/* * Copyright (C) 2012-2013 Michael Niedermayer (michaelni@gmx.at) * * This file is part of libswresample * * libswresample is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * libswresample is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with libswresample; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/avassert.h" #include "swresample_internal.h" #include "noise_shaping_data.c" void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSampleFormat noise_fmt) { double scale = s->dither.noise_scale; #define TMP_EXTRA 2 double *tmp = av_malloc((len + TMP_EXTRA) * sizeof(double)); int i; for(i=0; i<len + TMP_EXTRA; i++){ double v; seed = seed* 1664525 + 1013904223; switch(s->dither.method){ case SWR_DITHER_RECTANGULAR: v= ((double)seed) / UINT_MAX - 0.5; break; default: av_assert0(s->dither.method < SWR_DITHER_NB); v = ((double)seed) / UINT_MAX; seed = seed*1664525 + 1013904223; v-= ((double)seed) / UINT_MAX; break; } tmp[i] = v; } for(i=0; i<len; i++){ double v; switch(s->dither.method){ default: av_assert0(s->dither.method < SWR_DITHER_NB); v = tmp[i]; break; case SWR_DITHER_TRIANGULAR_HIGHPASS : v = (- tmp[i] + 2*tmp[i+1] - tmp[i+2]) / sqrt(6); break; } v*= scale; switch(noise_fmt){ case AV_SAMPLE_FMT_S16P: ((int16_t*)dst)[i] = v; break; case AV_SAMPLE_FMT_S32P: ((int32_t*)dst)[i] = v; break; case AV_SAMPLE_FMT_FLTP: ((float *)dst)[i] = v; break; case AV_SAMPLE_FMT_DBLP: ((double *)dst)[i] = v; break; default: av_assert0(0); } } av_free(tmp); } int swri_dither_init(SwrContext *s, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt) { int i; double scale = 0; if (s->dither.method > SWR_DITHER_TRIANGULAR_HIGHPASS && s->dither.method <= SWR_DITHER_NS) return AVERROR(EINVAL); out_fmt = av_get_packed_sample_fmt(out_fmt); in_fmt = av_get_packed_sample_fmt( in_fmt); if(in_fmt == AV_SAMPLE_FMT_FLT || in_fmt == AV_SAMPLE_FMT_DBL){ if(out_fmt == AV_SAMPLE_FMT_S32) scale = 1.0/(1L<<31); if(out_fmt == AV_SAMPLE_FMT_S16) scale = 1.0/(1L<<15); if(out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1.0/(1L<< 7); } if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S32 && (s->dither.output_sample_bits&31)) scale = 1; if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_S16) scale = 1L<<16; if(in_fmt == AV_SAMPLE_FMT_S32 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<24; if(in_fmt == AV_SAMPLE_FMT_S16 && out_fmt == AV_SAMPLE_FMT_U8 ) scale = 1L<<8; scale *= s->dither.scale; if (out_fmt == AV_SAMPLE_FMT_S32 && s->dither.output_sample_bits) scale *= 1<<(32-s->dither.output_sample_bits); s->dither.ns_pos = 0; s->dither.noise_scale= scale; s->dither.ns_scale = scale; s->dither.ns_scale_1 = scale ? 1/scale : 0; memset(s->dither.ns_errors, 0, sizeof(s->dither.ns_errors)); for (i=0; filters[i].coefs; i++) { const filter_t *f = &filters[i]; if (fabs(s->out_sample_rate - f->rate) / f->rate <= .05 && f->name == s->dither.method) { int j; s->dither.ns_taps = f->len; for (j=0; j<f->len; j++) s->dither.ns_coeffs[j] = f->coefs[j]; s->dither.ns_scale_1 *= 1 - exp(f->gain_cB * M_LN10 * 0.005) * 2 / (1<<(8*av_get_bytes_per_sample(out_fmt))); break; } } if (!filters[i].coefs && s->dither.method > SWR_DITHER_NS) { av_log(s, AV_LOG_WARNING, "Requested noise shaping dither not available at this sampling rate, using triangular hp dither\n"); s->dither.method = SWR_DITHER_TRIANGULAR_HIGHPASS; } av_assert0(!s->preout.count); s->dither.noise = s->preout; s->dither.temp = s->preout; if (s->dither.method > SWR_DITHER_NS) { s->dither.noise.bps = 4; s->dither.noise.fmt = AV_SAMPLE_FMT_FLTP; s->dither.noise_scale = 1; } return 0; } #define TEMPLATE_DITHER_S16 #include "dither_template.c" #undef TEMPLATE_DITHER_S16 #define TEMPLATE_DITHER_S32 #include "dither_template.c" #undef TEMPLATE_DITHER_S32 #define TEMPLATE_DITHER_FLT #include "dither_template.c" #undef TEMPLATE_DITHER_FLT #define TEMPLATE_DITHER_DBL #include "dither_template.c" #undef TEMPLATE_DITHER_DBL