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author | Clément Bœsch <ubitux@gmail.com> | 2011-12-29 23:45:45 +0100 |
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committer | Clément Bœsch <ubitux@gmail.com> | 2012-08-20 23:03:06 +0200 |
commit | ddda29b4a70e4f5239a2a913b87dab0977bd49b8 (patch) | |
tree | cec9cb79d8baafb3534b9a10d26c0caad8b20a94 /libavfilter/avf_showspectrum.c | |
parent | 786f06e109e7daef9b9f193eaf89c3493367615e (diff) | |
download | ffmpeg-streaming-ddda29b4a70e4f5239a2a913b87dab0977bd49b8.zip ffmpeg-streaming-ddda29b4a70e4f5239a2a913b87dab0977bd49b8.tar.gz |
lavfi: add showspectrum filter.
Diffstat (limited to 'libavfilter/avf_showspectrum.c')
-rw-r--r-- | libavfilter/avf_showspectrum.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c new file mode 100644 index 0000000..095b9c7 --- /dev/null +++ b/libavfilter/avf_showspectrum.c @@ -0,0 +1,314 @@ +/* + * Copyright (c) 2012 Clément Bœsch + * + * 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 + */ + +/** + * @file + * audio to spectrum (video) transmedia filter, based on ffplay rdft showmode + * (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini). + */ + +#include <math.h> + +#include "libavcodec/avfft.h" +#include "libavutil/audioconvert.h" +#include "libavutil/opt.h" +#include "avfilter.h" +#include "internal.h" + +typedef struct { + const AVClass *class; + int w, h; + AVFilterBufferRef *outpicref; + int req_fullfilled; + int xpos; ///< x position (current column) + RDFTContext *rdft; ///< Real Discrete Fourier Transform context + int rdft_bits; ///< number of bits (RDFT window size = 1<<rdft_bits) + FFTSample *rdft_data; ///< bins holder for each (displayed) channels + int filled; ///< number of samples (per channel) filled in current rdft_buffer + int consumed; ///< number of samples (per channel) consumed from the input frame + float *window_func_lut; ///< Window function LUT +} ShowSpectrumContext; + +#define OFFSET(x) offsetof(ShowSpectrumContext, x) + +static const AVOption showspectrum_options[] = { + { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0 }, + { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0 }, + { NULL }, +}; + +AVFILTER_DEFINE_CLASS(showspectrum); + +static av_cold int init(AVFilterContext *ctx, const char *args) +{ + ShowSpectrumContext *showspectrum = ctx->priv; + int err; + + showspectrum->class = &showspectrum_class; + av_opt_set_defaults(showspectrum); + + if ((err = av_set_options_string(showspectrum, args, "=", ":")) < 0) + return err; + + return 0; +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + ShowSpectrumContext *showspectrum = ctx->priv; + + av_rdft_end(showspectrum->rdft); + av_freep(&showspectrum->rdft_data); + av_freep(&showspectrum->window_func_lut); + avfilter_unref_bufferp(&showspectrum->outpicref); +} + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats = NULL; + AVFilterChannelLayouts *layouts = NULL; + AVFilterLink *inlink = ctx->inputs[0]; + AVFilterLink *outlink = ctx->outputs[0]; + static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16P, -1 }; + static const enum PixelFormat pix_fmts[] = { PIX_FMT_RGB24, -1 }; + + /* set input audio formats */ + formats = ff_make_format_list(sample_fmts); + if (!formats) + return AVERROR(ENOMEM); + ff_formats_ref(formats, &inlink->out_formats); + + layouts = ff_all_channel_layouts(); + if (!layouts) + return AVERROR(ENOMEM); + ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts); + + formats = ff_all_samplerates(); + if (!formats) + return AVERROR(ENOMEM); + ff_formats_ref(formats, &inlink->out_samplerates); + + /* set output video format */ + formats = ff_make_format_list(pix_fmts); + if (!formats) + return AVERROR(ENOMEM); + ff_formats_ref(formats, &outlink->in_formats); + + return 0; +} + +static int config_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + ShowSpectrumContext *showspectrum = ctx->priv; + int i, rdft_bits, win_size; + + outlink->w = showspectrum->w; + outlink->h = showspectrum->h; + + /* RDFT window size (precision) according to the requested output frame height */ + for (rdft_bits = 1; 1<<rdft_bits < 2*outlink->h; rdft_bits++); + win_size = 1 << rdft_bits; + + /* (re-)configuration if the video output changed (or first init) */ + if (rdft_bits != showspectrum->rdft_bits) { + AVFilterBufferRef *outpicref; + + av_rdft_end(showspectrum->rdft); + showspectrum->rdft = av_rdft_init(rdft_bits, DFT_R2C); + showspectrum->rdft_bits = rdft_bits; + + /* RDFT buffers: x2 for each (display) channel buffer */ + showspectrum->rdft_data = + av_realloc_f(showspectrum->rdft_data, 2 * win_size, + sizeof(*showspectrum->rdft_data)); + if (!showspectrum->rdft_data) + return AVERROR(ENOMEM); + showspectrum->filled = 0; + + /* pre-calc windowing function (hann here) */ + showspectrum->window_func_lut = + av_realloc_f(showspectrum->window_func_lut, win_size, + sizeof(*showspectrum->window_func_lut)); + if (!showspectrum->window_func_lut) + return AVERROR(ENOMEM); + for (i = 0; i < win_size; i++) + showspectrum->window_func_lut[i] = .5f * (1 - cos(2*M_PI*i / (win_size-1))); + + /* prepare the initial picref buffer (black frame) */ + avfilter_unref_bufferp(&showspectrum->outpicref); + showspectrum->outpicref = outpicref = + ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_PRESERVE|AV_PERM_REUSE2, + outlink->w, outlink->h); + if (!outpicref) + return AVERROR(ENOMEM); + outlink->sample_aspect_ratio = (AVRational){1,1}; + memset(outpicref->data[0], 0, outlink->h * outpicref->linesize[0]); + } + + if (showspectrum->xpos >= outlink->w) + showspectrum->xpos = 0; + + av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n", + showspectrum->w, showspectrum->h, win_size); + return 0; +} + +inline static void push_frame(AVFilterLink *outlink) +{ + ShowSpectrumContext *showspectrum = outlink->src->priv; + + showspectrum->xpos++; + if (showspectrum->xpos >= outlink->w) + showspectrum->xpos = 0; + showspectrum->filled = 0; + showspectrum->req_fullfilled = 1; + + ff_start_frame(outlink, avfilter_ref_buffer(showspectrum->outpicref, ~AV_PERM_WRITE)); + ff_draw_slice(outlink, 0, outlink->h, 1); + ff_end_frame(outlink); +} + +static int request_frame(AVFilterLink *outlink) +{ + ShowSpectrumContext *showspectrum = outlink->src->priv; + AVFilterLink *inlink = outlink->src->inputs[0]; + int ret; + + showspectrum->req_fullfilled = 0; + do { + ret = ff_request_frame(inlink); + } while (!showspectrum->req_fullfilled && ret >= 0); + + if (ret == AVERROR_EOF && showspectrum->outpicref) + push_frame(outlink); + return ret; +} + +static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insamples, int nb_samples) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + ShowSpectrumContext *showspectrum = ctx->priv; + AVFilterBufferRef *outpicref = showspectrum->outpicref; + const int nb_channels = av_get_channel_layout_nb_channels(insamples->audio->channel_layout); + + /* nb_freq contains the power of two superior or equal to the output image + * height (or half the RDFT window size) */ + const int nb_freq = 1 << (showspectrum->rdft_bits - 1); + const int win_size = nb_freq << 1; + + int ch, n, y; + FFTSample *data[2]; + const int nb_display_channels = FFMIN(nb_channels, 2); + const int start = showspectrum->filled; + const int add_samples = FFMIN(win_size - start, nb_samples); + + /* fill RDFT input with the number of samples available */ + for (ch = 0; ch < nb_display_channels; ch++) { + const int16_t *p = (int16_t *)insamples->extended_data[ch]; + + p += showspectrum->consumed; + data[ch] = showspectrum->rdft_data + win_size * ch; // select channel buffer + for (n = 0; n < add_samples; n++) + data[ch][start + n] = p[n] * showspectrum->window_func_lut[start + n]; + } + showspectrum->filled += add_samples; + + /* complete RDFT window size? */ + if (showspectrum->filled == win_size) { + + /* run RDFT on each samples set */ + for (ch = 0; ch < nb_display_channels; ch++) + av_rdft_calc(showspectrum->rdft, data[ch]); + + /* fill a new spectrum column */ +#define RE(ch) data[ch][2*y + 0] +#define IM(ch) data[ch][2*y + 1] +#define MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im)) + + for (y = 0; y < outlink->h; y++) { + // FIXME: bin[0] contains first and last bins + const int pos = showspectrum->xpos * 3 + (outlink->h - y - 1) * outpicref->linesize[0]; + const double w = 1. / sqrt(nb_freq); + int a = sqrt(w * MAGNITUDE(RE(0), IM(0))); + int b = nb_display_channels > 1 ? sqrt(w * MAGNITUDE(RE(1), IM(1))) : a; + + a = FFMIN(a, 255); + b = FFMIN(b, 255); + outpicref->data[0][pos] = a; + outpicref->data[0][pos+1] = b; + outpicref->data[0][pos+2] = (a + b) / 2; + } + outpicref->pts = insamples->pts + + av_rescale_q(showspectrum->consumed, + (AVRational){ 1, inlink->sample_rate }, + outlink->time_base); + push_frame(outlink); + } + + return add_samples; +} + +static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples) +{ + AVFilterContext *ctx = inlink->dst; + ShowSpectrumContext *showspectrum = ctx->priv; + int left_samples = insamples->audio->nb_samples; + + showspectrum->consumed = 0; + while (left_samples) { + const int added_samples = plot_spectrum_column(inlink, insamples, left_samples); + showspectrum->consumed += added_samples; + left_samples -= added_samples; + } + + avfilter_unref_buffer(insamples); + return 0; +} + +AVFilter avfilter_avf_showspectrum = { + .name = "showspectrum", + .description = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."), + .init = init, + .uninit = uninit, + .query_formats = query_formats, + .priv_size = sizeof(ShowSpectrumContext), + + .inputs = (const AVFilterPad[]) { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_samples = filter_samples, + .min_perms = AV_PERM_READ, + }, + { .name = NULL } + }, + + .outputs = (const AVFilterPad[]) { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_output, + .request_frame = request_frame, + }, + { .name = NULL } + }, +}; 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