Implements RGB to YV12 conversion in YASM.

media/base/yuv_convert.cc

Index: media/base/yuv_convert.cc
===================================================================
--- media/base/yuv_convert.cc	(revision 91457)
+++ media/base/yuv_convert.cc	(working copy)
@@ -19,6 +19,7 @@
 
 #include "build/build_config.h"
 #include "media/base/cpu_features.h"
+#include "media/base/simd/yuv_convert.h"
 #include "media/base/yuv_convert_internal.h"
 #include "media/base/yuv_row.h"
 
@@ -34,6 +35,8 @@
 #include <emmintrin.h>
 #endif
 
+#define USE_YASM

[Alpha Left Google, 2011/08/22 14:16:59]

It's better not to use this #ifdef.

+
 namespace media {
 
 // 16.16 fixed point arithmetic
@@ -52,6 +55,14 @@
                        int uv_pitch,
                        int rgb_pitch,
                        YUVType yuv_type) {
+#ifdef USE_YASM

[Alpha Left Google, 2011/08/22 14:16:59]

There seems to be a slow down using this new YUV->RGB32 function, I would like
to verify this.

+  if (hasSSE2()) {
+    simd::ConvertYUVtoRGB32(y_buf, u_buf, v_buf, rgb_buf, width, height,
+                            y_pitch, uv_pitch, rgb_pitch, yuv_type);
+    return;
+  }
+#endif
+
   unsigned int y_shift = yuv_type;
   for (int y = 0; y < height; ++y) {
     uint8* rgb_row = rgb_buf + y * rgb_pitch;
@@ -368,7 +379,11 @@
 #else
     // For x86 processors, check if SSE2 is supported.
     if (hasSSE2())

[Alpha Left Google, 2011/08/22 14:16:59]

if hasSSE2() compiles on all platform we can get rid of the above ifdef check
for ARM.

+#ifdef USE_YASM

[Alpha Left Google, 2011/08/22 14:16:59]

Don't use an ifdef, just apply the new function.

+      convert_proc = &simd::ConvertRGB32toYUV;
+#else
       convert_proc = &ConvertRGB32ToYUV_SSE2;

[Alpha Left Google, 2011/08/22 14:16:59]

Remove this line.

+#endif
     else
       convert_proc = &ConvertRGB32ToYUV_C;
 #endif
@@ -387,6 +402,13 @@
                        int rgbstride,
                        int ystride,
                        int uvstride) {
+#ifdef USE_YASM

[Alpha Left Google, 2011/08/22 14:16:59]

Same here use if without ifdef. Also because with this code, hasSSE2 cannot be
compiled on ARM. I think it's better to have hasSSE2 compiles on all platforms
and return false on ARM. 

+  if (hasSSE2()) {
+    simd::ConvertRGB24toYUV(rgbframe, yplane, uplane, vplane, width, height,
+                            rgbstride, ystride, uvstride);
+    return;
+  }
+#endif
   ConvertRGB24ToYUV_C(rgbframe, yplane, uplane, vplane, width, height,
                       rgbstride, ystride, uvstride);
 }