Add correct support for videos with YUVJ420P color format, in the software conversion path.

media/base/yuv_convert.h

 // 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.
 
 #ifndef MEDIA_BASE_YUV_CONVERT_H_
 #define MEDIA_BASE_YUV_CONVERT_H_
 
 #include "base/basictypes.h"
 #include "media/base/media_export.h"
 
 // Visual Studio 2010 does not support MMX intrinsics on x64.
 // Some win64 yuv_convert code paths use SSE+MMX yasm, so without rewriting
 // them, we use yasm EmptyRegisterState_MMX in place of _mm_empty() or
 // hide the versions implemented with heavy use of MMX intrinsics.
 // TODO(wolenetz): Use MMX intrinsics when compiling win64 with Visual
 // Studio 2012? http://crbug.com/173450
 #if defined(ARCH_CPU_X86_FAMILY) && \
     !(defined(ARCH_CPU_X86_64) && defined(COMPILER_MSVC))
 #define MEDIA_MMX_INTRINSICS_AVAILABLE
 #endif
 
 namespace media {
 
 // Type of YUV surface.
-// The value of these enums matter as they are used to shift vertical indices.
 enum YUVType {
-  YV16 = 0,  // YV16 is half width and full height chroma channels.
-  YV12 = 1,  // YV12 is half width and half height chroma channels.
+  YV16  = 0,  // YV16 is half width and full height chroma channels.
+  YV12  = 1,  // YV12 is half width and half height chroma channels.
+  YV12J = 2,  // YV12J is the same as YV12, but in JPEG color range.
 };
 
+// Get the appropriate value to bitshift by for vertical indices.
+int GetVerticalShift(YUVType type);
+
+#define GET_LOOKUP_TABLE(type) \

[rileya (GONE FROM CHROMIUM), 2014/04/22 17:57:50]

Ugly macro, since we can't return a sized/multidimensional array from a function
in C++. Making all the conversion functions take a plain pointer would let us
use a function instead, but I sort of like making the table size explicit in the
function signatures ("table[foo][bar]" also looks nicer than "table[foo + bar *
1024]"). Thoughts?

[scherkus (not reviewing), 2014/04/22 18:53:33]

so there is some heinous syntax you can use to pass back a const-reference to a
sized array

const int (&GetLookupTable(YUVType type))[1024][4] {
  ...
}

since the arrays are global statics it's safe to pass back const-ref

downside is all the parameters to functions get a bit ugly too:

void MyFunc(const int (&table)[1024][4]) {
  ...
}

[rileya (GONE FROM CHROMIUM), 2014/04/23 21:23:51]

Looks like that worked without needing to modify the parameters (though I won't
be too surprised if visual studio chokes on it...).

+  ((type) == YV12J ? kCoefficientsRgbY_JPEG : kCoefficientsRgbY)
+
 // Mirror means flip the image horizontally, as in looking in a mirror.
 // Rotate happens after mirroring.
 enum Rotate {
   ROTATE_0,           // Rotation off.
   ROTATE_90,          // Rotate clockwise.
   ROTATE_180,         // Rotate upside down.
   ROTATE_270,         // Rotate counter clockwise.
   MIRROR_ROTATE_0,    // Mirror horizontally.
   MIRROR_ROTATE_90,   // Mirror then Rotate clockwise.
   MIRROR_ROTATE_180,  // Mirror vertically.
@@ skipping 107 matching lines @@
                                    uint8* vplane,
                                    int width,
                                    int height);
 
 // Empty SIMD register state after calling optimized scaler functions.
 MEDIA_EXPORT void EmptyRegisterState();
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_YUV_CONVERT_H_