Commit | Line | Data |
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2ba45a60 DM |
1 | /* |
2 | * This file is part of FFmpeg. | |
3 | * | |
4 | * FFmpeg is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU Lesser General Public | |
6 | * License as published by the Free Software Foundation; either | |
7 | * version 2.1 of the License, or (at your option) any later version. | |
8 | * | |
9 | * FFmpeg is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * Lesser General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public | |
15 | * License along with FFmpeg; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #include <stdint.h> | |
20 | #include "libavutil/avutil.h" | |
21 | #include "mathops.h" | |
22 | ||
23 | #undef FUNC | |
24 | #undef sum_type | |
25 | #undef MUL | |
26 | #undef CLIP | |
27 | #undef FSUF | |
28 | ||
29 | #define FUNC(n) AV_JOIN(n ## _, SAMPLE_SIZE) | |
30 | ||
31 | #if SAMPLE_SIZE == 32 | |
32 | # define sum_type int64_t | |
33 | # define MUL(a, b) MUL64(a, b) | |
34 | # define CLIP(x) av_clipl_int32(x) | |
35 | #else | |
36 | # define sum_type int32_t | |
37 | # define MUL(a, b) ((a) * (b)) | |
38 | # define CLIP(x) (x) | |
39 | #endif | |
40 | ||
41 | #define LPC1(x) { \ | |
42 | int c = coefs[(x)-1]; \ | |
43 | p0 += MUL(c, s); \ | |
44 | s = smp[i-(x)+1]; \ | |
45 | p1 += MUL(c, s); \ | |
46 | } | |
47 | ||
48 | static av_always_inline void FUNC(lpc_encode_unrolled)(int32_t *res, | |
49 | const int32_t *smp, int len, int order, | |
50 | const int32_t *coefs, int shift, int big) | |
51 | { | |
52 | int i; | |
53 | for (i = order; i < len; i += 2) { | |
54 | int s = smp[i-order]; | |
55 | sum_type p0 = 0, p1 = 0; | |
56 | if (big) { | |
57 | switch (order) { | |
58 | case 32: LPC1(32) | |
59 | case 31: LPC1(31) | |
60 | case 30: LPC1(30) | |
61 | case 29: LPC1(29) | |
62 | case 28: LPC1(28) | |
63 | case 27: LPC1(27) | |
64 | case 26: LPC1(26) | |
65 | case 25: LPC1(25) | |
66 | case 24: LPC1(24) | |
67 | case 23: LPC1(23) | |
68 | case 22: LPC1(22) | |
69 | case 21: LPC1(21) | |
70 | case 20: LPC1(20) | |
71 | case 19: LPC1(19) | |
72 | case 18: LPC1(18) | |
73 | case 17: LPC1(17) | |
74 | case 16: LPC1(16) | |
75 | case 15: LPC1(15) | |
76 | case 14: LPC1(14) | |
77 | case 13: LPC1(13) | |
78 | case 12: LPC1(12) | |
79 | case 11: LPC1(11) | |
80 | case 10: LPC1(10) | |
81 | case 9: LPC1( 9) | |
82 | LPC1( 8) | |
83 | LPC1( 7) | |
84 | LPC1( 6) | |
85 | LPC1( 5) | |
86 | LPC1( 4) | |
87 | LPC1( 3) | |
88 | LPC1( 2) | |
89 | LPC1( 1) | |
90 | } | |
91 | } else { | |
92 | switch (order) { | |
93 | case 8: LPC1( 8) | |
94 | case 7: LPC1( 7) | |
95 | case 6: LPC1( 6) | |
96 | case 5: LPC1( 5) | |
97 | case 4: LPC1( 4) | |
98 | case 3: LPC1( 3) | |
99 | case 2: LPC1( 2) | |
100 | case 1: LPC1( 1) | |
101 | } | |
102 | } | |
103 | res[i ] = smp[i ] - CLIP(p0 >> shift); | |
104 | res[i+1] = smp[i+1] - CLIP(p1 >> shift); | |
105 | } | |
106 | } | |
107 | ||
108 | static void FUNC(flac_lpc_encode_c)(int32_t *res, const int32_t *smp, int len, | |
109 | int order, const int32_t *coefs, int shift) | |
110 | { | |
111 | int i; | |
112 | for (i = 0; i < order; i++) | |
113 | res[i] = smp[i]; | |
114 | #if CONFIG_SMALL | |
115 | for (i = order; i < len; i += 2) { | |
116 | int j; | |
117 | int s = smp[i]; | |
118 | sum_type p0 = 0, p1 = 0; | |
119 | for (j = 0; j < order; j++) { | |
120 | int c = coefs[j]; | |
121 | p1 += MUL(c, s); | |
122 | s = smp[i-j-1]; | |
123 | p0 += MUL(c, s); | |
124 | } | |
125 | res[i ] = smp[i ] - CLIP(p0 >> shift); | |
126 | res[i+1] = smp[i+1] - CLIP(p1 >> shift); | |
127 | } | |
128 | #else | |
129 | switch (order) { | |
130 | case 1: FUNC(lpc_encode_unrolled)(res, smp, len, 1, coefs, shift, 0); break; | |
131 | case 2: FUNC(lpc_encode_unrolled)(res, smp, len, 2, coefs, shift, 0); break; | |
132 | case 3: FUNC(lpc_encode_unrolled)(res, smp, len, 3, coefs, shift, 0); break; | |
133 | case 4: FUNC(lpc_encode_unrolled)(res, smp, len, 4, coefs, shift, 0); break; | |
134 | case 5: FUNC(lpc_encode_unrolled)(res, smp, len, 5, coefs, shift, 0); break; | |
135 | case 6: FUNC(lpc_encode_unrolled)(res, smp, len, 6, coefs, shift, 0); break; | |
136 | case 7: FUNC(lpc_encode_unrolled)(res, smp, len, 7, coefs, shift, 0); break; | |
137 | case 8: FUNC(lpc_encode_unrolled)(res, smp, len, 8, coefs, shift, 0); break; | |
138 | default: FUNC(lpc_encode_unrolled)(res, smp, len, order, coefs, shift, 1); break; | |
139 | } | |
140 | #endif | |
141 | } | |
142 | ||
143 | /* Comment for clarity/de-obfuscation. | |
144 | * | |
145 | * for (int i = order; i < len; i++) { | |
146 | * int32_t p = 0; | |
147 | * for (int j = 0; j < order; j++) { | |
148 | * int c = coefs[j]; | |
149 | * int s = smp[(i-1)-j]; | |
150 | * p += c*s; | |
151 | * } | |
152 | * res[i] = smp[i] - (p >> shift); | |
153 | * } | |
154 | * | |
155 | * The CONFIG_SMALL code above simplifies to this, in the case of SAMPLE_SIZE | |
156 | * not being equal to 32 (at the present time that means for 16-bit audio). The | |
157 | * code above does 2 samples per iteration. Commit bfdd5bc (made all the way | |
158 | * back in 2007) says that way is faster. | |
159 | */ |