1/*
2 * This file is part of libswresample
3 *
4 * libswresample 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 * libswresample 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 libswresample; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#if defined(TEMPLATE_DITHER_DBL)
20#    define RENAME(N) N ## _double
21#    define DELEM  double
22#    define CLIP(v) while(0)
23
24#elif defined(TEMPLATE_DITHER_FLT)
25#    define RENAME(N) N ## _float
26#    define DELEM  float
27#    define CLIP(v) while(0)
28
29#elif defined(TEMPLATE_DITHER_S32)
30#    define RENAME(N) N ## _int32
31#    define DELEM  int32_t
32#    define CLIP(v) v = FFMAX(FFMIN(v, INT32_MAX), INT32_MIN)
33
34#elif defined(TEMPLATE_DITHER_S16)
35#    define RENAME(N) N ## _int16
36#    define DELEM  int16_t
37#    define CLIP(v) v = FFMAX(FFMIN(v, INT16_MAX), INT16_MIN)
38
39#else
40ERROR
41#endif
42
43void RENAME(swri_noise_shaping)(SwrContext *s, AudioData *dsts, const AudioData *srcs, const AudioData *noises, int count){
44    int pos = s->dither.ns_pos;
45    int i, j, ch;
46    int taps  = s->dither.ns_taps;
47    float S   = s->dither.ns_scale;
48    float S_1 = s->dither.ns_scale_1;
49
50    av_assert2((taps&3) != 2);
51    av_assert2((taps&3) != 3 || s->dither.ns_coeffs[taps] == 0);
52
53    for (ch=0; ch<srcs->ch_count; ch++) {
54        const float *noise = ((const float *)noises->ch[ch]) + s->dither.noise_pos;
55        const DELEM *src = (const DELEM*)srcs->ch[ch];
56        DELEM *dst = (DELEM*)dsts->ch[ch];
57        float *ns_errors = s->dither.ns_errors[ch];
58        const float *ns_coeffs = s->dither.ns_coeffs;
59        pos  = s->dither.ns_pos;
60        for (i=0; i<count; i++) {
61            double d1, d = src[i]*S_1;
62            for(j=0; j<taps-2; j+=4) {
63                d -= ns_coeffs[j    ] * ns_errors[pos + j    ]
64                    +ns_coeffs[j + 1] * ns_errors[pos + j + 1]
65                    +ns_coeffs[j + 2] * ns_errors[pos + j + 2]
66                    +ns_coeffs[j + 3] * ns_errors[pos + j + 3];
67            }
68            if(j < taps)
69                d -= ns_coeffs[j] * ns_errors[pos + j];
70            pos = pos ? pos - 1 : taps - 1;
71            d1 = rint(d + noise[i]);
72            ns_errors[pos + taps] = ns_errors[pos] = d1 - d;
73            d1 *= S;
74            CLIP(d1);
75            dst[i] = d1;
76        }
77    }
78
79    s->dither.ns_pos = pos;
80}
81
82#undef RENAME
83#undef DELEM
84#undef CLIP
85