Add framerate to VideoSinkWants and ability to signal on overuse

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 20 matching lines @@
 #include "webrtc/media/engine/videoencodersoftwarefallbackwrapper.h"
 #include "webrtc/media/engine/videodecodersoftwarefallbackwrapper.h"
 #include "webrtc/media/engine/webrtcmediaengine.h"
 #include "webrtc/media/engine/webrtcvideoencoderfactory.h"
 #include "webrtc/media/engine/webrtcvoiceengine.h"
 #include "webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.h"
 #include "webrtc/system_wrappers/include/field_trial.h"
 #include "webrtc/video_decoder.h"
 #include "webrtc/video_encoder.h"
 
+using DegradationPreference = webrtc::VideoSendStream::DegradationPreference;

[nisse-webrtc, 2017/03/14 09:00:29]

Perhaps not for this cl, but if DegradationPreference is intended as a public
high-level API, it should perhaps be in the top-level webrtc namespace.

[sprang_webrtc, 2017/03/14 14:15:02]

Agreed. I think we need to overhaul a few pieces of our api's. But that usually
get's messy, so let's do it in something smaller and more easily revertable :)

+
 namespace cricket {
 namespace {
-
 // If this field trial is enabled, we will enable sending FlexFEC and disable
 // sending ULPFEC whenever the former has been negotiated. Receiving FlexFEC
 // is enabled whenever FlexFEC has been negotiated.
 bool IsFlexfecFieldTrialEnabled() {
   return webrtc::field_trial::FindFullName("WebRTC-FlexFEC-03") == "Enabled";
 }
 
 // Wrap cricket::WebRtcVideoEncoderFactory as a webrtc::VideoEncoderFactory.
 class EncoderFactoryAdapter : public webrtc::VideoEncoderFactory {
  public:
@@ skipping 1566 matching lines @@
       // changes that may require codec reconfiguration.
       old_options.is_screencast = options->is_screencast;
     }
     if (parameters_.options != old_options) {
       ReconfigureEncoder();
     }
   }
 
   if (source_ && stream_) {
     stream_->SetSource(
-        nullptr, webrtc::VideoSendStream::DegradationPreference::kBalanced);
+        nullptr,
+        webrtc::VideoSendStream::DegradationPreference::kDegradationDisabled);

[kthelgason, 2017/03/14 10:01:20]

just DegradationPreference::kDegradationDisabled given the using directive
above.

[sprang_webrtc, 2017/03/14 14:15:02]

Done.

   }
   // Switch to the new source.
   source_ = source;
   if (source && stream_) {
     // Do not adapt resolution for screen content as this will likely
     // result in blurry and unreadable text.
     // |this| acts like a VideoSource to make sure SinkWants are handled on the
     // correct thread.
-    stream_->SetSource(
-        this, enable_cpu_overuse_detection_ &&
-                      !parameters_.options.is_screencast.value_or(false)
-                  ? webrtc::VideoSendStream::DegradationPreference::kBalanced
-                  : webrtc::VideoSendStream::DegradationPreference::
-                        kMaintainResolution);
+    DegradationPreference degradation_preference;
+    if (!enable_cpu_overuse_detection_) {
+      degradation_preference = DegradationPreference::kDegradationDisabled;

[nisse-webrtc, 2017/03/14 09:00:29]

I wonder if this disable value should be made available to applications, all the
way up to js? I don't think the name is quite right in that context. 

[sprang_webrtc, 2017/03/14 14:15:02]

|enable_cpu_overuse_detection_| is currently populated from js as a media
constraint I believe. I'm just making a simple translation here. For ortc I
guess we wan't to just use degradation preference, right?

+    } else {
+      if (parameters_.options.is_screencast.value_or(false)) {
+        degradation_preference = DegradationPreference::kMaintainResolution;
+      } else {
+        degradation_preference = DegradationPreference::kMaintainFramerate;
+      }
+    }
+    stream_->SetSource(this, degradation_preference);
   }
   return true;
 }
 
 const std::vector<uint32_t>&
 WebRtcVideoChannel2::WebRtcVideoSendStream::GetSsrcs() const {
   return ssrcs_;
 }
 
 WebRtcVideoChannel2::WebRtcVideoSendStream::AllocatedEncoder
@@ skipping 426 matching lines @@
                                          parameters_.encoder_config.Copy());
 
   parameters_.encoder_config.encoder_specific_settings = NULL;
 
   if (source_) {
     // Do not adapt resolution for screen content as this will likely result in
     // blurry and unreadable text.
     // |this| acts like a VideoSource to make sure SinkWants are handled on the
     // correct thread.
     stream_->SetSource(
-        this, enable_cpu_overuse_detection_ &&
-                      !parameters_.options.is_screencast.value_or(false)
-                  ? webrtc::VideoSendStream::DegradationPreference::kBalanced
-                  : webrtc::VideoSendStream::DegradationPreference::
-                        kMaintainResolution);
+        this,
+        enable_cpu_overuse_detection_ &&
+                !parameters_.options.is_screencast.value_or(false)
+            ? webrtc::VideoSendStream::DegradationPreference::kMaintainFramerate

[nisse-webrtc, 2017/03/14 09:00:29]

Why is this logic different from logic in SetVideoSend, above?

It would be clearer if the logic were the same, and common code extracted to a
helper method.

[sprang_webrtc, 2017/03/14 14:15:02]

Done.

+            : webrtc::VideoSendStream::DegradationPreference::
+                  kMaintainResolution);
   }
 
   // Call stream_->Start() if necessary conditions are met.
   UpdateSendState();
 }
 
 WebRtcVideoChannel2::WebRtcVideoReceiveStream::WebRtcVideoReceiveStream(
     webrtc::Call* call,
     const StreamParams& sp,
     webrtc::VideoReceiveStream::Config config,
@@ skipping 436 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             ulpfec_config.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket