Rename interpretor to interpreter.

[Faustine.git] / interpreter / lib / src / libsndfile-1.0.25 / src / G72x / g723_24.c

diff --git a/interpreter/lib/src/libsndfile-1.0.25/src/G72x/g723_24.c b/interpreter/lib/src/libsndfile-1.0.25/src/G72x/g723_24.c
new file mode 100644 (file)
index 0000000..02b6c24
--- /dev/null
+++ b/interpreter/lib/src/libsndfile-1.0.25/src/G72x/g723_24.c
@@ -0,0 +1,139 @@
+/*
+ * This source code is a product of Sun Microsystems, Inc. and is provided
+ * for unrestricted use.  Users may copy or modify this source code without
+ * charge.
+ *
+ * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
+ * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
+ *
+ * Sun source code is provided with no support and without any obligation on
+ * the part of Sun Microsystems, Inc. to assist in its use, correction,
+ * modification or enhancement.
+ *
+ * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
+ * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
+ * OR ANY PART THEREOF.
+ *
+ * In no event will Sun Microsystems, Inc. be liable for any lost revenue
+ * or profits or other special, indirect and consequential damages, even if
+ * Sun has been advised of the possibility of such damages.
+ *
+ * Sun Microsystems, Inc.
+ * 2550 Garcia Avenue
+ * Mountain View, California  94043
+ */
+
+/*
+ * g723_24.c
+ *
+ * Description:
+ *
+ * g723_24_encoder(), g723_24_decoder()
+ *
+ * These routines comprise an implementation of the CCITT G.723 24 Kbps
+ * ADPCM coding algorithm.  Essentially, this implementation is identical to
+ * the bit level description except for a few deviations which take advantage
+ * of workstation attributes, such as hardware 2's complement arithmetic.
+ *
+ */
+
+#include "g72x.h"
+#include "g72x_priv.h"
+
+/*
+ * Maps G.723_24 code word to reconstructed scale factor normalized log
+ * magnitude values.
+ */
+static short   _dqlntab[8] = {-2048, 135, 273, 373, 373, 273, 135, -2048};
+
+/* Maps G.723_24 code word to log of scale factor multiplier. */
+static short   _witab[8] = {-128, 960, 4384, 18624, 18624, 4384, 960, -128};
+
+/*
+ * Maps G.723_24 code words to a set of values whose long and short
+ * term averages are computed and then compared to give an indication
+ * how stationary (steady state) the signal is.
+ */
+static short   _fitab[8] = {0, 0x200, 0x400, 0xE00, 0xE00, 0x400, 0x200, 0};
+
+static short qtab_723_24[3] = {8, 218, 331};
+
+/*
+ * g723_24_encoder()
+ *
+ * Encodes a linear PCM, A-law or u-law input sample and returns its 3-bit code.
+ * Returns -1 if invalid input coding value.
+ */
+int
+g723_24_encoder(
+       int             sl,
+       G72x_STATE *state_ptr)
+{
+       short           sei, sezi, se, sez;     /* ACCUM */
+       short           d;                      /* SUBTA */
+       short           y;                      /* MIX */
+       short           sr;                     /* ADDB */
+       short           dqsez;                  /* ADDC */
+       short           dq, i;
+
+       /* linearize input sample to 14-bit PCM */
+       sl >>= 2;               /* sl of 14-bit dynamic range */
+
+       sezi = predictor_zero(state_ptr);
+       sez = sezi >> 1;
+       sei = sezi + predictor_pole(state_ptr);
+       se = sei >> 1;                  /* se = estimated signal */
+
+       d = sl - se;                    /* d = estimation diff. */
+
+       /* quantize prediction difference d */
+       y = step_size(state_ptr);       /* quantizer step size */
+       i = quantize(d, y, qtab_723_24, 3);     /* i = ADPCM code */
+       dq = reconstruct(i & 4, _dqlntab[i], y); /* quantized diff. */
+
+       sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconstructed signal */
+
+       dqsez = sr + sez - se;          /* pole prediction diff. */
+
+       update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
+
+       return (i);
+}
+
+/*
+ * g723_24_decoder()
+ *
+ * Decodes a 3-bit CCITT G.723_24 ADPCM code and returns
+ * the resulting 16-bit linear PCM, A-law or u-law sample value.
+ * -1 is returned if the output coding is unknown.
+ */
+int
+g723_24_decoder(
+       int             i,
+       G72x_STATE *state_ptr)
+{
+       short           sezi, sei, sez, se;     /* ACCUM */
+       short           y;                      /* MIX */
+       short           sr;                     /* ADDB */
+       short           dq;
+       short           dqsez;
+
+       i &= 0x07;                      /* mask to get proper bits */
+       sezi = predictor_zero(state_ptr);
+       sez = sezi >> 1;
+       sei = sezi + predictor_pole(state_ptr);
+       se = sei >> 1;                  /* se = estimated signal */
+
+       y = step_size(state_ptr);       /* adaptive quantizer step size */
+       dq = reconstruct(i & 0x04, _dqlntab[i], y); /* unquantize pred diff */
+
+       sr = (dq < 0) ? (se - (dq & 0x3FFF)) : (se + dq); /* reconst. signal */
+
+       dqsez = sr - se + sez;                  /* pole prediction diff. */
+
+       update(3, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
+
+       return (sr << 2);       /* sr was of 14-bit dynamic range */
+}
+