mirror of https://github.com/FFmpeg/FFmpeg.git
Paul B Mahol
4 years ago
parent
68e452c367
commit
3c922681c3
6 changed files with 269 additions and 4 deletions
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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/channel_layout.h" |
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#include "libavutil/ffmath.h" |
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#include "libavutil/opt.h" |
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#include "avfilter.h" |
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#include "audio.h" |
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#include "formats.h" |
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typedef struct BiquadCoeffs { |
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double a1, a2; |
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double b0, b1, b2; |
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} BiquadCoeffs; |
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typedef struct ASuperCutContext { |
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const AVClass *class; |
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double cutoff; |
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int bypass; |
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BiquadCoeffs coeffs[5]; |
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AVFrame *w; |
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} ASuperCutContext; |
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static int query_formats(AVFilterContext *ctx) |
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{ |
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AVFilterFormats *formats = NULL; |
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AVFilterChannelLayouts *layouts = NULL; |
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static const enum AVSampleFormat sample_fmts[] = { |
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AV_SAMPLE_FMT_DBLP, |
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AV_SAMPLE_FMT_NONE |
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}; |
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int ret; |
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formats = ff_make_format_list(sample_fmts); |
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if (!formats) |
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return AVERROR(ENOMEM); |
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ret = ff_set_common_formats(ctx, formats); |
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if (ret < 0) |
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return ret; |
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layouts = ff_all_channel_counts(); |
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if (!layouts) |
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return AVERROR(ENOMEM); |
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ret = ff_set_common_channel_layouts(ctx, layouts); |
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if (ret < 0) |
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return ret; |
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formats = ff_all_samplerates(); |
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return ff_set_common_samplerates(ctx, formats); |
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} |
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static int get_coeffs(AVFilterContext *ctx) |
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{ |
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ASuperCutContext *s = ctx->priv; |
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AVFilterLink *inlink = ctx->inputs[0]; |
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double w0 = s->cutoff / inlink->sample_rate; |
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double K = tan(M_PI * w0); |
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double q[5]; |
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s->bypass = w0 >= 0.5; |
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if (s->bypass) |
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return 0; |
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q[0] = 0.50623256; |
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q[1] = 0.56116312; |
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q[2] = 0.70710678; |
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q[3] = 1.10134463; |
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q[4] = 3.19622661; |
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for (int b = 0; b < 5; b++) { |
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BiquadCoeffs *coeffs = &s->coeffs[b]; |
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double norm = 1.0 / (1.0 + K / q[b] + K * K); |
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coeffs->b0 = K * K * norm; |
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coeffs->b1 = 2.0 * coeffs->b0; |
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coeffs->b2 = coeffs->b0; |
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coeffs->a1 = -2.0 * (K * K - 1.0) * norm; |
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coeffs->a2 = -(1.0 - K / q[b] + K * K) * norm; |
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} |
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return 0; |
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} |
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static int config_input(AVFilterLink *inlink) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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ASuperCutContext *s = ctx->priv; |
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s->w = ff_get_audio_buffer(inlink, 2 * 5); |
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if (!s->w) |
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return AVERROR(ENOMEM); |
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return get_coeffs(ctx); |
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} |
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typedef struct ThreadData { |
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AVFrame *in, *out; |
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} ThreadData; |
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static int filter_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) |
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{ |
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ASuperCutContext *s = ctx->priv; |
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ThreadData *td = arg; |
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AVFrame *out = td->out; |
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AVFrame *in = td->in; |
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const int start = (in->channels * jobnr) / nb_jobs; |
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const int end = (in->channels * (jobnr+1)) / nb_jobs; |
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for (int ch = start; ch < end; ch++) { |
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const double *src = (const double *)in->extended_data[ch]; |
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double *dst = (double *)out->extended_data[ch]; |
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for (int b = 0; b < 5; b++) { |
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BiquadCoeffs *coeffs = &s->coeffs[b]; |
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const double a1 = coeffs->a1; |
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const double a2 = coeffs->a2; |
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const double b0 = coeffs->b0; |
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const double b1 = coeffs->b1; |
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const double b2 = coeffs->b2; |
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double *w = ((double *)s->w->extended_data[ch]) + b * 2; |
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for (int n = 0; n < in->nb_samples; n++) { |
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double sin = b ? dst[n] : src[n]; |
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double sout = sin * b0 + w[0]; |
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w[0] = b1 * sin + w[1] + a1 * sout; |
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w[1] = b2 * sin + a2 * sout; |
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dst[n] = sout; |
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} |
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} |
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} |
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return 0; |
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} |
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static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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ASuperCutContext *s = ctx->priv; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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ThreadData td; |
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AVFrame *out; |
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if (s->bypass) |
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return ff_filter_frame(outlink, in); |
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if (av_frame_is_writable(in)) { |
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out = in; |
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} else { |
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out = ff_get_audio_buffer(outlink, in->nb_samples); |
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if (!out) { |
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av_frame_free(&in); |
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return AVERROR(ENOMEM); |
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} |
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av_frame_copy_props(out, in); |
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} |
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td.in = in; td.out = out; |
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ctx->internal->execute(ctx, filter_channels, &td, NULL, FFMIN(inlink->channels, |
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ff_filter_get_nb_threads(ctx))); |
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if (out != in) |
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av_frame_free(&in); |
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return ff_filter_frame(outlink, out); |
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} |
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static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, |
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char *res, int res_len, int flags) |
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{ |
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int ret; |
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ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags); |
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if (ret < 0) |
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return ret; |
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return get_coeffs(ctx); |
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} |
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static av_cold void uninit(AVFilterContext *ctx) |
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{ |
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ASuperCutContext *s = ctx->priv; |
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av_frame_free(&s->w); |
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} |
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#define OFFSET(x) offsetof(ASuperCutContext, x) |
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM |
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static const AVOption asupercut_options[] = { |
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{ "cutoff", "set cutoff frequency", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=20000}, 20000, 192000, FLAGS }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(asupercut); |
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static const AVFilterPad inputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.filter_frame = filter_frame, |
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.config_props = config_input, |
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}, |
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{ NULL } |
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}; |
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static const AVFilterPad outputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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}, |
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{ NULL } |
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}; |
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AVFilter ff_af_asupercut = { |
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.name = "asupercut", |
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.description = NULL_IF_CONFIG_SMALL("Cut super frequencies."), |
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.query_formats = query_formats, |
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.priv_size = sizeof(ASuperCutContext), |
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.priv_class = &asupercut_class, |
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.uninit = uninit, |
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.inputs = inputs, |
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.outputs = outputs, |
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.process_command = process_command, |
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.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | |
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AVFILTER_FLAG_SLICE_THREADS, |
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}; |
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