mirror of
https://github.com/librempeg/librempeg
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85 lines
2.8 KiB
C
85 lines
2.8 KiB
C
/*
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* This file is part of libswresample
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*
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* libswresample is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* libswresample is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with libswresample; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#if defined(TEMPLATE_DITHER_DBL)
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# define RENAME(N) N ## _double
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# define DELEM double
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# define CLIP(v) while(0)
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#elif defined(TEMPLATE_DITHER_FLT)
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# define RENAME(N) N ## _float
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# define DELEM float
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# define CLIP(v) while(0)
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#elif defined(TEMPLATE_DITHER_S32)
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# define RENAME(N) N ## _int32
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# define DELEM int32_t
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# define CLIP(v) v = FFMAX(FFMIN(v, INT32_MAX), INT32_MIN)
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#elif defined(TEMPLATE_DITHER_S16)
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# define RENAME(N) N ## _int16
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# define DELEM int16_t
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# define CLIP(v) v = FFMAX(FFMIN(v, INT16_MAX), INT16_MIN)
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#else
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ERROR
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#endif
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void RENAME(swri_noise_shaping)(SwrContext *s, AudioData *dsts, const AudioData *srcs, const AudioData *noises, int count){
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int pos = s->dither.ns_pos;
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int i, j, ch;
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int taps = s->dither.ns_taps;
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float S = s->dither.ns_scale;
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float S_1 = s->dither.ns_scale_1;
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av_assert2((taps&3) != 2);
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av_assert2((taps&3) != 3 || s->dither.ns_coeffs[taps] == 0);
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for (ch=0; ch<srcs->ch_count; ch++) {
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const float *noise = ((const float *)noises->ch[ch]) + s->dither.noise_pos;
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const DELEM *src = (const DELEM*)srcs->ch[ch];
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DELEM *dst = (DELEM*)dsts->ch[ch];
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float *ns_errors = s->dither.ns_errors[ch];
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const float *ns_coeffs = s->dither.ns_coeffs;
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pos = s->dither.ns_pos;
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for (i=0; i<count; i++) {
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double d1, d = src[i]*S_1;
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for(j=0; j<taps-2; j+=4) {
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d -= ns_coeffs[j ] * ns_errors[pos + j ]
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+ns_coeffs[j + 1] * ns_errors[pos + j + 1]
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+ns_coeffs[j + 2] * ns_errors[pos + j + 2]
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+ns_coeffs[j + 3] * ns_errors[pos + j + 3];
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}
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if(j < taps)
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d -= ns_coeffs[j] * ns_errors[pos + j];
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pos = pos ? pos - 1 : taps - 1;
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d1 = rint(d + noise[i]);
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ns_errors[pos + taps] = ns_errors[pos] = d1 - d;
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d1 *= S;
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CLIP(d1);
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dst[i] = d1;
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}
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}
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s->dither.ns_pos = pos;
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}
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#undef RENAME
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#undef DELEM
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#undef CLIP
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