/* * Copyright (c) 2015 Kyle Swanson . * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/channel_layout.h" #include "libavutil/opt.h" #include "audio.h" #include "avfilter.h" #include "filters.h" #include "formats.h" #include "libavutil/lfg.h" #include "libavutil/random_seed.h" typedef struct ANoiseSrcContext { const AVClass *class; int sample_rate; double amplitude; double density; int64_t duration; int color; int64_t seed; int nb_samples; int64_t pts; int infinite; double (*filter)(double white, double *buf); double buf[7]; AVLFG c; } ANoiseSrcContext; enum NoiseMode { NM_WHITE, NM_PINK, NM_BROWN, NM_BLUE, NM_VIOLET, NM_VELVET, NM_NB }; #define OFFSET(x) offsetof(ANoiseSrcContext, x) #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption anoisesrc_options[] = { { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS }, { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS }, { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS }, { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS }, { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS }, { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS }, { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" }, { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" }, { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" }, { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, .unit = "color" }, { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, .unit = "color" }, { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, .unit = "color" }, { "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, .unit = "color" }, { "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, .unit = "color" }, { "velvet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VELVET}, 0, 0, FLAGS, .unit = "color" }, { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS }, { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS }, { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS }, { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS }, { "density", "set density", OFFSET(density), AV_OPT_TYPE_DOUBLE, {.dbl = 0.05}, 0., 1., FLAGS }, {NULL} }; AVFILTER_DEFINE_CLASS(anoisesrc); static av_cold int query_formats(AVFilterContext *ctx) { ANoiseSrcContext *s = ctx->priv; static const AVChannelLayout chlayouts[] = { AV_CHANNEL_LAYOUT_MONO, { 0 } }; int sample_rates[] = { s->sample_rate, -1 }; static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_NONE }; int ret = ff_set_common_formats_from_list(ctx, sample_fmts); if (ret < 0) return ret; ret = ff_set_common_channel_layouts_from_list(ctx, chlayouts); if (ret < 0) return ret; return ff_set_common_samplerates_from_list(ctx, sample_rates); } static double white_filter(double white, double *buf) { return white; } static double pink_filter(double white, double *buf) { double pink; /* http://www.musicdsp.org/files/pink.txt */ buf[0] = 0.99886 * buf[0] + white * 0.0555179; buf[1] = 0.99332 * buf[1] + white * 0.0750759; buf[2] = 0.96900 * buf[2] + white * 0.1538520; buf[3] = 0.86650 * buf[3] + white * 0.3104856; buf[4] = 0.55000 * buf[4] + white * 0.5329522; buf[5] = -0.7616 * buf[5] - white * 0.0168980; pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362; buf[6] = white * 0.115926; return pink * 0.11; } static double blue_filter(double white, double *buf) { double blue; /* Same as pink_filter but subtract the offsets rather than add */ buf[0] = 0.0555179 * white - 0.99886 * buf[0]; buf[1] = 0.0750759 * white - 0.99332 * buf[1]; buf[2] = 0.1538520 * white - 0.96900 * buf[2]; buf[3] = 0.3104856 * white - 0.86650 * buf[3]; buf[4] = 0.5329522 * white - 0.55000 * buf[4]; buf[5] = -0.016898 * white + 0.76160 * buf[5]; blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362; buf[6] = white * 0.115926; return blue * 0.11; } static double brown_filter(double white, double *buf) { double brown; brown = ((0.02 * white) + buf[0]) / 1.02; buf[0] = brown; return brown * 3.5; } static double violet_filter(double white, double *buf) { double violet; violet = ((0.02 * white) - buf[0]) / 1.02; buf[0] = violet; return violet * 3.5; } static double velvet_filter(double white, double *buf) { double awhite = fabs(white); return FFDIFFSIGN(white, 0.0) * buf[1] * (awhite < buf[0]); } static av_cold int config_props(AVFilterLink *outlink) { AVFilterContext *ctx = outlink->src; ANoiseSrcContext *s = ctx->priv; if (s->seed == -1) s->seed = av_get_random_seed(); av_lfg_init(&s->c, s->seed); if (s->duration == 0) s->infinite = 1; s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE); switch (s->color) { case NM_WHITE: s->filter = white_filter; break; case NM_PINK: s->filter = pink_filter; break; case NM_BROWN: s->filter = brown_filter; break; case NM_BLUE: s->filter = blue_filter; break; case NM_VIOLET: s->filter = violet_filter; break; case NM_VELVET: s->buf[0] = s->amplitude * s->density; s->buf[1] = s->amplitude; s->filter = velvet_filter; break; } return 0; } static int activate(AVFilterContext *ctx) { AVFilterLink *outlink = ctx->outputs[0]; ANoiseSrcContext *s = ctx->priv; AVFrame *frame; int nb_samples, i; double *dst; if (!ff_outlink_frame_wanted(outlink)) return FFERROR_NOT_READY; if (!s->infinite && s->duration <= 0) { ff_outlink_set_status(outlink, AVERROR_EOF, s->pts); return 0; } else if (!s->infinite && s->duration < s->nb_samples) { nb_samples = s->duration; } else { nb_samples = s->nb_samples; } if (!(frame = ff_get_audio_buffer(outlink, nb_samples))) return AVERROR(ENOMEM); dst = (double *)frame->data[0]; for (i = 0; i < nb_samples; i++) { double white; white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1); dst[i] = s->filter(white, s->buf); } if (!s->infinite) s->duration -= nb_samples; frame->pts = s->pts; s->pts += nb_samples; return ff_filter_frame(outlink, frame); } static const AVFilterPad anoisesrc_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .config_props = config_props, }, }; const AVFilter ff_asrc_anoisesrc = { .name = "anoisesrc", .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."), .priv_size = sizeof(ANoiseSrcContext), .inputs = NULL, .activate = activate, FILTER_OUTPUTS(anoisesrc_outputs), FILTER_QUERY_FUNC(query_formats), .priv_class = &anoisesrc_class, };