + delayed <= target_delay) { + current_delay_ += delayed; + } else { + current_delay_ = target_delay; + } +} + +void VCMTiming::StopDecodeTimer(TimeDelta decode_time, Timestamp now) { + MutexLock lock(&mutex_); + codec_timer_->AddTiming(decode_time.ms(), now.ms()); + RTC_DCHECK_GE(decode_time, TimeDelta::Zero()); + ++num_decoded_frames_; +} + +void VCMTiming::IncomingTimestamp(uint32_t rtp_timestamp, Timestamp now) { + MutexLock lock(&mutex_); + ts_extrapolator_->Update(now, rtp_timestamp); +} + +Timestamp VCMTiming::RenderTime(uint32_t frame_timestamp, Timestamp now) const { + MutexLock lock(&mutex_); + return RenderTimeInternal(frame_timestamp, now); +} + +void VCMTiming::SetLastDecodeScheduledTimestamp( + Timestamp last_decode_scheduled) { + MutexLock lock(&mutex_); + last_decode_scheduled_ = last_decode_scheduled; +} + +Timestamp VCMTiming::RenderTimeInternal(uint32_t frame_timestamp, + Timestamp now) const { + if (UseLowLatencyRendering()) { + // Render as soon as possible or with low-latency renderer algorithm. + return Timestamp::Zero(); + } + // Note that TimestampExtrapolator::ExtrapolateLocalTime is not a const + // method; it mutates the object's wraparound state. + Timestamp estimated_complete_time = + ts_extrapolator_->ExtrapolateLocalTime(frame_timestamp).value_or(now); + + // Make sure the actual delay stays in the range of `min_playout_delay_` + // and `max_playout_delay_`. + TimeDelta actual_delay = + current_delay_.Clamped(min_playout_delay_, max_playout_delay_); + return estimated_complete_time + actual_delay; +} + +TimeDelta VCMTiming::RequiredDecodeTime() const { + const int decode_time_ms = codec_timer_->RequiredDecodeTimeMs(); + RTC_DCHECK_GE(decode_time_ms, 0); + return TimeDelta::Millis(decode_time_ms); +} + +TimeDelta VCMTiming::MaxWaitingTime(Timestamp render_time, + Timestamp now, + bool too_many_frames_queued) const { + MutexLock lock(&mutex_); + + if (render_time.IsZero() && zero_playout_delay_min_pacing_->us() > 0 && + min_playout_delay_.IsZero() && max_playout_delay_ > TimeDelta::Zero()) { + // `render_time` == 0 indicates that the frame should be decoded and + // rendered as soon as possible. However, the decoder can be choked if too + // many frames are sent at once. Therefore, limit the interframe delay to + // |zero_playout_delay_min_pacing_| unless too many frames are queued in + // which case the frames are sent to the decoder at once. + if (too_many_frames_queued) { + return TimeDelta::Zero(); + } + Timestamp earliest_next_decode_start_time = + last_decode_scheduled_ + zero_playout_delay_min_pacing_; + TimeDelta max_wait_time = now >= earliest_next_decode_start_time + ? TimeDelta::Zero() + : earliest_next_decode_start_time - now; + return max_wait_time; + } + return render_time - now - RequiredDecodeTime() - render_delay_; +} + +TimeDelta VCMTiming::TargetVideoDelay() const { + MutexLock lock(&mutex_); + return TargetDelayInternal(); +} + +TimeDelta VCMTiming::TargetDelayInternal() const { + return std::max(min_playout_delay_, + jitter_delay_ + RequiredDecodeTime() + render_delay_); +} + +VideoFrame::RenderParameters VCMTiming::RenderParameters() const { + MutexLock lock(&mutex_); + return {.use_low_latency_rendering = UseLowLatencyRendering(), + .max_composition_delay_in_frames = max_composition_delay_in_frames_}; +} + +bool VCMTiming::UseLowLatencyRendering() const { + // min_playout_delay_==0, + // max_playout_delay_<=kLowLatencyStreamMaxPlayoutDelayThreshold indicates + // that the low-latency path should be used, which means that frames should be + // decoded and rendered as soon as possible. + return min_playout_delay_.IsZero() && + max_playout_delay_ <= kLowLatencyStreamMaxPlayoutDelayThreshold; +} + +VCMTiming::VideoDelayTimings VCMTiming::GetTimings() const { + MutexLock lock(&mutex_); + return VideoDelayTimings{.max_decode_duration = RequiredDecodeTime(), + .current_delay = current_delay_, + .target_delay = TargetDelayInternal(), + .jitter_buffer_delay = jitter_delay_, + .min_playout_delay = min_playout_delay_, + .max_playout_delay = max_playout_delay_, + .render_delay = render_delay_, + .num_decoded_frames = num_decoded_frames_}; +} + +void VCMTiming::SetTimingFrameInfo(const TimingFrameInfo& info) { + MutexLock lock(&mutex_); + timing_frame_info_.emplace(info); +} + +absl::optional<TimingFrameInfo> VCMTiming::GetTimingFrameInfo() { + MutexLock lock(&mutex_); + return timing_frame_info_; +} + +void VCMTiming::SetMaxCompositionDelayInFrames( + absl::optional<int> max_composition_delay_in_frames) { + MutexLock lock(&mutex_); + max_composition_delay_in_frames_ = max_composition_delay_in_frames; +} + +} // namespace webrtc |