2 * Copyright (c) 2018 Paul B Mahol
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public License
8 * as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "libavutil/opt.h"
25 #include "window_func.h"
27 typedef struct HilbertContext {
39 #define OFFSET(x) offsetof(HilbertContext, x)
40 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
42 static const AVOption hilbert_options[] = {
43 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS },
44 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS },
45 { "taps", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS },
46 { "t", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS },
47 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
48 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
49 { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64=WFUNC_BLACKMAN}, 0, NB_WFUNC-1, FLAGS, "win_func" },
50 { "w", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64=WFUNC_BLACKMAN}, 0, NB_WFUNC-1, FLAGS, "win_func" },
51 { "rect", "Rectangular", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT}, 0, 0, FLAGS, "win_func" },
52 { "bartlett", "Bartlett", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, FLAGS, "win_func" },
53 { "hanning", "Hanning", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, FLAGS, "win_func" },
54 { "hamming", "Hamming", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING}, 0, 0, FLAGS, "win_func" },
55 { "blackman", "Blackman", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BLACKMAN}, 0, 0, FLAGS, "win_func" },
56 { "welch", "Welch", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_WELCH}, 0, 0, FLAGS, "win_func" },
57 { "flattop", "Flat-top", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_FLATTOP}, 0, 0, FLAGS, "win_func" },
58 { "bharris", "Blackman-Harris", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BHARRIS}, 0, 0, FLAGS, "win_func" },
59 { "bnuttall", "Blackman-Nuttall", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BNUTTALL}, 0, 0, FLAGS, "win_func" },
60 { "bhann", "Bartlett-Hann", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BHANN}, 0, 0, FLAGS, "win_func" },
61 { "sine", "Sine", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE}, 0, 0, FLAGS, "win_func" },
62 { "nuttall", "Nuttall", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_NUTTALL}, 0, 0, FLAGS, "win_func" },
63 { "lanczos", "Lanczos", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS}, 0, 0, FLAGS, "win_func" },
64 { "gauss", "Gauss", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS}, 0, 0, FLAGS, "win_func" },
65 { "tukey", "Tukey", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_TUKEY}, 0, 0, FLAGS, "win_func" },
66 { "dolph", "Dolph-Chebyshev", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_DOLPH}, 0, 0, FLAGS, "win_func" },
67 { "cauchy", "Cauchy", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_CAUCHY}, 0, 0, FLAGS, "win_func" },
68 { "parzen", "Parzen", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_PARZEN}, 0, 0, FLAGS, "win_func" },
69 { "poisson", "Poisson", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_POISSON}, 0, 0, FLAGS, "win_func" },
73 AVFILTER_DEFINE_CLASS(hilbert);
75 static av_cold int init(AVFilterContext *ctx)
77 HilbertContext *s = ctx->priv;
79 if (!(s->nb_taps & 1)) {
80 av_log(s, AV_LOG_ERROR, "Number of taps %d must be odd length.\n", s->nb_taps);
81 return AVERROR(EINVAL);
87 static av_cold void uninit(AVFilterContext *ctx)
89 HilbertContext *s = ctx->priv;
94 static av_cold int query_formats(AVFilterContext *ctx)
96 HilbertContext *s = ctx->priv;
97 static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
98 int sample_rates[] = { s->sample_rate, -1 };
99 static const enum AVSampleFormat sample_fmts[] = {
104 AVFilterFormats *formats;
105 AVFilterChannelLayouts *layouts;
108 formats = ff_make_format_list(sample_fmts);
110 return AVERROR(ENOMEM);
111 ret = ff_set_common_formats (ctx, formats);
115 layouts = avfilter_make_format64_list(chlayouts);
117 return AVERROR(ENOMEM);
118 ret = ff_set_common_channel_layouts(ctx, layouts);
122 formats = ff_make_format_list(sample_rates);
124 return AVERROR(ENOMEM);
125 return ff_set_common_samplerates(ctx, formats);
128 static av_cold int config_props(AVFilterLink *outlink)
130 AVFilterContext *ctx = outlink->src;
131 HilbertContext *s = ctx->priv;
135 s->taps = av_malloc_array(s->nb_taps, sizeof(*s->taps));
137 return AVERROR(ENOMEM);
139 generate_window_func(s->taps, s->nb_taps, s->win_func, &overlap);
141 for (i = 0; i < s->nb_taps; i++) {
142 int k = -(s->nb_taps / 2) + i;
147 s->taps[i] *= (1.f - cosf(pk)) / pk;
158 static int request_frame(AVFilterLink *outlink)
160 AVFilterContext *ctx = outlink->src;
161 HilbertContext *s = ctx->priv;
165 nb_samples = FFMIN(s->nb_samples, s->nb_taps - s->pts);
169 if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
170 return AVERROR(ENOMEM);
172 memcpy(frame->data[0], s->taps + s->pts, nb_samples * sizeof(float));
175 s->pts += nb_samples;
176 return ff_filter_frame(outlink, frame);
179 static const AVFilterPad hilbert_outputs[] = {
182 .type = AVMEDIA_TYPE_AUDIO,
183 .request_frame = request_frame,
184 .config_props = config_props,
189 AVFilter ff_asrc_hilbert = {
191 .description = NULL_IF_CONFIG_SMALL("Generate a Hilbert transform FIR coefficients."),
192 .query_formats = query_formats,
195 .priv_size = sizeof(HilbertContext),
197 .outputs = hilbert_outputs,
198 .priv_class = &hilbert_class,