commit 1370e309e720b83b18f8dc7e3430e439481d8c51
author Seth Hampson <shampson@webrtc.org> Wed Feb 07 08:50:36 2018 -0800
committer Commit Bot <commit-bot@chromium.org> Mon Feb 12 20:08:34 2018 +0000
tree 78d784f0e4a1eb3213fd44b5ef022ec95e2da5c9
parent 6947025e95224c2ed4b4188faae619884e0c0987

Refactor of GetSimulcastConfig & EncoderStreamFactory.

The main pieces of this refactor are splitting up the creation of
simulcast layers for screenshare or the normal case, more consistent
naming, renaming streams to layers and trying to be more explicit with
some of the logic. Also added TODOs for future work to put more
application control into creating simulcast streams.

Bug: webrtc:8785
Change-Id: Ibf49fa0cc6d890ff96f8ee11c89d93a2c94119d6
Reviewed-on: https://webrtc-review.googlesource.com/47580
Commit-Queue: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Peter Thatcher <pthatcher@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21989}

media/engine/webrtcvideoengine.cc

diff --git a/media/engine/webrtcvideoengine.cc b/media/engine/webrtcvideoengine.cc
index dbf862a..8aa5aa2 100644
--- a/media/engine/webrtcvideoengine.cc
+++ b/media/engine/webrtcvideoengine.cc
@@ -1896,8 +1896,8 @@
   // configure a single stream.
   encoder_config.number_of_streams = parameters_.config.rtp.ssrcs.size();
   if (IsCodecBlacklistedForSimulcast(codec.name) ||
-      (is_screencast &&
-       (!UseSimulcastScreenshare() || !parameters_.conference_mode))) {
+      (is_screencast && (!ScreenshareSimulcastFieldTrialEnabled() ||
+                         !parameters_.conference_mode))) {
     encoder_config.number_of_streams = 1;
   }
 
@@ -2614,23 +2614,31 @@
   return video_codecs;
 }
 
-EncoderStreamFactory::EncoderStreamFactory(std::string codec_name,
-                                           int max_qp,
-                                           int max_framerate,
-                                           bool is_screencast,
-                                           bool conference_mode)
+// TODO(bugs.webrtc.org/8785): Consider removing max_qp and max_framerate
+// as members of EncoderStreamFactory and instead set these values individually
+// for each stream in the VideoEncoderConfig.simulcast_layers.
+EncoderStreamFactory::EncoderStreamFactory(
+    std::string codec_name,
+    int max_qp,
+    int max_framerate,
+    bool is_screenshare,
+    bool screenshare_config_explicitly_enabled)
+
     : codec_name_(codec_name),
       max_qp_(max_qp),
       max_framerate_(max_framerate),
-      is_screencast_(is_screencast),
-      conference_mode_(conference_mode) {}
+      is_screenshare_(is_screenshare),
+      screenshare_config_explicitly_enabled_(
+          screenshare_config_explicitly_enabled) {}
 
 std::vector<webrtc::VideoStream> EncoderStreamFactory::CreateEncoderStreams(
     int width,
     int height,
     const webrtc::VideoEncoderConfig& encoder_config) {
-  if (is_screencast_ &&
-      (!conference_mode_ || !cricket::UseSimulcastScreenshare())) {
+  bool screenshare_simulcast_enabled =
+      screenshare_config_explicitly_enabled_ &&
+      cricket::ScreenshareSimulcastFieldTrialEnabled();
+  if (is_screenshare_ && !screenshare_simulcast_enabled) {
     RTC_DCHECK_EQ(1, encoder_config.number_of_streams);
   }
   RTC_DCHECK_EQ(encoder_config.simulcast_layers.size(),
@@ -2638,12 +2646,12 @@
   std::vector<webrtc::VideoStream> layers;
 
   if (encoder_config.number_of_streams > 1 ||
-      (CodecNamesEq(codec_name_, kVp8CodecName) && is_screencast_ &&
-       conference_mode_)) {
+      (CodecNamesEq(codec_name_, kVp8CodecName) && is_screenshare_ &&
+       screenshare_config_explicitly_enabled_)) {
     layers = GetSimulcastConfig(encoder_config.number_of_streams, width, height,
                                 encoder_config.max_bitrate_bps,
                                 encoder_config.bitrate_priority, max_qp_,
-                                max_framerate_, is_screencast_);
+                                max_framerate_, is_screenshare_);
     // Update the active simulcast layers.
     for (size_t i = 0; i < layers.size(); ++i) {
       layers[i].active = encoder_config.simulcast_layers[i].active;
@@ -2666,7 +2674,7 @@
   layer.max_qp = max_qp_;
   layer.bitrate_priority = encoder_config.bitrate_priority;
 
-  if (CodecNamesEq(codec_name_, kVp9CodecName) && !is_screencast_) {
+  if (CodecNamesEq(codec_name_, kVp9CodecName) && !is_screenshare_) {
     layer.temporal_layer_thresholds_bps.resize(GetDefaultVp9TemporalLayers() -
                                                1);
   }