Rename acelp_math.[ch] to celp_math.[ch] to prepare for QCELP decoder merge.

patch by Kenan Gillet, kenan.gillet gmail com

Originally committed as revision 15679 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 86 insertions, 0 deletions

diff --git a/libavcodec/celp_math.h b/libavcodec/celp_math.h
new file mode 100644
index 0000000000..029b5310af
--- /dev/null
+++ b/libavcodec/celp_math.h
@@ -0,0 +1,86 @@
+/*
+ * Various fixed-point math operations
+ *
+ * Copyright (c) 2008 Vladimir Voroshilov
+ *
+ * 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 AVCODEC_CELP_MATH_H
+#define AVCODEC_CELP_MATH_H
+
+#include <stdint.h>
+
+/**
+ * fixed-point implementation of cosine in [0; PI) domain.
+ * @param arg fixed-point cosine argument, 0 <= arg < 0x4000
+ *
+ * @return value of (1<<15) * cos(arg * PI / (1<<14)), -0x8000 <= result <= 0x7fff
+ */
+int16_t ff_cos(uint16_t arg);
+
+/**
+ * fixed-point implementation of exp2(x) in [0; 1] domain.
+ * @param power argument to exp2, 0 <= power <= 0x7fff
+ *
+ * @return value of (1<<20) * exp2(power / (1<<15))
+ *         0x8000c <= result <= 0xfffea
+ */
+int ff_exp2(uint16_t power);
+
+/**
+ * Calculates log2(x).
+ * @param value function argument, 0 < value <= 7fff ffff
+ *
+ * @return value of (1<<15) * log2(value)
+ */
+int ff_log2(uint32_t value);
+
+/**
+ * returns the dot product.
+ * @param a input data array
+ * @param b input data array
+ * @param length number of elements
+ * @param shift right shift by this value will be done after multiplication
+ *
+ * @return dot product = sum of elementwise products
+ */
+static int dot_product(const int16_t* a, const int16_t* b, int length, int shift)
+{
+    int sum = 0;
+    int i;
+
+    for(i=0; i<length; i++)
+        sum += (a[i] * b[i]) >> shift;
+
+    return sum;
+}
+
+/**
+ * Shift value left or right depending on sign of offset parameter.
+ * @param value value to shift
+ * @param offset shift offset
+ *
+ * @return value << offset, if offset>=0; value >> -offset - otherwise
+ */
+static inline int bidir_sal(int value, int offset)
+{
+    if(offset < 0) return value >> -offset;
+    else           return value <<  offset;
+}
+
+#endif /* AVCODEC_CELP_MATH_H */