Avoid unnecessary HW video encoder reconfiguration

webrtc/media/engine/webrtcvideoengine2.h

Index: webrtc/media/engine/webrtcvideoengine2.h
diff --git a/webrtc/media/engine/webrtcvideoengine2.h b/webrtc/media/engine/webrtcvideoengine2.h
index 4c402d4256f1879763267283b1f090e857ac21ff..2a92ff4026a81cb2066557085307b25025ee787a 100644
--- a/webrtc/media/engine/webrtcvideoengine2.h
+++ b/webrtc/media/engine/webrtcvideoengine2.h
@@ -254,7 +254,7 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
         bool enable_cpu_overuse_detection,
         int max_bitrate_bps,
         const rtc::Optional<VideoCodecSettings>& codec_settings,
-        const std::vector<webrtc::RtpExtension>& rtp_extensions,
+        const rtc::Optional<std::vector<webrtc::RtpExtension>>& rtp_extensions,
         const VideoSendParameters& send_params);
     virtual ~WebRtcVideoSendStream();
 
@@ -351,9 +351,9 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
     void RecreateWebRtcStream() EXCLUSIVE_LOCKS_REQUIRED(lock_);
     webrtc::VideoEncoderConfig CreateVideoEncoderConfig(
         const Dimensions& dimensions,
+        bool encode_from_texture,
         const VideoCodec& codec) const EXCLUSIVE_LOCKS_REQUIRED(lock_);
-    void SetDimensions(int width, int height)
-        EXCLUSIVE_LOCKS_REQUIRED(lock_);
+    void ReconfigureEncoderIfNecessary() EXCLUSIVE_LOCKS_REQUIRED(lock_);
     bool ValidateRtpParameters(const webrtc::RtpParameters& parameters);
 
     // Calls Start or Stop according to whether or not |sending_| is true,
@@ -395,6 +395,7 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
     Dimensions last_dimensions_ GUARDED_BY(lock_);
     webrtc::VideoRotation last_rotation_ GUARDED_BY(lock_) =
         webrtc::kVideoRotation_0;
+    bool last_frame_is_texture_ GUARDED_BY(lock_) = false;

[pthatcher1, 2016/06/15 20:40:23]

We've got last_dimensions_, last_rotation_, and last_frame_is_texture_.  Could
we just have last_frame_info_ with those three in it?  In fact, we could even
get rid of the Dimensions struct, I think, and replace it with VideoFrameInfo.

Even better would be to just save the latest frame and send the frame
immediately after the first encoder config.  But we can save that for a future
CL.

[skvlad, 2016/06/15 22:10:36]

Replaced with VideoFrameInfo. Great suggestion, the code looks much clearer now.

 
     bool sending_ GUARDED_BY(lock_);
 
@@ -538,7 +539,7 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
   std::set<uint32_t> receive_ssrcs_ GUARDED_BY(stream_crit_);
 
   rtc::Optional<VideoCodecSettings> send_codec_;
-  std::vector<webrtc::RtpExtension> send_rtp_extensions_;
+  rtc::Optional<std::vector<webrtc::RtpExtension>> send_rtp_extensions_;
 
   WebRtcVideoEncoderFactory* const external_encoder_factory_;
   WebRtcVideoDecoderFactory* const external_decoder_factory_;