Revert of Merge webrtc/video_engine/ into webrtc/video/

webrtc/video/stream_synchronization.cc

-/*
- *  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/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