3 * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
4 * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
6 * This file is part of a52dec, a free ATSC A-52 stream decoder.
7 * See http://liba52.sourceforge.net/ for updates.
9 * a52dec is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * a52dec 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
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include "config-a52.h"
29 #include "a52_internal.h"
31 static int hthtab
[3][50] IDATA_ATTR
= {
32 {0x730, 0x730, 0x7c0, 0x800, 0x820, 0x840, 0x850, 0x850, 0x860, 0x860,
33 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x890, 0x890,
34 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900,
35 0x910, 0x910, 0x910, 0x910, 0x900, 0x8f0, 0x8c0, 0x870, 0x820, 0x7e0,
36 0x7a0, 0x770, 0x760, 0x7a0, 0x7c0, 0x7c0, 0x6e0, 0x400, 0x3c0, 0x3c0},
37 {0x710, 0x710, 0x7a0, 0x7f0, 0x820, 0x830, 0x840, 0x850, 0x850, 0x860,
38 0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880,
39 0x890, 0x890, 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8e0, 0x8f0,
40 0x900, 0x910, 0x910, 0x910, 0x910, 0x900, 0x8e0, 0x8b0, 0x870, 0x820,
41 0x7e0, 0x7b0, 0x760, 0x770, 0x7a0, 0x7c0, 0x780, 0x5d0, 0x3c0, 0x3c0},
42 {0x680, 0x680, 0x750, 0x7b0, 0x7e0, 0x810, 0x820, 0x830, 0x840, 0x850,
43 0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860,
44 0x870, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880, 0x890, 0x8a0, 0x8b0,
45 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x900, 0x8f0,
46 0x8d0, 0x8b0, 0x840, 0x7f0, 0x790, 0x760, 0x7a0, 0x7c0, 0x7b0, 0x720}
49 static int8_t baptab
[305] IDATA_ATTR
= {
50 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
51 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
52 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
53 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
54 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
55 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, /* 93 padding elems */
57 16, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14,
58 14, 12, 12, 12, 12, 11, 11, 11, 11, 10, 10, 10, 10, 9, 9, 9,
59 9, 8, 8, 8, 8, 7, 7, 7, 7, 6, 6, 6, 6, 5, 5, 5,
60 5, 4, 4, -3, -3, 3, 3, 3, -2, -2, -1, -1, -1, -1, -1, 0,
62 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
63 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
64 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
65 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
66 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
67 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
68 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
69 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
70 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
71 0, 0, 0, 0 /* 148 padding elems */
74 static int bndtab
[30] IDATA_ATTR
= {21, 22, 23, 24, 25, 26, 27, 28, 31, 34,
75 37, 40, 43, 46, 49, 55, 61, 67, 73, 79,
76 85, 97, 109, 121, 133, 157, 181, 205, 229, 253};
78 static int8_t latab
[256] IDATA_ATTR
= {
79 -64, -63, -62, -61, -60, -59, -58, -57, -56, -55, -54, -53,
80 -52, -52, -51, -50, -49, -48, -47, -47, -46, -45, -44, -44,
81 -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35,
82 -35, -34, -33, -33, -32, -32, -31, -30, -30, -29, -29, -28,
83 -28, -27, -27, -26, -26, -25, -25, -24, -24, -23, -23, -22,
84 -22, -21, -21, -21, -20, -20, -19, -19, -19, -18, -18, -18,
85 -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14,
86 -13, -13, -13, -13, -12, -12, -12, -12, -11, -11, -11, -11,
87 -10, -10, -10, -10, -10, -9, -9, -9, -9, -9, -8, -8,
88 -8, -8, -8, -8, -7, -7, -7, -7, -7, -7, -6, -6,
89 -6, -6, -6, -6, -6, -6, -5, -5, -5, -5, -5, -5,
90 -5, -5, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
91 -4, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
92 -3, -3, -3, -2, -2, -2, -2, -2, -2, -2, -2, -2,
93 -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1,
94 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
95 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
96 -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0,
97 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
98 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
99 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
103 #define UPDATE_LEAK() \
105 fastleak += fdecay; \
106 if (fastleak > psd + fgain) \
107 fastleak = psd + fgain; \
108 slowleak += sdecay; \
109 if (slowleak > psd + sgain) \
110 slowleak = psd + sgain; \
113 #define COMPUTE_MASK() \
116 mask -= (psd - dbknee) >> 2; \
117 if (mask > hth [i >> halfrate]) \
118 mask = hth [i >> halfrate]; \
119 mask -= snroffset + 128 * deltba[i]; \
120 mask = (mask > 0) ? 0 : ((-mask) >> 5); \
124 void a52_bit_allocate (a52_state_t
* state
, ba_t
* ba
, int bndstart
,
125 int start
, int end
, int fastleak
, int slowleak
,
128 static int slowgain
[4] = {0x540, 0x4d8, 0x478, 0x410};
129 static int dbpbtab
[4] = {0xc00, 0x500, 0x300, 0x100};
130 static int floortab
[8] = {0x910, 0x950, 0x990, 0x9d0,
131 0xa10, 0xa90, 0xb10, 0x1400};
136 int fdecay
, fgain
, sdecay
, sgain
, dbknee
, floor
, snroffset
;
142 halfrate
= state
->halfrate
;
143 fdecay
= (63 + 20 * ((state
->bai
>> 7) & 3)) >> halfrate
; /* fdcycod */
144 fgain
= 128 + 128 * (ba
->bai
& 7); /* fgaincod */
145 sdecay
= (15 + 2 * (state
->bai
>> 9)) >> halfrate
; /* sdcycod */
146 sgain
= slowgain
[(state
->bai
>> 5) & 3]; /* sgaincod */
147 dbknee
= dbpbtab
[(state
->bai
>> 3) & 3]; /* dbpbcod */
148 hth
= hthtab
[state
->fscod
];
150 * if there is no delta bit allocation, make deltba point to an area
151 * known to contain zeroes. baptab+156 here.
153 deltba
= (ba
->deltbae
== DELTA_BIT_NONE
) ? baptab
+ 156 : ba
->deltba
;
154 floor
= floortab
[state
->bai
& 7]; /* floorcod */
155 snroffset
= 960 - 64 * state
->csnroffst
- 4 * (ba
->bai
>> 3) + floor
;
163 if (start
== 0) { /* not the coupling channel */
170 if (exp
[i
+1] == exp
[i
] - 2)
172 else if (lowcomp
&& (exp
[i
+1] > exp
[i
]))
176 mask
= psd
+ fgain
+ lowcomp
;
178 bap
[i
] = (baptab
+156)[mask
+ 4 * exp
[i
]];
180 } while ((i
< 3) || ((i
< 7) && (exp
[i
] > exp
[i
-1])));
181 fastleak
= psd
+ fgain
;
182 slowleak
= psd
+ sgain
;
186 if (exp
[i
+1] == exp
[i
] - 2)
188 else if (lowcomp
&& (exp
[i
+1] > exp
[i
]))
193 mask
= ((fastleak
+ lowcomp
< slowleak
) ?
194 fastleak
+ lowcomp
: slowleak
);
196 bap
[i
] = (baptab
+156)[mask
+ 4 * exp
[i
]];
200 if (end
== 7) /* lfe channel */
204 if (exp
[i
+1] == exp
[i
] - 2)
206 else if (lowcomp
&& (exp
[i
+1] > exp
[i
]))
210 mask
= ((fastleak
+ lowcomp
< slowleak
) ?
211 fastleak
+ lowcomp
: slowleak
);
213 bap
[i
] = (baptab
+156)[mask
+ 4 * exp
[i
]];
217 while (lowcomp
> 128) { /* two iterations maximum */
221 mask
= ((fastleak
+ lowcomp
< slowleak
) ?
222 fastleak
+ lowcomp
: slowleak
);
224 bap
[i
] = (baptab
+156)[mask
+ 4 * exp
[i
]];
231 int startband
, endband
;
234 endband
= (bndtab
[i
-20] < end
) ? bndtab
[i
-20] : end
;
235 psd
= 128 * exp
[j
++];
236 while (j
< endband
) {
239 next
= 128 * exp
[j
++];
241 switch (delta
>> 9) {
242 case -6: case -5: case -4: case -3: case -2:
246 psd
= next
+ latab
[(-delta
) >> 1];
249 psd
+= latab
[delta
>> 1];
255 mask
= (fastleak
< slowleak
) ? fastleak
: slowleak
;
260 /* max(mask+4*exp)=147=-(minpsd+fgain-deltba-snroffset)>>5+4*exp */
261 /* min(mask+4*exp)=-156=-(sgain-deltba-snroffset)>>5 */
262 bap
[j
] = (baptab
+156)[mask
+ 4 * exp
[j
]];
263 } while (++j
< endband
);