Add support for I444 frames to VideoDecoderVpx.

VideoDecoderVpx has supported VP9 for a while, but was missing a colour
conversion codepath from I444 frames to ARGB.

BUG=377239,260879,134202

Review URL: https://codereview.chromium.org/300653002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272846 0039d316-1c4b-4281-b951-d872f2087c98

remoting/codec/video_decoder_vpx.cc

@@ -12,6 +12,7 @@
 #include "media/base/media.h"
 #include "media/base/yuv_convert.h"
 #include "remoting/base/util.h"
+#include "third_party/libyuv/include/libyuv/convert_argb.h"
 
 extern "C" {
 #define VPX_CODEC_DISABLE_COMPAT 1
@@ -177,10 +178,46 @@ void VideoDecoderVpx::RenderFrame(const webrtc::DesktopSize& view_size,
   webrtc::DesktopRect source_clip =
       webrtc::DesktopRect::MakeWH(last_image_->d_w, last_image_->d_h);
 
-  // ScaleYUVToRGB32WithRect does not currently support up-scaling.  We won't
-  // be asked to up-scale except during resizes or if page zoom is >100%, so
-  // we work-around the limitation by using the slower ScaleYUVToRGB32.
-  // TODO(wez): Remove this hack if/when ScaleYUVToRGB32WithRect can up-scale.
+  // VP8 only outputs I420 frames, but VP9 can also produce I444.
+  switch (last_image_->fmt) {
+    case VPX_IMG_FMT_I444: {
+      // TODO(wez): Add scaling support to the I444 conversion path.
+      if (view_size.equals(screen_size_)) {
+        for (webrtc::DesktopRegion::Iterator i(updated_region_);
+             !i.IsAtEnd(); i.Advance()) {
+          // Determine the scaled area affected by this rectangle changing.
+          webrtc::DesktopRect rect = i.rect();
+          rect.IntersectWith(source_clip);
+          rect.IntersectWith(clip_area);
+          if (rect.is_empty())
+            continue;
+
+          int image_offset = image_stride * rect.top() +
+                             rect.left() * VideoDecoder::kBytesPerPixel;
+          int y_offset = last_image_->stride[0] * rect.top() + rect.left();
+          int u_offset = last_image_->stride[1] * rect.top() + rect.left();
+          int v_offset = last_image_->stride[2] * rect.top() + rect.left();
+          libyuv::I444ToARGB(last_image_->planes[0] + y_offset,
+                             last_image_->stride[0],
+                             last_image_->planes[1] + u_offset,
+                             last_image_->stride[1],
+                             last_image_->planes[2] + v_offset,
+                             last_image_->stride[2],
+                             image_buffer + image_offset, image_stride,
+                             rect.width(), rect.height());
+
+          output_region->AddRect(rect);
+        }
+      }
+      break;
+    }
+    case VPX_IMG_FMT_I420: {
+      // ScaleYUVToRGB32WithRect does not currently support up-scaling.  We
+      // won't be asked to up-scale except during resizes or if page zoom is
+      // >100%, so we work-around the limitation by using the slower
+      // ScaleYUVToRGB32.
+      // TODO(wez): Remove this hack if/when ScaleYUVToRGB32WithRect can
+      // up-scale.
       if (!updated_region_.is_empty() &&
           (source_clip.width() < view_size.width() ||
            source_clip.height() < view_size.height())) {
@@ -194,7 +231,8 @@ void VideoDecoderVpx::RenderFrame(const webrtc::DesktopSize& view_size,
             source_rect.right(),
             source_rect.bottom());
 
-    // If there were no changes within the clip source area then don't render.
+        // If there were no changes within the clip source area then don't
+        // render.
         webrtc::DesktopRegion intersection(source_rect);
         intersection.IntersectWith(updated_region_);
         if (intersection.is_empty())
@@ -254,6 +292,13 @@ void VideoDecoderVpx::RenderFrame(const webrtc::DesktopSize& view_size,
       }
 
       updated_region_.Subtract(ScaleRect(clip_area, view_size, screen_size_));
+      break;
+    }
+    default: {
+      LOG(ERROR) << "Unsupported image format:" << last_image_->fmt;
+      return;
+    }
+  }
 
   for (webrtc::DesktopRegion::Iterator i(transparent_region_);
        !i.IsAtEnd(); i.Advance()) {