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Diffstat (limited to 'webrtc/modules/video_coding/timing.cc')
| -rw-r--r-- | webrtc/modules/video_coding/timing.cc | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/webrtc/modules/video_coding/timing.cc b/webrtc/modules/video_coding/timing.cc new file mode 100644 index 0000000000..08dc307524 --- /dev/null +++ b/webrtc/modules/video_coding/timing.cc @@ -0,0 +1,284 @@ +/* + * 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 "webrtc/modules/video_coding/timing.h" + +#include <algorithm> + +#include "webrtc/modules/video_coding/internal_defines.h" +#include "webrtc/modules/video_coding/jitter_buffer_common.h" +#include "webrtc/system_wrappers/include/clock.h" +#include "webrtc/system_wrappers/include/metrics.h" +#include "webrtc/system_wrappers/include/timestamp_extrapolator.h" + +namespace webrtc { + +VCMTiming::VCMTiming(Clock* clock, VCMTiming* master_timing) + : crit_sect_(CriticalSectionWrapper::CreateCriticalSection()), + clock_(clock), + master_(false), + ts_extrapolator_(), + codec_timer_(), + render_delay_ms_(kDefaultRenderDelayMs), + min_playout_delay_ms_(0), + jitter_delay_ms_(0), + current_delay_ms_(0), + last_decode_ms_(0), + prev_frame_timestamp_(0), + num_decoded_frames_(0), + num_delayed_decoded_frames_(0), + first_decoded_frame_ms_(-1), + sum_missed_render_deadline_ms_(0) { + if (master_timing == NULL) { + master_ = true; + ts_extrapolator_ = new TimestampExtrapolator(clock_->TimeInMilliseconds()); + } else { + ts_extrapolator_ = master_timing->ts_extrapolator_; + } +} + +VCMTiming::~VCMTiming() { + UpdateHistograms(); + if (master_) { + delete ts_extrapolator_; + } + delete crit_sect_; +} + +void VCMTiming::UpdateHistograms() const { + CriticalSectionScoped cs(crit_sect_); + if (num_decoded_frames_ == 0) { + return; + } + int64_t elapsed_sec = + (clock_->TimeInMilliseconds() - first_decoded_frame_ms_) / 1000; + if (elapsed_sec < metrics::kMinRunTimeInSeconds) { + return; + } + RTC_HISTOGRAM_COUNTS_SPARSE_100( + "WebRTC.Video.DecodedFramesPerSecond", + static_cast<int>((num_decoded_frames_ / elapsed_sec) + 0.5f)); + RTC_HISTOGRAM_PERCENTAGE_SPARSE( + "WebRTC.Video.DelayedFramesToRenderer", + num_delayed_decoded_frames_ * 100 / num_decoded_frames_); + if (num_delayed_decoded_frames_ > 0) { + RTC_HISTOGRAM_COUNTS_SPARSE_1000( + "WebRTC.Video.DelayedFramesToRenderer_AvgDelayInMs", + sum_missed_render_deadline_ms_ / num_delayed_decoded_frames_); + } +} + +void VCMTiming::Reset() { + CriticalSectionScoped cs(crit_sect_); + ts_extrapolator_->Reset(clock_->TimeInMilliseconds()); + codec_timer_.Reset(); + render_delay_ms_ = kDefaultRenderDelayMs; + min_playout_delay_ms_ = 0; + jitter_delay_ms_ = 0; + current_delay_ms_ = 0; + prev_frame_timestamp_ = 0; +} + +void VCMTiming::ResetDecodeTime() { + CriticalSectionScoped lock(crit_sect_); + codec_timer_.Reset(); +} + +void VCMTiming::set_render_delay(uint32_t render_delay_ms) { + CriticalSectionScoped cs(crit_sect_); + render_delay_ms_ = render_delay_ms; +} + +void VCMTiming::set_min_playout_delay(uint32_t min_playout_delay_ms) { + CriticalSectionScoped cs(crit_sect_); + min_playout_delay_ms_ = min_playout_delay_ms; +} + +void VCMTiming::SetJitterDelay(uint32_t jitter_delay_ms) { + CriticalSectionScoped cs(crit_sect_); + if (jitter_delay_ms != jitter_delay_ms_) { + jitter_delay_ms_ = jitter_delay_ms; + // When in initial state, set current delay to minimum delay. + if (current_delay_ms_ == 0) { + current_delay_ms_ = jitter_delay_ms_; + } + } +} + +void VCMTiming::UpdateCurrentDelay(uint32_t frame_timestamp) { + CriticalSectionScoped cs(crit_sect_); + uint32_t target_delay_ms = TargetDelayInternal(); + + if (current_delay_ms_ == 0) { + // Not initialized, set current delay to target. + current_delay_ms_ = target_delay_ms; + } else if (target_delay_ms != current_delay_ms_) { + int64_t delay_diff_ms = + static_cast<int64_t>(target_delay_ms) - current_delay_ms_; + // 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. + int64_t max_change_ms = 0; + if (frame_timestamp < 0x0000ffff && prev_frame_timestamp_ > 0xffff0000) { + // wrap + max_change_ms = kDelayMaxChangeMsPerS * + (frame_timestamp + (static_cast<int64_t>(1) << 32) - + prev_frame_timestamp_) / + 90000; + } else { + max_change_ms = kDelayMaxChangeMsPerS * + (frame_timestamp - prev_frame_timestamp_) / 90000; + } + if (max_change_ms <= 0) { + // 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_ms = std::max(delay_diff_ms, -max_change_ms); + delay_diff_ms = std::min(delay_diff_ms, max_change_ms); + + current_delay_ms_ = current_delay_ms_ + static_cast<int32_t>(delay_diff_ms); + } + prev_frame_timestamp_ = frame_timestamp; +} + +void VCMTiming::UpdateCurrentDelay(int64_t render_time_ms, + int64_t actual_decode_time_ms) { + CriticalSectionScoped cs(crit_sect_); + uint32_t target_delay_ms = TargetDelayInternal(); + int64_t delayed_ms = actual_decode_time_ms - + (render_time_ms - MaxDecodeTimeMs() - render_delay_ms_); + if (delayed_ms < 0) { + return; + } + if (current_delay_ms_ + delayed_ms <= target_delay_ms) { + current_delay_ms_ += static_cast<uint32_t>(delayed_ms); + } else { + current_delay_ms_ = target_delay_ms; + } +} + +int32_t VCMTiming::StopDecodeTimer(uint32_t time_stamp, + int32_t decode_time_ms, + int64_t now_ms, + int64_t render_time_ms) { + CriticalSectionScoped cs(crit_sect_); + codec_timer_.MaxFilter(decode_time_ms, now_ms); + assert(decode_time_ms >= 0); + last_decode_ms_ = decode_time_ms; + + // Update stats. + ++num_decoded_frames_; + if (num_decoded_frames_ == 1) { + first_decoded_frame_ms_ = now_ms; + } + int time_until_rendering_ms = render_time_ms - render_delay_ms_ - now_ms; + if (time_until_rendering_ms < 0) { + sum_missed_render_deadline_ms_ += -time_until_rendering_ms; + ++num_delayed_decoded_frames_; + } + return 0; +} + +void VCMTiming::IncomingTimestamp(uint32_t time_stamp, int64_t now_ms) { + CriticalSectionScoped cs(crit_sect_); + ts_extrapolator_->Update(now_ms, time_stamp); +} + +int64_t VCMTiming::RenderTimeMs(uint32_t frame_timestamp, + int64_t now_ms) const { + CriticalSectionScoped cs(crit_sect_); + const int64_t render_time_ms = RenderTimeMsInternal(frame_timestamp, now_ms); + return render_time_ms; +} + +int64_t VCMTiming::RenderTimeMsInternal(uint32_t frame_timestamp, + int64_t now_ms) const { + int64_t estimated_complete_time_ms = + ts_extrapolator_->ExtrapolateLocalTime(frame_timestamp); + if (estimated_complete_time_ms == -1) { + estimated_complete_time_ms = now_ms; + } + + // Make sure that we have at least the playout delay. + uint32_t actual_delay = std::max(current_delay_ms_, min_playout_delay_ms_); + return estimated_complete_time_ms + actual_delay; +} + +// Must be called from inside a critical section. +int32_t VCMTiming::MaxDecodeTimeMs( + FrameType frame_type /*= kVideoFrameDelta*/) const { + const int32_t decode_time_ms = codec_timer_.RequiredDecodeTimeMs(frame_type); + assert(decode_time_ms >= 0); + return decode_time_ms; +} + +uint32_t VCMTiming::MaxWaitingTime(int64_t render_time_ms, + int64_t now_ms) const { + CriticalSectionScoped cs(crit_sect_); + + const int64_t max_wait_time_ms = + render_time_ms - now_ms - MaxDecodeTimeMs() - render_delay_ms_; + + if (max_wait_time_ms < 0) { + return 0; + } + return static_cast<uint32_t>(max_wait_time_ms); +} + +bool VCMTiming::EnoughTimeToDecode( + uint32_t available_processing_time_ms) const { + CriticalSectionScoped cs(crit_sect_); + int32_t max_decode_time_ms = MaxDecodeTimeMs(); + if (max_decode_time_ms < 0) { + // Haven't decoded any frames yet, try decoding one to get an estimate + // of the decode time. + return true; + } else if (max_decode_time_ms == 0) { + // Decode time is less than 1, set to 1 for now since + // we don't have any better precision. Count ticks later? + max_decode_time_ms = 1; + } + return static_cast<int32_t>(available_processing_time_ms) - + max_decode_time_ms > + 0; +} + +uint32_t VCMTiming::TargetVideoDelay() const { + CriticalSectionScoped cs(crit_sect_); + return TargetDelayInternal(); +} + +uint32_t VCMTiming::TargetDelayInternal() const { + return std::max(min_playout_delay_ms_, + jitter_delay_ms_ + MaxDecodeTimeMs() + render_delay_ms_); +} + +void VCMTiming::GetTimings(int* decode_ms, + int* max_decode_ms, + int* current_delay_ms, + int* target_delay_ms, + int* jitter_buffer_ms, + int* min_playout_delay_ms, + int* render_delay_ms) const { + CriticalSectionScoped cs(crit_sect_); + *decode_ms = last_decode_ms_; + *max_decode_ms = MaxDecodeTimeMs(); + *current_delay_ms = current_delay_ms_; + *target_delay_ms = TargetDelayInternal(); + *jitter_buffer_ms = jitter_delay_ms_; + *min_playout_delay_ms = min_playout_delay_ms_; + *render_delay_ms = render_delay_ms_; +} + +} // namespace webrtc |