/* * Copyright (c) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Vladimir Sadovnikov and others * Copyright (c) 2015 Paul B Mahol * * 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/opt.h" #include "libavutil/samplefmt.h" #include "avfilter.h" #include "audio.h" #include "internal.h" typedef struct CompensationDelayContext { const AVClass *class; int distance_mm; int distance_cm; int distance_m; double dry, wet; int temp; unsigned delay; unsigned w_ptr; unsigned buf_size; AVFrame *delay_frame; } CompensationDelayContext; #define OFFSET(x) offsetof(CompensationDelayContext, x) #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption compensationdelay_options[] = { { "mm", "set mm distance", OFFSET(distance_mm), AV_OPT_TYPE_INT, {.i64=0}, 0, 10, A }, { "cm", "set cm distance", OFFSET(distance_cm), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, A }, { "m", "set meter distance", OFFSET(distance_m), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, A }, { "dry", "set dry amount", OFFSET(dry), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 1, A }, { "wet", "set wet amount", OFFSET(wet), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, A }, { "temp", "set temperature °C", OFFSET(temp), AV_OPT_TYPE_INT, {.i64=20}, -50, 50, A }, { NULL } }; AVFILTER_DEFINE_CLASS(compensationdelay); // The maximum distance for options #define COMP_DELAY_MAX_DISTANCE (100.0 * 100.0 + 100.0 * 1.0 + 1.0) // The actual speed of sound in normal conditions #define COMP_DELAY_SOUND_SPEED_KM_H(temp) 1.85325 * (643.95 * sqrt(((temp + 273.15) / 273.15))) #define COMP_DELAY_SOUND_SPEED_CM_S(temp) (COMP_DELAY_SOUND_SPEED_KM_H(temp) * (1000.0 * 100.0) /* cm/km */ / (60.0 * 60.0) /* s/h */) #define COMP_DELAY_SOUND_FRONT_DELAY(temp) (1.0 / COMP_DELAY_SOUND_SPEED_CM_S(temp)) // The maximum delay may be reached by this filter #define COMP_DELAY_MAX_DELAY (COMP_DELAY_MAX_DISTANCE * COMP_DELAY_SOUND_FRONT_DELAY(50)) static int query_formats(AVFilterContext *ctx) { AVFilterChannelLayouts *layouts; AVFilterFormats *formats; static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBLP, AV_SAMPLE_FMT_NONE }; int ret; layouts = ff_all_channel_counts(); if (!layouts) return AVERROR(ENOMEM); ret = ff_set_common_channel_layouts(ctx, layouts); if (ret < 0) return ret; formats = ff_make_format_list(sample_fmts); if (!formats) return AVERROR(ENOMEM); ret = ff_set_common_formats(ctx, formats); if (ret < 0) return ret; formats = ff_all_samplerates(); if (!formats) return AVERROR(ENOMEM); return ff_set_common_samplerates(ctx, formats); } static int config_input(AVFilterLink *inlink) { AVFilterContext *ctx = inlink->dst; CompensationDelayContext *s = ctx->priv; unsigned min_size, new_size = 1; s->delay = (s->distance_m * 100. + s->distance_cm * 1. + s->distance_mm * .1) * COMP_DELAY_SOUND_FRONT_DELAY(s->temp) * inlink->sample_rate; min_size = inlink->sample_rate * COMP_DELAY_MAX_DELAY; while (new_size < min_size) new_size <<= 1; s->delay_frame = av_frame_alloc(); if (!s->delay_frame) return AVERROR(ENOMEM); s->buf_size = new_size; s->delay_frame->format = inlink->format; s->delay_frame->nb_samples = new_size; s->delay_frame->channel_layout = inlink->channel_layout; return av_frame_get_buffer(s->delay_frame, 32); } static int filter_frame(AVFilterLink *inlink, AVFrame *in) { AVFilterContext *ctx = inlink->dst; CompensationDelayContext *s = ctx->priv; const unsigned b_mask = s->buf_size - 1; const unsigned buf_size = s->buf_size; const unsigned delay = s->delay; const double dry = s->dry; const double wet = s->wet; unsigned r_ptr, w_ptr; AVFrame *out; int n, ch; out = ff_get_audio_buffer(ctx->outputs[0], in->nb_samples); if (!out) { av_frame_free(&in); return AVERROR(ENOMEM); } av_frame_copy_props(out, in); for (ch = 0; ch < inlink->channels; ch++) { const double *src = (const double *)in->extended_data[ch]; double *dst = (double *)out->extended_data[ch]; double *buffer = (double *)s->delay_frame->extended_data[ch]; w_ptr = s->w_ptr; r_ptr = (w_ptr + buf_size - delay) & b_mask; for (n = 0; n < in->nb_samples; n++) { const double sample = src[n]; buffer[w_ptr] = sample; dst[n] = dry * sample + wet * buffer[r_ptr]; w_ptr = (w_ptr + 1) & b_mask; r_ptr = (r_ptr + 1) & b_mask; } } s->w_ptr = w_ptr; av_frame_free(&in); return ff_filter_frame(ctx->outputs[0], out); } static av_cold void uninit(AVFilterContext *ctx) { CompensationDelayContext *s = ctx->priv; av_frame_free(&s->delay_frame); } static const AVFilterPad compensationdelay_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .config_props = config_input, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad compensationdelay_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, }, { NULL } }; AVFilter ff_af_compensationdelay = { .name = "compensationdelay", .description = NULL_IF_CONFIG_SMALL("Audio Compensation Delay Line."), .query_formats = query_formats, .priv_size = sizeof(CompensationDelayContext), .priv_class = &compensationdelay_class, .uninit = uninit, .inputs = compensationdelay_inputs, .outputs = compensationdelay_outputs, };