Choose h264 chroma dc dequant function dynamically.

[ffmpeg] / libavcodec / h264idct.c

diff --git a/libavcodec/h264idct.c b/libavcodec/h264idct.c
index f5b05ac24fe7265794ded068f736948692f8dd92..7c96f424b440884e26994c7d49e7bddcdd7ec3e7 100644 (file)
--- a/libavcodec/h264idct.c
+++ b/libavcodec/h264idct.c
@@ -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;
 }