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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. 

  132.     /* set input audio formats */

  133.     formats = ff_make_format_list(sample_fmts);

  134.     if (!formats)

  135.         return AVERROR(ENOMEM);

  136.     ff_formats_ref(formats, &inlink->out_formats);

  137. 

  138.     layouts = ff_all_channel_layouts();

  139.     if (!layouts)

  140.         return AVERROR(ENOMEM);

  141.     ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);

  142. 

  143.     formats = ff_all_samplerates();

  144.     if (!formats)

  145.         return AVERROR(ENOMEM);

  146.     ff_formats_ref(formats, &inlink->out_samplerates);

  147. 

  148.     /* set output video format */

  149.     formats = ff_make_format_list(pix_fmts);

  150.     if (!formats)

  151.         return AVERROR(ENOMEM);

  152.     ff_formats_ref(formats, &outlink->in_formats);

  153. 

  154.     return 0;

  155. }

  156. 

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

  158. {

  159.     int n;

  160. 

  161.     switch (win_func) {

  162.     case WFUNC_RECT:

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

  164.             lut[n] = 1.;

  165.         *overlap = 0.;

  166.         break;

  167.     case WFUNC_BARTLETT:

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

  169.             lut[n] = 1.-FFABS((n-(N-1)/2.)/((N-1)/2.));

  170.         *overlap = 0.5;

  171.         break;

  172.     case WFUNC_HANNING:

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

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

  175.         *overlap = 0.5;

  176.         break;

  177.     case WFUNC_HAMMING:

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

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

  180.         *overlap = 0.5;

  181.         break;

  182.     case WFUNC_BLACKMAN:

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

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

  185.         *overlap = 0.661;

  186.         break;

  187.     case WFUNC_WELCH:

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

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

  190.         *overlap = 0.293;

  191.         break;

  192.     case WFUNC_FLATTOP:

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

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

  195.                         1.282075284005*cos( 6*M_PI*n/(N-1))+0.667777530266*cos( 8*M_PI*n/(N-1))-

  196.                         0.240160796576*cos(10*M_PI*n/(N-1))+0.056656381764*cos(12*M_PI*n/(N-1))-

  197.                         0.008134974479*cos(14*M_PI*n/(N-1))+0.000624544650*cos(16*M_PI*n/(N-1))-

  198.                         0.000019808998*cos(18*M_PI*n/(N-1))+0.000000132974*cos(20*M_PI*n/(N-1));

  199.         *overlap = 0.841;

  200.         break;

  201.     case WFUNC_BHARRIS:

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

  203.             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));

  204.         *overlap = 0.661;

  205.         break;

  206.     case WFUNC_BNUTTALL:

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

  208.             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));

  209.         *overlap = 0.661;

  210.         break;

  211.     case WFUNC_BHANN:

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

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

  214.         *overlap = 0.5;

  215.         break;

  216.     case WFUNC_SINE:

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

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

  219.         *overlap = 0.75;

  220.         break;

  221.     case WFUNC_NUTTALL:

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

  223.             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));

  224.         *overlap = 0.663;

  225.         break;

  226.     case WFUNC_LANCZOS:

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

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

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

  230.         *overlap = 0.75;

  231.         break;

  232.     case WFUNC_GAUSS:

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

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

  235.         *overlap = 0.75;

  236.         break;

  237.     default:

  238.         av_assert0(0);

  239.     }

  240. }

  241. 

  242. static int config_output(AVFilterLink *outlink)

  243. {

  244.     AVFilterContext *ctx = outlink->src;

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

  246.     ShowFreqsContext *s = ctx->priv;

  247.     float overlap;

  248.     int i;

  249. 

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

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

  252.     av_audio_fifo_free(s->fifo);

  253.     av_fft_end(s->fft);

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

  255.     if (!s->fft) {

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

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

  258.         return AVERROR(ENOMEM);

  259.     }

  260. 

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

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

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

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

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

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

  267.     }

  268.     av_freep(&s->fft_data);

  269.     av_freep(&s->avg_data);

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

  271. 

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

  273.     if (!s->fft_data)

  274.         return AVERROR(ENOMEM);

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

  276.     if (!s->fft_data)

  277.         return AVERROR(ENOMEM);

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

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

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

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

  282.             return AVERROR(ENOMEM);

  283.     }

  284. 

  285.     /* pre-calc windowing function */

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

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

  288.     if (!s->window_func_lut)

  289.         return AVERROR(ENOMEM);

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

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

  292.         s->overlap = overlap;

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

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

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

  296.         return AVERROR(EINVAL);

  297.     }

  298. 

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

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

  301.     }

  302. 

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

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

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

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

  307. 

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

  309.     if (!s->fifo)

  310.         return AVERROR(ENOMEM);

  311.     return 0;

  312. }

  313. 

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

  315. {

  316. 

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

  318. 

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

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

  321.     else

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

  323. }

  324. 

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

  326. {

  327.     switch (s->fscale) {

  328.     case FS_LINEAR:

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

  330.     case FS_LOG:

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

  332.     case FS_RLOG:

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

  334.     }

  335. 

  336.     return 0;

  337. }

  338. 

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

  340. {

  341.     switch (s->fscale) {

  342.     case FS_LINEAR:

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

  344.     case FS_LOG:

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

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

  347.     case FS_RLOG:

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

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

  350.     }

  351. 

  352.     return 1.;

  353. }

  354. 

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

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

  357.                              AVFrame *out, AVFilterLink *outlink)

  358. {

  359.     const int w = s->w;

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

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

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

  363.     int x, y, i;

  364. 

  365.     switch(s->ascale) {

  366.     case AS_SQRT:

  367.         a = 1.0 - sqrt(a);

  368.         break;

  369.     case AS_CBRT:

  370.         a = 1.0 - cbrt(a);

  371.         break;

  372.     case AS_LOG:

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

  374.         break;

  375.     case AS_LINEAR:

  376.         a = 1.0 - a;

  377.         break;

  378.     }

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

  380.     if (y < 0)

  381.         return;

  382. 

  383.     switch (s->avg) {

  384.     case 0:

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

  386.         break;

  387.     case 1:

  388.         break;

  389.     default:

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

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

  392.         break;

  393.     }

  394. 

  395.     switch(s->mode) {

  396.     case LINE:

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

  398.             *prev_y = y;

  399.         }

  400.         if (y <= *prev_y) {

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

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

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

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

  405.         } else {

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

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

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

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

  410.         }

  411.         *prev_y = y;

  412.         break;

  413.     case BAR:

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

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

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

  417.         break;

  418.     case DOT:

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

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

  421.         break;

  422.     }

  423. }

  424. 

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

  426. {

  427.     AVFilterContext *ctx = inlink->dst;

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

  429.     ShowFreqsContext *s = ctx->priv;

  430.     const int win_size = s->win_size;

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

  432.     AVFrame *out;

  433.     int ch, n;

  434. 

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

  436.     if (!out)

  437.         return AVERROR(ENOMEM);

  438. 

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

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

  441. 

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

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

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

  445. 

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

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

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

  449.         }

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

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

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

  453.         }

  454.     }

  455. 

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

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

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

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

  460.     }

  461. 

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

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

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

  465. 

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

  467.     if (!colors) {

  468.         av_frame_free(&out);

  469.         return AVERROR(ENOMEM);

  470.     }

  471. 

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

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

  474.         int prev_y = -1, f;

  475.         double a;

  476. 

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

  478.         if (color)

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

  480. 

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

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

  483. 

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

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

  486. 

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

  488.         }

  489.     }

  490. 

  491.     av_free(colors);

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

  493.     return ff_filter_frame(outlink, out);

  494. }

  495. 

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

  497. {

  498.     AVFilterContext *ctx = inlink->dst;

  499.     ShowFreqsContext *s = ctx->priv;

  500.     AVFrame *fin = NULL;

  501.     int ret = 0;

  502. 

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

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

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

  506.         if (!fin) {

  507.             ret = AVERROR(ENOMEM);

  508.             goto fail;

  509.         }

  510. 

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

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

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

  514.         if (ret < 0)

  515.             goto fail;

  516. 

  517.         ret = plot_freqs(inlink, fin);

  518.         av_frame_free(&fin);

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

  520.         if (ret < 0)

  521.             goto fail;

  522.     }

  523. 

  524. fail:

  525.     av_frame_free(&fin);

  526.     av_frame_free(&in);

  527.     return ret;

  528. }

  529. 

  530. static av_cold void uninit(AVFilterContext *ctx)

  531. {

  532.     ShowFreqsContext *s = ctx->priv;

  533.     int i;

  534. 

  535.     av_fft_end(s->fft);

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

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

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

  539.     }

  540.     av_freep(&s->fft_data);

  541.     av_freep(&s->avg_data);

  542.     av_freep(&s->window_func_lut);

  543.     av_audio_fifo_free(s->fifo);

  544. }

  545. 

  546. static const AVFilterPad showfreqs_inputs[] = {

  547.     {

  548.         .name         = "default",

  549.         .type         = AVMEDIA_TYPE_AUDIO,

  550.         .filter_frame = filter_frame,

  551.     },

  552.     { NULL }

  553. };

  554. 

  555. static const AVFilterPad showfreqs_outputs[] = {

  556.     {

  557.         .name          = "default",

  558.         .type          = AVMEDIA_TYPE_VIDEO,

  559.         .config_props  = config_output,

  560.     },

  561.     { NULL }

  562. };

  563. 

  564. AVFilter ff_avf_showfreqs = {

  565.     .name          = "showfreqs",

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

  567.     .uninit        = uninit,

  568.     .query_formats = query_formats,

  569.     .priv_size     = sizeof(ShowFreqsContext),

  570.     .inputs        = showfreqs_inputs,

  571.     .outputs       = showfreqs_outputs,

  572.     .priv_class    = &showfreqs_class,

  573. };