1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /*
19 ------------------------------------------------------------------------------
20
21 PacketVideo Corp.
22 MP3 Decoder Library
23
24 Filename: pvmp3_get_scale_factors.cpp
25
26 Date: 09/21/2007
27
28 ------------------------------------------------------------------------------
29 REVISION HISTORY
30
31
32 Description:
33
34 ------------------------------------------------------------------------------
35 INPUT AND OUTPUT DEFINITIONS
36
37 Input
38 mp3ScaleFactors *scalefac,
39 mp3SideInfo *si, side info
40 int32 gr, granule
41 int32 ch, channel
42 tbits *pMainData bit stream
43
44 Returns
45
46 mp3ScaleFactors *scalefac, scale factors
47
48 ------------------------------------------------------------------------------
49 FUNCTION DESCRIPTION
50
51 get scale factors
52
53 ------------------------------------------------------------------------------
54 REQUIREMENTS
55
56
57 ------------------------------------------------------------------------------
58 REFERENCES
59
60 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996)
61 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
62
63 ------------------------------------------------------------------------------
64 PSEUDO-CODE
65
66 ------------------------------------------------------------------------------
67 */
68
69
70 /*----------------------------------------------------------------------------
71 ; INCLUDES
72 ----------------------------------------------------------------------------*/
73
74 #include "pvmp3_get_scale_factors.h"
75 #include "pvmp3_getbits.h"
76 #include "mp3_mem_funcs.h"
77
78 /*----------------------------------------------------------------------------
79 ; MACROS
80 ; Define module specific macros here
81 ----------------------------------------------------------------------------*/
82
83
84 /*----------------------------------------------------------------------------
85 ; DEFINES
86 ; Include all pre-processor statements here. Include conditional
87 ; compile variables also.
88 ----------------------------------------------------------------------------*/
89 #define Qfmt_28(a)(int32(double(0x10000000)*(a)))
90
91 /*----------------------------------------------------------------------------
92 ; LOCAL FUNCTION DEFINITIONS
93 ; Function Prototype declaration
94 ----------------------------------------------------------------------------*/
95
96 /*----------------------------------------------------------------------------
97 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
98 ; Variable declaration - defined here and used outside this module
99 ----------------------------------------------------------------------------*/
100 const int32 slen[2][16] =
101 {
102 {0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},
103 {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}
104 };
105
106 const struct
107 {
108 int32 l[5];
109 int32 s[3];
110 } sfbtable =
111 {
112 {0, 6, 11, 16, 21},
113 {0, 6, 12}
114 };
115
116 const int32 long_sfbtable[4] = { 6, 5, 5, 5};
117
118 /*----------------------------------------------------------------------------
119 ; EXTERNAL FUNCTION REFERENCES
120 ; Declare functions defined elsewhere and referenced in this module
121 ----------------------------------------------------------------------------*/
122
123 /*----------------------------------------------------------------------------
124 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
125 ; Declare variables used in this module but defined elsewhere
126 ----------------------------------------------------------------------------*/
127
128 /*----------------------------------------------------------------------------
129 ; FUNCTION CODE
130 ----------------------------------------------------------------------------*/
131
pvmp3_get_scale_factors(mp3ScaleFactors * scalefac,mp3SideInfo * si,int32 gr,int32 ch,tmp3Bits * pMainData)132 void pvmp3_get_scale_factors(mp3ScaleFactors *scalefac,
133 mp3SideInfo *si,
134 int32 gr,
135 int32 ch,
136 tmp3Bits *pMainData)
137 {
138 int32 sfb;
139 int32 i;
140 int32 window;
141 granuleInfo *gr_info = &(si->ch[ch].gran[gr]);
142
143 if (gr_info->window_switching_flag && (gr_info->block_type == 2))
144 {
145 if (gr_info->mixed_block_flag)
146 { /* MIXED */
147 for (sfb = 0; sfb < 8; sfb++)
148 {
149 scalefac->l[sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]);
150 }
151
152 for (sfb = 3; sfb < 6; sfb++)
153 {
154 for (window = 0; window < 3; window++)
155 {
156 scalefac->s[window][sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]);
157 }
158 }
159 for (sfb = 6; sfb < 12; sfb++)
160 {
161 for (window = 0; window < 3; window++)
162 {
163 scalefac->s[window][sfb] = getNbits(pMainData, slen[1][gr_info->scalefac_compress]);
164 }
165 }
166 }
167 else
168 { /* SHORT*/
169 for (i = 0; i < 2; i++)
170 {
171 for (sfb = sfbtable.s[i]; sfb < sfbtable.s[i+1]; sfb++)
172 {
173 for (window = 0; window < 3; window++)
174 {
175 scalefac->s[window][sfb] = getNbits(pMainData, slen[i][gr_info->scalefac_compress]);
176 }
177 }
178 }
179 }
180
181 scalefac->s[0][12] = 0; /* sfb = 12 win= 0 */
182 scalefac->s[1][12] = 0; /* sfb = 12 win= 1 */
183 scalefac->s[2][12] = 0; /* sfb = 12 win= 2 */
184 }
185 else
186 { /* LONG types 0,1,3 */
187
188 int32 *ptr = &scalefac->l[0];
189
190 for (i = 0; i < 4; i++)
191 {
192 int32 tmp4 = long_sfbtable[i];
193
194 if ((si->ch[ch].scfsi[i] == 0) || (gr == 0))
195 {
196 int32 tmp1 = slen[(i>>1)][gr_info->scalefac_compress];
197
198 if (tmp1)
199 {
200 int32 tmp2 = tmp1 * tmp4;
201 uint32 tmp3 = getNbits(pMainData, tmp2);
202 tmp4 = 32 - tmp1;
203 for (; tmp2 > 0; tmp2 -= tmp1)
204 {
205 *(ptr++) = (tmp3 << (32 - tmp2)) >> tmp4;
206 }
207 }
208 else
209 {
210 for (sfb = tmp4; sfb != 0; sfb--)
211 {
212 *(ptr++) = 0;
213 }
214
215 }
216 }
217 else
218 {
219 ptr += tmp4;
220 }
221 }
222 scalefac->l[21] = 0;
223 scalefac->l[22] = 0;
224 }
225 }
226
227