1 /*
2 * common functions for the ATRAC family of decoders
3 *
4 * Copyright (c) 2006-2013 Maxim Poliakovski
5 * Copyright (c) 2006-2008 Benjamin Larsson
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file
26 */
27
28 #include <math.h>
29 #include <string.h>
30
33
35
38
40 -0.00001461907, -0.00009205479,-0.000056157569,0.00030117269,
41 0.0002422519, -0.00085293897,-0.0005205574, 0.0020340169,
42 0.00078333891, -0.0042153862, -0.00075614988, 0.0078402944,
43 -0.000061169922,-0.01344162, 0.0024626821, 0.021736089,
44 -0.007801671, -0.034090221, 0.01880949, 0.054326009,
45 -0.043596379, -0.099384367, 0.13207909, 0.46424159
46 };
47
49 {
50 /* Generate scale factors */
51 for (
int i = 0;
i < 64;
i++)
53
54 /* Generate the QMF window. */
55 for (
int i = 0;
i < 24;
i++) {
58 }
59 }
60
62 {
65 }
66
68 int loc_scale)
69 {
71
75
76 /* Generate gain level table. */
77 for (
i = 0;
i < 16;
i++)
79
80 /* Generate gain interpolation table. */
81 for (
i = -15;
i < 16;
i++)
83 }
84
87 int num_samples,
float *
out)
88 {
89 float lev, gc_scale, gain_inc;
91
93 : 1.0f;
94
98 } else {
100
103
108
109 /* apply constant gain level and overlap */
112
113 /* interpolate between two different gain levels */
117 }
118 }
119
120 for (;
pos < num_samples;
pos++)
122 }
123
124 /* copy the overlapping part into the delay buffer */
125 memcpy(prev, &in[num_samples], num_samples * sizeof(float));
126 }
127
129 float *delayBuf,
float *
temp)
130 {
132 float *p1, *p3;
133
134 memcpy(
temp, delayBuf, 46*
sizeof(
float));
135
137
138 /* loop1 */
139 for(
i=0;
i<nIn;
i+=2){
140 p3[2*
i+0] = inlo[
i ] + inhi[
i ];
141 p3[2*
i+1] = inlo[
i ] - inhi[
i ];
142 p3[2*
i+2] = inlo[
i+1] + inhi[
i+1];
143 p3[2*
i+3] = inlo[
i+1] - inhi[
i+1];
144 }
145
146 /* loop2 */
148 for (j = nIn; j != 0; j--) {
149 float s1 = 0.0;
150 float s2 = 0.0;
151
152 for (
i = 0;
i < 48;
i += 2) {
155 }
156
157 pOut[0] = s2;
158 pOut[1] = s1;
159
160 p1 += 2;
161 pOut += 2;
162 }
163
164 /* Update the delay buffer. */
165 memcpy(delayBuf,
temp + nIn*2, 46*
sizeof(
float));
166 }