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avf_showwaves.c
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1 /*
2  * Copyright (c) 2012 Stefano Sabatini
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 /**
22  * @file
23  * audio to video multimedia filter
24  */
25 
26 #include "libavutil/channel_layout.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/parseutils.h"
29 #include "avfilter.h"
30 #include "formats.h"
31 #include "audio.h"
32 #include "video.h"
33 #include "internal.h"
34 
35 enum ShowWavesMode {
36  MODE_POINT,
37  MODE_LINE,
38  MODE_P2P,
39  MODE_CENTERED_LINE,
40  MODE_NB,
41 };
42 
43 typedef struct {
44  const AVClass *class;
45  int w, h;
46  AVRational rate;
47  int buf_idx;
48  int16_t *buf_idy; /* y coordinate of previous sample for each channel */
49  AVFrame *outpicref;
50  int req_fullfilled;
51  int n;
52  int sample_count_mod;
53  enum ShowWavesMode mode;
54  int split_channels;
55  void (*draw_sample)(uint8_t *buf, int height, int linesize,
56  int16_t sample, int16_t *prev_y, int intensity);
57 } ShowWavesContext;
58 
59 #define OFFSET(x) offsetof(ShowWavesContext, x)
60 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
61 
62 static const AVOption showwaves_options[] = {
63  { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "600x240"}, 0, 0, FLAGS },
64  { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "600x240"}, 0, 0, FLAGS },
65  { "mode", "select display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_POINT}, 0, MODE_NB-1, FLAGS, "mode"},
66  { "point", "draw a point for each sample", 0, AV_OPT_TYPE_CONST, {.i64=MODE_POINT}, .flags=FLAGS, .unit="mode"},
67  { "line", "draw a line for each sample", 0, AV_OPT_TYPE_CONST, {.i64=MODE_LINE}, .flags=FLAGS, .unit="mode"},
68  { "p2p", "draw a line between samples", 0, AV_OPT_TYPE_CONST, {.i64=MODE_P2P}, .flags=FLAGS, .unit="mode"},
69  { "cline", "draw a centered line for each sample", 0, AV_OPT_TYPE_CONST, {.i64=MODE_CENTERED_LINE}, .flags=FLAGS, .unit="mode"},
70  { "n", "set how many samples to show in the same point", OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
71  { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
72  { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
73  { "split_channels", "draw channels separately", OFFSET(split_channels), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
74  { NULL }
75 };
76 
77 AVFILTER_DEFINE_CLASS(showwaves);
78 
79 static av_cold void uninit(AVFilterContext *ctx)
80 {
81  ShowWavesContext *showwaves = ctx->priv;
82 
83  av_frame_free(&showwaves->outpicref);
84  av_freep(&showwaves->buf_idy);
85 }
86 
87 static int query_formats(AVFilterContext *ctx)
88 {
89  AVFilterFormats *formats = NULL;
90  AVFilterChannelLayouts *layouts = NULL;
91  AVFilterLink *inlink = ctx->inputs[0];
92  AVFilterLink *outlink = ctx->outputs[0];
93  static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE };
94  static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
95 
96  /* set input audio formats */
97  formats = ff_make_format_list(sample_fmts);
98  if (!formats)
99  return AVERROR(ENOMEM);
100  ff_formats_ref(formats, &inlink->out_formats);
101 
102  layouts = ff_all_channel_layouts();
103  if (!layouts)
104  return AVERROR(ENOMEM);
105  ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
106 
107  formats = ff_all_samplerates();
108  if (!formats)
109  return AVERROR(ENOMEM);
110  ff_formats_ref(formats, &inlink->out_samplerates);
111 
112  /* set output video format */
113  formats = ff_make_format_list(pix_fmts);
114  if (!formats)
115  return AVERROR(ENOMEM);
116  ff_formats_ref(formats, &outlink->in_formats);
117 
118  return 0;
119 }
120 
121 static int config_output(AVFilterLink *outlink)
122 {
123  AVFilterContext *ctx = outlink->src;
124  AVFilterLink *inlink = ctx->inputs[0];
125  ShowWavesContext *showwaves = ctx->priv;
126  int nb_channels = inlink->channels;
127 
128  if (!showwaves->n)
129  showwaves->n = FFMAX(1, ((double)inlink->sample_rate / (showwaves->w * av_q2d(showwaves->rate))) + 0.5);
130 
131  showwaves->buf_idx = 0;
132  if (!(showwaves->buf_idy = av_mallocz_array(nb_channels, sizeof(*showwaves->buf_idy)))) {
133  av_log(ctx, AV_LOG_ERROR, "Could not allocate showwaves buffer\n");
134  return AVERROR(ENOMEM);
135  }
136  outlink->w = showwaves->w;
137  outlink->h = showwaves->h;
138  outlink->sample_aspect_ratio = (AVRational){1,1};
139 
140  outlink->frame_rate = av_div_q((AVRational){inlink->sample_rate,showwaves->n},
141  (AVRational){showwaves->w,1});
142 
143  av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d r:%f n:%d\n",
144  showwaves->w, showwaves->h, av_q2d(outlink->frame_rate), showwaves->n);
145  return 0;
146 }
147 
148 inline static int push_frame(AVFilterLink *outlink)
149 {
150  AVFilterContext *ctx = outlink->src;
151  AVFilterLink *inlink = ctx->inputs[0];
152  ShowWavesContext *showwaves = outlink->src->priv;
153  int nb_channels = inlink->channels;
154  int ret, i;
155 
156  if ((ret = ff_filter_frame(outlink, showwaves->outpicref)) >= 0)
157  showwaves->req_fullfilled = 1;
158  showwaves->outpicref = NULL;
159  showwaves->buf_idx = 0;
160  for (i = 0; i <= nb_channels; i++)
161  showwaves->buf_idy[i] = 0;
162  return ret;
163 }
164 
165 static int request_frame(AVFilterLink *outlink)
166 {
167  ShowWavesContext *showwaves = outlink->src->priv;
168  AVFilterLink *inlink = outlink->src->inputs[0];
169  int ret;
170 
171  showwaves->req_fullfilled = 0;
172  do {
173  ret = ff_request_frame(inlink);
174  } while (!showwaves->req_fullfilled && ret >= 0);
175 
176  if (ret == AVERROR_EOF && showwaves->outpicref)
177  push_frame(outlink);
178  return ret;
179 }
180 
181 #define MAX_INT16 ((1<<15) -1)
182 
183 static void draw_sample_point(uint8_t *buf, int height, int linesize,
184  int16_t sample, int16_t *prev_y, int intensity)
185 {
186  const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
187  if (h >= 0 && h < height)
188  buf[h * linesize] += intensity;
189 }
190 
191 static void draw_sample_line(uint8_t *buf, int height, int linesize,
192  int16_t sample, int16_t *prev_y, int intensity)
193 {
194  int k;
195  const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
196  int start = height/2;
197  int end = av_clip(h, 0, height-1);
198  if (start > end)
199  FFSWAP(int16_t, start, end);
200  for (k = start; k < end; k++)
201  buf[k * linesize] += intensity;
202 }
203 
204 static void draw_sample_p2p(uint8_t *buf, int height, int linesize,
205  int16_t sample, int16_t *prev_y, int intensity)
206 {
207  int k;
208  const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
209  if (h >= 0 && h < height) {
210  buf[h * linesize] += intensity;
211  if (*prev_y && h != *prev_y) {
212  int start = *prev_y;
213  int end = av_clip(h, 0, height-1);
214  if (start > end)
215  FFSWAP(int16_t, start, end);
216  for (k = start + 1; k < end; k++)
217  buf[k * linesize] += intensity;
218  }
219  }
220  *prev_y = h;
221 }
222 
223 static void draw_sample_cline(uint8_t *buf, int height, int linesize,
224  int16_t sample, int16_t *prev_y, int intensity)
225 {
226  int k;
227  const int h = av_rescale(abs(sample), height, UINT16_MAX);
228  const int start = (height - h) / 2;
229  const int end = start + h;
230  for (k = start; k < end; k++)
231  buf[k * linesize] += intensity;
232 }
233 
234 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
235 {
236  AVFilterContext *ctx = inlink->dst;
237  AVFilterLink *outlink = ctx->outputs[0];
238  ShowWavesContext *showwaves = ctx->priv;
239  const int nb_samples = insamples->nb_samples;
240  AVFrame *outpicref = showwaves->outpicref;
241  int linesize = outpicref ? outpicref->linesize[0] : 0;
242  int16_t *p = (int16_t *)insamples->data[0];
243  int nb_channels = inlink->channels;
244  int i, j, ret = 0;
245  const int n = showwaves->n;
246  const int x = 255 / ((showwaves->split_channels ? 1 : nb_channels) * n); /* multiplication factor, pre-computed to avoid in-loop divisions */
247  const int ch_height = showwaves->split_channels ? outlink->h / nb_channels : outlink->h;
248 
249  /* draw data in the buffer */
250  for (i = 0; i < nb_samples; i++) {
251  if (!showwaves->outpicref) {
252  showwaves->outpicref = outpicref =
253  ff_get_video_buffer(outlink, outlink->w, outlink->h);
254  if (!outpicref)
255  return AVERROR(ENOMEM);
256  outpicref->width = outlink->w;
257  outpicref->height = outlink->h;
258  outpicref->pts = insamples->pts +
259  av_rescale_q((p - (int16_t *)insamples->data[0]) / nb_channels,
260  (AVRational){ 1, inlink->sample_rate },
261  outlink->time_base);
262  linesize = outpicref->linesize[0];
263  for (j = 0; j < outlink->h; j++)
264  memset(outpicref->data[0] + j * linesize, 0, outlink->w);
265  }
266  for (j = 0; j < nb_channels; j++) {
267  uint8_t *buf = outpicref->data[0] + showwaves->buf_idx;
268  if (showwaves->split_channels)
269  buf += j*ch_height*linesize;
270  showwaves->draw_sample(buf, ch_height, linesize, *p++,
271  &showwaves->buf_idy[j], x);
272  }
273 
274  showwaves->sample_count_mod++;
275  if (showwaves->sample_count_mod == n) {
276  showwaves->sample_count_mod = 0;
277  showwaves->buf_idx++;
278  }
279  if (showwaves->buf_idx == showwaves->w)
280  if ((ret = push_frame(outlink)) < 0)
281  break;
282  outpicref = showwaves->outpicref;
283  }
284 
285  av_frame_free(&insamples);
286  return ret;
287 }
288 
289 static av_cold int init(AVFilterContext *ctx)
290 {
291  ShowWavesContext *showwaves = ctx->priv;
292 
293  switch (showwaves->mode) {
294  case MODE_POINT: showwaves->draw_sample = draw_sample_point; break;
295  case MODE_LINE: showwaves->draw_sample = draw_sample_line; break;
296  case MODE_P2P: showwaves->draw_sample = draw_sample_p2p; break;
297  case MODE_CENTERED_LINE: showwaves->draw_sample = draw_sample_cline; break;
298  default:
299  return AVERROR_BUG;
300  }
301  return 0;
302 }
303 
304 static const AVFilterPad showwaves_inputs[] = {
305  {
306  .name = "default",
307  .type = AVMEDIA_TYPE_AUDIO,
308  .filter_frame = filter_frame,
309  },
310  { NULL }
311 };
312 
313 static const AVFilterPad showwaves_outputs[] = {
314  {
315  .name = "default",
316  .type = AVMEDIA_TYPE_VIDEO,
317  .config_props = config_output,
318  .request_frame = request_frame,
319  },
320  { NULL }
321 };
322 
323 AVFilter ff_avf_showwaves = {
324  .name = "showwaves",
325  .description = NULL_IF_CONFIG_SMALL("Convert input audio to a video output."),
326  .init = init,
327  .uninit = uninit,
328  .query_formats = query_formats,
329  .priv_size = sizeof(ShowWavesContext),
330  .inputs = showwaves_inputs,
331  .outputs = showwaves_outputs,
332  .priv_class = &showwaves_class,
333 };
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