Support VP9 video in the BT709 color space.

media/filters/vpx_video_decoder.cc

Index: media/filters/vpx_video_decoder.cc
diff --git a/media/filters/vpx_video_decoder.cc b/media/filters/vpx_video_decoder.cc
index dd436796ce1c20500cc5dc38f251fb0b81b9caac..747659cb83d9a264a30c496a5d4daf9eb53ab7b0 100644
--- a/media/filters/vpx_video_decoder.cc
+++ b/media/filters/vpx_video_decoder.cc
@@ -460,7 +460,11 @@ void VpxVideoDecoder::CopyVpxImageTo(const vpx_image* vpx_image,
   VideoFrame::Format codec_format = VideoFrame::YV12;
   int uv_rows = (vpx_image->d_h + 1) / 2;
 
-  if (vpx_image->fmt == VPX_IMG_FMT_I444) {
+  if ((vpx_image->fmt == VPX_IMG_FMT_YV12 ||
+       vpx_image->fmt == VPX_IMG_FMT_I420) &&
+      vpx_image->cs == VPX_CS_BT_709) {

[xhwang, 2015/03/03 19:53:30]

Can vpx_codec_alpha_ be true here?

[watk, 2015/03/03 22:01:28]

Yeah, it can. Unfortunately we have to choose between alpha and BT709, but I
made the wrong choice! Alpha should be preferred.

+    codec_format = VideoFrame::YV12HD;
+  } else if (vpx_image->fmt == VPX_IMG_FMT_I444) {

[xhwang, 2015/03/03 19:53:30]

Can vpx_image->cs == VPX_CS_BT_709 here?

[watk, 2015/03/03 22:01:28]

It can, but we can't support it at the moment :( I added a comment

     CHECK(!vpx_codec_alpha_);
     codec_format = VideoFrame::YV24;
     uv_rows = vpx_image->d_h;