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Diffstat (limited to 'webrtc/video_engine/stream_synchronization.cc')
| -rw-r--r-- | webrtc/video_engine/stream_synchronization.cc | 226 |
1 files changed, 0 insertions, 226 deletions
diff --git a/webrtc/video_engine/stream_synchronization.cc b/webrtc/video_engine/stream_synchronization.cc deleted file mode 100644 index b78cfe8874..0000000000 --- a/webrtc/video_engine/stream_synchronization.cc +++ /dev/null @@ -1,226 +0,0 @@ -/* - * Copyright (c) 2012 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/video_engine/stream_synchronization.h" - -#include <assert.h> -#include <math.h> -#include <stdlib.h> - -#include <algorithm> - -#include "webrtc/base/logging.h" - -namespace webrtc { - -static const int kMaxChangeMs = 80; -static const int kMaxDeltaDelayMs = 10000; -static const int kFilterLength = 4; -// Minimum difference between audio and video to warrant a change. -static const int kMinDeltaMs = 30; - -struct ViESyncDelay { - ViESyncDelay() { - extra_video_delay_ms = 0; - last_video_delay_ms = 0; - extra_audio_delay_ms = 0; - last_audio_delay_ms = 0; - network_delay = 120; - } - - int extra_video_delay_ms; - int last_video_delay_ms; - int extra_audio_delay_ms; - int last_audio_delay_ms; - int network_delay; -}; - -StreamSynchronization::StreamSynchronization(uint32_t video_primary_ssrc, - int audio_channel_id) - : channel_delay_(new ViESyncDelay), - video_primary_ssrc_(video_primary_ssrc), - audio_channel_id_(audio_channel_id), - base_target_delay_ms_(0), - avg_diff_ms_(0) { -} - -StreamSynchronization::~StreamSynchronization() { - delete channel_delay_; -} - -bool StreamSynchronization::ComputeRelativeDelay( - const Measurements& audio_measurement, - const Measurements& video_measurement, - int* relative_delay_ms) { - assert(relative_delay_ms); - if (audio_measurement.rtcp.size() < 2 || video_measurement.rtcp.size() < 2) { - // We need two RTCP SR reports per stream to do synchronization. - return false; - } - int64_t audio_last_capture_time_ms; - if (!RtpToNtpMs(audio_measurement.latest_timestamp, - audio_measurement.rtcp, - &audio_last_capture_time_ms)) { - return false; - } - int64_t video_last_capture_time_ms; - if (!RtpToNtpMs(video_measurement.latest_timestamp, - video_measurement.rtcp, - &video_last_capture_time_ms)) { - return false; - } - if (video_last_capture_time_ms < 0) { - return false; - } - // Positive diff means that video_measurement is behind audio_measurement. - *relative_delay_ms = video_measurement.latest_receive_time_ms - - audio_measurement.latest_receive_time_ms - - (video_last_capture_time_ms - audio_last_capture_time_ms); - if (*relative_delay_ms > kMaxDeltaDelayMs || - *relative_delay_ms < -kMaxDeltaDelayMs) { - return false; - } - return true; -} - -bool StreamSynchronization::ComputeDelays(int relative_delay_ms, - int current_audio_delay_ms, - int* total_audio_delay_target_ms, - int* total_video_delay_target_ms) { - assert(total_audio_delay_target_ms && total_video_delay_target_ms); - - int current_video_delay_ms = *total_video_delay_target_ms; - LOG(LS_VERBOSE) << "Audio delay: " << current_audio_delay_ms - << ", network delay diff: " << channel_delay_->network_delay - << " current diff: " << relative_delay_ms - << " for channel " << audio_channel_id_; - // Calculate the difference between the lowest possible video delay and - // the current audio delay. - int current_diff_ms = current_video_delay_ms - current_audio_delay_ms + - relative_delay_ms; - - avg_diff_ms_ = ((kFilterLength - 1) * avg_diff_ms_ + - current_diff_ms) / kFilterLength; - if (abs(avg_diff_ms_) < kMinDeltaMs) { - // Don't adjust if the diff is within our margin. - return false; - } - - // Make sure we don't move too fast. - int diff_ms = avg_diff_ms_ / 2; - diff_ms = std::min(diff_ms, kMaxChangeMs); - diff_ms = std::max(diff_ms, -kMaxChangeMs); - - // Reset the average after a move to prevent overshooting reaction. - avg_diff_ms_ = 0; - - if (diff_ms > 0) { - // The minimum video delay is longer than the current audio delay. - // We need to decrease extra video delay, or add extra audio delay. - if (channel_delay_->extra_video_delay_ms > base_target_delay_ms_) { - // We have extra delay added to ViE. Reduce this delay before adding - // extra delay to VoE. - channel_delay_->extra_video_delay_ms -= diff_ms; - channel_delay_->extra_audio_delay_ms = base_target_delay_ms_; - } else { // channel_delay_->extra_video_delay_ms > 0 - // We have no extra video delay to remove, increase the audio delay. - channel_delay_->extra_audio_delay_ms += diff_ms; - channel_delay_->extra_video_delay_ms = base_target_delay_ms_; - } - } else { // if (diff_ms > 0) - // The video delay is lower than the current audio delay. - // We need to decrease extra audio delay, or add extra video delay. - if (channel_delay_->extra_audio_delay_ms > base_target_delay_ms_) { - // We have extra delay in VoiceEngine. - // Start with decreasing the voice delay. - // Note: diff_ms is negative; add the negative difference. - channel_delay_->extra_audio_delay_ms += diff_ms; - channel_delay_->extra_video_delay_ms = base_target_delay_ms_; - } else { // channel_delay_->extra_audio_delay_ms > base_target_delay_ms_ - // We have no extra delay in VoiceEngine, increase the video delay. - // Note: diff_ms is negative; subtract the negative difference. - channel_delay_->extra_video_delay_ms -= diff_ms; // X - (-Y) = X + Y. - channel_delay_->extra_audio_delay_ms = base_target_delay_ms_; - } - } - - // Make sure that video is never below our target. - channel_delay_->extra_video_delay_ms = std::max( - channel_delay_->extra_video_delay_ms, base_target_delay_ms_); - - int new_video_delay_ms; - if (channel_delay_->extra_video_delay_ms > base_target_delay_ms_) { - new_video_delay_ms = channel_delay_->extra_video_delay_ms; - } else { - // No change to the extra video delay. We are changing audio and we only - // allow to change one at the time. - new_video_delay_ms = channel_delay_->last_video_delay_ms; - } - - // Make sure that we don't go below the extra video delay. - new_video_delay_ms = std::max( - new_video_delay_ms, channel_delay_->extra_video_delay_ms); - - // Verify we don't go above the maximum allowed video delay. - new_video_delay_ms = - std::min(new_video_delay_ms, base_target_delay_ms_ + kMaxDeltaDelayMs); - - int new_audio_delay_ms; - if (channel_delay_->extra_audio_delay_ms > base_target_delay_ms_) { - new_audio_delay_ms = channel_delay_->extra_audio_delay_ms; - } else { - // No change to the audio delay. We are changing video and we only - // allow to change one at the time. - new_audio_delay_ms = channel_delay_->last_audio_delay_ms; - } - - // Make sure that we don't go below the extra audio delay. - new_audio_delay_ms = std::max( - new_audio_delay_ms, channel_delay_->extra_audio_delay_ms); - - // Verify we don't go above the maximum allowed audio delay. - new_audio_delay_ms = - std::min(new_audio_delay_ms, base_target_delay_ms_ + kMaxDeltaDelayMs); - - // Remember our last audio and video delays. - channel_delay_->last_video_delay_ms = new_video_delay_ms; - channel_delay_->last_audio_delay_ms = new_audio_delay_ms; - - LOG(LS_VERBOSE) << "Sync video delay " << new_video_delay_ms - << " for video primary SSRC " << video_primary_ssrc_ - << " and audio delay " << channel_delay_->extra_audio_delay_ms - << " for audio channel " << audio_channel_id_; - - // Return values. - *total_video_delay_target_ms = new_video_delay_ms; - *total_audio_delay_target_ms = new_audio_delay_ms; - return true; -} - -void StreamSynchronization::SetTargetBufferingDelay(int target_delay_ms) { - // Initial extra delay for audio (accounting for existing extra delay). - channel_delay_->extra_audio_delay_ms += - target_delay_ms - base_target_delay_ms_; - channel_delay_->last_audio_delay_ms += - target_delay_ms - base_target_delay_ms_; - - // The video delay is compared to the last value (and how much we can update - // is limited by that as well). - channel_delay_->last_video_delay_ms += - target_delay_ms - base_target_delay_ms_; - - channel_delay_->extra_video_delay_ms += - target_delay_ms - base_target_delay_ms_; - - // Video is already delayed by the desired amount. - base_target_delay_ms_ = target_delay_ms; -} - -} // namespace webrtc |