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FFmpeg/libavfilter/avf_showfreqs.c

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  1. /*

  2.  * Copyright (c) 2015 Paul B Mahol

  3.  *

  4.  * This file is part of FFmpeg.

  5.  *

  6.  * FFmpeg is free software; you can redistribute it and/or

  7.  * modify it under the terms of the GNU Lesser General Public

  8.  * License as published by the Free Software Foundation; either

  9.  * version 2.1 of the License, or (at your option) any later version.

  10.  *

  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 GNU

  14.  * Lesser General Public License for more details.

  15.  *

  16.  * You should have received a copy of the GNU Lesser General Public

  17.  * License along with FFmpeg; if not, write to the Free Software

  18.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  19.  */

  20. 

  21. #include <math.h>

  22. 

  23. #include "libavcodec/avfft.h"

  24. #include "libavutil/audio_fifo.h"

  25. #include "libavutil/avassert.h"

  26. #include "libavutil/avstring.h"

  27. #include "libavutil/channel_layout.h"

  28. #include "libavutil/intreadwrite.h"

  29. #include "libavutil/opt.h"

  30. #include "libavutil/parseutils.h"

  31. #include "audio.h"

  32. #include "video.h"

  33. #include "avfilter.h"

  34. #include "internal.h"

  35. 

  36. enum DisplayMode    { LINE, BAR, DOT, NB_MODES };

  37. enum FrequencyScale { FS_LINEAR, FS_LOG, FS_RLOG, NB_FSCALES };

  38. enum AmplitudeScale { AS_LINEAR, AS_SQRT, AS_CBRT, AS_LOG, NB_ASCALES };

  39. enum WindowFunc     { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,

  40.                       WFUNC_BARTLETT, WFUNC_WELCH, WFUNC_FLATTOP,

  41.                       WFUNC_BHARRIS, WFUNC_BNUTTALL, WFUNC_SINE, WFUNC_NUTTALL,

  42.                       WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, NB_WFUNC };

  43. 

  44. typedef struct ShowFreqsContext {

  45.     const AVClass *class;

  46.     int w, h;

  47.     int mode;

  48.     int fft_bits;

  49.     int ascale, fscale;

  50.     int avg;

  51.     int win_func;

  52.     FFTContext *fft;

  53.     FFTComplex **fft_data;

  54.     float **avg_data;

  55.     float *window_func_lut;

  56.     float overlap;

  57.     int skip_samples;

  58.     int nb_channels;

  59.     int nb_freq;

  60.     int win_size;

  61.     float scale;

  62.     char *colors;

  63.     AVAudioFifo *fifo;

  64.     int64_t pts;

  65. } ShowFreqsContext;

  66. 

  67. #define OFFSET(x) offsetof(ShowFreqsContext, x)

  68. #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

  69. 

  70. static const AVOption showfreqs_options[] = {

  71.     { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "1024x512"}, 0, 0, FLAGS },

  72.     { "s",    "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "1024x512"}, 0, 0, FLAGS },

  73.     { "mode", "set display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=BAR}, 0, NB_MODES-1, FLAGS, "mode" },

  74.         { "line", "show lines",  0, AV_OPT_TYPE_CONST, {.i64=LINE},   0, 0, FLAGS, "mode" },

  75.         { "bar",  "show bars",   0, AV_OPT_TYPE_CONST, {.i64=BAR},    0, 0, FLAGS, "mode" },

  76.         { "dot",  "show dots",   0, AV_OPT_TYPE_CONST, {.i64=DOT},    0, 0, FLAGS, "mode" },

  77.     { "ascale", "set amplitude scale", OFFSET(ascale), AV_OPT_TYPE_INT, {.i64=AS_LOG}, 0, NB_ASCALES-1, FLAGS, "ascale" },

  78.         { "lin",  "linear",      0, AV_OPT_TYPE_CONST, {.i64=AS_LINEAR}, 0, 0, FLAGS, "ascale" },

  79.         { "sqrt", "square root", 0, AV_OPT_TYPE_CONST, {.i64=AS_SQRT},   0, 0, FLAGS, "ascale" },

  80.         { "cbrt", "cubic root",  0, AV_OPT_TYPE_CONST, {.i64=AS_CBRT},   0, 0, FLAGS, "ascale" },

  81.         { "log",  "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=AS_LOG},    0, 0, FLAGS, "ascale" },

  82.     { "fscale", "set frequency scale", OFFSET(fscale), AV_OPT_TYPE_INT, {.i64=FS_LINEAR}, 0, NB_FSCALES-1, FLAGS, "fscale" },

  83.         { "lin",  "linear",              0, AV_OPT_TYPE_CONST, {.i64=FS_LINEAR}, 0, 0, FLAGS, "fscale" },

  84.         { "log",  "logarithmic",         0, AV_OPT_TYPE_CONST, {.i64=FS_LOG},    0, 0, FLAGS, "fscale" },

  85.         { "rlog", "reverse logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=FS_RLOG},   0, 0, FLAGS, "fscale" },

  86.     { "win_size", "set window size", OFFSET(fft_bits), AV_OPT_TYPE_INT, {.i64=11}, 4, 16, FLAGS, "fft" },

  87.         { "w16",    0, 0, AV_OPT_TYPE_CONST, {.i64=4},  0, 0, FLAGS, "fft" },

  88.         { "w32",    0, 0, AV_OPT_TYPE_CONST, {.i64=5},  0, 0, FLAGS, "fft" },

  89.         { "w64",    0, 0, AV_OPT_TYPE_CONST, {.i64=6},  0, 0, FLAGS, "fft" },

  90.         { "w128",   0, 0, AV_OPT_TYPE_CONST, {.i64=7},  0, 0, FLAGS, "fft" },

  91.         { "w256",   0, 0, AV_OPT_TYPE_CONST, {.i64=8},  0, 0, FLAGS, "fft" },

  92.         { "w512",   0, 0, AV_OPT_TYPE_CONST, {.i64=9},  0, 0, FLAGS, "fft" },

  93.         { "w1024",  0, 0, AV_OPT_TYPE_CONST, {.i64=10}, 0, 0, FLAGS, "fft" },

  94.         { "w2048",  0, 0, AV_OPT_TYPE_CONST, {.i64=11}, 0, 0, FLAGS, "fft" },

  95.         { "w4096",  0, 0, AV_OPT_TYPE_CONST, {.i64=12}, 0, 0, FLAGS, "fft" },

  96.         { "w8192",  0, 0, AV_OPT_TYPE_CONST, {.i64=13}, 0, 0, FLAGS, "fft" },

  97.         { "w16384", 0, 0, AV_OPT_TYPE_CONST, {.i64=14}, 0, 0, FLAGS, "fft" },

  98.         { "w32768", 0, 0, AV_OPT_TYPE_CONST, {.i64=15}, 0, 0, FLAGS, "fft" },

  99.         { "w65536", 0, 0, AV_OPT_TYPE_CONST, {.i64=16}, 0, 0, FLAGS, "fft" },

  100.     { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64=WFUNC_HANNING}, 0, NB_WFUNC-1, FLAGS, "win_func" },

  101.         { "rect",     "Rectangular",      0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT},     0, 0, FLAGS, "win_func" },

  102.         { "bartlett", "Bartlett",         0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, FLAGS, "win_func" },

  103.         { "hanning",  "Hanning",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING},  0, 0, FLAGS, "win_func" },

  104.         { "hamming",  "Hamming",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING},  0, 0, FLAGS, "win_func" },

  105.         { "blackman", "Blackman",         0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BLACKMAN}, 0, 0, FLAGS, "win_func" },

  106.         { "welch",    "Welch",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_WELCH},    0, 0, FLAGS, "win_func" },

  107.         { "flattop",  "Flat-top",         0, AV_OPT_TYPE_CONST, {.i64=WFUNC_FLATTOP},  0, 0, FLAGS, "win_func" },

  108.         { "bharris",  "Blackman-Harris",  0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BHARRIS},  0, 0, FLAGS, "win_func" },

  109.         { "bnuttall", "Blackman-Nuttall", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BNUTTALL}, 0, 0, FLAGS, "win_func" },

  110.         { "bhann",    "Bartlett-Hann",    0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BHANN},    0, 0, FLAGS, "win_func" },

  111.         { "sine",     "Sine",             0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE},     0, 0, FLAGS, "win_func" },

  112.         { "nuttall",  "Nuttall",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_NUTTALL},  0, 0, FLAGS, "win_func" },

  113.         { "lanczos",  "Lanczos",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS},  0, 0, FLAGS, "win_func" },

  114.         { "gauss",    "Gauss",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS},    0, 0, FLAGS, "win_func" },

  115.     { "overlap",  "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=1.}, 0., 1., FLAGS },

  116.     { "averaging", "set time averaging", OFFSET(avg), AV_OPT_TYPE_INT, {.i64=1}, 0, INT32_MAX, FLAGS },

  117.     { "colors", "set channels colors", OFFSET(colors), AV_OPT_TYPE_STRING, {.str = "red|green|blue|yellow|orange|lime|pink|magenta|brown" }, 0, 0, FLAGS },

  118.     { NULL }

  119. };

  120. 

  121. AVFILTER_DEFINE_CLASS(showfreqs);

  122. 

  123. static int query_formats(AVFilterContext *ctx)

  124. {

  125.     AVFilterFormats *formats = NULL;

  126.     AVFilterChannelLayouts *layouts = NULL;

  127.     AVFilterLink *inlink = ctx->inputs[0];

  128.     AVFilterLink *outlink = ctx->outputs[0];

  129.     static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };

  130.     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };

  131.     int ret;

  132. 

  133.     /* set input audio formats */

  134.     formats = ff_make_format_list(sample_fmts);

  135.     if ((ret = ff_formats_ref(formats, &inlink->out_formats)) < 0)

  136.         return ret;

  137. 

  138.     layouts = ff_all_channel_layouts();

  139.     if ((ret = ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts)) < 0)

  140.         return ret;

  141. 

  142.     formats = ff_all_samplerates();

  143.     if ((ret = ff_formats_ref(formats, &inlink->out_samplerates)) < 0)

  144.         return ret;

  145. 

  146.     /* set output video format */

  147.     formats = ff_make_format_list(pix_fmts);

  148.     if ((ret = ff_formats_ref(formats, &outlink->in_formats)) < 0)

  149.         return ret;

  150. 

  151.     return 0;

  152. }

  153. 

  154. static void generate_window_func(float *lut, int N, int win_func, float *overlap)

  155. {

  156.     int n;

  157. 

  158.     switch (win_func) {

  159.     case WFUNC_RECT:

  160.         for (n = 0; n < N; n++)

  161.             lut[n] = 1.;

  162.         *overlap = 0.;

  163.         break;

  164.     case WFUNC_BARTLETT:

  165.         for (n = 0; n < N; n++)

  166.             lut[n] = 1.-fabs((n-(N-1)/2.)/((N-1)/2.));

  167.         *overlap = 0.5;

  168.         break;

  169.     case WFUNC_HANNING:

  170.         for (n = 0; n < N; n++)

  171.             lut[n] = .5*(1-cos(2*M_PI*n/(N-1)));

  172.         *overlap = 0.5;

  173.         break;

  174.     case WFUNC_HAMMING:

  175.         for (n = 0; n < N; n++)

  176.             lut[n] = .54-.46*cos(2*M_PI*n/(N-1));

  177.         *overlap = 0.5;

  178.         break;

  179.     case WFUNC_BLACKMAN:

  180.         for (n = 0; n < N; n++)

  181.             lut[n] = .42659-.49656*cos(2*M_PI*n/(N-1))+.076849*cos(4*M_PI*n/(N-1));

  182.         *overlap = 0.661;

  183.         break;

  184.     case WFUNC_WELCH:

  185.         for (n = 0; n < N; n++)

  186.             lut[n] = 1.-(n-(N-1)/2.)/((N-1)/2.)*(n-(N-1)/2.)/((N-1)/2.);

  187.         *overlap = 0.293;

  188.         break;

  189.     case WFUNC_FLATTOP:

  190.         for (n = 0; n < N; n++)

  191.             lut[n] = 1.-1.985844164102*cos( 2*M_PI*n/(N-1))+1.791176438506*cos( 4*M_PI*n/(N-1))-

  192.                         1.282075284005*cos( 6*M_PI*n/(N-1))+0.667777530266*cos( 8*M_PI*n/(N-1))-

  193.                         0.240160796576*cos(10*M_PI*n/(N-1))+0.056656381764*cos(12*M_PI*n/(N-1))-

  194.                         0.008134974479*cos(14*M_PI*n/(N-1))+0.000624544650*cos(16*M_PI*n/(N-1))-

  195.                         0.000019808998*cos(18*M_PI*n/(N-1))+0.000000132974*cos(20*M_PI*n/(N-1));

  196.         *overlap = 0.841;

  197.         break;

  198.     case WFUNC_BHARRIS:

  199.         for (n = 0; n < N; n++)

  200.             lut[n] = 0.35875-0.48829*cos(2*M_PI*n/(N-1))+0.14128*cos(4*M_PI*n/(N-1))-0.01168*cos(6*M_PI*n/(N-1));

  201.         *overlap = 0.661;

  202.         break;

  203.     case WFUNC_BNUTTALL:

  204.         for (n = 0; n < N; n++)

  205.             lut[n] = 0.3635819-0.4891775*cos(2*M_PI*n/(N-1))+0.1365995*cos(4*M_PI*n/(N-1))-0.0106411*cos(6*M_PI*n/(N-1));

  206.         *overlap = 0.661;

  207.         break;

  208.     case WFUNC_BHANN:

  209.         for (n = 0; n < N; n++)

  210.             lut[n] = 0.62-0.48*fabs(n/(double)(N-1)-.5)-0.38*cos(2*M_PI*n/(N-1));

  211.         *overlap = 0.5;

  212.         break;

  213.     case WFUNC_SINE:

  214.         for (n = 0; n < N; n++)

  215.             lut[n] = sin(M_PI*n/(N-1));

  216.         *overlap = 0.75;

  217.         break;

  218.     case WFUNC_NUTTALL:

  219.         for (n = 0; n < N; n++)

  220.             lut[n] = 0.355768-0.487396*cos(2*M_PI*n/(N-1))+0.144232*cos(4*M_PI*n/(N-1))-0.012604*cos(6*M_PI*n/(N-1));

  221.         *overlap = 0.663;

  222.         break;

  223.     case WFUNC_LANCZOS:

  224. #define SINC(x) (!(x)) ? 1 : sin(M_PI * (x))/(M_PI * (x));

  225.         for (n = 0; n < N; n++)

  226.             lut[n] = SINC((2.*n)/(N-1)-1);

  227.         *overlap = 0.75;

  228.         break;

  229.     case WFUNC_GAUSS:

  230.         for (n = 0; n < N; n++)

  231.             lut[n] = pow(M_E,-0.5*pow((n-(N-1)/2)/(0.4*(N-1)/2.f),2));

  232.         *overlap = 0.75;

  233.         break;

  234.     default:

  235.         av_assert0(0);

  236.     }

  237. }

  238. 

  239. static int config_output(AVFilterLink *outlink)

  240. {

  241.     AVFilterContext *ctx = outlink->src;

  242.     AVFilterLink *inlink = ctx->inputs[0];

  243.     ShowFreqsContext *s = ctx->priv;

  244.     float overlap;

  245.     int i;

  246. 

  247.     s->nb_freq = 1 << (s->fft_bits - 1);

  248.     s->win_size = s->nb_freq << 1;

  249.     av_audio_fifo_free(s->fifo);

  250.     av_fft_end(s->fft);

  251.     s->fft = av_fft_init(s->fft_bits, 0);

  252.     if (!s->fft) {

  253.         av_log(ctx, AV_LOG_ERROR, "Unable to create FFT context. "

  254.                "The window size might be too high.\n");

  255.         return AVERROR(ENOMEM);

  256.     }

  257. 

  258.     /* FFT buffers: x2 for each (display) channel buffer.

  259.      * Note: we use free and malloc instead of a realloc-like function to

  260.      * make sure the buffer is aligned in memory for the FFT functions. */

  261.     for (i = 0; i < s->nb_channels; i++) {

  262.         av_freep(&s->fft_data[i]);

  263.         av_freep(&s->avg_data[i]);

  264.     }

  265.     av_freep(&s->fft_data);

  266.     av_freep(&s->avg_data);

  267.     s->nb_channels = inlink->channels;

  268. 

  269.     s->fft_data = av_calloc(s->nb_channels, sizeof(*s->fft_data));

  270.     if (!s->fft_data)

  271.         return AVERROR(ENOMEM);

  272.     s->avg_data = av_calloc(s->nb_channels, sizeof(*s->avg_data));

  273.     if (!s->fft_data)

  274.         return AVERROR(ENOMEM);

  275.     for (i = 0; i < s->nb_channels; i++) {

  276.         s->fft_data[i] = av_calloc(s->win_size, sizeof(**s->fft_data));

  277.         s->avg_data[i] = av_calloc(s->nb_freq, sizeof(**s->avg_data));

  278.         if (!s->fft_data[i] || !s->avg_data[i])

  279.             return AVERROR(ENOMEM);

  280.     }

  281. 

  282.     /* pre-calc windowing function */

  283.     s->window_func_lut = av_realloc_f(s->window_func_lut, s->win_size,

  284.                                       sizeof(*s->window_func_lut));

  285.     if (!s->window_func_lut)

  286.         return AVERROR(ENOMEM);

  287.     generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);

  288.     if (s->overlap == 1.)

  289.         s->overlap = overlap;

  290.     s->skip_samples = (1. - s->overlap) * s->win_size;

  291.     if (s->skip_samples < 1) {

  292.         av_log(ctx, AV_LOG_ERROR, "overlap %f too big\n", s->overlap);

  293.         return AVERROR(EINVAL);

  294.     }

  295. 

  296.     for (s->scale = 0, i = 0; i < s->win_size; i++) {

  297.         s->scale += s->window_func_lut[i] * s->window_func_lut[i];

  298.     }

  299. 

  300.     outlink->frame_rate = av_make_q(inlink->sample_rate, s->win_size * (1.-s->overlap));

  301.     outlink->sample_aspect_ratio = (AVRational){1,1};

  302.     outlink->w = s->w;

  303.     outlink->h = s->h;

  304. 

  305.     s->fifo = av_audio_fifo_alloc(inlink->format, inlink->channels, s->win_size);

  306.     if (!s->fifo)

  307.         return AVERROR(ENOMEM);

  308.     return 0;

  309. }

  310. 

  311. static inline void draw_dot(AVFrame *out, int x, int y, uint8_t fg[4])

  312. {

  313. 

  314.     uint32_t color = AV_RL32(out->data[0] + y * out->linesize[0] + x * 4);

  315. 

  316.     if ((color & 0xffffff) != 0)

  317.         AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg) | color);

  318.     else

  319.         AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));

  320. }

  321. 

  322. static int get_sx(ShowFreqsContext *s, int f)

  323. {

  324.     switch (s->fscale) {

  325.     case FS_LINEAR:

  326.         return (s->w/(float)s->nb_freq)*f;

  327.     case FS_LOG:

  328.         return s->w-pow(s->w, (s->nb_freq-f-1)/(s->nb_freq-1.));

  329.     case FS_RLOG:

  330.         return pow(s->w, f/(s->nb_freq-1.));

  331.     }

  332. 

  333.     return 0;

  334. }

  335. 

  336. static float get_bsize(ShowFreqsContext *s, int f)

  337. {

  338.     switch (s->fscale) {

  339.     case FS_LINEAR:

  340.         return s->w/(float)s->nb_freq;

  341.     case FS_LOG:

  342.         return pow(s->w, (s->nb_freq-f-1)/(s->nb_freq-1.))-

  343.                pow(s->w, (s->nb_freq-f-2)/(s->nb_freq-1.));

  344.     case FS_RLOG:

  345.         return pow(s->w, (f+1)/(s->nb_freq-1.))-

  346.                pow(s->w,  f   /(s->nb_freq-1.));

  347.     }

  348. 

  349.     return 1.;

  350. }

  351. 

  352. static inline void plot_freq(ShowFreqsContext *s, int ch,

  353.                              double a, int f, uint8_t fg[4], int *prev_y,

  354.                              AVFrame *out, AVFilterLink *outlink)

  355. {

  356.     const int w = s->w;

  357.     const float avg = s->avg_data[ch][f];

  358.     const float bsize = get_bsize(s, f);

  359.     const int sx = get_sx(s, f);

  360.     int x, y, i;

  361. 

  362.     switch(s->ascale) {

  363.     case AS_SQRT:

  364.         a = 1.0 - sqrt(a);

  365.         break;

  366.     case AS_CBRT:

  367.         a = 1.0 - cbrt(a);

  368.         break;

  369.     case AS_LOG:

  370.         a = log(av_clipd(a, 1e-6, 1)) / log(1e-6);

  371.         break;

  372.     case AS_LINEAR:

  373.         a = 1.0 - a;

  374.         break;

  375.     }

  376.     y = a * outlink->h - 1;

  377.     if (y < 0)

  378.         return;

  379. 

  380.     switch (s->avg) {

  381.     case 0:

  382.         y = s->avg_data[ch][f] = !outlink->frame_count ? y : FFMIN(avg, y);

  383.         break;

  384.     case 1:

  385.         break;

  386.     default:

  387.         s->avg_data[ch][f] = avg + y * (y - avg) / (FFMIN(outlink->frame_count + 1, s->avg) * y);

  388.         y = s->avg_data[ch][f];

  389.         break;

  390.     }

  391. 

  392.     switch(s->mode) {

  393.     case LINE:

  394.         if (*prev_y == -1) {

  395.             *prev_y = y;

  396.         }

  397.         if (y <= *prev_y) {

  398.             for (x = sx + 1; x < sx + bsize && x < w; x++)

  399.                 draw_dot(out, x, y, fg);

  400.             for (i = y; i <= *prev_y; i++)

  401.                 draw_dot(out, sx, i, fg);

  402.         } else {

  403.             for (i = *prev_y; i <= y; i++)

  404.                 draw_dot(out, sx, i, fg);

  405.             for (x = sx + 1; x < sx + bsize && x < w; x++)

  406.                 draw_dot(out, x, i - 1, fg);

  407.         }

  408.         *prev_y = y;

  409.         break;

  410.     case BAR:

  411.         for (x = sx; x < sx + bsize && x < w; x++)

  412.             for (i = y; i < outlink->h; i++)

  413.                 draw_dot(out, x, i, fg);

  414.         break;

  415.     case DOT:

  416.         for (x = sx; x < sx + bsize && x < w; x++)

  417.             draw_dot(out, x, y, fg);

  418.         break;

  419.     }

  420. }

  421. 

  422. static int plot_freqs(AVFilterLink *inlink, AVFrame *in)

  423. {

  424.     AVFilterContext *ctx = inlink->dst;

  425.     AVFilterLink *outlink = ctx->outputs[0];

  426.     ShowFreqsContext *s = ctx->priv;

  427.     const int win_size = s->win_size;

  428.     char *colors, *color, *saveptr = NULL;

  429.     AVFrame *out;

  430.     int ch, n;

  431. 

  432.     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);

  433.     if (!out)

  434.         return AVERROR(ENOMEM);

  435. 

  436.     for (n = 0; n < outlink->h; n++)

  437.         memset(out->data[0] + out->linesize[0] * n, 0, outlink->w * 4);

  438. 

  439.     /* fill FFT input with the number of samples available */

  440.     for (ch = 0; ch < s->nb_channels; ch++) {

  441.         const float *p = (float *)in->extended_data[ch];

  442. 

  443.         for (n = 0; n < in->nb_samples; n++) {

  444.             s->fft_data[ch][n].re = p[n] * s->window_func_lut[n];

  445.             s->fft_data[ch][n].im = 0;

  446.         }

  447.         for (; n < win_size; n++) {

  448.             s->fft_data[ch][n].re = 0;

  449.             s->fft_data[ch][n].im = 0;

  450.         }

  451.     }

  452. 

  453.     /* run FFT on each samples set */

  454.     for (ch = 0; ch < s->nb_channels; ch++) {

  455.         av_fft_permute(s->fft, s->fft_data[ch]);

  456.         av_fft_calc(s->fft, s->fft_data[ch]);

  457.     }

  458. 

  459. #define RE(x, ch) s->fft_data[ch][x].re

  460. #define IM(x, ch) s->fft_data[ch][x].im

  461. #define M(a, b) (sqrt((a) * (a) + (b) * (b)))

  462. 

  463.     colors = av_strdup(s->colors);

  464.     if (!colors) {

  465.         av_frame_free(&out);

  466.         return AVERROR(ENOMEM);

  467.     }

  468. 

  469.     for (ch = 0; ch < s->nb_channels; ch++) {

  470.         uint8_t fg[4] = { 0xff, 0xff, 0xff, 0xff };

  471.         int prev_y = -1, f;

  472.         double a;

  473. 

  474.         color = av_strtok(ch == 0 ? colors : NULL, " |", &saveptr);

  475.         if (color)

  476.             av_parse_color(fg, color, -1, ctx);

  477. 

  478.         a = av_clipd(M(RE(0, ch), 0) / s->scale, 0, 1);

  479.         plot_freq(s, ch, a, 0, fg, &prev_y, out, outlink);

  480. 

  481.         for (f = 1; f < s->nb_freq; f++) {

  482.             a = av_clipd(M(RE(f, ch), IM(f, ch)) / s->scale, 0, 1);

  483. 

  484.             plot_freq(s, ch, a, f, fg, &prev_y, out, outlink);

  485.         }

  486.     }

  487. 

  488.     av_free(colors);

  489.     out->pts = in->pts;

  490.     return ff_filter_frame(outlink, out);

  491. }

  492. 

  493. static int filter_frame(AVFilterLink *inlink, AVFrame *in)

  494. {

  495.     AVFilterContext *ctx = inlink->dst;

  496.     ShowFreqsContext *s = ctx->priv;

  497.     AVFrame *fin = NULL;

  498.     int ret = 0;

  499. 

  500.     av_audio_fifo_write(s->fifo, (void **)in->extended_data, in->nb_samples);

  501.     while (av_audio_fifo_size(s->fifo) >= s->win_size) {

  502.         fin = ff_get_audio_buffer(inlink, s->win_size);

  503.         if (!fin) {

  504.             ret = AVERROR(ENOMEM);

  505.             goto fail;

  506.         }

  507. 

  508.         fin->pts = s->pts;

  509.         s->pts += s->skip_samples;

  510.         ret = av_audio_fifo_peek(s->fifo, (void **)fin->extended_data, s->win_size);

  511.         if (ret < 0)

  512.             goto fail;

  513. 

  514.         ret = plot_freqs(inlink, fin);

  515.         av_frame_free(&fin);

  516.         av_audio_fifo_drain(s->fifo, s->skip_samples);

  517.         if (ret < 0)

  518.             goto fail;

  519.     }

  520. 

  521. fail:

  522.     av_frame_free(&fin);

  523.     av_frame_free(&in);

  524.     return ret;

  525. }

  526. 

  527. static av_cold void uninit(AVFilterContext *ctx)

  528. {

  529.     ShowFreqsContext *s = ctx->priv;

  530.     int i;

  531. 

  532.     av_fft_end(s->fft);

  533.     for (i = 0; i < s->nb_channels; i++) {

  534.         av_freep(&s->fft_data[i]);

  535.         av_freep(&s->avg_data[i]);

  536.     }

  537.     av_freep(&s->fft_data);

  538.     av_freep(&s->avg_data);

  539.     av_freep(&s->window_func_lut);

  540.     av_audio_fifo_free(s->fifo);

  541. }

  542. 

  543. static const AVFilterPad showfreqs_inputs[] = {

  544.     {

  545.         .name         = "default",

  546.         .type         = AVMEDIA_TYPE_AUDIO,

  547.         .filter_frame = filter_frame,

  548.     },

  549.     { NULL }

  550. };

  551. 

  552. static const AVFilterPad showfreqs_outputs[] = {

  553.     {

  554.         .name          = "default",

  555.         .type          = AVMEDIA_TYPE_VIDEO,

  556.         .config_props  = config_output,

  557.     },

  558.     { NULL }

  559. };

  560. 

  561. AVFilter ff_avf_showfreqs = {

  562.     .name          = "showfreqs",

  563.     .description   = NULL_IF_CONFIG_SMALL("Convert input audio to a frequencies video output."),

  564.     .uninit        = uninit,

  565.     .query_formats = query_formats,

  566.     .priv_size     = sizeof(ShowFreqsContext),

  567.     .inputs        = showfreqs_inputs,

  568.     .outputs       = showfreqs_outputs,

  569.     .priv_class    = &showfreqs_class,

  570. };