Merge remote-tracking branch 'qatar/master'

[ffmpeg] / libavcodec / faandct.c

diff --git a/libavcodec/faandct.c b/libavcodec/faandct.c
index 1f0f1b89aad23f2e12a35e7a0d88b41e1efa85e9..a986f654400a8fae8ab22e6217309e8c884ae5f3 100644 (file)
--- a/libavcodec/faandct.c
+++ b/libavcodec/faandct.c
@@ -1,31 +1,25 @@
 /*
  * Floating point AAN DCT
- * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
- *
  * this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
  *
- * This file is part of FFmpeg.
- *
- * 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.
- *
- * 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.
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2003 Roman Shaposhnik
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
  *
- * The AAN DCT in this file except ff_faandct248() can also be used under the
- * new (3 clause) BSD license.
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
 /**
- * @file faandct.c
+ * @file
  * @brief
  *     Floating point AAN DCT
  * @author Michael Niedermayer <michaelni@gmx.at>
@@ -62,7 +56,7 @@ for(i=0; i<8; i++){
 #define A5 0.38268343236508977170 // cos(pi*6/16)
 #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2)
 
-static FLOAT postscale[64]={
+static const FLOAT postscale[64]={
 B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7,
 B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7,
 B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7,
@@ -77,7 +71,8 @@ static av_always_inline void row_fdct(FLOAT temp[64], DCTELEM * data)
 {
     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
     FLOAT tmp10, tmp11, tmp12, tmp13;
-    FLOAT z2, z3, z4, z5, z11, z13;
+    FLOAT z2, z4, z11, z13;
+    FLOAT av_unused z5;
     int i;
 
     for (i=0; i<8*8; i+=8) {
@@ -107,13 +102,18 @@ static av_always_inline void row_fdct(FLOAT temp[64], DCTELEM * data)
         tmp5 += tmp6;
         tmp6 += tmp7;
 
+#if 0
         z5= (tmp4 - tmp6) * A5;
         z2= tmp4*A2 + z5;
         z4= tmp6*A4 + z5;
-        z3= tmp5*A1;
+#else
+        z2= tmp4*(A2+A5) - tmp6*A5;
+        z4= tmp6*(A4-A5) + tmp4*A5;
+#endif
+        tmp5*=A1;
 
-        z11= tmp7 + z3;
-        z13= tmp7 - z3;
+        z11= tmp7 + tmp5;
+        z13= tmp7 - tmp5;
 
         temp[5 + i]= z13 + z2;
         temp[3 + i]= z13 - z2;
@@ -126,7 +126,8 @@ void ff_faandct(DCTELEM * data)
 {
     FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
     FLOAT tmp10, tmp11, tmp12, tmp13;
-    FLOAT z2, z3, z4, z5, z11, z13;
+    FLOAT z2, z4, z11, z13;
+    FLOAT av_unused z5;
     FLOAT temp[64];
     int i;
 
@@ -161,13 +162,18 @@ void ff_faandct(DCTELEM * data)
         tmp5 += tmp6;
         tmp6 += tmp7;
 
+#if 0
         z5= (tmp4 - tmp6) * A5;
         z2= tmp4*A2 + z5;
         z4= tmp6*A4 + z5;
-        z3= tmp5*A1;
+#else
+        z2= tmp4*(A2+A5) - tmp6*A5;
+        z4= tmp6*(A4-A5) + tmp4*A5;
+#endif
+        tmp5*=A1;
 
-        z11= tmp7 + z3;
-        z13= tmp7 - z3;
+        z11= tmp7 + tmp5;
+        z13= tmp7 - tmp5;
 
         data[8*5 + i]= lrintf(SCALE(8*5 + i) * (z13 + z2));
         data[8*3 + i]= lrintf(SCALE(8*3 + i) * (z13 - z2));