1/*
2 * Copyright (c) 2014 Muhammad Faiz <mfcc64@gmail.com>
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 "config.h"
22#include "libavcodec/avfft.h"
23#include "libavutil/avassert.h"
24#include "libavutil/channel_layout.h"
25#include "libavutil/opt.h"
26#include "libavutil/xga_font_data.h"
27#include "libavutil/qsort.h"
28#include "libavutil/time.h"
29#include "avfilter.h"
30#include "internal.h"
31
32#include <math.h>
33#include <stdlib.h>
34
35#if CONFIG_LIBFREETYPE
36#include <ft2build.h>
37#include FT_FREETYPE_H
38#endif
39
40/* this filter is designed to do 16 bins/semitones constant Q transform with Brown-Puckette algorithm
41 * start from E0 to D#10 (10 octaves)
42 * so there are 16 bins/semitones * 12 semitones/octaves * 10 octaves = 1920 bins
43 * match with full HD resolution */
44
45#define VIDEO_WIDTH 1920
46#define VIDEO_HEIGHT 1080
47#define FONT_HEIGHT 32
48#define SPECTOGRAM_HEIGHT ((VIDEO_HEIGHT-FONT_HEIGHT)/2)
49#define SPECTOGRAM_START (VIDEO_HEIGHT-SPECTOGRAM_HEIGHT)
50#define BASE_FREQ 20.051392800492
51#define COEFF_CLAMP 1.0e-4
52
53typedef struct {
54    FFTSample value;
55    int index;
56} SparseCoeff;
57
58typedef struct {
59    const AVClass *class;
60    AVFrame *outpicref;
61    FFTContext *fft_context;
62    FFTComplex *fft_data;
63    FFTComplex *fft_result_left;
64    FFTComplex *fft_result_right;
65    uint8_t *spectogram;
66    SparseCoeff *coeff_sort;
67    SparseCoeff *coeffs[VIDEO_WIDTH];
68    uint8_t *font_alpha;
69    char *fontfile;     /* using freetype */
70    int coeffs_len[VIDEO_WIDTH];
71    uint8_t font_color[VIDEO_WIDTH];
72    int64_t frame_count;
73    int spectogram_count;
74    int spectogram_index;
75    int fft_bits;
76    int req_fullfilled;
77    int remaining_fill;
78    double volume;
79    double timeclamp;   /* lower timeclamp, time-accurate, higher timeclamp, freq-accurate (at low freq)*/
80    float coeffclamp;   /* lower coeffclamp, more precise, higher coeffclamp, faster */
81    int fullhd;         /* if true, output video is at full HD resolution, otherwise it will be halved */
82    float gamma;        /* lower gamma, more contrast, higher gamma, more range */
83    int fps;            /* the required fps is so strict, so it's enough to be int, but 24000/1001 etc cannot be encoded */
84    int count;          /* fps * count = transform rate */
85} ShowCQTContext;
86
87#define OFFSET(x) offsetof(ShowCQTContext, x)
88#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
89
90static const AVOption showcqt_options[] = {
91    { "volume", "set volume", OFFSET(volume), AV_OPT_TYPE_DOUBLE, { .dbl = 16 }, 0.1, 100, FLAGS },
92    { "timeclamp", "set timeclamp", OFFSET(timeclamp), AV_OPT_TYPE_DOUBLE, { .dbl = 0.17 }, 0.1, 1.0, FLAGS },
93    { "coeffclamp", "set coeffclamp", OFFSET(coeffclamp), AV_OPT_TYPE_FLOAT, { .dbl = 1 }, 0.1, 10, FLAGS },
94    { "gamma", "set gamma", OFFSET(gamma), AV_OPT_TYPE_FLOAT, { .dbl = 3 }, 1, 7, FLAGS },
95    { "fullhd", "set full HD resolution", OFFSET(fullhd), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, FLAGS },
96    { "fps", "set video fps", OFFSET(fps), AV_OPT_TYPE_INT, { .i64 = 25 }, 10, 100, FLAGS },
97    { "count", "set number of transform per frame", OFFSET(count), AV_OPT_TYPE_INT, { .i64 = 6 }, 1, 30, FLAGS },
98    { "fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, { .str = NULL }, CHAR_MIN, CHAR_MAX, FLAGS },
99    { NULL }
100};
101
102AVFILTER_DEFINE_CLASS(showcqt);
103
104static av_cold void uninit(AVFilterContext *ctx)
105{
106    int k;
107
108    ShowCQTContext *s = ctx->priv;
109    av_fft_end(s->fft_context);
110    s->fft_context = NULL;
111    for (k = 0; k < VIDEO_WIDTH; k++)
112        av_freep(&s->coeffs[k]);
113    av_freep(&s->fft_data);
114    av_freep(&s->fft_result_left);
115    av_freep(&s->fft_result_right);
116    av_freep(&s->coeff_sort);
117    av_freep(&s->spectogram);
118    av_freep(&s->font_alpha);
119    av_frame_free(&s->outpicref);
120}
121
122static int query_formats(AVFilterContext *ctx)
123{
124    AVFilterFormats *formats = NULL;
125    AVFilterChannelLayouts *layouts = NULL;
126    AVFilterLink *inlink = ctx->inputs[0];
127    AVFilterLink *outlink = ctx->outputs[0];
128    static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_NONE };
129    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGB24, AV_PIX_FMT_NONE };
130    static const int64_t channel_layouts[] = { AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_STEREO_DOWNMIX, -1 };
131    static const int samplerates[] = { 44100, 48000, -1 };
132
133    /* set input audio formats */
134    formats = ff_make_format_list(sample_fmts);
135    if (!formats)
136        return AVERROR(ENOMEM);
137    ff_formats_ref(formats, &inlink->out_formats);
138
139    layouts = avfilter_make_format64_list(channel_layouts);
140    if (!layouts)
141        return AVERROR(ENOMEM);
142    ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
143
144    formats = ff_make_format_list(samplerates);
145    if (!formats)
146        return AVERROR(ENOMEM);
147    ff_formats_ref(formats, &inlink->out_samplerates);
148
149    /* set output video format */
150    formats = ff_make_format_list(pix_fmts);
151    if (!formats)
152        return AVERROR(ENOMEM);
153    ff_formats_ref(formats, &outlink->in_formats);
154
155    return 0;
156}
157
158#if CONFIG_LIBFREETYPE
159static void load_freetype_font(AVFilterContext *ctx)
160{
161    static const char str[] = "EF G A BC D ";
162    ShowCQTContext *s = ctx->priv;
163    FT_Library lib = NULL;
164    FT_Face face = NULL;
165    int video_scale = s->fullhd ? 2 : 1;
166    int video_width = (VIDEO_WIDTH/2) * video_scale;
167    int font_height = (FONT_HEIGHT/2) * video_scale;
168    int font_width = 8 * video_scale;
169    int font_repeat = font_width * 12;
170    int linear_hori_advance = font_width * 65536;
171    int non_monospace_warning = 0;
172    int x;
173
174    s->font_alpha = NULL;
175
176    if (!s->fontfile)
177        return;
178
179    if (FT_Init_FreeType(&lib))
180        goto fail;
181
182    if (FT_New_Face(lib, s->fontfile, 0, &face))
183        goto fail;
184
185    if (FT_Set_Char_Size(face, 16*64, 0, 0, 0))
186        goto fail;
187
188    if (FT_Load_Char(face, 'A', FT_LOAD_RENDER))
189        goto fail;
190
191    if (FT_Set_Char_Size(face, 16*64 * linear_hori_advance / face->glyph->linearHoriAdvance, 0, 0, 0))
192        goto fail;
193
194    s->font_alpha = av_malloc(font_height * video_width);
195    if (!s->font_alpha)
196        goto fail;
197
198    memset(s->font_alpha, 0, font_height * video_width);
199
200    for (x = 0; x < 12; x++) {
201        int sx, sy, rx, bx, by, dx, dy;
202
203        if (str[x] == ' ')
204            continue;
205
206        if (FT_Load_Char(face, str[x], FT_LOAD_RENDER))
207            goto fail;
208
209        if (face->glyph->advance.x != font_width*64 && !non_monospace_warning) {
210            av_log(ctx, AV_LOG_WARNING, "Font is not monospace\n");
211            non_monospace_warning = 1;
212        }
213
214        sy = font_height - 4*video_scale - face->glyph->bitmap_top;
215        for (rx = 0; rx < 10; rx++) {
216            sx = rx * font_repeat + x * font_width + face->glyph->bitmap_left;
217            for (by = 0; by < face->glyph->bitmap.rows; by++) {
218                dy = by + sy;
219                if (dy < 0)
220                    continue;
221                if (dy >= font_height)
222                    break;
223
224                for (bx = 0; bx < face->glyph->bitmap.width; bx++) {
225                    dx = bx + sx;
226                    if (dx < 0)
227                        continue;
228                    if (dx >= video_width)
229                        break;
230                    s->font_alpha[dy*video_width+dx] = face->glyph->bitmap.buffer[by*face->glyph->bitmap.width+bx];
231                }
232            }
233        }
234    }
235
236    FT_Done_Face(face);
237    FT_Done_FreeType(lib);
238    return;
239
240    fail:
241    av_log(ctx, AV_LOG_WARNING, "Error while loading freetype font, using default font instead\n");
242    FT_Done_Face(face);
243    FT_Done_FreeType(lib);
244    av_freep(&s->font_alpha);
245    return;
246}
247#endif
248
249static inline int qsort_sparsecoeff(const SparseCoeff *a, const SparseCoeff *b)
250{
251    if (fabsf(a->value) >= fabsf(b->value))
252        return 1;
253    else
254        return -1;
255}
256
257static int config_output(AVFilterLink *outlink)
258{
259    AVFilterContext *ctx = outlink->src;
260    AVFilterLink *inlink = ctx->inputs[0];
261    ShowCQTContext *s = ctx->priv;
262    int fft_len, k, x, y;
263    int num_coeffs = 0;
264    int rate = inlink->sample_rate;
265    double max_len = rate * (double) s->timeclamp;
266    int64_t start_time, end_time;
267    int video_scale = s->fullhd ? 2 : 1;
268    int video_width = (VIDEO_WIDTH/2) * video_scale;
269    int video_height = (VIDEO_HEIGHT/2) * video_scale;
270    int spectogram_height = (SPECTOGRAM_HEIGHT/2) * video_scale;
271
272    s->fft_bits = ceil(log2(max_len));
273    fft_len = 1 << s->fft_bits;
274
275    if (rate % (s->fps * s->count)) {
276        av_log(ctx, AV_LOG_ERROR, "Rate (%u) is not divisible by fps*count (%u*%u)\n", rate, s->fps, s->count);
277        return AVERROR(EINVAL);
278    }
279
280    s->fft_data         = av_malloc_array(fft_len, sizeof(*s->fft_data));
281    s->coeff_sort       = av_malloc_array(fft_len, sizeof(*s->coeff_sort));
282    s->fft_result_left  = av_malloc_array(fft_len, sizeof(*s->fft_result_left));
283    s->fft_result_right = av_malloc_array(fft_len, sizeof(*s->fft_result_right));
284    s->fft_context      = av_fft_init(s->fft_bits, 0);
285
286    if (!s->fft_data || !s->coeff_sort || !s->fft_result_left || !s->fft_result_right || !s->fft_context)
287        return AVERROR(ENOMEM);
288
289    /* initializing font */
290    for (x = 0; x < video_width; x++) {
291        if (x >= (12*3+8)*8*video_scale && x < (12*4+8)*8*video_scale) {
292            float fx = (x-(12*3+8)*8*video_scale) * (2.0f/(192.0f*video_scale));
293            float sv = sinf(M_PI*fx);
294            s->font_color[x] = sv*sv*255.0f + 0.5f;
295        } else {
296            s->font_color[x] = 0;
297        }
298    }
299
300#if CONFIG_LIBFREETYPE
301    load_freetype_font(ctx);
302#else
303    if (s->fontfile)
304        av_log(ctx, AV_LOG_WARNING, "Freetype is not available, ignoring fontfile option\n");
305    s->font_alpha = NULL;
306#endif
307
308    av_log(ctx, AV_LOG_INFO, "Calculating spectral kernel, please wait\n");
309    start_time = av_gettime_relative();
310    for (k = 0; k < VIDEO_WIDTH; k++) {
311        int hlen = fft_len >> 1;
312        float total = 0;
313        float partial = 0;
314        double freq = BASE_FREQ * exp2(k * (1.0/192.0));
315        double tlen = rate * (24.0 * 16.0) /freq;
316        /* a window function from Albert H. Nuttall,
317         * "Some Windows with Very Good Sidelobe Behavior"
318         * -93.32 dB peak sidelobe and 18 dB/octave asymptotic decay
319         * coefficient normalized to a0 = 1 */
320        double a0 = 0.355768;
321        double a1 = 0.487396/a0;
322        double a2 = 0.144232/a0;
323        double a3 = 0.012604/a0;
324        double sv_step, cv_step, sv, cv;
325        double sw_step, cw_step, sw, cw, w;
326
327        tlen = tlen * max_len / (tlen + max_len);
328        s->fft_data[0].re = 0;
329        s->fft_data[0].im = 0;
330        s->fft_data[hlen].re = (1.0 + a1 + a2 + a3) * (1.0/tlen) * s->volume * (1.0/fft_len);
331        s->fft_data[hlen].im = 0;
332        sv_step = sv = sin(2.0*M_PI*freq*(1.0/rate));
333        cv_step = cv = cos(2.0*M_PI*freq*(1.0/rate));
334        /* also optimizing window func */
335        sw_step = sw = sin(2.0*M_PI*(1.0/tlen));
336        cw_step = cw = cos(2.0*M_PI*(1.0/tlen));
337        for (x = 1; x < 0.5 * tlen; x++) {
338            double cv_tmp, cw_tmp;
339            double cw2, cw3, sw2;
340
341            cw2 = cw * cw - sw * sw;
342            sw2 = cw * sw + sw * cw;
343            cw3 = cw * cw2 - sw * sw2;
344            w = (1.0 + a1 * cw + a2 * cw2 + a3 * cw3) * (1.0/tlen) * s->volume * (1.0/fft_len);
345            s->fft_data[hlen + x].re = w * cv;
346            s->fft_data[hlen + x].im = w * sv;
347            s->fft_data[hlen - x].re = s->fft_data[hlen + x].re;
348            s->fft_data[hlen - x].im = -s->fft_data[hlen + x].im;
349
350            cv_tmp = cv * cv_step - sv * sv_step;
351            sv = sv * cv_step + cv * sv_step;
352            cv = cv_tmp;
353            cw_tmp = cw * cw_step - sw * sw_step;
354            sw = sw * cw_step + cw * sw_step;
355            cw = cw_tmp;
356        }
357        for (; x < hlen; x++) {
358            s->fft_data[hlen + x].re = 0;
359            s->fft_data[hlen + x].im = 0;
360            s->fft_data[hlen - x].re = 0;
361            s->fft_data[hlen - x].im = 0;
362        }
363        av_fft_permute(s->fft_context, s->fft_data);
364        av_fft_calc(s->fft_context, s->fft_data);
365
366        for (x = 0; x < fft_len; x++) {
367            s->coeff_sort[x].index = x;
368            s->coeff_sort[x].value = s->fft_data[x].re;
369        }
370
371        AV_QSORT(s->coeff_sort, fft_len, SparseCoeff, qsort_sparsecoeff);
372        for (x = 0; x < fft_len; x++)
373            total += fabsf(s->coeff_sort[x].value);
374
375        for (x = 0; x < fft_len; x++) {
376            partial += fabsf(s->coeff_sort[x].value);
377            if (partial > total * s->coeffclamp * COEFF_CLAMP) {
378                s->coeffs_len[k] = fft_len - x;
379                num_coeffs += s->coeffs_len[k];
380                s->coeffs[k] = av_malloc_array(s->coeffs_len[k], sizeof(*s->coeffs[k]));
381                if (!s->coeffs[k])
382                    return AVERROR(ENOMEM);
383                for (y = 0; y < s->coeffs_len[k]; y++)
384                    s->coeffs[k][y] = s->coeff_sort[x+y];
385                break;
386            }
387        }
388    }
389    end_time = av_gettime_relative();
390    av_log(ctx, AV_LOG_INFO, "Elapsed time %.6f s (fft_len=%u, num_coeffs=%u)\n", 1e-6 * (end_time-start_time), fft_len, num_coeffs);
391
392    outlink->w = video_width;
393    outlink->h = video_height;
394
395    s->req_fullfilled = 0;
396    s->spectogram_index = 0;
397    s->frame_count = 0;
398    s->spectogram_count = 0;
399    s->remaining_fill = fft_len >> 1;
400    memset(s->fft_data, 0, fft_len * sizeof(*s->fft_data));
401
402    s->outpicref = ff_get_video_buffer(outlink, outlink->w, outlink->h);
403    if (!s->outpicref)
404        return AVERROR(ENOMEM);
405
406    s->spectogram = av_calloc(spectogram_height, s->outpicref->linesize[0]);
407    if (!s->spectogram)
408        return AVERROR(ENOMEM);
409
410    outlink->sample_aspect_ratio = av_make_q(1, 1);
411    outlink->time_base = av_make_q(1, s->fps);
412    outlink->frame_rate = av_make_q(s->fps, 1);
413    return 0;
414}
415
416static int plot_cqt(AVFilterLink *inlink)
417{
418    AVFilterContext *ctx = inlink->dst;
419    ShowCQTContext *s = ctx->priv;
420    AVFilterLink *outlink = ctx->outputs[0];
421    int fft_len = 1 << s->fft_bits;
422    FFTSample result[VIDEO_WIDTH][4];
423    int x, y, ret = 0;
424    int linesize = s->outpicref->linesize[0];
425    int video_scale = s->fullhd ? 2 : 1;
426    int video_width = (VIDEO_WIDTH/2) * video_scale;
427    int spectogram_height = (SPECTOGRAM_HEIGHT/2) * video_scale;
428    int spectogram_start = (SPECTOGRAM_START/2) * video_scale;
429    int font_height = (FONT_HEIGHT/2) * video_scale;
430
431    /* real part contains left samples, imaginary part contains right samples */
432    memcpy(s->fft_result_left, s->fft_data, fft_len * sizeof(*s->fft_data));
433    av_fft_permute(s->fft_context, s->fft_result_left);
434    av_fft_calc(s->fft_context, s->fft_result_left);
435
436    /* separate left and right, (and multiply by 2.0) */
437    s->fft_result_right[0].re = 2.0f * s->fft_result_left[0].im;
438    s->fft_result_right[0].im = 0;
439    s->fft_result_left[0].re = 2.0f * s->fft_result_left[0].re;
440    s->fft_result_left[0].im = 0;
441    for (x = 1; x <= fft_len >> 1; x++) {
442        FFTSample tmpy = s->fft_result_left[fft_len-x].im - s->fft_result_left[x].im;
443
444        s->fft_result_right[x].re = s->fft_result_left[x].im + s->fft_result_left[fft_len-x].im;
445        s->fft_result_right[x].im = s->fft_result_left[x].re - s->fft_result_left[fft_len-x].re;
446        s->fft_result_right[fft_len-x].re = s->fft_result_right[x].re;
447        s->fft_result_right[fft_len-x].im = -s->fft_result_right[x].im;
448
449        s->fft_result_left[x].re = s->fft_result_left[x].re + s->fft_result_left[fft_len-x].re;
450        s->fft_result_left[x].im = tmpy;
451        s->fft_result_left[fft_len-x].re = s->fft_result_left[x].re;
452        s->fft_result_left[fft_len-x].im = -s->fft_result_left[x].im;
453    }
454
455    /* calculating cqt */
456    for (x = 0; x < VIDEO_WIDTH; x++) {
457        int u;
458        float g = 1.0f / s->gamma;
459        FFTComplex l = {0,0};
460        FFTComplex r = {0,0};
461
462        for (u = 0; u < s->coeffs_len[x]; u++) {
463            FFTSample value = s->coeffs[x][u].value;
464            int index = s->coeffs[x][u].index;
465            l.re += value * s->fft_result_left[index].re;
466            l.im += value * s->fft_result_left[index].im;
467            r.re += value * s->fft_result_right[index].re;
468            r.im += value * s->fft_result_right[index].im;
469        }
470        /* result is power, not amplitude */
471        result[x][0] = l.re * l.re + l.im * l.im;
472        result[x][2] = r.re * r.re + r.im * r.im;
473        result[x][1] = 0.5f * (result[x][0] + result[x][2]);
474        result[x][3] = result[x][1];
475        result[x][0] = 255.0f * powf(FFMIN(1.0f,result[x][0]), g);
476        result[x][1] = 255.0f * powf(FFMIN(1.0f,result[x][1]), g);
477        result[x][2] = 255.0f * powf(FFMIN(1.0f,result[x][2]), g);
478    }
479
480    if (!s->fullhd) {
481        for (x = 0; x < video_width; x++) {
482            result[x][0] = 0.5f * (result[2*x][0] + result[2*x+1][0]);
483            result[x][1] = 0.5f * (result[2*x][1] + result[2*x+1][1]);
484            result[x][2] = 0.5f * (result[2*x][2] + result[2*x+1][2]);
485            result[x][3] = 0.5f * (result[2*x][3] + result[2*x+1][3]);
486        }
487    }
488
489    for (x = 0; x < video_width; x++) {
490        s->spectogram[s->spectogram_index*linesize + 3*x] = result[x][0] + 0.5f;
491        s->spectogram[s->spectogram_index*linesize + 3*x + 1] = result[x][1] + 0.5f;
492        s->spectogram[s->spectogram_index*linesize + 3*x + 2] = result[x][2] + 0.5f;
493    }
494
495    /* drawing */
496    if (!s->spectogram_count) {
497        uint8_t *data = (uint8_t*) s->outpicref->data[0];
498        float rcp_result[VIDEO_WIDTH];
499        int total_length = linesize * spectogram_height;
500        int back_length = linesize * s->spectogram_index;
501
502        for (x = 0; x < video_width; x++)
503            rcp_result[x] = 1.0f / (result[x][3]+0.0001f);
504
505        /* drawing bar */
506        for (y = 0; y < spectogram_height; y++) {
507            float height = (spectogram_height - y) * (1.0f/spectogram_height);
508            uint8_t *lineptr = data + y * linesize;
509            for (x = 0; x < video_width; x++) {
510                float mul;
511                if (result[x][3] <= height) {
512                    *lineptr++ = 0;
513                    *lineptr++ = 0;
514                    *lineptr++ = 0;
515                } else {
516                    mul = (result[x][3] - height) * rcp_result[x];
517                    *lineptr++ = mul * result[x][0] + 0.5f;
518                    *lineptr++ = mul * result[x][1] + 0.5f;
519                    *lineptr++ = mul * result[x][2] + 0.5f;
520                }
521            }
522        }
523
524        /* drawing font */
525        if (s->font_alpha) {
526            for (y = 0; y < font_height; y++) {
527                uint8_t *lineptr = data + (spectogram_height + y) * linesize;
528                uint8_t *spectogram_src = s->spectogram + s->spectogram_index * linesize;
529                for (x = 0; x < video_width; x++) {
530                    uint8_t alpha = s->font_alpha[y*video_width+x];
531                    uint8_t color = s->font_color[x];
532                    lineptr[3*x] = (spectogram_src[3*x] * (255-alpha) + (255-color) * alpha + 255) >> 8;
533                    lineptr[3*x+1] = (spectogram_src[3*x+1] * (255-alpha) + 255) >> 8;
534                    lineptr[3*x+2] = (spectogram_src[3*x+2] * (255-alpha) + color * alpha + 255) >> 8;
535                }
536            }
537        } else {
538            for (y = 0; y < font_height; y++) {
539                uint8_t *lineptr = data + (spectogram_height + y) * linesize;
540                memcpy(lineptr, s->spectogram + s->spectogram_index * linesize, video_width*3);
541            }
542            for (x = 0; x < video_width; x += video_width/10) {
543                int u;
544                static const char str[] = "EF G A BC D ";
545                uint8_t *startptr = data + spectogram_height * linesize + x * 3;
546                for (u = 0; str[u]; u++) {
547                    int v;
548                    for (v = 0; v < 16; v++) {
549                        uint8_t *p = startptr + v * linesize * video_scale + 8 * 3 * u * video_scale;
550                        int ux = x + 8 * u * video_scale;
551                        int mask;
552                        for (mask = 0x80; mask; mask >>= 1) {
553                            if (mask & avpriv_vga16_font[str[u] * 16 + v]) {
554                                p[0] = 255 - s->font_color[ux];
555                                p[1] = 0;
556                                p[2] = s->font_color[ux];
557                                if (video_scale == 2) {
558                                    p[linesize] = p[0];
559                                    p[linesize+1] = p[1];
560                                    p[linesize+2] = p[2];
561                                    p[3] = p[linesize+3] = 255 - s->font_color[ux+1];
562                                    p[4] = p[linesize+4] = 0;
563                                    p[5] = p[linesize+5] = s->font_color[ux+1];
564                                }
565                            }
566                            p  += 3 * video_scale;
567                            ux += video_scale;
568                        }
569                    }
570                }
571            }
572        }
573
574        /* drawing spectogram/sonogram */
575        data += spectogram_start * linesize;
576        memcpy(data, s->spectogram + s->spectogram_index*linesize, total_length - back_length);
577
578        data += total_length - back_length;
579        if (back_length)
580            memcpy(data, s->spectogram, back_length);
581
582        s->outpicref->pts = s->frame_count;
583        ret = ff_filter_frame(outlink, av_frame_clone(s->outpicref));
584        s->req_fullfilled = 1;
585        s->frame_count++;
586    }
587    s->spectogram_count = (s->spectogram_count + 1) % s->count;
588    s->spectogram_index = (s->spectogram_index + spectogram_height - 1) % spectogram_height;
589    return ret;
590}
591
592static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
593{
594    AVFilterContext *ctx = inlink->dst;
595    ShowCQTContext *s = ctx->priv;
596    int step = inlink->sample_rate / (s->fps * s->count);
597    int fft_len = 1 << s->fft_bits;
598    int remaining;
599    float *audio_data;
600
601    if (!insamples) {
602        while (s->remaining_fill < (fft_len >> 1)) {
603            int ret, x;
604            memset(&s->fft_data[fft_len - s->remaining_fill], 0, sizeof(*s->fft_data) * s->remaining_fill);
605            ret = plot_cqt(inlink);
606            if (ret < 0)
607                return ret;
608            for (x = 0; x < (fft_len-step); x++)
609                s->fft_data[x] = s->fft_data[x+step];
610            s->remaining_fill += step;
611        }
612        return AVERROR(EOF);
613    }
614
615    remaining = insamples->nb_samples;
616    audio_data = (float*) insamples->data[0];
617
618    while (remaining) {
619        if (remaining >= s->remaining_fill) {
620            int i = insamples->nb_samples - remaining;
621            int j = fft_len - s->remaining_fill;
622            int m, ret;
623            for (m = 0; m < s->remaining_fill; m++) {
624                s->fft_data[j+m].re = audio_data[2*(i+m)];
625                s->fft_data[j+m].im = audio_data[2*(i+m)+1];
626            }
627            ret = plot_cqt(inlink);
628            if (ret < 0) {
629                av_frame_free(&insamples);
630                return ret;
631            }
632            remaining -= s->remaining_fill;
633            for (m = 0; m < fft_len-step; m++)
634                s->fft_data[m] = s->fft_data[m+step];
635            s->remaining_fill = step;
636        } else {
637            int i = insamples->nb_samples - remaining;
638            int j = fft_len - s->remaining_fill;
639            int m;
640            for (m = 0; m < remaining; m++) {
641                s->fft_data[m+j].re = audio_data[2*(i+m)];
642                s->fft_data[m+j].im = audio_data[2*(i+m)+1];
643            }
644            s->remaining_fill -= remaining;
645            remaining = 0;
646        }
647    }
648    av_frame_free(&insamples);
649    return 0;
650}
651
652static int request_frame(AVFilterLink *outlink)
653{
654    ShowCQTContext *s = outlink->src->priv;
655    AVFilterLink *inlink = outlink->src->inputs[0];
656    int ret;
657
658    s->req_fullfilled = 0;
659    do {
660        ret = ff_request_frame(inlink);
661    } while (!s->req_fullfilled && ret >= 0);
662
663    if (ret == AVERROR_EOF && s->outpicref)
664        filter_frame(inlink, NULL);
665    return ret;
666}
667
668static const AVFilterPad showcqt_inputs[] = {
669    {
670        .name         = "default",
671        .type         = AVMEDIA_TYPE_AUDIO,
672        .filter_frame = filter_frame,
673    },
674    { NULL }
675};
676
677static const AVFilterPad showcqt_outputs[] = {
678    {
679        .name          = "default",
680        .type          = AVMEDIA_TYPE_VIDEO,
681        .config_props  = config_output,
682        .request_frame = request_frame,
683    },
684    { NULL }
685};
686
687AVFilter ff_avf_showcqt = {
688    .name          = "showcqt",
689    .description   = NULL_IF_CONFIG_SMALL("Convert input audio to a CQT (Constant Q Transform) spectrum video output."),
690    .uninit        = uninit,
691    .query_formats = query_formats,
692    .priv_size     = sizeof(ShowCQTContext),
693    .inputs        = showcqt_inputs,
694    .outputs       = showcqt_outputs,
695    .priv_class    = &showcqt_class,
696};
697