| /* |
| * Copyright (c) 2018 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/channel_layout.h" |
| #include "libavutil/mem.h" |
| #include "libavutil/opt.h" |
| #include "audio.h" |
| #include "avfilter.h" |
| #include "formats.h" |
| #include "internal.h" |
| #include "filters.h" |
| #include "window_func.h" |
| |
| typedef struct HilbertContext { |
| const AVClass *class; |
| |
| int sample_rate; |
| int nb_taps; |
| int nb_samples; |
| int win_func; |
| |
| float *taps; |
| int64_t pts; |
| } HilbertContext; |
| |
| #define OFFSET(x) offsetof(HilbertContext, x) |
| #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
| |
| static const AVOption hilbert_options[] = { |
| { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS }, |
| { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS }, |
| { "taps", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS }, |
| { "t", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS }, |
| { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS }, |
| { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS }, |
| WIN_FUNC_OPTION("win_func", OFFSET(win_func), FLAGS, WFUNC_BLACKMAN), |
| WIN_FUNC_OPTION("w", OFFSET(win_func), FLAGS, WFUNC_BLACKMAN), |
| {NULL} |
| }; |
| |
| AVFILTER_DEFINE_CLASS(hilbert); |
| |
| static av_cold int init(AVFilterContext *ctx) |
| { |
| HilbertContext *s = ctx->priv; |
| |
| if (!(s->nb_taps & 1)) { |
| av_log(s, AV_LOG_ERROR, "Number of taps %d must be odd length.\n", s->nb_taps); |
| return AVERROR(EINVAL); |
| } |
| |
| return 0; |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| HilbertContext *s = ctx->priv; |
| |
| av_freep(&s->taps); |
| } |
| |
| static av_cold int query_formats(AVFilterContext *ctx) |
| { |
| HilbertContext *s = ctx->priv; |
| static const AVChannelLayout chlayouts[] = { AV_CHANNEL_LAYOUT_MONO, { 0 } }; |
| int sample_rates[] = { s->sample_rate, -1 }; |
| static const enum AVSampleFormat sample_fmts[] = { |
| AV_SAMPLE_FMT_FLT, |
| AV_SAMPLE_FMT_NONE |
| }; |
| int ret = ff_set_common_formats_from_list(ctx, sample_fmts); |
| if (ret < 0) |
| return ret; |
| |
| ret = ff_set_common_channel_layouts_from_list(ctx, chlayouts); |
| if (ret < 0) |
| return ret; |
| |
| return ff_set_common_samplerates_from_list(ctx, sample_rates); |
| } |
| |
| static av_cold int config_props(AVFilterLink *outlink) |
| { |
| AVFilterContext *ctx = outlink->src; |
| HilbertContext *s = ctx->priv; |
| float overlap; |
| int i; |
| |
| s->taps = av_malloc_array(s->nb_taps, sizeof(*s->taps)); |
| if (!s->taps) |
| return AVERROR(ENOMEM); |
| |
| generate_window_func(s->taps, s->nb_taps, s->win_func, &overlap); |
| |
| for (i = 0; i < s->nb_taps; i++) { |
| int k = -(s->nb_taps / 2) + i; |
| |
| if (k & 1) { |
| float pk = M_PI * k; |
| |
| s->taps[i] *= (1.f - cosf(pk)) / pk; |
| } else { |
| s->taps[i] = 0.f; |
| } |
| } |
| |
| s->pts = 0; |
| |
| return 0; |
| } |
| |
| static int activate(AVFilterContext *ctx) |
| { |
| AVFilterLink *outlink = ctx->outputs[0]; |
| HilbertContext *s = ctx->priv; |
| AVFrame *frame; |
| int nb_samples; |
| |
| if (!ff_outlink_frame_wanted(outlink)) |
| return FFERROR_NOT_READY; |
| |
| nb_samples = FFMIN(s->nb_samples, s->nb_taps - s->pts); |
| if (nb_samples <= 0) { |
| ff_outlink_set_status(outlink, AVERROR_EOF, s->pts); |
| return 0; |
| } |
| |
| if (!(frame = ff_get_audio_buffer(outlink, nb_samples))) |
| return AVERROR(ENOMEM); |
| |
| memcpy(frame->data[0], s->taps + s->pts, nb_samples * sizeof(float)); |
| |
| frame->pts = s->pts; |
| s->pts += nb_samples; |
| return ff_filter_frame(outlink, frame); |
| } |
| |
| static const AVFilterPad hilbert_outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .config_props = config_props, |
| }, |
| }; |
| |
| const AVFilter ff_asrc_hilbert = { |
| .name = "hilbert", |
| .description = NULL_IF_CONFIG_SMALL("Generate a Hilbert transform FIR coefficients."), |
| .init = init, |
| .uninit = uninit, |
| .activate = activate, |
| .priv_size = sizeof(HilbertContext), |
| .inputs = NULL, |
| FILTER_OUTPUTS(hilbert_outputs), |
| FILTER_QUERY_FUNC(query_formats), |
| .priv_class = &hilbert_class, |
| }; |