Add support for hardcoding the mpegaudiodec tables.

Reduces .bss size by about 194 kB.

Originally committed as revision 20400 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 68 insertions, 0 deletions

diff --git a/libavcodec/mpegaudio_tablegen.h b/libavcodec/mpegaudio_tablegen.h
new file mode 100644
index 0000000000..362b545e0f
--- /dev/null
+++ b/libavcodec/mpegaudio_tablegen.h
@@ -0,0 +1,68 @@
+/*
+ * Header file for hardcoded mpegaudiodec 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
+ */
+
+#ifndef MPEGAUDIO_TABLEGEN_H
+#define MPEGAUDIO_TABLEGEN_H
+
+#include <stdint.h>
+// do not use libavutil/mathematics.h since this is compiled both
+// for the host and the target and config.h is only valid for the target
+#include <math.h>
+
+#define TABLE_4_3_SIZE (8191 + 16)*4
+#if CONFIG_HARDCODED_TABLES
+#define mpegaudio_tableinit()
+#include "mpegaudio_tables.h"
+#else
+static int8_t  table_4_3_exp[TABLE_4_3_SIZE];
+static uint32_t table_4_3_value[TABLE_4_3_SIZE];
+static uint32_t exp_table[512];
+static uint32_t expval_table[512][16];
+
+static void mpegaudio_tableinit(void)
+{
+    int i;
+    for(i=1;i<TABLE_4_3_SIZE;i++) {
+        double value = i/4;
+        double f, fm;
+        int e, m;
+        f = value * cbrtf(value) * pow(2, (i&3)*0.25);
+        fm = frexp(f, &e);
+        m = (uint32_t)(fm*(1LL<<31) + 0.5);
+        e+= FRAC_BITS - 31 + 5 - 100;
+
+        /* normalized to FRAC_BITS */
+        table_4_3_value[i] = m;
+        table_4_3_exp[i] = -e;
+    }
+    for(i=0; i<512*16; i++){
+        double value = i & 15;
+        int exponent= (i>>4);
+        double f= value * cbrtf(value) * pow(2, (exponent-400)*0.25 + FRAC_BITS + 5);
+        expval_table[exponent][i&15]= llrint(f);
+        if((i&15)==1)
+            exp_table[exponent]= llrint(f);
+    }
+}
+#endif /* CONFIG_HARDCODED_TABLES && !TABLEGEN */
+
+#endif /* MPEGAUDIO_TABLEGEN_H */