mirror of https://github.com/FFmpeg/FFmpeg.git
Paul B Mahol
2 years ago
parent
1ab0f83b0a
commit
ac7d21284b
6 changed files with 204 additions and 1 deletions
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/*
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* Copyright (c) 2023 Paul B Mahol |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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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#include "libavutil/avassert.h" |
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#include "libavutil/channel_layout.h" |
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#include "libavutil/opt.h" |
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#include "audio.h" |
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#include "avfilter.h" |
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#include "filters.h" |
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#include "internal.h" |
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typedef struct AFDelaySrcContext { |
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const AVClass *class; |
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double delay; |
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int sample_rate; |
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int nb_samples; |
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int nb_taps; |
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AVChannelLayout chlayout; |
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char *chlayout_str; |
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int64_t pts; |
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} AFDelaySrcContext; |
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static av_cold int init(AVFilterContext *ctx) |
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{ |
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AFDelaySrcContext *s = ctx->priv; |
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int ret; |
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ret = ff_parse_channel_layout(&s->chlayout, NULL, s->chlayout_str, ctx); |
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if (ret < 0) |
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return ret; |
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return 0; |
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} |
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static float sincf(float x) |
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{ |
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if (x == 0.f) |
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return 1.f; |
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return sinf(M_PI * x) / (M_PI * x); |
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} |
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static int activate(AVFilterContext *ctx) |
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{ |
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AVFilterLink *outlink = ctx->outputs[0]; |
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AFDelaySrcContext *s = ctx->priv; |
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AVFrame *frame = NULL; |
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int nb_samples; |
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float *dst; |
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if (!ff_outlink_frame_wanted(outlink)) |
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return FFERROR_NOT_READY; |
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nb_samples = FFMIN(s->nb_samples, s->nb_taps - s->pts); |
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if (nb_samples <= 0) { |
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ff_outlink_set_status(outlink, AVERROR_EOF, s->pts); |
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return 0; |
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} |
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if (!(frame = ff_get_audio_buffer(outlink, nb_samples))) |
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return AVERROR(ENOMEM); |
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dst = (float *)frame->extended_data[0]; |
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for (int n = 0; n < nb_samples; n++) { |
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float x = s->pts + n; |
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dst[n] = sincf(x - s->delay) * cosf(M_PI * (x - s->delay) / s->nb_taps) / sincf((x - s->delay) / s->nb_taps); |
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} |
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for (int ch = 1; ch < frame->ch_layout.nb_channels; ch++) |
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memcpy(frame->extended_data[ch], dst, sizeof(*dst) * nb_samples); |
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frame->pts = s->pts; |
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s->pts += nb_samples; |
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return ff_filter_frame(outlink, frame); |
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} |
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static int query_formats(AVFilterContext *ctx) |
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{ |
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AFDelaySrcContext *s = ctx->priv; |
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AVChannelLayout chlayouts[] = { s->chlayout, { 0 } }; |
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int sample_rates[] = { s->sample_rate, -1 }; |
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static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, |
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AV_SAMPLE_FMT_NONE }; |
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int ret = ff_set_common_formats_from_list(ctx, sample_fmts); |
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if (ret < 0) |
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return ret; |
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ret = ff_set_common_channel_layouts_from_list(ctx, chlayouts); |
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if (ret < 0) |
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return ret; |
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return ff_set_common_samplerates_from_list(ctx, sample_rates); |
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} |
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static int config_output(AVFilterLink *outlink) |
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{ |
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AVFilterContext *ctx = outlink->src; |
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AFDelaySrcContext *s = ctx->priv; |
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outlink->sample_rate = s->sample_rate; |
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s->pts = 0; |
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if (s->nb_taps <= 0) |
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s->nb_taps = s->delay * 8 + 1; |
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return 0; |
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} |
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static const AVFilterPad afdelaysrc_outputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.config_props = config_output, |
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}, |
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}; |
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static av_cold void uninit(AVFilterContext *ctx) |
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{ |
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AFDelaySrcContext *s = ctx->priv; |
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av_channel_layout_uninit(&s->chlayout); |
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} |
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#define AF AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
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#define OFFSET(x) offsetof(AFDelaySrcContext, x) |
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static const AVOption afdelaysrc_options[] = { |
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{ "delay", "set fractional delay", OFFSET(delay), AV_OPT_TYPE_DOUBLE,{.dbl=0}, 0, INT16_MAX, AF }, |
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{ "d", "set fractional delay", OFFSET(delay), AV_OPT_TYPE_DOUBLE,{.dbl=0}, 0, INT16_MAX, AF }, |
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{ "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, AF }, |
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{ "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, AF }, |
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{ "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, AF }, |
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{ "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, AF }, |
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{ "taps", "set number of taps for delay filter", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=0}, 0, 32768, AF }, |
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{ "t", "set number of taps for delay filter", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=0}, 0, 32768, AF }, |
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{ "channel_layout", "set channel layout", OFFSET(chlayout_str),AV_OPT_TYPE_STRING,{.str="stereo"},0, 0, AF }, |
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{ "c", "set channel layout", OFFSET(chlayout_str),AV_OPT_TYPE_STRING,{.str="stereo"},0, 0, AF }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(afdelaysrc); |
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const AVFilter ff_asrc_afdelaysrc = { |
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.name = "afdelaysrc", |
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.description = NULL_IF_CONFIG_SMALL("Generate a Fractional delay FIR coefficients."), |
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.priv_size = sizeof(AFDelaySrcContext), |
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.priv_class = &afdelaysrc_class, |
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.init = init, |
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.activate = activate, |
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.uninit = uninit, |
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.inputs = NULL, |
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FILTER_OUTPUTS(afdelaysrc_outputs), |
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FILTER_QUERY_FUNC(query_formats), |
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}; |
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