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Make struct SynchronizationDelays more general.

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Bug: none
Change-Id: Iab263789cc8b51917acb3db2803fa71a927bc62a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161640
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Commit-Queue: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30060}
This commit is contained in:
Åsa Persson
2019-12-09 12:41:56 +01:00
committed by Commit Bot
parent 3fdb3cbc6a
commit 4fc52c8329
2 changed files with 46 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
video/stream_synchronization.cc
View File

@ -10,7 +10,6 @@
#include "video/stream_synchronization.h"
#include <assert.h>
#include <stdlib.h>
#include <algorithm>
@ -36,7 +35,6 @@ bool StreamSynchronization::ComputeRelativeDelay(
const Measurements& audio_measurement,
const Measurements& video_measurement,
int* relative_delay_ms) {
assert(relative_delay_ms);
int64_t audio_last_capture_time_ms;
if (!audio_measurement.rtp_to_ntp.Estimate(audio_measurement.latest_timestamp,
&audio_last_capture_time_ms)) {
@ -66,14 +64,14 @@ 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;
RTC_LOG(LS_VERBOSE) << "Audio delay: " << current_audio_delay_ms
<< " current diff: " << relative_delay_ms
<< " for stream " << audio_stream_id_;
// Calculate the difference between the lowest possible video delay and
// the current audio delay.
// 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;
@ -95,82 +93,77 @@ bool StreamSynchronization::ComputeDelays(int relative_delay_ms,
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_) {
if (video_delay_.extra_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
video_delay_.extra_ms -= diff_ms;
audio_delay_.extra_ms = base_target_delay_ms_;
} else { // video_delay_.extra_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_;
audio_delay_.extra_ms += diff_ms;
video_delay_.extra_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_) {
if (audio_delay_.extra_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_
audio_delay_.extra_ms += diff_ms;
video_delay_.extra_ms = base_target_delay_ms_;
} else { // audio_delay_.extra_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_;
video_delay_.extra_ms -= diff_ms; // X - (-Y) = X + Y.
audio_delay_.extra_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_);
video_delay_.extra_ms =
std::max(video_delay_.extra_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;
if (video_delay_.extra_ms > base_target_delay_ms_) {
new_video_delay_ms = video_delay_.extra_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;
new_video_delay_ms = video_delay_.last_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);
new_video_delay_ms = std::max(new_video_delay_ms, video_delay_.extra_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;
if (audio_delay_.extra_ms > base_target_delay_ms_) {
new_audio_delay_ms = audio_delay_.extra_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;
// No change to the audio delay. We are changing video and we only allow to
// change one at the time.
new_audio_delay_ms = audio_delay_.last_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);
new_audio_delay_ms = std::max(new_audio_delay_ms, audio_delay_.extra_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;
video_delay_.last_ms = new_video_delay_ms;
audio_delay_.last_ms = new_audio_delay_ms;
RTC_LOG(LS_VERBOSE) << "Sync video delay " << new_video_delay_ms
<< " for video stream " << video_stream_id_
<< " and audio delay "
<< channel_delay_.extra_audio_delay_ms
<< " and audio delay " << audio_delay_.extra_ms
<< " for audio stream " << audio_stream_id_;
// Return values.
*total_video_delay_target_ms = new_video_delay_ms;
*total_audio_delay_target_ms = new_audio_delay_ms;
return true;
@ -178,16 +171,14 @@ bool StreamSynchronization::ComputeDelays(int relative_delay_ms,
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_;
audio_delay_.extra_ms += target_delay_ms - base_target_delay_ms_;
audio_delay_.last_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_;
video_delay_.last_ms += target_delay_ms - base_target_delay_ms_;
channel_delay_.extra_video_delay_ms +=
target_delay_ms - base_target_delay_ms_;
video_delay_.extra_ms += target_delay_ms - base_target_delay_ms_;
// Video is already delayed by the desired amount.
base_target_delay_ms_ = target_delay_ms;

22
video/stream_synchronization.h
View File

@ -30,28 +30,28 @@ class StreamSynchronization {
bool ComputeDelays(int relative_delay_ms,
int current_audio_delay_ms,
int* extra_audio_delay_ms,
int* total_audio_delay_target_ms,
int* total_video_delay_target_ms);
// On success |relative_delay| contains the number of milliseconds later video
// is rendered relative audio. If audio is played back later than video a
// |relative_delay| will be negative.
// On success |relative_delay_ms| contains the number of milliseconds later
// video is rendered relative audio. If audio is played back later than video
// |relative_delay_ms| will be negative.
static bool ComputeRelativeDelay(const Measurements& audio_measurement,
const Measurements& video_measurement,
int* relative_delay_ms);
// Set target buffering delay - All audio and video will be delayed by at
// least target_delay_ms.
// Set target buffering delay. Audio and video will be delayed by at least
// |target_delay_ms|.
void SetTargetBufferingDelay(int target_delay_ms);
private:
struct SynchronizationDelays {
int extra_video_delay_ms = 0;
int last_video_delay_ms = 0;
int extra_audio_delay_ms = 0;
int last_audio_delay_ms = 0;
int extra_ms = 0;
int last_ms = 0;
};
SynchronizationDelays channel_delay_;
SynchronizationDelays audio_delay_;
SynchronizationDelays video_delay_;
const int video_stream_id_;
const int audio_stream_id_;
int base_target_delay_ms_;