Choose h264 chroma dc dequant function dynamically.

[ffmpeg] / libavcodec / h264idct.c

diff --git a/libavcodec/h264idct.c b/libavcodec/h264idct.c
index ecf669ebd0c39bae09a0f9806dcae3e8f8db246c..7c96f424b440884e26994c7d49e7bddcdd7ec3e7 100644 (file)
--- a/libavcodec/h264idct.c
+++ b/libavcodec/h264idct.c
@@ -2,20 +2,20 @@
  * H.264 IDCT
  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -250,4 +250,26 @@ void ff_h264_luma_dc_dequant_idct_c(DCTELEM *output, DCTELEM *input, int qmul){
         output[stride* 4+offset]= ((((z1 - z2)*qmul + 128 ) >> 8));
         output[stride* 5+offset]= ((((z0 - z3)*qmul + 128 ) >> 8));
     }
+#undef stride
+}
+
+void ff_h264_chroma_dc_dequant_idct_c(DCTELEM *block, int qmul){
+    const int stride= 16*2;
+    const int xStride= 16;
+    int a,b,c,d,e;
+
+    a= block[stride*0 + xStride*0];
+    b= block[stride*0 + xStride*1];
+    c= block[stride*1 + xStride*0];
+    d= block[stride*1 + xStride*1];
+
+    e= a-b;
+    a= a+b;
+    b= c-d;
+    c= c+d;
+
+    block[stride*0 + xStride*0]= ((a+c)*qmul) >> 7;
+    block[stride*0 + xStride*1]= ((e+b)*qmul) >> 7;
+    block[stride*1 + xStride*0]= ((a-c)*qmul) >> 7;
+    block[stride*1 + xStride*1]= ((e-b)*qmul) >> 7;
 }