From 738f83582a3aaabb81309eacd4ab9c3d2acb4071 Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Wed, 26 Feb 2014 01:47:40 -0500 Subject: lavfi: add compand audio filter Signed-off-by: Anton Khirnov --- libavfilter/af_compand.c | 587 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 587 insertions(+) create mode 100644 libavfilter/af_compand.c (limited to 'libavfilter/af_compand.c') diff --git a/libavfilter/af_compand.c b/libavfilter/af_compand.c new file mode 100644 index 0000000000..19065944f9 --- /dev/null +++ b/libavfilter/af_compand.c @@ -0,0 +1,587 @@ +/* + * Copyright (c) 1999 Chris Bagwell + * Copyright (c) 1999 Nick Bailey + * Copyright (c) 2007 Rob Sykes + * Copyright (c) 2013 Paul B Mahol + * Copyright (c) 2014 Andrew Kelley + * + * This file is part of libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * audio compand filter + */ + +#include + +#include "libavutil/channel_layout.h" +#include "libavutil/common.h" +#include "libavutil/mathematics.h" +#include "libavutil/mem.h" +#include "libavutil/opt.h" +#include "audio.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" + +typedef struct ChanParam { + float attack; + float decay; + float volume; +} ChanParam; + +typedef struct CompandSegment { + float x, y; + float a, b; +} CompandSegment; + +typedef struct CompandContext { + const AVClass *class; + int nb_channels; + int nb_segments; + char *attacks, *decays, *points; + CompandSegment *segments; + ChanParam *channels; + float in_min_lin; + float out_min_lin; + double curve_dB; + double gain_dB; + double initial_volume; + double delay; + AVFrame *delay_frame; + int delay_samples; + int delay_count; + int delay_index; + int64_t pts; + + int (*compand)(AVFilterContext *ctx, AVFrame *frame); +} CompandContext; + +#define OFFSET(x) offsetof(CompandContext, x) +#define A AV_OPT_FLAG_AUDIO_PARAM + +static const AVOption compand_options[] = { + { "attacks", "set time over which increase of volume is determined", OFFSET(attacks), AV_OPT_TYPE_STRING, { .str = "0.3" }, 0, 0, A }, + { "decays", "set time over which decrease of volume is determined", OFFSET(decays), AV_OPT_TYPE_STRING, { .str = "0.8" }, 0, 0, A }, + { "points", "set points of transfer function", OFFSET(points), AV_OPT_TYPE_STRING, { .str = "-70/-70|-60/-20" }, 0, 0, A }, + { "soft-knee", "set soft-knee", OFFSET(curve_dB), AV_OPT_TYPE_DOUBLE, { .dbl = 0.01 }, 0.01, 900, A }, + { "gain", "set output gain", OFFSET(gain_dB), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -900, 900, A }, + { "volume", "set initial volume", OFFSET(initial_volume), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -900, 0, A }, + { "delay", "set delay for samples before sending them to volume adjuster", OFFSET(delay), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, 0, 20, A }, + { NULL } +}; + +static const AVClass compand_class = { + .class_name = "compand filter", + .item_name = av_default_item_name, + .option = compand_options, + .version = LIBAVUTIL_VERSION_INT, +}; + +static av_cold int init(AVFilterContext *ctx) +{ + CompandContext *s = ctx->priv; + s->pts = AV_NOPTS_VALUE; + return 0; +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + CompandContext *s = ctx->priv; + + av_freep(&s->channels); + av_freep(&s->segments); + av_frame_free(&s->delay_frame); +} + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterChannelLayouts *layouts; + AVFilterFormats *formats; + static const enum AVSampleFormat sample_fmts[] = { + AV_SAMPLE_FMT_FLTP, + AV_SAMPLE_FMT_NONE + }; + + layouts = ff_all_channel_layouts(); + if (!layouts) + return AVERROR(ENOMEM); + ff_set_common_channel_layouts(ctx, layouts); + + formats = ff_make_format_list(sample_fmts); + if (!formats) + return AVERROR(ENOMEM); + ff_set_common_formats(ctx, formats); + + formats = ff_all_samplerates(); + if (!formats) + return AVERROR(ENOMEM); + ff_set_common_samplerates(ctx, formats); + + return 0; +} + +static void count_items(char *item_str, int *nb_items) +{ + char *p; + + *nb_items = 1; + for (p = item_str; *p; p++) { + if (*p == '|') + (*nb_items)++; + } +} + +static void update_volume(ChanParam *cp, float in) +{ + float delta = in - cp->volume; + + if (delta > 0.0) + cp->volume += delta * cp->attack; + else + cp->volume += delta * cp->decay; +} + +static float get_volume(CompandContext *s, float in_lin) +{ + CompandSegment *cs; + float in_log, out_log; + int i; + + if (in_lin < s->in_min_lin) + return s->out_min_lin; + + in_log = logf(in_lin); + + for (i = 1; i < s->nb_segments; i++) + if (in_log <= s->segments[i].x) + break; + cs = &s->segments[i - 1]; + in_log -= cs->x; + out_log = cs->y + in_log * (cs->a * in_log + cs->b); + + return expf(out_log); +} + +static int compand_nodelay(AVFilterContext *ctx, AVFrame *frame) +{ + CompandContext *s = ctx->priv; + AVFilterLink *inlink = ctx->inputs[0]; + const int channels = s->nb_channels; + const int nb_samples = frame->nb_samples; + AVFrame *out_frame; + int chan, i; + int err; + + if (av_frame_is_writable(frame)) { + out_frame = frame; + } else { + out_frame = ff_get_audio_buffer(inlink, nb_samples); + if (!out_frame) { + av_frame_free(&frame); + return AVERROR(ENOMEM); + } + err = av_frame_copy_props(out_frame, frame); + if (err < 0) { + av_frame_free(&out_frame); + av_frame_free(&frame); + return err; + } + } + + for (chan = 0; chan < channels; chan++) { + const float *src = (float *)frame->extended_data[chan]; + float *dst = (float *)out_frame->extended_data[chan]; + ChanParam *cp = &s->channels[chan]; + + for (i = 0; i < nb_samples; i++) { + update_volume(cp, fabs(src[i])); + + dst[i] = av_clipf(src[i] * get_volume(s, cp->volume), -1.0f, 1.0f); + } + } + + if (frame != out_frame) + av_frame_free(&frame); + + return ff_filter_frame(ctx->outputs[0], out_frame); +} + +#define MOD(a, b) (((a) >= (b)) ? (a) - (b) : (a)) + +static int compand_delay(AVFilterContext *ctx, AVFrame *frame) +{ + CompandContext *s = ctx->priv; + AVFilterLink *inlink = ctx->inputs[0]; + const int channels = s->nb_channels; + const int nb_samples = frame->nb_samples; + int chan, i, dindex = 0, oindex, count = 0; + AVFrame *out_frame = NULL; + int err; + + if (s->pts == AV_NOPTS_VALUE) { + s->pts = (frame->pts == AV_NOPTS_VALUE) ? 0 : frame->pts; + } + + for (chan = 0; chan < channels; chan++) { + AVFrame *delay_frame = s->delay_frame; + const float *src = (float *)frame->extended_data[chan]; + float *dbuf = (float *)delay_frame->extended_data[chan]; + ChanParam *cp = &s->channels[chan]; + float *dst; + + count = s->delay_count; + dindex = s->delay_index; + for (i = 0, oindex = 0; i < nb_samples; i++) { + const float in = src[i]; + update_volume(cp, fabs(in)); + + if (count >= s->delay_samples) { + if (!out_frame) { + out_frame = ff_get_audio_buffer(inlink, nb_samples - i); + if (!out_frame) { + av_frame_free(&frame); + return AVERROR(ENOMEM); + } + err = av_frame_copy_props(out_frame, frame); + if (err < 0) { + av_frame_free(&out_frame); + av_frame_free(&frame); + return err; + } + out_frame->pts = s->pts; + s->pts += av_rescale_q(nb_samples - i, + (AVRational){ 1, inlink->sample_rate }, + inlink->time_base); + } + + dst = (float *)out_frame->extended_data[chan]; + dst[oindex++] = av_clipf(dbuf[dindex] * + get_volume(s, cp->volume), -1.0f, 1.0f); + } else { + count++; + } + + dbuf[dindex] = in; + dindex = MOD(dindex + 1, s->delay_samples); + } + } + + s->delay_count = count; + s->delay_index = dindex; + + av_frame_free(&frame); + return out_frame ? ff_filter_frame(ctx->outputs[0], out_frame) : 0; +} + +static int compand_drain(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + CompandContext *s = ctx->priv; + const int channels = s->nb_channels; + AVFrame *frame = NULL; + int chan, i, dindex; + + /* 2048 is to limit output frame size during drain */ + frame = ff_get_audio_buffer(outlink, FFMIN(2048, s->delay_count)); + if (!frame) + return AVERROR(ENOMEM); + frame->pts = s->pts; + s->pts += av_rescale_q(frame->nb_samples, + (AVRational){ 1, outlink->sample_rate }, outlink->time_base); + + for (chan = 0; chan < channels; chan++) { + AVFrame *delay_frame = s->delay_frame; + float *dbuf = (float *)delay_frame->extended_data[chan]; + float *dst = (float *)frame->extended_data[chan]; + ChanParam *cp = &s->channels[chan]; + + dindex = s->delay_index; + for (i = 0; i < frame->nb_samples; i++) { + dst[i] = av_clipf(dbuf[dindex] * get_volume(s, cp->volume), + -1.0f, 1.0f); + dindex = MOD(dindex + 1, s->delay_samples); + } + } + s->delay_count -= frame->nb_samples; + s->delay_index = dindex; + + return ff_filter_frame(outlink, frame); +} + +static int config_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + CompandContext *s = ctx->priv; + const int sample_rate = outlink->sample_rate; + double radius = s->curve_dB * M_LN10 / 20.0; + char *p, *saveptr = NULL; + const int channels = + av_get_channel_layout_nb_channels(outlink->channel_layout); + int nb_attacks, nb_decays, nb_points; + int new_nb_items, num; + int i; + int err; + + + count_items(s->attacks, &nb_attacks); + count_items(s->decays, &nb_decays); + count_items(s->points, &nb_points); + + if (channels <= 0) { + av_log(ctx, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels); + return AVERROR(EINVAL); + } + + if (nb_attacks > channels || nb_decays > channels) { + av_log(ctx, AV_LOG_ERROR, + "Number of attacks/decays bigger than number of channels.\n"); + return AVERROR(EINVAL); + } + + uninit(ctx); + + s->nb_channels = channels; + s->channels = av_mallocz_array(channels, sizeof(*s->channels)); + s->nb_segments = (nb_points + 4) * 2; + s->segments = av_mallocz_array(s->nb_segments, sizeof(*s->segments)); + + if (!s->channels || !s->segments) { + uninit(ctx); + return AVERROR(ENOMEM); + } + + p = s->attacks; + for (i = 0, new_nb_items = 0; i < nb_attacks; i++) { + char *tstr = strtok_r(p, "|", &saveptr); + p = NULL; + new_nb_items += sscanf(tstr, "%f", &s->channels[i].attack) == 1; + if (s->channels[i].attack < 0) { + uninit(ctx); + return AVERROR(EINVAL); + } + } + nb_attacks = new_nb_items; + + p = s->decays; + for (i = 0, new_nb_items = 0; i < nb_decays; i++) { + char *tstr = strtok_r(p, "|", &saveptr); + p = NULL; + new_nb_items += sscanf(tstr, "%f", &s->channels[i].decay) == 1; + if (s->channels[i].decay < 0) { + uninit(ctx); + return AVERROR(EINVAL); + } + } + nb_decays = new_nb_items; + + if (nb_attacks != nb_decays) { + av_log(ctx, AV_LOG_ERROR, + "Number of attacks %d differs from number of decays %d.\n", + nb_attacks, nb_decays); + uninit(ctx); + return AVERROR(EINVAL); + } + +#define S(x) s->segments[2 * ((x) + 1)] + p = s->points; + for (i = 0, new_nb_items = 0; i < nb_points; i++) { + char *tstr = strtok_r(p, "|", &saveptr); + p = NULL; + if (sscanf(tstr, "%f/%f", &S(i).x, &S(i).y) != 2) { + av_log(ctx, AV_LOG_ERROR, + "Invalid and/or missing input/output value.\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + if (i && S(i - 1).x > S(i).x) { + av_log(ctx, AV_LOG_ERROR, + "Transfer function input values must be increasing.\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + S(i).y -= S(i).x; + av_log(ctx, AV_LOG_DEBUG, "%d: x=%f y=%f\n", i, S(i).x, S(i).y); + new_nb_items++; + } + num = new_nb_items; + + /* Add 0,0 if necessary */ + if (num == 0 || S(num - 1).x) + num++; + +#undef S +#define S(x) s->segments[2 * (x)] + /* Add a tail off segment at the start */ + S(0).x = S(1).x - 2 * s->curve_dB; + S(0).y = S(1).y; + num++; + + /* Join adjacent colinear segments */ + for (i = 2; i < num; i++) { + double g1 = (S(i - 1).y - S(i - 2).y) * (S(i - 0).x - S(i - 1).x); + double g2 = (S(i - 0).y - S(i - 1).y) * (S(i - 1).x - S(i - 2).x); + int j; + + /* here we purposefully lose precision so that we can compare floats */ + if (fabs(g1 - g2)) + continue; + num--; + for (j = --i; j < num; j++) + S(j) = S(j + 1); + } + + for (i = 0; !i || s->segments[i - 2].x; i += 2) { + s->segments[i].y += s->gain_dB; + s->segments[i].x *= M_LN10 / 20; + s->segments[i].y *= M_LN10 / 20; + } + +#define L(x) s->segments[i - (x)] + for (i = 4; s->segments[i - 2].x; i += 2) { + double x, y, cx, cy, in1, in2, out1, out2, theta, len, r; + + L(4).a = 0; + L(4).b = (L(2).y - L(4).y) / (L(2).x - L(4).x); + + L(2).a = 0; + L(2).b = (L(0).y - L(2).y) / (L(0).x - L(2).x); + + theta = atan2(L(2).y - L(4).y, L(2).x - L(4).x); + len = sqrt(pow(L(2).x - L(4).x, 2.) + pow(L(2).y - L(4).y, 2.)); + r = FFMIN(radius, len); + L(3).x = L(2).x - r * cos(theta); + L(3).y = L(2).y - r * sin(theta); + + theta = atan2(L(0).y - L(2).y, L(0).x - L(2).x); + len = sqrt(pow(L(0).x - L(2).x, 2.) + pow(L(0).y - L(2).y, 2.)); + r = FFMIN(radius, len / 2); + x = L(2).x + r * cos(theta); + y = L(2).y + r * sin(theta); + + cx = (L(3).x + L(2).x + x) / 3; + cy = (L(3).y + L(2).y + y) / 3; + + L(2).x = x; + L(2).y = y; + + in1 = cx - L(3).x; + out1 = cy - L(3).y; + in2 = L(2).x - L(3).x; + out2 = L(2).y - L(3).y; + L(3).a = (out2 / in2 - out1 / in1) / (in2 - in1); + L(3).b = out1 / in1 - L(3).a * in1; + } + L(3).x = 0; + L(3).y = L(2).y; + + s->in_min_lin = exp(s->segments[1].x); + s->out_min_lin = exp(s->segments[1].y); + + for (i = 0; i < channels; i++) { + ChanParam *cp = &s->channels[i]; + + if (cp->attack > 1.0 / sample_rate) + cp->attack = 1.0 - exp(-1.0 / (sample_rate * cp->attack)); + else + cp->attack = 1.0; + if (cp->decay > 1.0 / sample_rate) + cp->decay = 1.0 - exp(-1.0 / (sample_rate * cp->decay)); + else + cp->decay = 1.0; + cp->volume = pow(10.0, s->initial_volume / 20); + } + + s->delay_samples = s->delay * sample_rate; + if (s->delay_samples <= 0) { + s->compand = compand_nodelay; + return 0; + } + + s->delay_frame = av_frame_alloc(); + if (!s->delay_frame) { + uninit(ctx); + return AVERROR(ENOMEM); + } + + s->delay_frame->format = outlink->format; + s->delay_frame->nb_samples = s->delay_samples; + s->delay_frame->channel_layout = outlink->channel_layout; + + err = av_frame_get_buffer(s->delay_frame, 32); + if (err) + return err; + + s->compand = compand_delay; + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *frame) +{ + AVFilterContext *ctx = inlink->dst; + CompandContext *s = ctx->priv; + + return s->compand(ctx, frame); +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + CompandContext *s = ctx->priv; + int ret; + + ret = ff_request_frame(ctx->inputs[0]); + + if (ret == AVERROR_EOF && s->delay_count) + ret = compand_drain(outlink); + + return ret; +} + +static const AVFilterPad compand_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad compand_outputs[] = { + { + .name = "default", + .request_frame = request_frame, + .config_props = config_output, + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + + +AVFilter ff_af_compand = { + .name = "compand", + .description = NULL_IF_CONFIG_SMALL( + "Compress or expand audio dynamic range."), + .query_formats = query_formats, + .priv_size = sizeof(CompandContext), + .priv_class = &compand_class, + .init = init, + .uninit = uninit, + .inputs = compand_inputs, + .outputs = compand_outputs, +}; 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