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af_channelmap.c
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1 /*
2  * Copyright (c) 2012 Google, Inc.
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 channel mapping filter
24  */
25 
26 #include <ctype.h>
27 
28 #include "libavutil/avstring.h"
30 #include "libavutil/common.h"
31 #include "libavutil/mathematics.h"
32 #include "libavutil/opt.h"
33 #include "libavutil/samplefmt.h"
34 
35 #include "audio.h"
36 #include "avfilter.h"
37 #include "formats.h"
38 #include "internal.h"
39 
40 struct ChannelMap {
41  uint64_t in_channel;
42  uint64_t out_channel;
45 };
46 
55 };
56 
57 #define MAX_CH 64
58 typedef struct ChannelMapContext {
59  const AVClass *class;
61  char *mapping_str;
63  uint64_t output_layout;
65  int nch;
68 
69 #define OFFSET(x) offsetof(ChannelMapContext, x)
70 #define A AV_OPT_FLAG_AUDIO_PARAM
71 #define F AV_OPT_FLAG_FILTERING_PARAM
72 static const AVOption channelmap_options[] = {
73  { "map", "A comma-separated list of input channel numbers in output order.",
74  OFFSET(mapping_str), AV_OPT_TYPE_STRING, .flags = A|F },
75  { "channel_layout", "Output channel layout.",
76  OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, .flags = A|F },
77  { NULL }
78 };
79 
80 AVFILTER_DEFINE_CLASS(channelmap);
81 
82 static char* split(char *message, char delim) {
83  char *next = strchr(message, delim);
84  if (next)
85  *next++ = '\0';
86  return next;
87 }
88 
89 static int get_channel_idx(char **map, int *ch, char delim, int max_ch)
90 {
91  char *next = split(*map, delim);
92  int len;
93  int n = 0;
94  if (!next && delim == '-')
95  return AVERROR(EINVAL);
96  if (!*map)
97  return AVERROR(EINVAL);
98  len = strlen(*map);
99  sscanf(*map, "%d%n", ch, &n);
100  if (n != len)
101  return AVERROR(EINVAL);
102  if (*ch < 0 || *ch > max_ch)
103  return AVERROR(EINVAL);
104  *map = next;
105  return 0;
106 }
107 
108 static int get_channel(char **map, uint64_t *ch, char delim)
109 {
110  char *next = split(*map, delim);
111  if (!next && delim == '-')
112  return AVERROR(EINVAL);
113  *ch = av_get_channel_layout(*map);
114  if (av_get_channel_layout_nb_channels(*ch) != 1)
115  return AVERROR(EINVAL);
116  *map = next;
117  return 0;
118 }
119 
121 {
122  ChannelMapContext *s = ctx->priv;
123  char *mapping, separator = '|';
124  int map_entries = 0;
125  char buf[256];
126  enum MappingMode mode;
127  uint64_t out_ch_mask = 0;
128  int i;
129 
130  mapping = s->mapping_str;
131 
132  if (!mapping) {
133  mode = MAP_NONE;
134  } else {
135  char *dash = strchr(mapping, '-');
136  if (!dash) { // short mapping
137  if (av_isdigit(*mapping))
138  mode = MAP_ONE_INT;
139  else
140  mode = MAP_ONE_STR;
141  } else if (av_isdigit(*mapping)) {
142  if (av_isdigit(*(dash+1)))
143  mode = MAP_PAIR_INT_INT;
144  else
145  mode = MAP_PAIR_INT_STR;
146  } else {
147  if (av_isdigit(*(dash+1)))
148  mode = MAP_PAIR_STR_INT;
149  else
150  mode = MAP_PAIR_STR_STR;
151  }
152 #if FF_API_OLD_FILTER_OPTS
153  if (strchr(mapping, ',')) {
154  av_log(ctx, AV_LOG_WARNING, "This syntax is deprecated, use "
155  "'|' to separate the mappings.\n");
156  separator = ',';
157  }
158 #endif
159  }
160 
161  if (mode != MAP_NONE) {
162  char *sep = mapping;
163  map_entries = 1;
164  while ((sep = strchr(sep, separator))) {
165  if (*++sep) // Allow trailing comma
166  map_entries++;
167  }
168  }
169 
170  if (map_entries > MAX_CH) {
171  av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n", map_entries);
172  return AVERROR(EINVAL);
173  }
174 
175  for (i = 0; i < map_entries; i++) {
176  int in_ch_idx = -1, out_ch_idx = -1;
177  uint64_t in_ch = 0, out_ch = 0;
178  static const char err[] = "Failed to parse channel map\n";
179  switch (mode) {
180  case MAP_ONE_INT:
181  if (get_channel_idx(&mapping, &in_ch_idx, separator, MAX_CH) < 0) {
182  av_log(ctx, AV_LOG_ERROR, err);
183  return AVERROR(EINVAL);
184  }
185  s->map[i].in_channel_idx = in_ch_idx;
186  s->map[i].out_channel_idx = i;
187  break;
188  case MAP_ONE_STR:
189  if (get_channel(&mapping, &in_ch, separator) < 0) {
190  av_log(ctx, AV_LOG_ERROR, err);
191  return AVERROR(EINVAL);
192  }
193  s->map[i].in_channel = in_ch;
194  s->map[i].out_channel_idx = i;
195  break;
196  case MAP_PAIR_INT_INT:
197  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
198  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
199  av_log(ctx, AV_LOG_ERROR, err);
200  return AVERROR(EINVAL);
201  }
202  s->map[i].in_channel_idx = in_ch_idx;
203  s->map[i].out_channel_idx = out_ch_idx;
204  break;
205  case MAP_PAIR_INT_STR:
206  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
207  get_channel(&mapping, &out_ch, separator) < 0 ||
208  out_ch & out_ch_mask) {
209  av_log(ctx, AV_LOG_ERROR, err);
210  return AVERROR(EINVAL);
211  }
212  s->map[i].in_channel_idx = in_ch_idx;
213  s->map[i].out_channel = out_ch;
214  out_ch_mask |= out_ch;
215  break;
216  case MAP_PAIR_STR_INT:
217  if (get_channel(&mapping, &in_ch, '-') < 0 ||
218  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
219  av_log(ctx, AV_LOG_ERROR, err);
220  return AVERROR(EINVAL);
221  }
222  s->map[i].in_channel = in_ch;
223  s->map[i].out_channel_idx = out_ch_idx;
224  break;
225  case MAP_PAIR_STR_STR:
226  if (get_channel(&mapping, &in_ch, '-') < 0 ||
227  get_channel(&mapping, &out_ch, separator) < 0 ||
228  out_ch & out_ch_mask) {
229  av_log(ctx, AV_LOG_ERROR, err);
230  return AVERROR(EINVAL);
231  }
232  s->map[i].in_channel = in_ch;
233  s->map[i].out_channel = out_ch;
234  out_ch_mask |= out_ch;
235  break;
236  }
237  }
238  s->mode = mode;
239  s->nch = map_entries;
240  s->output_layout = out_ch_mask ? out_ch_mask :
241  av_get_default_channel_layout(map_entries);
242 
243  if (s->channel_layout_str) {
244  uint64_t fmt;
245  if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
246  av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout: '%s'.\n",
247  s->channel_layout_str);
248  return AVERROR(EINVAL);
249  }
250  if (mode == MAP_NONE) {
251  int i;
253  for (i = 0; i < s->nch; i++) {
254  s->map[i].in_channel_idx = i;
255  s->map[i].out_channel_idx = i;
256  }
257  } else if (out_ch_mask && out_ch_mask != fmt) {
258  av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
259  av_log(ctx, AV_LOG_ERROR,
260  "Output channel layout '%s' does not match the list of channel mapped: '%s'.\n",
261  s->channel_layout_str, buf);
262  return AVERROR(EINVAL);
263  } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
264  av_log(ctx, AV_LOG_ERROR,
265  "Output channel layout %s does not match the number of channels mapped %d.\n",
266  s->channel_layout_str, s->nch);
267  return AVERROR(EINVAL);
268  }
269  s->output_layout = fmt;
270  }
271  if (!s->output_layout) {
272  av_log(ctx, AV_LOG_ERROR, "Output channel layout is not set and "
273  "cannot be guessed from the maps.\n");
274  return AVERROR(EINVAL);
275  }
276 
278 
279  if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
280  for (i = 0; i < s->nch; i++) {
282  s->output_layout, s->map[i].out_channel);
283  }
284  }
285 
286  return 0;
287 }
288 
290 {
291  ChannelMapContext *s = ctx->priv;
293 
296 
297  layouts = ff_all_channel_layouts();
298  if (!layouts)
299  return AVERROR(ENOMEM);
300 
303 
304  return 0;
305 }
306 
308 {
309  AVFilterContext *ctx = inlink->dst;
310  AVFilterLink *outlink = ctx->outputs[0];
311  const ChannelMapContext *s = ctx->priv;
312  const int nch_in = av_get_channel_layout_nb_channels(inlink->channel_layout);
313  const int nch_out = s->nch;
314  int ch;
315  uint8_t *source_planes[MAX_CH];
316 
317  memcpy(source_planes, buf->extended_data,
318  nch_in * sizeof(source_planes[0]));
319 
320  if (nch_out > nch_in) {
321  if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
322  uint8_t **new_extended_data =
323  av_mallocz_array(nch_out, sizeof(*buf->extended_data));
324  if (!new_extended_data) {
325  av_frame_free(&buf);
326  return AVERROR(ENOMEM);
327  }
328  if (buf->extended_data == buf->data) {
329  buf->extended_data = new_extended_data;
330  } else {
331  av_free(buf->extended_data);
332  buf->extended_data = new_extended_data;
333  }
334  } else if (buf->extended_data != buf->data) {
335  av_free(buf->extended_data);
336  buf->extended_data = buf->data;
337  }
338  }
339 
340  for (ch = 0; ch < nch_out; ch++) {
341  buf->extended_data[s->map[ch].out_channel_idx] =
342  source_planes[s->map[ch].in_channel_idx];
343  }
344 
345  if (buf->data != buf->extended_data)
346  memcpy(buf->data, buf->extended_data,
347  FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
348 
349  buf->channel_layout = outlink->channel_layout;
350 
351  return ff_filter_frame(outlink, buf);
352 }
353 
355 {
356  AVFilterContext *ctx = inlink->dst;
357  ChannelMapContext *s = ctx->priv;
359  int i, err = 0;
360  const char *channel_name;
361  char layout_name[256];
362 
363  for (i = 0; i < s->nch; i++) {
364  struct ChannelMap *m = &s->map[i];
365 
366  if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
368  inlink->channel_layout, m->in_channel);
369  }
370 
371  if (m->in_channel_idx < 0 || m->in_channel_idx >= nb_channels) {
372  av_get_channel_layout_string(layout_name, sizeof(layout_name),
373  0, inlink->channel_layout);
374  if (m->in_channel) {
375  channel_name = av_get_channel_name(m->in_channel);
376  av_log(ctx, AV_LOG_ERROR,
377  "input channel '%s' not available from input layout '%s'\n",
378  channel_name, layout_name);
379  } else {
380  av_log(ctx, AV_LOG_ERROR,
381  "input channel #%d not available from input layout '%s'\n",
382  m->in_channel_idx, layout_name);
383  }
384  err = AVERROR(EINVAL);
385  }
386  }
387 
388  return err;
389 }
390 
392  {
393  .name = "default",
394  .type = AVMEDIA_TYPE_AUDIO,
395  .filter_frame = channelmap_filter_frame,
396  .config_props = channelmap_config_input,
397  .needs_writable = 1,
398  },
399  { NULL }
400 };
401 
403  {
404  .name = "default",
405  .type = AVMEDIA_TYPE_AUDIO
406  },
407  { NULL }
408 };
409 
411  .name = "channelmap",
412  .description = NULL_IF_CONFIG_SMALL("Remap audio channels."),
413  .init = channelmap_init,
414  .query_formats = channelmap_query_formats,
415  .priv_size = sizeof(ChannelMapContext),
416  .priv_class = &channelmap_class,
417  .inputs = avfilter_af_channelmap_inputs,
418  .outputs = avfilter_af_channelmap_outputs,
419 };