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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