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_side_info.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 mp3SideInfo *si,
39 mp3Header *info, mp3 header information
40 uint32 *crc initialized crc value (if enabled)
41
42
43 Returns
44
45 mp3SideInfo *si, side information
46
47
48 ------------------------------------------------------------------------------
49 FUNCTION DESCRIPTION
50
51 acquires side information
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_side_info.h"
75 #include "pvmp3_crc.h"
76
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
90 /*----------------------------------------------------------------------------
91 ; LOCAL FUNCTION DEFINITIONS
92 ; Function Prototype declaration
93 ----------------------------------------------------------------------------*/
94
95 /*----------------------------------------------------------------------------
96 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
97 ; Variable declaration - defined here and used outside this module
98 ----------------------------------------------------------------------------*/
99
100 /*----------------------------------------------------------------------------
101 ; EXTERNAL FUNCTION REFERENCES
102 ; Declare functions defined elsewhere and referenced in this module
103 ----------------------------------------------------------------------------*/
104
105 /*----------------------------------------------------------------------------
106 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
107 ; Declare variables used in this module but defined elsewhere
108 ----------------------------------------------------------------------------*/
109
110 /*----------------------------------------------------------------------------
111 ; FUNCTION CODE
112 ----------------------------------------------------------------------------*/
113
pvmp3_get_side_info(tmp3Bits * inputStream,mp3SideInfo * si,mp3Header * info,uint32 * crc)114 ERROR_CODE pvmp3_get_side_info(tmp3Bits *inputStream,
115 mp3SideInfo *si,
116 mp3Header *info,
117 uint32 *crc)
118 {
119 int32 ch, gr;
120 uint32 tmp;
121
122 int stereo = (info->mode == MPG_MD_MONO) ? 1 : 2;
123
124 if (info->version_x == MPEG_1)
125 {
126 if (stereo == 1)
127 {
128 tmp = getbits_crc(inputStream, 14, crc, info->error_protection);
129 si->main_data_begin = (tmp << 18) >> 23; /* 9 */
130 si->private_bits = (tmp << 23) >> 27; /* 5 */
131 }
132 else
133 {
134 tmp = getbits_crc(inputStream, 12, crc, info->error_protection);
135 si->main_data_begin = (tmp << 20) >> 23; /* 9 */
136 si->private_bits = (tmp << 23) >> 29; /* 3 */
137
138 }
139
140 for (ch = 0; ch < stereo; ch++)
141 {
142 tmp = getbits_crc(inputStream, 4, crc, info->error_protection);
143 si->ch[ch].scfsi[0] = (tmp << 28) >> 31; /* 1 */
144 si->ch[ch].scfsi[1] = (tmp << 29) >> 31; /* 1 */
145 si->ch[ch].scfsi[2] = (tmp << 30) >> 31; /* 1 */
146 si->ch[ch].scfsi[3] = tmp & 1; /* 1 */
147 }
148
149 for (gr = 0; gr < 2 ; gr++)
150 {
151 for (ch = 0; ch < stereo; ch++)
152 {
153 si->ch[ch].gran[gr].part2_3_length = getbits_crc(inputStream, 12, crc, info->error_protection);
154 tmp = getbits_crc(inputStream, 22, crc, info->error_protection);
155
156 si->ch[ch].gran[gr].big_values = (tmp << 10) >> 23; /* 9 */
157 si->ch[ch].gran[gr].global_gain = ((tmp << 19) >> 24) - 210; /* 8 */
158 si->ch[ch].gran[gr].scalefac_compress = (tmp << 27) >> 28; /* 4 */
159 si->ch[ch].gran[gr].window_switching_flag = tmp & 1; /* 1 */
160
161 if (si->ch[ch].gran[gr].window_switching_flag)
162 {
163 tmp = getbits_crc(inputStream, 22, crc, info->error_protection);
164
165 si->ch[ch].gran[gr].block_type = (tmp << 10) >> 30; /* 2 */;
166 si->ch[ch].gran[gr].mixed_block_flag = (tmp << 12) >> 31; /* 1 */;
167
168 si->ch[ch].gran[gr].table_select[0] = (tmp << 13) >> 27; /* 5 */;
169 si->ch[ch].gran[gr].table_select[1] = (tmp << 18) >> 27; /* 5 */;
170
171 si->ch[ch].gran[gr].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */;
172 si->ch[ch].gran[gr].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */;
173 si->ch[ch].gran[gr].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */;
174
175 /* Set region_count parameters since they are implicit in this case. */
176
177 if (si->ch[ch].gran[gr].block_type == 0)
178 {
179 return(SIDE_INFO_ERROR);
180 }
181 else if ((si->ch[ch].gran[gr].block_type == 2)
182 && (si->ch[ch].gran[gr].mixed_block_flag == 0))
183 {
184 si->ch[ch].gran[gr].region0_count = 8; /* MI 9; */
185 si->ch[ch].gran[gr].region1_count = 12;
186 }
187 else
188 {
189 si->ch[ch].gran[gr].region0_count = 7; /* MI 8; */
190 si->ch[ch].gran[gr].region1_count = 13;
191 }
192 }
193 else
194 {
195 tmp = getbits_crc(inputStream, 22, crc, info->error_protection);
196
197 si->ch[ch].gran[gr].table_select[0] = (tmp << 10) >> 27; /* 5 */;
198 si->ch[ch].gran[gr].table_select[1] = (tmp << 15) >> 27; /* 5 */;
199 si->ch[ch].gran[gr].table_select[2] = (tmp << 20) >> 27; /* 5 */;
200
201 si->ch[ch].gran[gr].region0_count = (tmp << 25) >> 28; /* 4 */;
202 si->ch[ch].gran[gr].region1_count = (tmp << 29) >> 29; /* 3 */;
203
204 si->ch[ch].gran[gr].block_type = 0;
205 }
206
207 tmp = getbits_crc(inputStream, 3, crc, info->error_protection);
208 si->ch[ch].gran[gr].preflag = (tmp << 29) >> 31; /* 1 */
209 si->ch[ch].gran[gr].scalefac_scale = (tmp << 30) >> 31; /* 1 */
210 si->ch[ch].gran[gr].count1table_select = tmp & 1; /* 1 */
211 }
212 }
213 }
214 else /* Layer 3 LSF */
215 {
216 si->main_data_begin = getbits_crc(inputStream, 8, crc, info->error_protection);
217 si->private_bits = getbits_crc(inputStream, stereo, crc, info->error_protection);
218
219 for (ch = 0; ch < stereo; ch++)
220 {
221 tmp = getbits_crc(inputStream, 21, crc, info->error_protection);
222 si->ch[ch].gran[0].part2_3_length = (tmp << 11) >> 20; /* 12 */
223 si->ch[ch].gran[0].big_values = (tmp << 23) >> 23; /* 9 */
224
225 tmp = getbits_crc(inputStream, 18, crc, info->error_protection);
226 si->ch[ch].gran[0].global_gain = ((tmp << 14) >> 24) - 210; /* 8 */
227 si->ch[ch].gran[0].scalefac_compress = (tmp << 22) >> 23; /* 9 */
228 si->ch[ch].gran[0].window_switching_flag = tmp & 1; /* 1 */
229
230 if (si->ch[ch].gran[0].window_switching_flag)
231 {
232
233 tmp = getbits_crc(inputStream, 22, crc, info->error_protection);
234
235 si->ch[ch].gran[0].block_type = (tmp << 10) >> 30; /* 2 */;
236 si->ch[ch].gran[0].mixed_block_flag = (tmp << 12) >> 31; /* 1 */;
237
238 si->ch[ch].gran[0].table_select[0] = (tmp << 13) >> 27; /* 5 */;
239 si->ch[ch].gran[0].table_select[1] = (tmp << 18) >> 27; /* 5 */;
240
241 si->ch[ch].gran[0].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */;
242 si->ch[ch].gran[0].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */;
243 si->ch[ch].gran[0].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */;
244
245 /* Set region_count parameters since they are implicit in this case. */
246
247 if (si->ch[ch].gran[0].block_type == 0)
248 {
249 return(SIDE_INFO_ERROR);
250 }
251 else if ((si->ch[ch].gran[0].block_type == 2)
252 && (si->ch[ch].gran[0].mixed_block_flag == 0))
253 {
254 si->ch[ch].gran[0].region0_count = 8; /* MI 9; */
255 si->ch[ch].gran[0].region1_count = 12;
256 }
257 else
258 {
259 si->ch[ch].gran[0].region0_count = 7; /* MI 8; */
260 si->ch[ch].gran[0].region1_count = 13;
261 }
262 }
263 else
264 {
265 tmp = getbits_crc(inputStream, 22, crc, info->error_protection);
266
267 si->ch[ch].gran[0].table_select[0] = (tmp << 10) >> 27; /* 5 */;
268 si->ch[ch].gran[0].table_select[1] = (tmp << 15) >> 27; /* 5 */;
269 si->ch[ch].gran[0].table_select[2] = (tmp << 20) >> 27; /* 5 */;
270
271 si->ch[ch].gran[0].region0_count = (tmp << 25) >> 28; /* 4 */;
272 si->ch[ch].gran[0].region1_count = (tmp << 29) >> 29; /* 3 */;
273
274 si->ch[ch].gran[0].block_type = 0;
275 }
276
277 tmp = getbits_crc(inputStream, 2, crc, info->error_protection);
278 si->ch[ch].gran[0].scalefac_scale = tmp >> 1; /* 1 */
279 si->ch[ch].gran[0].count1table_select = tmp & 1; /* 1 */
280
281 }
282 }
283 return (NO_DECODING_ERROR);
284 }
285
286