forked from sox_ng/sox_ng
575 lines
21 KiB
C
575 lines
21 KiB
C
/* Common routines for G.721 and G.723 conversions.
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*
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* (c) SoX Contributors
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*
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* This library is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or (at
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* your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
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* General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*
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* This code is based on code from Sun, which came with the following
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* copyright notice:
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* -----------------------------------------------------------------------
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* This source code is a product of Sun Microsystems, Inc. and is provided
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* for unrestricted use. Users may copy or modify this source code without
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* charge.
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*
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* SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
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* THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
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*
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* Sun source code is provided with no support and without any obligation on
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* the part of Sun Microsystems, Inc. to assist in its use, correction,
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* modification or enhancement.
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*
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* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
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* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
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* OR ANY PART THEREOF.
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*
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* In no event will Sun Microsystems, Inc. be liable for any lost revenue
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* or profits or other special, indirect and consequential damages, even if
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* Sun has been advised of the possibility of such damages.
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*
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* Sun Microsystems, Inc.
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* 2550 Garcia Avenue
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* Mountain View, California 94043
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* -----------------------------------------------------------------------
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*/
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#include "sox_i.h"
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#include "g711.h"
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#include "g72x.h"
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static const char LogTable256[] =
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{
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0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
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5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
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7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
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};
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static inline int log2plus1(int val)
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{
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/* From http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup */
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unsigned int v = (unsigned int)val; /* 32-bit word to find the log of */
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unsigned r; /* r will be lg(v) */
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register unsigned int t, tt; /* temporaries */
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if ((tt = v >> 16))
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{
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r = (t = tt >> 8) ? 24 + LogTable256[t] : 16 + LogTable256[tt];
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}
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else
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{
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r = (t = v >> 8) ? 8 + LogTable256[t] : LogTable256[v];
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}
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return r + 1;
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}
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/*
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* quan()
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*
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* quantizes the input val against the table of size short integers.
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* It returns i if table[i - 1] <= val < table[i].
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*
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* Using linear search for simple coding.
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*/
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static int quan(int val, short const *table, int size)
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{
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int i;
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for (i = 0; i < size; i++)
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if (val < *table++)
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break;
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return (i);
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}
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/*
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* fmult()
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*
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* returns the integer product of the 14-bit integer "an" and
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* "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
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*/
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static int fmult(int an, int srn)
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{
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short anmag, anexp, anmant;
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short wanexp, wanmant;
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short retval;
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anmag = (an > 0) ? an : ((-an) & 0x1FFF);
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anexp = log2plus1(anmag) - 6;
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anmant = (anmag == 0) ? 32 :
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(anexp >= 0) ? anmag >> anexp : anmag << -anexp;
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wanexp = anexp + ((srn >> 6) & 0xF) - 13;
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wanmant = (anmant * (srn & 077) + 0x30) >> 4;
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retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
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(wanmant >> -wanexp);
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return (((an ^ srn) < 0) ? -retval : retval);
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}
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/*
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* g72x_init_state()
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*
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* This routine initializes and/or resets the g72x_state structure
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* pointed to by 'state_ptr'.
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* All the initial state values are specified in the CCITT G.721 document.
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*/
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void g72x_init_state(struct g72x_state *state_ptr)
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{
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int cnta;
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state_ptr->yl = 34816;
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state_ptr->yu = 544;
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state_ptr->dms = 0;
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state_ptr->dml = 0;
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state_ptr->ap = 0;
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for (cnta = 0; cnta < 2; cnta++) {
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state_ptr->a[cnta] = 0;
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state_ptr->pk[cnta] = 0;
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state_ptr->sr[cnta] = 32;
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}
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for (cnta = 0; cnta < 6; cnta++) {
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state_ptr->b[cnta] = 0;
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state_ptr->dq[cnta] = 32;
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}
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state_ptr->td = 0;
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}
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/*
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* predictor_zero()
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*
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* computes the estimated signal from 6-zero predictor.
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*
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*/
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int predictor_zero(struct g72x_state *state_ptr)
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{
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int i;
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int sezi;
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sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]);
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for (i = 1; i < 6; i++) /* ACCUM */
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sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);
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return (sezi);
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}
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/*
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* predictor_pole()
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*
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* computes the estimated signal from 2-pole predictor.
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*
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*/
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int predictor_pole(struct g72x_state *state_ptr)
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{
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return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +
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fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));
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}
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/*
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* step_size()
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*
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* computes the quantization step size of the adaptive quantizer.
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*
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*/
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int step_size(struct g72x_state *state_ptr)
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{
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int y;
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int dif;
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int al;
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if (state_ptr->ap >= 256)
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return (state_ptr->yu);
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else {
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y = state_ptr->yl >> 6;
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dif = state_ptr->yu - y;
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al = state_ptr->ap >> 2;
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if (dif > 0)
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y += (dif * al) >> 6;
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else if (dif < 0)
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y += (dif * al + 0x3F) >> 6;
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return (y);
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}
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}
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/*
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* quantize()
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*
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* Given a raw sample, 'd', of the difference signal and a
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* quantization step size scale factor, 'y', this routine returns the
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* ADPCM codeword to which that sample gets quantized. The step
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* size scale factor division operation is done in the log base 2 domain
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* as a subtraction.
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*/
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int quantize(int d, int y, short const *table, int size)
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{
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short dqm; /* Magnitude of 'd' */
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short exp; /* Integer part of base 2 log of 'd' */
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short mant; /* Fractional part of base 2 log */
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short dl; /* Log of magnitude of 'd' */
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short dln; /* Step size scale factor normalized log */
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int i;
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/*
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* LOG
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*
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* Compute base 2 log of 'd', and store in 'dl'.
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*/
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dqm = abs(d);
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exp = log2plus1(dqm >> 1);
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mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */
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dl = (exp << 7) + mant;
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/*
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* SUBTB
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*
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* "Divide" by step size multiplier.
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*/
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dln = dl - (y >> 2);
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/*
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* QUAN
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*
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* Obtain codword i for 'd'.
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*/
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i = quan(dln, table, size);
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if (d < 0) /* take 1's complement of i */
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return ((size << 1) + 1 - i);
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else if (i == 0) /* take 1's complement of 0 */
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return ((size << 1) + 1); /* new in 1988 */
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else
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return (i);
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}
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/*
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* reconstruct()
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*
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* Returns reconstructed difference signal 'dq' obtained from
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* codeword 'i' and quantization step size scale factor 'y'.
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* Multiplication is performed in log base 2 domain as addition.
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*/
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int reconstruct(int sign, int dqln, int y)
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{
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short dql; /* Log of 'dq' magnitude */
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short dex; /* Integer part of log */
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short dqt;
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short dq; /* Reconstructed difference signal sample */
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dql = dqln + (y >> 2); /* ADDA */
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if (dql < 0) {
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return ((sign) ? -0x8000 : 0);
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} else { /* ANTILOG */
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dex = (dql >> 7) & 15;
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dqt = 128 + (dql & 127);
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dq = (dqt << 7) >> (14 - dex);
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return ((sign) ? (dq - 0x8000) : dq);
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}
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}
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/*
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* update()
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*
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* updates the state variables for each output code
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*/
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void update(int code_size, int y, int wi, int fi, int dq, int sr,
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int dqsez, struct g72x_state *state_ptr)
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{
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int cnt;
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short mag, exp; /* Adaptive predictor, FLOAT A */
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short a2p=0; /* LIMC */
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short a1ul; /* UPA1 */
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short pks1; /* UPA2 */
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short fa1;
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char tr; /* tone/transition detector */
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short ylint, thr2, dqthr;
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short ylfrac, thr1;
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short pk0;
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pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */
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mag = dq & 0x7FFF; /* prediction difference magnitude */
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/* TRANS */
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ylint = state_ptr->yl >> 15; /* exponent part of yl */
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ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */
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thr1 = (32 + ylfrac) << ylint; /* threshold */
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thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */
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dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */
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if (state_ptr->td == 0) /* signal supposed voice */
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tr = 0;
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else if (mag <= dqthr) /* supposed data, but small mag */
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tr = 0; /* treated as voice */
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else /* signal is data (modem) */
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tr = 1;
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/*
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* Quantizer scale factor adaptation.
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*/
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/* FUNCTW & FILTD & DELAY */
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/* update non-steady state step size multiplier */
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state_ptr->yu = y + ((wi - y) >> 5);
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/* LIMB */
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if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */
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state_ptr->yu = 544;
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else if (state_ptr->yu > 5120)
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state_ptr->yu = 5120;
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/* FILTE & DELAY */
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/* update steady state step size multiplier */
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state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);
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/*
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* Adaptive predictor coefficients.
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*/
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if (tr == 1) { /* reset a's and b's for modem signal */
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state_ptr->a[0] = 0;
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state_ptr->a[1] = 0;
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state_ptr->b[0] = 0;
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state_ptr->b[1] = 0;
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state_ptr->b[2] = 0;
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state_ptr->b[3] = 0;
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state_ptr->b[4] = 0;
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state_ptr->b[5] = 0;
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} else { /* update a's and b's */
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pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */
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/* update predictor pole a[1] */
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a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);
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if (dqsez != 0) {
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fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];
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if (fa1 < -8191) /* a2p = function of fa1 */
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a2p -= 0x100;
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else if (fa1 > 8191)
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a2p += 0xFF;
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else
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a2p += fa1 >> 5;
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if (pk0 ^ state_ptr->pk[1])
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{
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/* LIMC */
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if (a2p <= -12160)
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a2p = -12288;
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else if (a2p >= 12416)
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a2p = 12288;
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else
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a2p -= 0x80;
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}
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else if (a2p <= -12416)
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a2p = -12288;
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else if (a2p >= 12160)
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a2p = 12288;
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else
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a2p += 0x80;
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}
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/* Possible bug: a2p not initialized if dqsez == 0) */
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/* TRIGB & DELAY */
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state_ptr->a[1] = a2p;
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/* UPA1 */
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/* update predictor pole a[0] */
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state_ptr->a[0] -= state_ptr->a[0] >> 8;
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if (dqsez != 0)
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{
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if (pks1 == 0)
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state_ptr->a[0] += 192;
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else
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state_ptr->a[0] -= 192;
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}
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/* LIMD */
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a1ul = 15360 - a2p;
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if (state_ptr->a[0] < -a1ul)
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state_ptr->a[0] = -a1ul;
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else if (state_ptr->a[0] > a1ul)
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state_ptr->a[0] = a1ul;
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/* UPB : update predictor zeros b[6] */
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for (cnt = 0; cnt < 6; cnt++) {
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if (code_size == 5) /* for 40Kbps G.723 */
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state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;
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else /* for G.721 and 24Kbps G.723 */
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state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;
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if (dq & 0x7FFF) { /* XOR */
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if ((dq ^ state_ptr->dq[cnt]) >= 0)
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state_ptr->b[cnt] += 128;
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else
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state_ptr->b[cnt] -= 128;
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}
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}
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}
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for (cnt = 5; cnt > 0; cnt--)
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state_ptr->dq[cnt] = state_ptr->dq[cnt-1];
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/* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */
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if (mag == 0) {
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state_ptr->dq[0] = (dq >= 0) ? 0x20 : (short)(unsigned short)0xFC20;
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} else {
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exp = log2plus1(mag);
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state_ptr->dq[0] = (dq >= 0) ?
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(exp << 6) + ((mag << 6) >> exp) :
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(exp << 6) + ((mag << 6) >> exp) - 0x400;
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}
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state_ptr->sr[1] = state_ptr->sr[0];
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/* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */
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if (sr == 0) {
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state_ptr->sr[0] = 0x20;
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} else if (sr > 0) {
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exp = log2plus1(sr);
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state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp);
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} else if (sr > -32768) {
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mag = -sr;
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exp = log2plus1(mag);
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state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400;
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} else
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state_ptr->sr[0] = (short)(unsigned short)0xFC20;
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/* DELAY A */
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state_ptr->pk[1] = state_ptr->pk[0];
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state_ptr->pk[0] = pk0;
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/* TONE */
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if (tr == 1) /* this sample has been treated as data */
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state_ptr->td = 0; /* next one will be treated as voice */
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else if (a2p < -11776) /* small sample-to-sample correlation */
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state_ptr->td = 1; /* signal may be data */
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else /* signal is voice */
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state_ptr->td = 0;
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/*
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* Adaptation speed control.
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*/
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state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */
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state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */
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if (tr == 1)
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state_ptr->ap = 256;
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else if (y < 1536) /* SUBTC */
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state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
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else if (state_ptr->td == 1)
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state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
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else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=
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(state_ptr->dml >> 3))
|
|
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
|
|
else
|
|
state_ptr->ap += (-state_ptr->ap) >> 4;
|
|
}
|
|
|
|
/*
|
|
* tandem_adjust(sr, se, y, i, sign)
|
|
*
|
|
* At the end of ADPCM decoding, it simulates an encoder which may be receiving
|
|
* the output of this decoder as a tandem process. If the output of the
|
|
* simulated encoder differs from the input to this decoder, the decoder output
|
|
* is adjusted by one level of A-law or u-law codes.
|
|
*
|
|
* Input:
|
|
* sr decoder output linear PCM sample,
|
|
* se predictor estimate sample,
|
|
* y quantizer step size,
|
|
* i decoder input code,
|
|
* sign sign bit of code i
|
|
*
|
|
* Return:
|
|
* adjusted A-law or u-law compressed sample.
|
|
*/
|
|
int tandem_adjust_alaw(int sr, int se, int y, int i, int sign, short const *qtab)
|
|
{
|
|
unsigned char sp; /* A-law compressed 8-bit code */
|
|
short dx; /* prediction error */
|
|
char id; /* quantized prediction error */
|
|
int sd; /* adjusted A-law decoded sample value */
|
|
int im; /* biased magnitude of i */
|
|
int imx; /* biased magnitude of id */
|
|
|
|
if (sr <= -32768)
|
|
sr = -1;
|
|
sp = sox_13linear2alaw(((sr >> 1) << 3));/* short to A-law compression */
|
|
dx = (sox_alaw2linear16(sp) >> 2) - se; /* 16-bit prediction error */
|
|
id = quantize(dx, y, qtab, sign - 1);
|
|
|
|
if (id == i) { /* no adjustment on sp */
|
|
return (sp);
|
|
} else { /* sp adjustment needed */
|
|
/* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */
|
|
im = i ^ sign; /* 2's complement to biased unsigned */
|
|
imx = id ^ sign;
|
|
|
|
if (imx > im) { /* sp adjusted to next lower value */
|
|
if (sp & 0x80) {
|
|
sd = (sp == 0xD5) ? 0x55 :
|
|
((sp ^ 0x55) - 1) ^ 0x55;
|
|
} else {
|
|
sd = (sp == 0x2A) ? 0x2A :
|
|
((sp ^ 0x55) + 1) ^ 0x55;
|
|
}
|
|
} else { /* sp adjusted to next higher value */
|
|
if (sp & 0x80)
|
|
sd = (sp == 0xAA) ? 0xAA :
|
|
((sp ^ 0x55) + 1) ^ 0x55;
|
|
else
|
|
sd = (sp == 0x55) ? 0xD5 :
|
|
((sp ^ 0x55) - 1) ^ 0x55;
|
|
}
|
|
return (sd);
|
|
}
|
|
}
|
|
|
|
int tandem_adjust_ulaw(int sr, int se, int y, int i, int sign, short const *qtab)
|
|
{
|
|
unsigned char sp; /* u-law compressed 8-bit code */
|
|
short dx; /* prediction error */
|
|
char id; /* quantized prediction error */
|
|
int sd; /* adjusted u-law decoded sample value */
|
|
int im; /* biased magnitude of i */
|
|
int imx; /* biased magnitude of id */
|
|
|
|
if (sr <= -32768)
|
|
sr = 0;
|
|
sp = sox_14linear2ulaw((sr << 2));/* short to u-law compression */
|
|
dx = (sox_ulaw2linear16(sp) >> 2) - se; /* 16-bit prediction error */
|
|
id = quantize(dx, y, qtab, sign - 1);
|
|
if (id == i) {
|
|
return (sp);
|
|
} else {
|
|
/* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */
|
|
im = i ^ sign; /* 2's complement to biased unsigned */
|
|
imx = id ^ sign;
|
|
if (imx > im) { /* sp adjusted to next lower value */
|
|
if (sp & 0x80)
|
|
sd = (sp == 0xFF) ? 0x7E : sp + 1;
|
|
else
|
|
sd = (sp == 0) ? 0 : sp - 1;
|
|
|
|
} else { /* sp adjusted to next higher value */
|
|
if (sp & 0x80)
|
|
sd = (sp == 0x80) ? 0x80 : sp - 1;
|
|
else
|
|
sd = (sp == 0x7F) ? 0xFE : sp + 1;
|
|
}
|
|
return (sd);
|
|
}
|
|
}
|