webrtc/modules/video_coding/utility/simulcast_utility.cc
Florent Castelli d3511010d9 Reland "Only enable conference mode simulcast allocations with flag enabled"
This is a reland of 32ca95145c

Fix includes not enabling the screenshare conference behavior on non
screenshare sources even if the flag is enabled.

Original change's description:
> Only enable conference mode simulcast allocations with flag enabled
>
> Non-conference mode simulcast screenshares were mistakenly using the
> conference mode semantics in the simulcast rate allocator, which broke
> spec compliant usage in some situation.
>
> This behavior should only be used when explicitly using the SDP entry
> "a=x-google-flag:conference" in both offer and answer.
>
> Bug: webrtc:11310, chromium:1093819
> Change-Id: Ibcba75c88a8405d60467546b33977a782e04e469
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/179081
> Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
> Commit-Queue: Florent Castelli <orphis@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#31828}

Bug: webrtc:11310
Bug: chromium:1093819
Change-Id: Ic933f93a5c4bad20583354fe821f8a1170e911cd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/180802
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31847}
2020-08-04 10:30:08 +00:00

104 lines
3.3 KiB
C++

/*
* Copyright (c) 2018 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/utility/simulcast_utility.h"
#include <algorithm>
#include <cmath>
#include "rtc_base/checks.h"
namespace webrtc {
uint32_t SimulcastUtility::SumStreamMaxBitrate(int streams,
const VideoCodec& codec) {
uint32_t bitrate_sum = 0;
for (int i = 0; i < streams; ++i) {
bitrate_sum += codec.simulcastStream[i].maxBitrate;
}
return bitrate_sum;
}
int SimulcastUtility::NumberOfSimulcastStreams(const VideoCodec& codec) {
int streams =
codec.numberOfSimulcastStreams < 1 ? 1 : codec.numberOfSimulcastStreams;
uint32_t simulcast_max_bitrate = SumStreamMaxBitrate(streams, codec);
if (simulcast_max_bitrate == 0) {
streams = 1;
}
return streams;
}
bool SimulcastUtility::ValidSimulcastParameters(const VideoCodec& codec,
int num_streams) {
// Check resolution.
if (codec.width != codec.simulcastStream[num_streams - 1].width ||
codec.height != codec.simulcastStream[num_streams - 1].height) {
return false;
}
for (int i = 0; i < num_streams; ++i) {
if (codec.width * codec.simulcastStream[i].height !=
codec.height * codec.simulcastStream[i].width) {
return false;
}
}
if (codec.codecType == webrtc::kVideoCodecVP8) {
for (int i = 1; i < num_streams; ++i) {
if (codec.simulcastStream[i].width < codec.simulcastStream[i - 1].width) {
return false;
}
}
} else {
// TODO(mirtad): H264 encoder implementation still assumes the default
// resolution downscaling is used.
for (int i = 1; i < num_streams; ++i) {
if (codec.simulcastStream[i].width !=
codec.simulcastStream[i - 1].width * 2) {
return false;
}
}
}
// Check frame-rate.
for (int i = 1; i < num_streams; ++i) {
if (fabs(codec.simulcastStream[i].maxFramerate -
codec.simulcastStream[i - 1].maxFramerate) > 1e-9) {
return false;
}
}
// Check temporal layers.
for (int i = 0; i < num_streams - 1; ++i) {
if (codec.simulcastStream[i].numberOfTemporalLayers !=
codec.simulcastStream[i + 1].numberOfTemporalLayers)
return false;
}
return true;
}
bool SimulcastUtility::IsConferenceModeScreenshare(const VideoCodec& codec) {
return codec.mode == VideoCodecMode::kScreensharing &&
codec.legacy_conference_mode;
}
int SimulcastUtility::NumberOfTemporalLayers(const VideoCodec& codec,
int spatial_id) {
uint8_t num_temporal_layers =
std::max<uint8_t>(1, codec.VP8().numberOfTemporalLayers);
if (codec.numberOfSimulcastStreams > 0) {
RTC_DCHECK_LT(spatial_id, codec.numberOfSimulcastStreams);
num_temporal_layers =
std::max(num_temporal_layers,
codec.simulcastStream[spatial_id].numberOfTemporalLayers);
}
return num_temporal_layers;
}
} // namespace webrtc