From ca07a9833149d270d1e5b44cfa381ac6ac03e39c Mon Sep 17 00:00:00 2001
From: Benny Prijono <bennylp@teluu.com>
Date: Sat, 7 Apr 2007 14:53:15 +0000
Subject: Moved resample to third_party directory

git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/split-3rd-party@1170 74dad513-b988-da41-8d7b-12977e46ad98
---
 third_party/resample/src/resample.h | 86 +++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 third_party/resample/src/resample.h

(limited to 'third_party/resample/src/resample.h')

diff --git a/third_party/resample/src/resample.h b/third_party/resample/src/resample.h
new file mode 100644
index 00000000..c09e891b
--- /dev/null
+++ b/third_party/resample/src/resample.h
@@ -0,0 +1,86 @@
+/*
+ * FILE: resample.h
+ *
+ * The configuration constants below govern
+ * the number of bits in the input sample and filter coefficients, the 
+ * number of bits to the right of the binary-point for fixed-point math, etc.
+ *
+ */
+
+#include "stdefs.h"
+
+/* Conversion constants */
+#define Nhc       8
+#define Na        7
+#define Np       (Nhc+Na)
+#define Npc      (1<<Nhc)
+#define Amask    ((1<<Na)-1)
+#define Pmask    ((1<<Np)-1)
+#define Nh       16
+#define Nb       16
+#define Nhxn     14
+#define Nhg      (Nh-Nhxn)
+#define NLpScl   13
+
+/* Description of constants:
+ *
+ * Npc - is the number of look-up values available for the lowpass filter
+ *    between the beginning of its impulse response and the "cutoff time"
+ *    of the filter.  The cutoff time is defined as the reciprocal of the
+ *    lowpass-filter cut off frequence in Hz.  For example, if the
+ *    lowpass filter were a sinc function, Npc would be the index of the
+ *    impulse-response lookup-table corresponding to the first zero-
+ *    crossing of the sinc function.  (The inverse first zero-crossing
+ *    time of a sinc function equals its nominal cutoff frequency in Hz.)
+ *    Npc must be a power of 2 due to the details of the current
+ *    implementation. The default value of 512 is sufficiently high that
+ *    using linear interpolation to fill in between the table entries
+ *    gives approximately 16-bit accuracy in filter coefficients.
+ *
+ * Nhc - is log base 2 of Npc.
+ *
+ * Na - is the number of bits devoted to linear interpolation of the
+ *    filter coefficients.
+ *
+ * Np - is Na + Nhc, the number of bits to the right of the binary point
+ *    in the integer "time" variable. To the left of the point, it indexes
+ *    the input array (X), and to the right, it is interpreted as a number
+ *    between 0 and 1 sample of the input X.  Np must be less than 16 in
+ *    this implementation.
+ *
+ * Nh - is the number of bits in the filter coefficients. The sum of Nh and
+ *    the number of bits in the input data (typically 16) cannot exceed 32.
+ *    Thus Nh should be 16.  The largest filter coefficient should nearly
+ *    fill 16 bits (32767).
+ *
+ * Nb - is the number of bits in the input data. The sum of Nb and Nh cannot
+ *    exceed 32.
+ *
+ * Nhxn - is the number of bits to right shift after multiplying each input
+ *    sample times a filter coefficient. It can be as great as Nh and as
+ *    small as 0. Nhxn = Nh-2 gives 2 guard bits in the multiply-add
+ *    accumulation.  If Nhxn=0, the accumulation will soon overflow 32 bits.
+ *
+ * Nhg - is the number of guard bits in mpy-add accumulation (equal to Nh-Nhxn)
+ *
+ * NLpScl - is the number of bits allocated to the unity-gain normalization
+ *    factor.  The output of the lowpass filter is multiplied by LpScl and
+ *    then right-shifted NLpScl bits. To avoid overflow, we must have 
+ *    Nb+Nhg+NLpScl < 32.
+ */
+
+
+int resample(			/* number of output sample returned */
+    double factor,		/* factor = Sndout/Sndin */
+    int    infd,		/* input and output file descriptors */
+    int    outfd,
+    int inCount,		/* number of input samples to convert */
+    int outCount,		/* number of output samples to compute */
+    int nChans,			/* number of sound channels (1 or 2) */
+    BOOL interpFilt,		/* TRUE means interpolate filter coeffs */
+    int fastMode,		/* 0 = highest quality, slowest speed */
+    BOOL largeFilter,		/* TRUE means use 65-tap FIR filter */
+    char *filterFile		/* NULL for internal filter, else filename */
+);
+
+//#define MUS_SAMPLE_TYPE mus_sample_t; // more incompatible changes to sndlib
-- 
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