Cast: Prefer VP8 over H.264 for hardware encoder

chrome/renderer/media/cast_rtp_stream.cc

Index: chrome/renderer/media/cast_rtp_stream.cc
diff --git a/chrome/renderer/media/cast_rtp_stream.cc b/chrome/renderer/media/cast_rtp_stream.cc
index 7c40523c302e21a5d7856d653839a2e3b91cd9f3..92c7e16ea3e13bd7de92fa5d56258d74b895c56e 100644
--- a/chrome/renderer/media/cast_rtp_stream.cc
+++ b/chrome/renderer/media/cast_rtp_stream.cc
@@ -151,9 +151,14 @@ std::vector<CastRtpParams> SupportedAudioParams() {
 
 std::vector<CastRtpParams> SupportedVideoParams() {
   std::vector<CastRtpParams> supported_params;
-  if (IsHardwareH264EncodingSupported())
-    supported_params.push_back(CastRtpParams(DefaultH264Payload()));
-  supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
+  // Prefer VP8 over H.264 for hardware encoder.
+  if (IsHardwareVP8EncodingSupported()) {
+    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));

[miu, 2015/03/27 20:41:06]

It's fine to prefer the VP8 HW encoder, but I think you should also include
H.264 as a second option, to let an extension decide which to use.  Meaning,
this method should be:

std::vector<CastRtpParams> SupportedVideoParams() {
  std::vector<CastRtpParams> supported_params;

  if (IsHardwareVP8EncodingSupported())
    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
  if (IsHardwareH264EncodingSupported())
    supported_params.push_back(CastRtpParams(DefaultH264Payload()));

  // Propose the default software VP8 encoder, if no hardware encoders are
available.
  if (supported_params.empty())
    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));

  return supported_params;
}

+  } else {
+    if (IsHardwareH264EncodingSupported())
+      supported_params.push_back(CastRtpParams(DefaultH264Payload()));
+    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
+  }
   return supported_params;
 }