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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 
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 
39 };
40 
41 typedef struct {
42  const AVClass *class;
43  int w, h;
45  int buf_idx;
48  int n;
52 
53 #define OFFSET(x) offsetof(ShowWavesContext, x)
54 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
55 
56 static const AVOption showwaves_options[] = {
57  { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "600x240"}, 0, 0, FLAGS },
58  { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "600x240"}, 0, 0, FLAGS },
59  { "mode", "select display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_POINT}, 0, MODE_NB-1, FLAGS, "mode"},
60  { "point", "draw a point for each sample", 0, AV_OPT_TYPE_CONST, {.i64=MODE_POINT}, .flags=FLAGS, .unit="mode"},
61  { "line", "draw a line for each sample", 0, AV_OPT_TYPE_CONST, {.i64=MODE_LINE}, .flags=FLAGS, .unit="mode"},
62  { "n", "set how many samples to show in the same point", OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
63  { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
64  { "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
65  { NULL }
66 };
67 
68 AVFILTER_DEFINE_CLASS(showwaves);
69 
70 static av_cold void uninit(AVFilterContext *ctx)
71 {
72  ShowWavesContext *showwaves = ctx->priv;
73 
74  av_frame_free(&showwaves->outpicref);
75 }
76 
78 {
79  AVFilterFormats *formats = NULL;
81  AVFilterLink *inlink = ctx->inputs[0];
82  AVFilterLink *outlink = ctx->outputs[0];
84  static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
85 
86  /* set input audio formats */
87  formats = ff_make_format_list(sample_fmts);
88  if (!formats)
89  return AVERROR(ENOMEM);
90  ff_formats_ref(formats, &inlink->out_formats);
91 
92  layouts = ff_all_channel_layouts();
93  if (!layouts)
94  return AVERROR(ENOMEM);
96 
97  formats = ff_all_samplerates();
98  if (!formats)
99  return AVERROR(ENOMEM);
100  ff_formats_ref(formats, &inlink->out_samplerates);
101 
102  /* set output video format */
103  formats = ff_make_format_list(pix_fmts);
104  if (!formats)
105  return AVERROR(ENOMEM);
106  ff_formats_ref(formats, &outlink->in_formats);
107 
108  return 0;
109 }
110 
111 static int config_output(AVFilterLink *outlink)
112 {
113  AVFilterContext *ctx = outlink->src;
114  AVFilterLink *inlink = ctx->inputs[0];
115  ShowWavesContext *showwaves = ctx->priv;
116 
117  if (!showwaves->n)
118  showwaves->n = FFMAX(1, ((double)inlink->sample_rate / (showwaves->w * av_q2d(showwaves->rate))) + 0.5);
119 
120  showwaves->buf_idx = 0;
121  outlink->w = showwaves->w;
122  outlink->h = showwaves->h;
123  outlink->sample_aspect_ratio = (AVRational){1,1};
124 
125  outlink->frame_rate = av_div_q((AVRational){inlink->sample_rate,showwaves->n},
126  (AVRational){showwaves->w,1});
127 
128  av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d r:%f n:%d\n",
129  showwaves->w, showwaves->h, av_q2d(outlink->frame_rate), showwaves->n);
130  return 0;
131 }
132 
133 inline static int push_frame(AVFilterLink *outlink)
134 {
135  ShowWavesContext *showwaves = outlink->src->priv;
136  int ret;
137 
138  if ((ret = ff_filter_frame(outlink, showwaves->outpicref)) >= 0)
139  showwaves->req_fullfilled = 1;
140  showwaves->outpicref = NULL;
141  showwaves->buf_idx = 0;
142  return ret;
143 }
144 
145 static int request_frame(AVFilterLink *outlink)
146 {
147  ShowWavesContext *showwaves = outlink->src->priv;
148  AVFilterLink *inlink = outlink->src->inputs[0];
149  int ret;
150 
151  showwaves->req_fullfilled = 0;
152  do {
153  ret = ff_request_frame(inlink);
154  } while (!showwaves->req_fullfilled && ret >= 0);
155 
156  if (ret == AVERROR_EOF && showwaves->outpicref)
157  push_frame(outlink);
158  return ret;
159 }
160 
161 #define MAX_INT16 ((1<<15) -1)
162 
163 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
164 {
165  AVFilterContext *ctx = inlink->dst;
166  AVFilterLink *outlink = ctx->outputs[0];
167  ShowWavesContext *showwaves = ctx->priv;
168  const int nb_samples = insamples->nb_samples;
169  AVFrame *outpicref = showwaves->outpicref;
170  int linesize = outpicref ? outpicref->linesize[0] : 0;
171  int16_t *p = (int16_t *)insamples->data[0];
172  int nb_channels = inlink->channels;
173  int i, j, k, h, ret = 0;
174  const int n = showwaves->n;
175  const int x = 255 / (nb_channels * n); /* multiplication factor, pre-computed to avoid in-loop divisions */
176 
177  /* draw data in the buffer */
178  for (i = 0; i < nb_samples; i++) {
179  if (!showwaves->outpicref) {
180  showwaves->outpicref = outpicref =
181  ff_get_video_buffer(outlink, outlink->w, outlink->h);
182  if (!outpicref)
183  return AVERROR(ENOMEM);
184  outpicref->width = outlink->w;
185  outpicref->height = outlink->h;
186  outpicref->pts = insamples->pts +
187  av_rescale_q((p - (int16_t *)insamples->data[0]) / nb_channels,
188  (AVRational){ 1, inlink->sample_rate },
189  outlink->time_base);
190  linesize = outpicref->linesize[0];
191  for (j = 0; j < outlink->h; j++)
192  memset(outpicref->data[0] + j * linesize, 0, outlink->w);
193  }
194  for (j = 0; j < nb_channels; j++) {
195  h = showwaves->h/2 - av_rescale(*p++, showwaves->h/2, MAX_INT16);
196  switch (showwaves->mode) {
197  case MODE_POINT:
198  if (h >= 0 && h < outlink->h)
199  *(outpicref->data[0] + showwaves->buf_idx + h * linesize) += x;
200  break;
201 
202  case MODE_LINE:
203  {
204  int start = showwaves->h/2, end = av_clip(h, 0, outlink->h-1);
205  if (start > end) FFSWAP(int16_t, start, end);
206  for (k = start; k < end; k++)
207  *(outpicref->data[0] + showwaves->buf_idx + k * linesize) += x;
208  break;
209  }
210  }
211  }
212 
213  showwaves->sample_count_mod++;
214  if (showwaves->sample_count_mod == n) {
215  showwaves->sample_count_mod = 0;
216  showwaves->buf_idx++;
217  }
218  if (showwaves->buf_idx == showwaves->w)
219  if ((ret = push_frame(outlink)) < 0)
220  break;
221  outpicref = showwaves->outpicref;
222  }
223 
224  av_frame_free(&insamples);
225  return ret;
226 }
227 
228 static const AVFilterPad showwaves_inputs[] = {
229  {
230  .name = "default",
231  .type = AVMEDIA_TYPE_AUDIO,
232  .filter_frame = filter_frame,
233  },
234  { NULL }
235 };
236 
237 static const AVFilterPad showwaves_outputs[] = {
238  {
239  .name = "default",
240  .type = AVMEDIA_TYPE_VIDEO,
241  .config_props = config_output,
242  .request_frame = request_frame,
243  },
244  { NULL }
245 };
246 
248  .name = "showwaves",
249  .description = NULL_IF_CONFIG_SMALL("Convert input audio to a video output."),
250  .uninit = uninit,
251  .query_formats = query_formats,
252  .priv_size = sizeof(ShowWavesContext),
253  .inputs = showwaves_inputs,
254  .outputs = showwaves_outputs,
255  .priv_class = &showwaves_class,
256 };