Use hardcoded instead of runtime-calculated ff_cos_* tables if

--enable-hardcoded-tables was used.
Due to the size, the code for the tables is generated at compile time.

Originally committed as revision 20232 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 50 insertions, 0 deletions

diff --git a/libavcodec/costablegen.c b/libavcodec/costablegen.c
new file mode 100644
index 0000000000..c27d887795
--- /dev/null
+++ b/libavcodec/costablegen.c
@@ -0,0 +1,50 @@
+/*
+ * Generate a header file for hardcoded ff_cos_* tables
+ *
+ * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
+ *
+ * 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.
+ *
+ * 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
+ */
+
+#include <stdio.h>
+#include <math.h>
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+#define BITS 16
+#define FLOATFMT "%.18e"
+
+int main(void)
+{
+    int i, j;
+    printf("/* This file was generated by libavcodec/costablegen */\n");
+    printf("#include \"dsputil.h\"\n");
+    for (i = 4; i <= BITS; i++) {
+        int m = 1 << i;
+        double freq = 2*M_PI/m;
+        printf("const DECLARE_ALIGNED_16(FFTSample, ff_cos_%i[]) = {\n   ", m);
+        for (j = 0; j < m/2 - 1; j++) {
+            int idx = j > m/4 ? m/2 - j : j;
+            printf(" "FLOATFMT",", cos(idx*freq));
+            if ((j & 3) == 3)
+                printf("\n   ");
+        }
+        printf(" "FLOATFMT"\n};\n", cos(freq));
+    }
+    return 0;
+}