Support for YUV 4:4:4 subsampling in vpx decoder.

media/filters/vpx_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/vpx_video_decoder.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 432 matching lines @@
   CopyVpxImageTo(vpx_image, vpx_image_alpha, video_frame);
   (*video_frame)->set_timestamp(base::TimeDelta::FromMicroseconds(timestamp));
   return true;
 }
 
 void VpxVideoDecoder::CopyVpxImageTo(const vpx_image* vpx_image,
                                      const struct vpx_image* vpx_image_alpha,
                                      scoped_refptr<VideoFrame>* video_frame) {
   CHECK(vpx_image);
   CHECK(vpx_image->fmt == VPX_IMG_FMT_I420 ||
-        vpx_image->fmt == VPX_IMG_FMT_YV12);
+        vpx_image->fmt == VPX_IMG_FMT_YV12 ||
+        vpx_image->fmt == VPX_IMG_FMT_I444);
+
+  VideoFrame::Format codec_format;

[scherkus (not reviewing), 2014/05/29 02:30:26]

nit: we typically try to initialize variables to some known value as the
compiler will do the right thing when optimizing the code

(if your conditions below ever get shuffled around, it's better to have known
values there in the first place so we don't end up with uninitialized values
down the road)

[sandersd (OOO until July 31), 2014/05/29 20:39:09]

Done. I don't think that it's easier to read, but you are right that it's a
little safer.

+  int uv_rows;
+
+  if (vpx_image->fmt == VPX_IMG_FMT_I444) {
+    CHECK(!vpx_codec_alpha_);
+    codec_format = VideoFrame::YV24;
+    uv_rows = vpx_image->d_h;
+  } else {
+    codec_format = vpx_codec_alpha_ ? VideoFrame::YV12A : VideoFrame::YV12;
+    uv_rows = (vpx_image->d_h + 1) / 2;
+  }
 
   gfx::Size size(vpx_image->d_w, vpx_image->d_h);
 
   if (!vpx_codec_alpha_ && memory_pool_) {
     *video_frame = VideoFrame::WrapExternalYuvData(
-                       VideoFrame::YV12,
-                       size, gfx::Rect(size), config_.natural_size(),
-                       vpx_image->stride[VPX_PLANE_Y],
-                       vpx_image->stride[VPX_PLANE_U],
-                       vpx_image->stride[VPX_PLANE_V],
-                       vpx_image->planes[VPX_PLANE_Y],
-                       vpx_image->planes[VPX_PLANE_U],
-                       vpx_image->planes[VPX_PLANE_V],
-                       kNoTimestamp(),
-                       memory_pool_->CreateFrameCallback(vpx_image->fb_priv));
+        codec_format,
+        size, gfx::Rect(size), config_.natural_size(),
+        vpx_image->stride[VPX_PLANE_Y],
+        vpx_image->stride[VPX_PLANE_U],
+        vpx_image->stride[VPX_PLANE_V],
+        vpx_image->planes[VPX_PLANE_Y],
+        vpx_image->planes[VPX_PLANE_U],
+        vpx_image->planes[VPX_PLANE_V],
+        kNoTimestamp(),
+        memory_pool_->CreateFrameCallback(vpx_image->fb_priv));
     return;
   }
 
   *video_frame = frame_pool_.CreateFrame(
-      vpx_codec_alpha_ ? VideoFrame::YV12A : VideoFrame::YV12,
+      codec_format,
       size,
       gfx::Rect(size),
       config_.natural_size(),
       kNoTimestamp());
 
   CopyYPlane(vpx_image->planes[VPX_PLANE_Y],
              vpx_image->stride[VPX_PLANE_Y],
              vpx_image->d_h,
              video_frame->get());
   CopyUPlane(vpx_image->planes[VPX_PLANE_U],
              vpx_image->stride[VPX_PLANE_U],
-             (vpx_image->d_h + 1) / 2,
+             uv_rows,
              video_frame->get());
   CopyVPlane(vpx_image->planes[VPX_PLANE_V],
              vpx_image->stride[VPX_PLANE_V],
-             (vpx_image->d_h + 1) / 2,
+             uv_rows,
              video_frame->get());
   if (!vpx_codec_alpha_)
     return;
   if (!vpx_image_alpha) {
     MakeOpaqueAPlane(
         vpx_image->stride[VPX_PLANE_Y], vpx_image->d_h, video_frame->get());
     return;
   }
   CopyAPlane(vpx_image_alpha->planes[VPX_PLANE_Y],
              vpx_image->stride[VPX_PLANE_Y],
              vpx_image->d_h,
              video_frame->get());
 }
 
 }  // namespace media