Avoid resetting video encoder for similar configs.

BUG=1681
R=holmer@google.com, mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1442006

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4008 4adac7df-926f-26a2-2b94-8c16560cd09d

2 files changed, 69 insertions, 7 deletions

diff --git a/modules/video_coding/main/source/video_coding_impl.cc b/modules/video_coding/main/source/video_coding_impl.cc
index 4ed2e805..af326091 100644
--- a/modules/video_coding/main/source/video_coding_impl.cc
+++ b/modules/video_coding/main/source/video_coding_impl.cc
@@ -318,6 +318,63 @@ VideoCodingModuleImpl::InitializeSender()
     return VCM_OK;
 }
 
+bool VideoCodingModuleImpl::RequiresEncoderReset(const VideoCodec& send_codec) {
+  VideoCodec current_codec;
+
+  if (!_codecDataBase.SendCodec(&current_codec)) {
+    return true;
+  }
+
+  if (current_codec.codecType != send_codec.codecType ||
+      strcmp(current_codec.plName, send_codec.plName) != 0 ||
+      current_codec.plType != send_codec.plType ||
+      current_codec.width != send_codec.width ||
+      current_codec.height != send_codec.height ||
+      current_codec.qpMax != send_codec.qpMax ||
+      current_codec.numberOfSimulcastStreams !=
+          send_codec.numberOfSimulcastStreams ||
+      current_codec.mode != send_codec.mode ||
+      current_codec.extra_options != send_codec.extra_options) {
+    return true;
+  }
+
+  switch (current_codec.codecType) {
+    case kVideoCodecVP8:
+      if (memcmp(&current_codec.codecSpecific.VP8,
+                 &send_codec.codecSpecific.VP8,
+                 sizeof(current_codec.codecSpecific.VP8)) != 0) {
+        return true;
+      }
+      break;
+    case kVideoCodecGeneric:
+      if (memcmp(&current_codec.codecSpecific.Generic,
+                 &send_codec.codecSpecific.Generic,
+                 sizeof(current_codec.codecSpecific.Generic)) != 0) {
+        return true;
+      }
+      break;
+    // Known codecs without payload-specifics
+    case kVideoCodecI420:
+    case kVideoCodecRED:
+    case kVideoCodecULPFEC:
+      break;
+    // Unknown codec type, reset just to be sure.
+    case kVideoCodecUnknown:
+      return true;
+  }
+
+  if (current_codec.numberOfSimulcastStreams > 0) {
+    for (unsigned char i = 0; i < current_codec.numberOfSimulcastStreams; ++i) {
+      if (memcmp(&current_codec.simulcastStream[i],
+                 &send_codec.simulcastStream[i],
+                 sizeof(current_codec.simulcastStream[i])) != 0) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 // Register the send codec to be used.
 int32_t
 VideoCodingModuleImpl::RegisterSendCodec(const VideoCodec* sendCodec,
@@ -329,13 +386,18 @@ VideoCodingModuleImpl::RegisterSendCodec(const VideoCodec* sendCodec,
     {
         return VCM_PARAMETER_ERROR;
     }
-    bool ret = _codecDataBase.RegisterSendCodec(sendCodec, numberOfCores,
-                                                maxPayloadSize);
-    if (!ret)
-    {
+
+    bool requires_reconfigure = RequiresEncoderReset(*sendCodec);
+
+    if (!_codecDataBase.RegisterSendCodec(sendCodec, numberOfCores,
+                                          maxPayloadSize)) {
         return -1;
     }
 
+    if (!requires_reconfigure) {
+      return VCM_OK;
+    }
+
     _encoder = _codecDataBase.GetEncoder(sendCodec, &_encodedFrameCallback);
     if (_encoder == NULL)
     {
diff --git a/modules/video_coding/main/source/video_coding_impl.h b/modules/video_coding/main/source/video_coding_impl.h
index 0ffc14f0..a2338b25 100644
--- a/modules/video_coding/main/source/video_coding_impl.h
+++ b/modules/video_coding/main/source/video_coding_impl.h
@@ -279,13 +279,13 @@ public:
 
 protected:
     int32_t Decode(const webrtc::VCMEncodedFrame& frame);
+    bool RequiresEncoderReset(const VideoCodec& send_codec);
     int32_t RequestKeyFrame();
-    int32_t RequestSliceLossIndication(
-        const uint64_t pictureID) const;
+    int32_t RequestSliceLossIndication(const uint64_t pictureID) const;
     int32_t NackList(uint16_t* nackList, uint16_t& size);
 
 private:
-    int32_t                       _id;
+    int32_t                             _id;
     Clock*                              clock_;
     CriticalSectionWrapper*             _receiveCritSect;
     bool                                _receiverInited;