| /* |
| * Copyright (c) 2016 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/audio_fifo.h" |
| #include "libavutil/avstring.h" |
| #include "libavfilter/internal.h" |
| #include "libavutil/common.h" |
| #include "libavutil/opt.h" |
| #include "libavcodec/avfft.h" |
| #include "libavutil/eval.h" |
| #include "audio.h" |
| #include "window_func.h" |
| |
| typedef struct AFFTFiltContext { |
| const AVClass *class; |
| char *real_str; |
| char *img_str; |
| int fft_bits; |
| |
| FFTContext *fft, *ifft; |
| FFTComplex **fft_data; |
| int nb_exprs; |
| int window_size; |
| AVExpr **real; |
| AVExpr **imag; |
| AVAudioFifo *fifo; |
| int64_t pts; |
| int hop_size; |
| float overlap; |
| AVFrame *buffer; |
| int start, end; |
| int win_func; |
| float win_scale; |
| float *window_func_lut; |
| } AFFTFiltContext; |
| |
| static const char *const var_names[] = { "sr", "b", "nb", "ch", "chs", "pts", NULL }; |
| enum { VAR_SAMPLE_RATE, VAR_BIN, VAR_NBBINS, VAR_CHANNEL, VAR_CHANNELS, VAR_PTS, VAR_VARS_NB }; |
| |
| #define OFFSET(x) offsetof(AFFTFiltContext, x) |
| #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
| |
| static const AVOption afftfilt_options[] = { |
| { "real", "set channels real expressions", OFFSET(real_str), AV_OPT_TYPE_STRING, {.str = "1" }, 0, 0, A }, |
| { "imag", "set channels imaginary expressions", OFFSET(img_str), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, A }, |
| { "win_size", "set window size", OFFSET(fft_bits), AV_OPT_TYPE_INT, {.i64=12}, 4, 16, A, "fft" }, |
| { "w16", 0, 0, AV_OPT_TYPE_CONST, {.i64=4}, 0, 0, A, "fft" }, |
| { "w32", 0, 0, AV_OPT_TYPE_CONST, {.i64=5}, 0, 0, A, "fft" }, |
| { "w64", 0, 0, AV_OPT_TYPE_CONST, {.i64=6}, 0, 0, A, "fft" }, |
| { "w128", 0, 0, AV_OPT_TYPE_CONST, {.i64=7}, 0, 0, A, "fft" }, |
| { "w256", 0, 0, AV_OPT_TYPE_CONST, {.i64=8}, 0, 0, A, "fft" }, |
| { "w512", 0, 0, AV_OPT_TYPE_CONST, {.i64=9}, 0, 0, A, "fft" }, |
| { "w1024", 0, 0, AV_OPT_TYPE_CONST, {.i64=10}, 0, 0, A, "fft" }, |
| { "w2048", 0, 0, AV_OPT_TYPE_CONST, {.i64=11}, 0, 0, A, "fft" }, |
| { "w4096", 0, 0, AV_OPT_TYPE_CONST, {.i64=12}, 0, 0, A, "fft" }, |
| { "w8192", 0, 0, AV_OPT_TYPE_CONST, {.i64=13}, 0, 0, A, "fft" }, |
| { "w16384", 0, 0, AV_OPT_TYPE_CONST, {.i64=14}, 0, 0, A, "fft" }, |
| { "w32768", 0, 0, AV_OPT_TYPE_CONST, {.i64=15}, 0, 0, A, "fft" }, |
| { "w65536", 0, 0, AV_OPT_TYPE_CONST, {.i64=16}, 0, 0, A, "fft" }, |
| { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64 = WFUNC_HANNING}, 0, NB_WFUNC-1, A, "win_func" }, |
| { "rect", "Rectangular", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT}, 0, 0, A, "win_func" }, |
| { "bartlett", "Bartlett", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, A, "win_func" }, |
| { "hann", "Hann", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" }, |
| { "hanning", "Hanning", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" }, |
| { "hamming", "Hamming", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING}, 0, 0, A, "win_func" }, |
| { "sine", "Sine", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE}, 0, 0, A, "win_func" }, |
| { "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=0.75}, 0, 1, A }, |
| { NULL }, |
| }; |
| |
| AVFILTER_DEFINE_CLASS(afftfilt); |
| |
| static int config_input(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AFFTFiltContext *s = ctx->priv; |
| char *saveptr = NULL; |
| int ret = 0, ch, i; |
| float overlap; |
| char *args; |
| const char *last_expr = "1"; |
| |
| s->fft = av_fft_init(s->fft_bits, 0); |
| s->ifft = av_fft_init(s->fft_bits, 1); |
| if (!s->fft || !s->ifft) |
| return AVERROR(ENOMEM); |
| |
| s->window_size = 1 << s->fft_bits; |
| |
| s->fft_data = av_calloc(inlink->channels, sizeof(*s->fft_data)); |
| if (!s->fft_data) |
| return AVERROR(ENOMEM); |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| s->fft_data[ch] = av_calloc(s->window_size, sizeof(**s->fft_data)); |
| if (!s->fft_data[ch]) |
| return AVERROR(ENOMEM); |
| } |
| |
| s->real = av_calloc(inlink->channels, sizeof(*s->real)); |
| if (!s->real) |
| return AVERROR(ENOMEM); |
| |
| s->imag = av_calloc(inlink->channels, sizeof(*s->imag)); |
| if (!s->imag) |
| return AVERROR(ENOMEM); |
| |
| args = av_strdup(s->real_str); |
| if (!args) |
| return AVERROR(ENOMEM); |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| char *arg = av_strtok(ch == 0 ? args : NULL, "|", &saveptr); |
| |
| ret = av_expr_parse(&s->real[ch], arg ? arg : last_expr, var_names, |
| NULL, NULL, NULL, NULL, 0, ctx); |
| if (ret < 0) |
| break; |
| if (arg) |
| last_expr = arg; |
| s->nb_exprs++; |
| } |
| |
| av_free(args); |
| |
| args = av_strdup(s->img_str ? s->img_str : s->real_str); |
| if (!args) |
| return AVERROR(ENOMEM); |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| char *arg = av_strtok(ch == 0 ? args : NULL, "|", &saveptr); |
| |
| ret = av_expr_parse(&s->imag[ch], arg ? arg : last_expr, var_names, |
| NULL, NULL, NULL, NULL, 0, ctx); |
| if (ret < 0) |
| break; |
| if (arg) |
| last_expr = arg; |
| } |
| |
| av_free(args); |
| |
| s->fifo = av_audio_fifo_alloc(inlink->format, inlink->channels, s->window_size); |
| if (!s->fifo) |
| return AVERROR(ENOMEM); |
| |
| s->window_func_lut = av_realloc_f(s->window_func_lut, s->window_size, |
| sizeof(*s->window_func_lut)); |
| if (!s->window_func_lut) |
| return AVERROR(ENOMEM); |
| ff_generate_window_func(s->window_func_lut, s->window_size, s->win_func, &overlap); |
| if (s->overlap == 1) |
| s->overlap = overlap; |
| |
| for (s->win_scale = 0, i = 0; i < s->window_size; i++) { |
| s->win_scale += s->window_func_lut[i] * s->window_func_lut[i]; |
| } |
| |
| s->hop_size = s->window_size * (1 - s->overlap); |
| if (s->hop_size <= 0) |
| return AVERROR(EINVAL); |
| |
| s->buffer = ff_get_audio_buffer(inlink, s->window_size * 2); |
| if (!s->buffer) |
| return AVERROR(ENOMEM); |
| |
| return ret; |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *frame) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| AFFTFiltContext *s = ctx->priv; |
| const int window_size = s->window_size; |
| const float f = 1. / s->win_scale; |
| double values[VAR_VARS_NB]; |
| AVFrame *out, *in = NULL; |
| int ch, n, ret, i, j, k; |
| int start = s->start, end = s->end; |
| |
| av_audio_fifo_write(s->fifo, (void **)frame->extended_data, frame->nb_samples); |
| av_frame_free(&frame); |
| |
| while (av_audio_fifo_size(s->fifo) >= window_size) { |
| if (!in) { |
| in = ff_get_audio_buffer(outlink, window_size); |
| if (!in) |
| return AVERROR(ENOMEM); |
| } |
| |
| ret = av_audio_fifo_peek(s->fifo, (void **)in->extended_data, window_size); |
| if (ret < 0) |
| break; |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| const float *src = (float *)in->extended_data[ch]; |
| FFTComplex *fft_data = s->fft_data[ch]; |
| |
| for (n = 0; n < in->nb_samples; n++) { |
| fft_data[n].re = src[n] * s->window_func_lut[n]; |
| fft_data[n].im = 0; |
| } |
| |
| for (; n < window_size; n++) { |
| fft_data[n].re = 0; |
| fft_data[n].im = 0; |
| } |
| } |
| |
| values[VAR_PTS] = s->pts; |
| values[VAR_SAMPLE_RATE] = inlink->sample_rate; |
| values[VAR_NBBINS] = window_size / 2; |
| values[VAR_CHANNELS] = inlink->channels; |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| FFTComplex *fft_data = s->fft_data[ch]; |
| float *buf = (float *)s->buffer->extended_data[ch]; |
| int x; |
| |
| values[VAR_CHANNEL] = ch; |
| |
| av_fft_permute(s->fft, fft_data); |
| av_fft_calc(s->fft, fft_data); |
| |
| for (n = 0; n < window_size / 2; n++) { |
| float fr, fi; |
| |
| values[VAR_BIN] = n; |
| |
| fr = av_expr_eval(s->real[ch], values, s); |
| fi = av_expr_eval(s->imag[ch], values, s); |
| |
| fft_data[n].re *= fr; |
| fft_data[n].im *= fi; |
| } |
| |
| for (n = window_size / 2 + 1, x = window_size / 2 - 1; n < window_size; n++, x--) { |
| fft_data[n].re = fft_data[x].re; |
| fft_data[n].im = -fft_data[x].im; |
| } |
| |
| av_fft_permute(s->ifft, fft_data); |
| av_fft_calc(s->ifft, fft_data); |
| |
| start = s->start; |
| end = s->end; |
| k = end; |
| for (i = 0, j = start; j < k && i < window_size; i++, j++) { |
| buf[j] += s->fft_data[ch][i].re * f; |
| } |
| |
| for (; i < window_size; i++, j++) { |
| buf[j] = s->fft_data[ch][i].re * f; |
| } |
| |
| start += s->hop_size; |
| end = j; |
| } |
| |
| s->start = start; |
| s->end = end; |
| |
| if (start >= window_size) { |
| float *dst, *buf; |
| |
| start -= window_size; |
| end -= window_size; |
| |
| s->start = start; |
| s->end = end; |
| |
| out = ff_get_audio_buffer(outlink, window_size); |
| if (!out) { |
| ret = AVERROR(ENOMEM); |
| break; |
| } |
| |
| out->pts = s->pts; |
| s->pts += window_size; |
| |
| for (ch = 0; ch < inlink->channels; ch++) { |
| dst = (float *)out->extended_data[ch]; |
| buf = (float *)s->buffer->extended_data[ch]; |
| |
| for (n = 0; n < window_size; n++) { |
| dst[n] = buf[n] * (1 - s->overlap); |
| } |
| memmove(buf, buf + window_size, window_size * 4); |
| } |
| |
| ret = ff_filter_frame(outlink, out); |
| if (ret < 0) |
| break; |
| } |
| |
| av_audio_fifo_drain(s->fifo, s->hop_size); |
| } |
| |
| av_frame_free(&in); |
| return ret; |
| } |
| |
| static int query_formats(AVFilterContext *ctx) |
| { |
| AVFilterFormats *formats; |
| AVFilterChannelLayouts *layouts; |
| static const enum AVSampleFormat sample_fmts[] = { |
| AV_SAMPLE_FMT_FLTP, |
| AV_SAMPLE_FMT_NONE |
| }; |
| int ret; |
| |
| layouts = ff_all_channel_counts(); |
| if (!layouts) |
| return AVERROR(ENOMEM); |
| ret = ff_set_common_channel_layouts(ctx, layouts); |
| if (ret < 0) |
| return ret; |
| |
| formats = ff_make_format_list(sample_fmts); |
| if (!formats) |
| return AVERROR(ENOMEM); |
| ret = ff_set_common_formats(ctx, formats); |
| if (ret < 0) |
| return ret; |
| |
| formats = ff_all_samplerates(); |
| if (!formats) |
| return AVERROR(ENOMEM); |
| return ff_set_common_samplerates(ctx, formats); |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| AFFTFiltContext *s = ctx->priv; |
| int i; |
| |
| av_fft_end(s->fft); |
| av_fft_end(s->ifft); |
| |
| for (i = 0; i < s->nb_exprs; i++) { |
| if (s->fft_data) |
| av_freep(&s->fft_data[i]); |
| } |
| av_freep(&s->fft_data); |
| |
| for (i = 0; i < s->nb_exprs; i++) { |
| av_expr_free(s->real[i]); |
| av_expr_free(s->imag[i]); |
| } |
| |
| av_freep(&s->real); |
| av_freep(&s->imag); |
| av_frame_free(&s->buffer); |
| } |
| |
| static const AVFilterPad inputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .config_props = config_input, |
| .filter_frame = filter_frame, |
| }, |
| { NULL } |
| }; |
| |
| static const AVFilterPad outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| }, |
| { NULL } |
| }; |
| |
| AVFilter ff_af_afftfilt = { |
| .name = "afftfilt", |
| .description = NULL_IF_CONFIG_SMALL("Apply arbitrary expressions to samples in frequency domain."), |
| .priv_size = sizeof(AFFTFiltContext), |
| .priv_class = &afftfilt_class, |
| .inputs = inputs, |
| .outputs = outputs, |
| .query_formats = query_formats, |
| .uninit = uninit, |
| }; |
