blob: a81fd8831b9961e6f0eb2f2c52c8ca1130620889
1 | /* |
2 | * various filters for ACELP-based codecs |
3 | * |
4 | * Copyright (c) 2008 Vladimir Voroshilov |
5 | * |
6 | * This file is part of FFmpeg. |
7 | * |
8 | * FFmpeg is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU Lesser General Public |
10 | * License as published by the Free Software Foundation; either |
11 | * version 2.1 of the License, or (at your option) any later version. |
12 | * |
13 | * FFmpeg is distributed in the hope that it will be useful, |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
16 | * Lesser General Public License for more details. |
17 | * |
18 | * You should have received a copy of the GNU Lesser General Public |
19 | * License along with FFmpeg; if not, write to the Free Software |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
21 | */ |
22 | |
23 | #include <inttypes.h> |
24 | |
25 | #include "avcodec.h" |
26 | #include "celp_filters.h" |
27 | #include "libavutil/avassert.h" |
28 | #include "libavutil/common.h" |
29 | |
30 | void ff_celp_convolve_circ(int16_t* fc_out, const int16_t* fc_in, |
31 | const int16_t* filter, int len) |
32 | { |
33 | int i, k; |
34 | |
35 | memset(fc_out, 0, len * sizeof(int16_t)); |
36 | |
37 | /* Since there are few pulses over an entire subframe (i.e. almost |
38 | all fc_in[i] are zero) it is faster to loop over fc_in first. */ |
39 | for (i = 0; i < len; i++) { |
40 | if (fc_in[i]) { |
41 | for (k = 0; k < i; k++) |
42 | fc_out[k] += (fc_in[i] * filter[len + k - i]) >> 15; |
43 | |
44 | for (k = i; k < len; k++) |
45 | fc_out[k] += (fc_in[i] * filter[ k - i]) >> 15; |
46 | } |
47 | } |
48 | } |
49 | |
50 | void ff_celp_circ_addf(float *out, const float *in, |
51 | const float *lagged, int lag, float fac, int n) |
52 | { |
53 | int k; |
54 | for (k = 0; k < lag; k++) |
55 | out[k] = in[k] + fac * lagged[n + k - lag]; |
56 | for (; k < n; k++) |
57 | out[k] = in[k] + fac * lagged[ k - lag]; |
58 | } |
59 | |
60 | int ff_celp_lp_synthesis_filter(int16_t *out, const int16_t *filter_coeffs, |
61 | const int16_t *in, int buffer_length, |
62 | int filter_length, int stop_on_overflow, |
63 | int shift, int rounder) |
64 | { |
65 | int i,n; |
66 | |
67 | for (n = 0; n < buffer_length; n++) { |
68 | int sum = -rounder, sum1; |
69 | for (i = 1; i <= filter_length; i++) |
70 | sum += filter_coeffs[i-1] * out[n-i]; |
71 | |
72 | sum1 = ((-sum >> 12) + in[n]) >> shift; |
73 | sum = av_clip_int16(sum1); |
74 | |
75 | if (stop_on_overflow && sum != sum1) |
76 | return 1; |
77 | |
78 | out[n] = sum; |
79 | } |
80 | |
81 | return 0; |
82 | } |
83 | |
84 | void ff_celp_lp_synthesis_filterf(float *out, const float *filter_coeffs, |
85 | const float* in, int buffer_length, |
86 | int filter_length) |
87 | { |
88 | int i,n; |
89 | |
90 | #if 0 // Unoptimized code path for improved readability |
91 | for (n = 0; n < buffer_length; n++) { |
92 | out[n] = in[n]; |
93 | for (i = 1; i <= filter_length; i++) |
94 | out[n] -= filter_coeffs[i-1] * out[n-i]; |
95 | } |
96 | #else |
97 | float out0, out1, out2, out3; |
98 | float old_out0, old_out1, old_out2, old_out3; |
99 | float a,b,c; |
100 | |
101 | a = filter_coeffs[0]; |
102 | b = filter_coeffs[1]; |
103 | c = filter_coeffs[2]; |
104 | b -= filter_coeffs[0] * filter_coeffs[0]; |
105 | c -= filter_coeffs[1] * filter_coeffs[0]; |
106 | c -= filter_coeffs[0] * b; |
107 | |
108 | av_assert2((filter_length&1)==0 && filter_length>=4); |
109 | |
110 | old_out0 = out[-4]; |
111 | old_out1 = out[-3]; |
112 | old_out2 = out[-2]; |
113 | old_out3 = out[-1]; |
114 | for (n = 0; n <= buffer_length - 4; n+=4) { |
115 | float tmp0,tmp1,tmp2; |
116 | float val; |
117 | |
118 | out0 = in[0]; |
119 | out1 = in[1]; |
120 | out2 = in[2]; |
121 | out3 = in[3]; |
122 | |
123 | out0 -= filter_coeffs[2] * old_out1; |
124 | out1 -= filter_coeffs[2] * old_out2; |
125 | out2 -= filter_coeffs[2] * old_out3; |
126 | |
127 | out0 -= filter_coeffs[1] * old_out2; |
128 | out1 -= filter_coeffs[1] * old_out3; |
129 | |
130 | out0 -= filter_coeffs[0] * old_out3; |
131 | |
132 | val = filter_coeffs[3]; |
133 | |
134 | out0 -= val * old_out0; |
135 | out1 -= val * old_out1; |
136 | out2 -= val * old_out2; |
137 | out3 -= val * old_out3; |
138 | |
139 | for (i = 5; i < filter_length; i += 2) { |
140 | old_out3 = out[-i]; |
141 | val = filter_coeffs[i-1]; |
142 | |
143 | out0 -= val * old_out3; |
144 | out1 -= val * old_out0; |
145 | out2 -= val * old_out1; |
146 | out3 -= val * old_out2; |
147 | |
148 | old_out2 = out[-i-1]; |
149 | |
150 | val = filter_coeffs[i]; |
151 | |
152 | out0 -= val * old_out2; |
153 | out1 -= val * old_out3; |
154 | out2 -= val * old_out0; |
155 | out3 -= val * old_out1; |
156 | |
157 | FFSWAP(float, old_out0, old_out2); |
158 | old_out1 = old_out3; |
159 | } |
160 | |
161 | tmp0 = out0; |
162 | tmp1 = out1; |
163 | tmp2 = out2; |
164 | |
165 | out3 -= a * tmp2; |
166 | out2 -= a * tmp1; |
167 | out1 -= a * tmp0; |
168 | |
169 | out3 -= b * tmp1; |
170 | out2 -= b * tmp0; |
171 | |
172 | out3 -= c * tmp0; |
173 | |
174 | |
175 | out[0] = out0; |
176 | out[1] = out1; |
177 | out[2] = out2; |
178 | out[3] = out3; |
179 | |
180 | old_out0 = out0; |
181 | old_out1 = out1; |
182 | old_out2 = out2; |
183 | old_out3 = out3; |
184 | |
185 | out += 4; |
186 | in += 4; |
187 | } |
188 | |
189 | out -= n; |
190 | in -= n; |
191 | for (; n < buffer_length; n++) { |
192 | out[n] = in[n]; |
193 | for (i = 1; i <= filter_length; i++) |
194 | out[n] -= filter_coeffs[i-1] * out[n-i]; |
195 | } |
196 | #endif |
197 | } |
198 | |
199 | void ff_celp_lp_zero_synthesis_filterf(float *out, const float *filter_coeffs, |
200 | const float *in, int buffer_length, |
201 | int filter_length) |
202 | { |
203 | int i,n; |
204 | |
205 | for (n = 0; n < buffer_length; n++) { |
206 | out[n] = in[n]; |
207 | for (i = 1; i <= filter_length; i++) |
208 | out[n] += filter_coeffs[i-1] * in[n-i]; |
209 | } |
210 | } |
211 | |
212 | void ff_celp_filter_init(CELPFContext *c) |
213 | { |
214 | c->celp_lp_synthesis_filterf = ff_celp_lp_synthesis_filterf; |
215 | c->celp_lp_zero_synthesis_filterf = ff_celp_lp_zero_synthesis_filterf; |
216 | |
217 | if(HAVE_MIPSFPU) |
218 | ff_celp_filter_init_mips(c); |
219 | } |
220 |