1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * CDDL HEADER START
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance
7*0Sstevel@tonic-gate * with the License.
8*0Sstevel@tonic-gate *
9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate * and limitations under the License.
13*0Sstevel@tonic-gate *
14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate *
20*0Sstevel@tonic-gate * CDDL HEADER END
21*0Sstevel@tonic-gate */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate * Copyright (c) 1992-2001 by Sun Microsystems, Inc.
24*0Sstevel@tonic-gate * All rights reserved.
25*0Sstevel@tonic-gate */
26*0Sstevel@tonic-gate
27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI"
28*0Sstevel@tonic-gate
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate * This is a impementation of sampling rate conversion for low-passed signals.
31*0Sstevel@tonic-gate *
32*0Sstevel@tonic-gate * To convert the input signal of sampling rate of fi to another rate of fo,
33*0Sstevel@tonic-gate * the least common multiple of fi and fo is derived first:
34*0Sstevel@tonic-gate * fm = L * fi = M * fo.
35*0Sstevel@tonic-gate * Then the input signal is up-sampled to fm by inserting (L -1) zero valued
36*0Sstevel@tonic-gate * samples after each input sample, low-pass filtered, and down-smapled by
37*0Sstevel@tonic-gate * saving one sample for every M samples. The implementation takes advantages
38*0Sstevel@tonic-gate * of the (L - 1) zero values in the filter input and the (M - 1) output
39*0Sstevel@tonic-gate * samples to be disregarded.
40*0Sstevel@tonic-gate *
41*0Sstevel@tonic-gate * If L = 1 or M = 1, a simpler decimation or interpolation is used.
42*0Sstevel@tonic-gate */
43*0Sstevel@tonic-gate #include <memory.h>
44*0Sstevel@tonic-gate #include <math.h>
45*0Sstevel@tonic-gate
46*0Sstevel@tonic-gate #include <Resample.h>
47*0Sstevel@tonic-gate
48*0Sstevel@tonic-gate extern "C" {
49*0Sstevel@tonic-gate char *bcopy(char *, char *, int);
50*0Sstevel@tonic-gate char *memmove(char *, char *, int);
51*0Sstevel@tonic-gate }
52*0Sstevel@tonic-gate
53*0Sstevel@tonic-gate #define BCOPY(src, dest, num) memmove(dest, src, num)
54*0Sstevel@tonic-gate
55*0Sstevel@tonic-gate // convolve(), short2double() and double2short() are defined in Fir.cc.
56*0Sstevel@tonic-gate extern double convolve(double *, double *, int);
57*0Sstevel@tonic-gate extern void short2double(double *, short *, int);
58*0Sstevel@tonic-gate extern short double2short(double);
59*0Sstevel@tonic-gate
60*0Sstevel@tonic-gate // generate truncated ideal LPF
sinc_coef(int fold,int order,double * coef)61*0Sstevel@tonic-gate static void sinc_coef(int fold, // sample rate change
62*0Sstevel@tonic-gate int order, // LP FIR filter order
63*0Sstevel@tonic-gate double *coef) // filter coefficients
64*0Sstevel@tonic-gate {
65*0Sstevel@tonic-gate int i;
66*0Sstevel@tonic-gate float alpha;
67*0Sstevel@tonic-gate double bandwidth = M_PI / fold; // digital bandwidth of pass band
68*0Sstevel@tonic-gate
69*0Sstevel@tonic-gate int half = order >> 1;
70*0Sstevel@tonic-gate if (order & 1) { // order is odd, center = half + 0.5
71*0Sstevel@tonic-gate float center = half + 0.5;
72*0Sstevel@tonic-gate for (i = 0; i <= half; i++) {
73*0Sstevel@tonic-gate alpha = center - i;
74*0Sstevel@tonic-gate coef[i] = sin(bandwidth * alpha) / (M_PI * alpha);
75*0Sstevel@tonic-gate }
76*0Sstevel@tonic-gate } else { // order is even, center = half
77*0Sstevel@tonic-gate for (i = 0; i < half; i++) {
78*0Sstevel@tonic-gate alpha = half - i;
79*0Sstevel@tonic-gate coef[i] = sin(bandwidth * alpha) / (M_PI * alpha);
80*0Sstevel@tonic-gate }
81*0Sstevel@tonic-gate coef[i++] = bandwidth / M_PI;
82*0Sstevel@tonic-gate }
83*0Sstevel@tonic-gate for (; i <= order; i++) // symmetric FIR
84*0Sstevel@tonic-gate coef[i] = coef[order - i];
85*0Sstevel@tonic-gate }
86*0Sstevel@tonic-gate
87*0Sstevel@tonic-gate /*
88*0Sstevel@tonic-gate * poly_conv() = coef[0] * data[length - 1] +
89*0Sstevel@tonic-gate * coef[inc_coef] * data[length - 2] +
90*0Sstevel@tonic-gate * ...
91*0Sstevel@tonic-gate * coef[(length - 1) * inc_coef] * data[0] +
92*0Sstevel@tonic-gate *
93*0Sstevel@tonic-gate * convolution of coef[order + 1] and data[length] up-sampled by a factor
94*0Sstevel@tonic-gate * of inc_coef. The terms of coef[1, 2, ... inc_coef - 1] multiplying 0
95*0Sstevel@tonic-gate * are ignored.
96*0Sstevel@tonic-gate */
97*0Sstevel@tonic-gate // polyphase filter convolution
98*0Sstevel@tonic-gate double
poly_conv(double * coef,int order,int inc_coef,double * data,int length)99*0Sstevel@tonic-gate poly_conv(double *coef, // filter coef array
100*0Sstevel@tonic-gate int order, // filter order
101*0Sstevel@tonic-gate int inc_coef, // 1-to-L up-sample for data[length]
102*0Sstevel@tonic-gate double *data, // data array
103*0Sstevel@tonic-gate int length) // data array length
104*0Sstevel@tonic-gate {
105*0Sstevel@tonic-gate if ((order < 0) || (inc_coef < 1) || (length < 1))
106*0Sstevel@tonic-gate return (0.0);
107*0Sstevel@tonic-gate else {
108*0Sstevel@tonic-gate double sum = 0.0;
109*0Sstevel@tonic-gate double *coef_end = coef + order;
110*0Sstevel@tonic-gate double *data_end = data + length;
111*0Sstevel@tonic-gate while ((coef <= coef_end) && (data < data_end)) {
112*0Sstevel@tonic-gate sum += *coef * *--data_end;
113*0Sstevel@tonic-gate coef += inc_coef;
114*0Sstevel@tonic-gate }
115*0Sstevel@tonic-gate return (sum);
116*0Sstevel@tonic-gate }
117*0Sstevel@tonic-gate }
118*0Sstevel@tonic-gate
119*0Sstevel@tonic-gate int
gcf(int a,int b)120*0Sstevel@tonic-gate gcf(int a, int b) // greatest common factor between a and b
121*0Sstevel@tonic-gate {
122*0Sstevel@tonic-gate int remainder = a % b;
123*0Sstevel@tonic-gate return (remainder == 0)? b : gcf(b, remainder);
124*0Sstevel@tonic-gate }
125*0Sstevel@tonic-gate
126*0Sstevel@tonic-gate void ResampleFilter::
updateState(double * in,int size)127*0Sstevel@tonic-gate updateState(
128*0Sstevel@tonic-gate double *in,
129*0Sstevel@tonic-gate int size)
130*0Sstevel@tonic-gate {
131*0Sstevel@tonic-gate if (up <= 1)
132*0Sstevel@tonic-gate Fir::updateState(in, size);
133*0Sstevel@tonic-gate else if (size >= num_state)
134*0Sstevel@tonic-gate memcpy(state, in + size - num_state,
135*0Sstevel@tonic-gate num_state * sizeof (double));
136*0Sstevel@tonic-gate else {
137*0Sstevel@tonic-gate int old = num_state - size;
138*0Sstevel@tonic-gate BCOPY((char *)(state + size), (char *)state,
139*0Sstevel@tonic-gate old * sizeof (double));
140*0Sstevel@tonic-gate memcpy(state + old, in, size * sizeof (double));
141*0Sstevel@tonic-gate }
142*0Sstevel@tonic-gate }
143*0Sstevel@tonic-gate
144*0Sstevel@tonic-gate ResampleFilter:: // constructor
ResampleFilter(int rate_in,int rate_out)145*0Sstevel@tonic-gate ResampleFilter(
146*0Sstevel@tonic-gate int rate_in, // sampling rate of input signal
147*0Sstevel@tonic-gate int rate_out) // sampling rate of output signal
148*0Sstevel@tonic-gate {
149*0Sstevel@tonic-gate // filter sampling rate = common multiple of rate_in and rate_out
150*0Sstevel@tonic-gate int commonfactor = gcf(rate_in, rate_out);
151*0Sstevel@tonic-gate up = rate_out / commonfactor;
152*0Sstevel@tonic-gate down = rate_in / commonfactor;
153*0Sstevel@tonic-gate
154*0Sstevel@tonic-gate int fold = (up > down)? up : down; // take the bigger rate change
155*0Sstevel@tonic-gate order = (fold << 4) - 2; // filter order = fold * 16 - 2
156*0Sstevel@tonic-gate coef = new double[order + 1];
157*0Sstevel@tonic-gate sinc_coef(fold, order, coef); // required bandwidth = PI/fold
158*0Sstevel@tonic-gate
159*0Sstevel@tonic-gate if (up > 1) { // need (order/up) states
160*0Sstevel@tonic-gate num_state = (order + up - 1) / up;
161*0Sstevel@tonic-gate state = new double[num_state];
162*0Sstevel@tonic-gate for (int i = 0; i < num_state; i++) // reset states
163*0Sstevel@tonic-gate state[i] = 0.0;
164*0Sstevel@tonic-gate } else {
165*0Sstevel@tonic-gate num_state = order;
166*0Sstevel@tonic-gate state = new double[order]; // need order states
167*0Sstevel@tonic-gate resetState();
168*0Sstevel@tonic-gate }
169*0Sstevel@tonic-gate delay = (order + 1) >> 1; // assuming symmetric FIR
170*0Sstevel@tonic-gate down_offset = 0;
171*0Sstevel@tonic-gate up_offset = 0;
172*0Sstevel@tonic-gate }
173*0Sstevel@tonic-gate
174*0Sstevel@tonic-gate // down-to-1 decimation
175*0Sstevel@tonic-gate int ResampleFilter::
decimate_noadjust(short * in,int size,short * out)176*0Sstevel@tonic-gate decimate_noadjust(short *in,
177*0Sstevel@tonic-gate int size,
178*0Sstevel@tonic-gate short *out)
179*0Sstevel@tonic-gate {
180*0Sstevel@tonic-gate int i;
181*0Sstevel@tonic-gate
182*0Sstevel@tonic-gate if (size <= 0)
183*0Sstevel@tonic-gate return (0);
184*0Sstevel@tonic-gate else if (down <= 1) // normal filter
185*0Sstevel@tonic-gate return (Fir::filter_noadjust(in, size, out));
186*0Sstevel@tonic-gate else if (size <= down_offset) { // just update states
187*0Sstevel@tonic-gate update_short(in, size);
188*0Sstevel@tonic-gate down_offset -= size;
189*0Sstevel@tonic-gate return (0);
190*0Sstevel@tonic-gate }
191*0Sstevel@tonic-gate
192*0Sstevel@tonic-gate double *in_buf = new double[size];
193*0Sstevel@tonic-gate short2double(in_buf, in, size);
194*0Sstevel@tonic-gate
195*0Sstevel@tonic-gate // filter and decimate and output
196*0Sstevel@tonic-gate short *out_ptr = out;
197*0Sstevel@tonic-gate int init_size = (size <= order)? size : order;
198*0Sstevel@tonic-gate for (i = down_offset; i < init_size; i += down)
199*0Sstevel@tonic-gate *out_ptr++ = double2short(convolve(coef, in_buf, i + 1) +
200*0Sstevel@tonic-gate convolve(coef + i + 1, state + i, order - i));
201*0Sstevel@tonic-gate for (; i < size; i += down)
202*0Sstevel@tonic-gate *out_ptr++ = double2short(convolve(coef, in_buf + i - order,
203*0Sstevel@tonic-gate order + 1));
204*0Sstevel@tonic-gate down_offset = i - size;
205*0Sstevel@tonic-gate
206*0Sstevel@tonic-gate updateState(in_buf, size);
207*0Sstevel@tonic-gate delete in_buf;
208*0Sstevel@tonic-gate return (out_ptr - out);
209*0Sstevel@tonic-gate }
210*0Sstevel@tonic-gate
211*0Sstevel@tonic-gate // decimate with group delay adjusted to 0
212*0Sstevel@tonic-gate int ResampleFilter::
decimate(short * in,int size,short * out)213*0Sstevel@tonic-gate decimate(short *in,
214*0Sstevel@tonic-gate int size,
215*0Sstevel@tonic-gate short *out)
216*0Sstevel@tonic-gate {
217*0Sstevel@tonic-gate if (delay <= 0)
218*0Sstevel@tonic-gate return (decimate_noadjust(in, size, out));
219*0Sstevel@tonic-gate else if (size <= delay) {
220*0Sstevel@tonic-gate update_short(in, size);
221*0Sstevel@tonic-gate delay -= size;
222*0Sstevel@tonic-gate return (0);
223*0Sstevel@tonic-gate } else {
224*0Sstevel@tonic-gate update_short(in, delay);
225*0Sstevel@tonic-gate in += delay;
226*0Sstevel@tonic-gate size -= delay;
227*0Sstevel@tonic-gate delay = 0;
228*0Sstevel@tonic-gate return (decimate_noadjust(in, size, out));
229*0Sstevel@tonic-gate }
230*0Sstevel@tonic-gate }
231*0Sstevel@tonic-gate
232*0Sstevel@tonic-gate // flush decimate filter
233*0Sstevel@tonic-gate int ResampleFilter::
decimate_flush(short * out)234*0Sstevel@tonic-gate decimate_flush(short *out)
235*0Sstevel@tonic-gate {
236*0Sstevel@tonic-gate int num_in = Fir::getFlushSize();
237*0Sstevel@tonic-gate short *in = new short[num_in];
238*0Sstevel@tonic-gate memset(in, 0, num_in * sizeof (short));
239*0Sstevel@tonic-gate int num_out = decimate_noadjust(in, num_in, out);
240*0Sstevel@tonic-gate delay += num_in;
241*0Sstevel@tonic-gate delete in;
242*0Sstevel@tonic-gate return (num_out);
243*0Sstevel@tonic-gate }
244*0Sstevel@tonic-gate
245*0Sstevel@tonic-gate // 1-to-up interpolation
246*0Sstevel@tonic-gate int ResampleFilter::
interpolate_noadjust(short * in,int size,short * out)247*0Sstevel@tonic-gate interpolate_noadjust(short *in,
248*0Sstevel@tonic-gate int size,
249*0Sstevel@tonic-gate short *out)
250*0Sstevel@tonic-gate {
251*0Sstevel@tonic-gate int i, j;
252*0Sstevel@tonic-gate
253*0Sstevel@tonic-gate if (size <= 0)
254*0Sstevel@tonic-gate return (0);
255*0Sstevel@tonic-gate else if (up <= 1) // regular filter
256*0Sstevel@tonic-gate return (Fir::filter_noadjust(in, size, out));
257*0Sstevel@tonic-gate
258*0Sstevel@tonic-gate double *in_buf = new double[size];
259*0Sstevel@tonic-gate short2double(in_buf, in, size);
260*0Sstevel@tonic-gate short *out_ptr = out;
261*0Sstevel@tonic-gate // befor the 1st input sample, generate "-up_offset" output samples
262*0Sstevel@tonic-gate int coef_offset = up + up_offset;
263*0Sstevel@tonic-gate for (j = up_offset; j < 0; j++) {
264*0Sstevel@tonic-gate *out_ptr++ = double2short(up * poly_conv(coef + coef_offset,
265*0Sstevel@tonic-gate order - coef_offset, up, state, num_state));
266*0Sstevel@tonic-gate coef_offset++;
267*0Sstevel@tonic-gate }
268*0Sstevel@tonic-gate // for each of the rest input samples, generate up output samples
269*0Sstevel@tonic-gate for (i = 1; i < size; i++) {
270*0Sstevel@tonic-gate for (j = 0; j < up; j++) {
271*0Sstevel@tonic-gate *out_ptr++ = double2short(up * (poly_conv(coef + j,
272*0Sstevel@tonic-gate order - j, up, in_buf, i) + poly_conv(
273*0Sstevel@tonic-gate coef + coef_offset, order - coef_offset, up, state,
274*0Sstevel@tonic-gate num_state)));
275*0Sstevel@tonic-gate coef_offset++;
276*0Sstevel@tonic-gate }
277*0Sstevel@tonic-gate }
278*0Sstevel@tonic-gate
279*0Sstevel@tonic-gate // for the last input samples, generate "up_offset + up" output samples
280*0Sstevel@tonic-gate for (j = 0; j < (up_offset + up); j++) {
281*0Sstevel@tonic-gate *out_ptr++ = double2short(up * (poly_conv(coef + j,
282*0Sstevel@tonic-gate order - j, up, in_buf, size) + poly_conv(
283*0Sstevel@tonic-gate coef + coef_offset, order - coef_offset, up, state,
284*0Sstevel@tonic-gate num_state)));
285*0Sstevel@tonic-gate coef_offset++;
286*0Sstevel@tonic-gate }
287*0Sstevel@tonic-gate updateState(in_buf, size);
288*0Sstevel@tonic-gate delete in_buf;
289*0Sstevel@tonic-gate return (out_ptr - out);
290*0Sstevel@tonic-gate }
291*0Sstevel@tonic-gate
292*0Sstevel@tonic-gate // flush interpolate filter
293*0Sstevel@tonic-gate int ResampleFilter::
interpolate_flush(short * out)294*0Sstevel@tonic-gate interpolate_flush(short *out)
295*0Sstevel@tonic-gate {
296*0Sstevel@tonic-gate int num = (Fir::getFlushSize() + up - 1) / up;
297*0Sstevel@tonic-gate
298*0Sstevel@tonic-gate short *in = new short[num];
299*0Sstevel@tonic-gate memset(in, 0, num * sizeof (short));
300*0Sstevel@tonic-gate int out_num = interpolate_noadjust(in, num, out);
301*0Sstevel@tonic-gate delay += num * up;
302*0Sstevel@tonic-gate delete in;
303*0Sstevel@tonic-gate return (out_num);
304*0Sstevel@tonic-gate }
305*0Sstevel@tonic-gate
306*0Sstevel@tonic-gate // interpolate with delay adjusted
307*0Sstevel@tonic-gate int ResampleFilter::
interpolate(short * in,int size,short * out)308*0Sstevel@tonic-gate interpolate(short *in,
309*0Sstevel@tonic-gate int size,
310*0Sstevel@tonic-gate short *out)
311*0Sstevel@tonic-gate {
312*0Sstevel@tonic-gate if (size <= 0)
313*0Sstevel@tonic-gate return (interpolate_flush(out));
314*0Sstevel@tonic-gate else if (delay <= 0)
315*0Sstevel@tonic-gate return (interpolate_noadjust(in, size, out));
316*0Sstevel@tonic-gate else {
317*0Sstevel@tonic-gate int delay_in = (delay + up - 1) / up;
318*0Sstevel@tonic-gate if (size < delay_in)
319*0Sstevel@tonic-gate delay_in = size;
320*0Sstevel@tonic-gate double *in_buf = new double[delay_in];
321*0Sstevel@tonic-gate short2double(in_buf, in, delay_in);
322*0Sstevel@tonic-gate updateState(in_buf, delay_in);
323*0Sstevel@tonic-gate delete in_buf;
324*0Sstevel@tonic-gate delay -= delay_in * up;
325*0Sstevel@tonic-gate up_offset = delay;
326*0Sstevel@tonic-gate return (interpolate_noadjust(in + delay_in, size -
327*0Sstevel@tonic-gate delay_in, out));
328*0Sstevel@tonic-gate }
329*0Sstevel@tonic-gate }
330*0Sstevel@tonic-gate
331*0Sstevel@tonic-gate int ResampleFilter::
filter_noadjust(short * in,int size,short * out)332*0Sstevel@tonic-gate filter_noadjust(short *in, // non-integer sampling rate conversion
333*0Sstevel@tonic-gate int size,
334*0Sstevel@tonic-gate short *out)
335*0Sstevel@tonic-gate {
336*0Sstevel@tonic-gate int i, j;
337*0Sstevel@tonic-gate
338*0Sstevel@tonic-gate if (size <= 0)
339*0Sstevel@tonic-gate return (0);
340*0Sstevel@tonic-gate else if (up <= 1)
341*0Sstevel@tonic-gate return (decimate_noadjust(in, size, out));
342*0Sstevel@tonic-gate else if (down <= 1)
343*0Sstevel@tonic-gate return (interpolate_noadjust(in, size, out));
344*0Sstevel@tonic-gate
345*0Sstevel@tonic-gate double *in_buf = new double[size];
346*0Sstevel@tonic-gate short2double(in_buf, in, size);
347*0Sstevel@tonic-gate short *init_out = out;
348*0Sstevel@tonic-gate int coef_offset = up_offset + down_offset + up;
349*0Sstevel@tonic-gate
350*0Sstevel@tonic-gate /*
351*0Sstevel@tonic-gate * before the 1st input sample,
352*0Sstevel@tonic-gate * start from "up_offset + down_offset"th up-sampled sample
353*0Sstevel@tonic-gate */
354*0Sstevel@tonic-gate for (j = up_offset + down_offset; j < 0; j += down) {
355*0Sstevel@tonic-gate *out++ = double2short(up * poly_conv(coef + coef_offset,
356*0Sstevel@tonic-gate order - coef_offset, up, state, num_state));
357*0Sstevel@tonic-gate coef_offset += down;
358*0Sstevel@tonic-gate }
359*0Sstevel@tonic-gate
360*0Sstevel@tonic-gate // process the input samples until the last one
361*0Sstevel@tonic-gate for (i = 1; i < size; i++) {
362*0Sstevel@tonic-gate for (; j < up; j += down) {
363*0Sstevel@tonic-gate *out++ = double2short(up * (poly_conv(coef + j,
364*0Sstevel@tonic-gate order - j, up, in_buf, i) + poly_conv(
365*0Sstevel@tonic-gate coef + coef_offset, order - coef_offset, up, state,
366*0Sstevel@tonic-gate num_state)));
367*0Sstevel@tonic-gate coef_offset += down;
368*0Sstevel@tonic-gate }
369*0Sstevel@tonic-gate j -= up;
370*0Sstevel@tonic-gate }
371*0Sstevel@tonic-gate
372*0Sstevel@tonic-gate // for the last input sample, end at the "up + up_offset"th
373*0Sstevel@tonic-gate for (; j < (up + up_offset); j += down) {
374*0Sstevel@tonic-gate *out++ = double2short(up * (poly_conv(coef + j, order - j, up,
375*0Sstevel@tonic-gate in_buf, size) + poly_conv(coef + coef_offset,
376*0Sstevel@tonic-gate order - coef_offset, up, state, num_state)));
377*0Sstevel@tonic-gate coef_offset += down;
378*0Sstevel@tonic-gate }
379*0Sstevel@tonic-gate down_offset = j - (up + up_offset);
380*0Sstevel@tonic-gate
381*0Sstevel@tonic-gate updateState(in_buf, size);
382*0Sstevel@tonic-gate delete in_buf;
383*0Sstevel@tonic-gate return (out - init_out);
384*0Sstevel@tonic-gate }
385*0Sstevel@tonic-gate
386*0Sstevel@tonic-gate int ResampleFilter::
getFlushSize(void)387*0Sstevel@tonic-gate getFlushSize(void)
388*0Sstevel@tonic-gate {
389*0Sstevel@tonic-gate int num_in = (Fir::getFlushSize() + up - 1) / up;
390*0Sstevel@tonic-gate return ((num_in * up + down - 1 - down_offset) / down);
391*0Sstevel@tonic-gate }
392*0Sstevel@tonic-gate
393*0Sstevel@tonic-gate int ResampleFilter::
flush(short * out)394*0Sstevel@tonic-gate flush(short *out) // flush resampling filter
395*0Sstevel@tonic-gate
396*0Sstevel@tonic-gate {
397*0Sstevel@tonic-gate if (down <= 1)
398*0Sstevel@tonic-gate return (interpolate_flush(out));
399*0Sstevel@tonic-gate else if (up <= 1)
400*0Sstevel@tonic-gate return (decimate_flush(out));
401*0Sstevel@tonic-gate
402*0Sstevel@tonic-gate int num = (Fir::getFlushSize() + up - 1) / up;
403*0Sstevel@tonic-gate
404*0Sstevel@tonic-gate short *in = new short[num];
405*0Sstevel@tonic-gate memset(in, 0, num * sizeof (short));
406*0Sstevel@tonic-gate int out_num = filter_noadjust(in, num, out);
407*0Sstevel@tonic-gate delete in;
408*0Sstevel@tonic-gate delay += num * up;
409*0Sstevel@tonic-gate return (out_num);
410*0Sstevel@tonic-gate }
411*0Sstevel@tonic-gate
412*0Sstevel@tonic-gate /*
413*0Sstevel@tonic-gate * sampling rate conversion with filter delay adjusted
414*0Sstevel@tonic-gate */
415*0Sstevel@tonic-gate int ResampleFilter::
filter(short * in,int size,short * out)416*0Sstevel@tonic-gate filter(
417*0Sstevel@tonic-gate short *in,
418*0Sstevel@tonic-gate int size,
419*0Sstevel@tonic-gate short *out)
420*0Sstevel@tonic-gate {
421*0Sstevel@tonic-gate if (size <= 0)
422*0Sstevel@tonic-gate return (flush(out));
423*0Sstevel@tonic-gate else if (up <= 1)
424*0Sstevel@tonic-gate return (decimate(in, size, out));
425*0Sstevel@tonic-gate else if (down <= 1)
426*0Sstevel@tonic-gate return (interpolate(in, size, out));
427*0Sstevel@tonic-gate else if (delay <= 0)
428*0Sstevel@tonic-gate return (filter_noadjust(in, size, out));
429*0Sstevel@tonic-gate else {
430*0Sstevel@tonic-gate int delay_in = (delay + up - 1) / up;
431*0Sstevel@tonic-gate if (size < delay_in)
432*0Sstevel@tonic-gate delay_in = size;
433*0Sstevel@tonic-gate double *in_buf = new double[delay_in];
434*0Sstevel@tonic-gate short2double(in_buf, in, delay_in);
435*0Sstevel@tonic-gate updateState(in_buf, delay_in);
436*0Sstevel@tonic-gate delete in_buf;
437*0Sstevel@tonic-gate delay -= up * delay_in;
438*0Sstevel@tonic-gate if (delay <= 0) {
439*0Sstevel@tonic-gate up_offset = delay;
440*0Sstevel@tonic-gate down_offset = 0;
441*0Sstevel@tonic-gate }
442*0Sstevel@tonic-gate return (filter_noadjust(in + delay_in, size - delay_in, out));
443*0Sstevel@tonic-gate }
444*0Sstevel@tonic-gate }
445