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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  len = strlen(*map);
97  sscanf(*map, "%d%n", ch, &n);
98  if (n != len)
99  return AVERROR(EINVAL);
100  if (*ch < 0 || *ch > max_ch)
101  return AVERROR(EINVAL);
102  *map = next;
103  return 0;
104 }
105 
106 static int get_channel(char **map, uint64_t *ch, char delim)
107 {
108  char *next = split(*map, delim);
109  if (!next && delim == '-')
110  return AVERROR(EINVAL);
111  *ch = av_get_channel_layout(*map);
112  if (av_get_channel_layout_nb_channels(*ch) != 1)
113  return AVERROR(EINVAL);
114  *map = next;
115  return 0;
116 }
117 
119 {
120  ChannelMapContext *s = ctx->priv;
121  char *mapping, separator = '|';
122  int map_entries = 0;
123  char buf[256];
124  enum MappingMode mode;
125  uint64_t out_ch_mask = 0;
126  int i;
127 
128  mapping = s->mapping_str;
129 
130  if (!mapping) {
131  mode = MAP_NONE;
132  } else {
133  char *dash = strchr(mapping, '-');
134  if (!dash) { // short mapping
135  if (av_isdigit(*mapping))
136  mode = MAP_ONE_INT;
137  else
138  mode = MAP_ONE_STR;
139  } else if (av_isdigit(*mapping)) {
140  if (av_isdigit(*(dash+1)))
141  mode = MAP_PAIR_INT_INT;
142  else
143  mode = MAP_PAIR_INT_STR;
144  } else {
145  if (av_isdigit(*(dash+1)))
146  mode = MAP_PAIR_STR_INT;
147  else
148  mode = MAP_PAIR_STR_STR;
149  }
150 #if FF_API_OLD_FILTER_OPTS
151  if (strchr(mapping, ',')) {
152  av_log(ctx, AV_LOG_WARNING, "This syntax is deprecated, use "
153  "'|' to separate the mappings.\n");
154  separator = ',';
155  }
156 #endif
157  }
158 
159  if (mode != MAP_NONE) {
160  char *sep = mapping;
161  map_entries = 1;
162  while ((sep = strchr(sep, separator))) {
163  if (*++sep) // Allow trailing comma
164  map_entries++;
165  }
166  }
167 
168  if (map_entries > MAX_CH) {
169  av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n", map_entries);
170  return AVERROR(EINVAL);
171  }
172 
173  for (i = 0; i < map_entries; i++) {
174  int in_ch_idx = -1, out_ch_idx = -1;
175  uint64_t in_ch = 0, out_ch = 0;
176  static const char err[] = "Failed to parse channel map\n";
177  switch (mode) {
178  case MAP_ONE_INT:
179  if (get_channel_idx(&mapping, &in_ch_idx, separator, MAX_CH) < 0) {
180  av_log(ctx, AV_LOG_ERROR, err);
181  return AVERROR(EINVAL);
182  }
183  s->map[i].in_channel_idx = in_ch_idx;
184  s->map[i].out_channel_idx = i;
185  break;
186  case MAP_ONE_STR:
187  if (!get_channel(&mapping, &in_ch, separator)) {
188  av_log(ctx, AV_LOG_ERROR, err);
189  return AVERROR(EINVAL);
190  }
191  s->map[i].in_channel = in_ch;
192  s->map[i].out_channel_idx = i;
193  break;
194  case MAP_PAIR_INT_INT:
195  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
196  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
197  av_log(ctx, AV_LOG_ERROR, err);
198  return AVERROR(EINVAL);
199  }
200  s->map[i].in_channel_idx = in_ch_idx;
201  s->map[i].out_channel_idx = out_ch_idx;
202  break;
203  case MAP_PAIR_INT_STR:
204  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
205  get_channel(&mapping, &out_ch, separator) < 0 ||
206  out_ch & out_ch_mask) {
207  av_log(ctx, AV_LOG_ERROR, err);
208  return AVERROR(EINVAL);
209  }
210  s->map[i].in_channel_idx = in_ch_idx;
211  s->map[i].out_channel = out_ch;
212  out_ch_mask |= out_ch;
213  break;
214  case MAP_PAIR_STR_INT:
215  if (get_channel(&mapping, &in_ch, '-') < 0 ||
216  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
217  av_log(ctx, AV_LOG_ERROR, err);
218  return AVERROR(EINVAL);
219  }
220  s->map[i].in_channel = in_ch;
221  s->map[i].out_channel_idx = out_ch_idx;
222  break;
223  case MAP_PAIR_STR_STR:
224  if (get_channel(&mapping, &in_ch, '-') < 0 ||
225  get_channel(&mapping, &out_ch, separator) < 0 ||
226  out_ch & out_ch_mask) {
227  av_log(ctx, AV_LOG_ERROR, err);
228  return AVERROR(EINVAL);
229  }
230  s->map[i].in_channel = in_ch;
231  s->map[i].out_channel = out_ch;
232  out_ch_mask |= out_ch;
233  break;
234  }
235  }
236  s->mode = mode;
237  s->nch = map_entries;
238  s->output_layout = out_ch_mask ? out_ch_mask :
239  av_get_default_channel_layout(map_entries);
240 
241  if (s->channel_layout_str) {
242  uint64_t fmt;
243  if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
244  av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout: '%s'.\n",
245  s->channel_layout_str);
246  return AVERROR(EINVAL);
247  }
248  if (mode == MAP_NONE) {
249  int i;
251  for (i = 0; i < s->nch; i++) {
252  s->map[i].in_channel_idx = i;
253  s->map[i].out_channel_idx = i;
254  }
255  } else if (out_ch_mask && out_ch_mask != fmt) {
256  av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
257  av_log(ctx, AV_LOG_ERROR,
258  "Output channel layout '%s' does not match the list of channel mapped: '%s'.\n",
259  s->channel_layout_str, buf);
260  return AVERROR(EINVAL);
261  } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
262  av_log(ctx, AV_LOG_ERROR,
263  "Output channel layout %s does not match the number of channels mapped %d.\n",
264  s->channel_layout_str, s->nch);
265  return AVERROR(EINVAL);
266  }
267  s->output_layout = fmt;
268  }
269  if (!s->output_layout) {
270  av_log(ctx, AV_LOG_ERROR, "Output channel layout is not set and "
271  "cannot be guessed from the maps.\n");
272  return AVERROR(EINVAL);
273  }
274 
276 
277  if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
278  for (i = 0; i < s->nch; i++) {
280  s->output_layout, s->map[i].out_channel);
281  }
282  }
283 
284  return 0;
285 }
286 
288 {
289  ChannelMapContext *s = ctx->priv;
290 
295 
296  return 0;
297 }
298 
300 {
301  AVFilterContext *ctx = inlink->dst;
302  AVFilterLink *outlink = ctx->outputs[0];
303  const ChannelMapContext *s = ctx->priv;
304  const int nch_in = av_get_channel_layout_nb_channels(inlink->channel_layout);
305  const int nch_out = s->nch;
306  int ch;
307  uint8_t *source_planes[MAX_CH];
308 
309  memcpy(source_planes, buf->extended_data,
310  nch_in * sizeof(source_planes[0]));
311 
312  if (nch_out > nch_in) {
313  if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
314  uint8_t **new_extended_data =
315  av_mallocz(nch_out * sizeof(*buf->extended_data));
316  if (!new_extended_data) {
317  av_frame_free(&buf);
318  return AVERROR(ENOMEM);
319  }
320  if (buf->extended_data == buf->data) {
321  buf->extended_data = new_extended_data;
322  } else {
323  av_free(buf->extended_data);
324  buf->extended_data = new_extended_data;
325  }
326  } else if (buf->extended_data != buf->data) {
327  av_free(buf->extended_data);
328  buf->extended_data = buf->data;
329  }
330  }
331 
332  for (ch = 0; ch < nch_out; ch++) {
333  buf->extended_data[s->map[ch].out_channel_idx] =
334  source_planes[s->map[ch].in_channel_idx];
335  }
336 
337  if (buf->data != buf->extended_data)
338  memcpy(buf->data, buf->extended_data,
339  FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
340 
341  return ff_filter_frame(outlink, buf);
342 }
343 
345 {
346  AVFilterContext *ctx = inlink->dst;
347  ChannelMapContext *s = ctx->priv;
349  int i, err = 0;
350  const char *channel_name;
351  char layout_name[256];
352 
353  for (i = 0; i < s->nch; i++) {
354  struct ChannelMap *m = &s->map[i];
355 
356  if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
358  inlink->channel_layout, m->in_channel);
359  }
360 
361  if (m->in_channel_idx < 0 || m->in_channel_idx >= nb_channels) {
362  av_get_channel_layout_string(layout_name, sizeof(layout_name),
363  0, inlink->channel_layout);
364  if (m->in_channel) {
365  channel_name = av_get_channel_name(m->in_channel);
366  av_log(ctx, AV_LOG_ERROR,
367  "input channel '%s' not available from input layout '%s'\n",
368  channel_name, layout_name);
369  } else {
370  av_log(ctx, AV_LOG_ERROR,
371  "input channel #%d not available from input layout '%s'\n",
372  m->in_channel_idx, layout_name);
373  }
374  err = AVERROR(EINVAL);
375  }
376  }
377 
378  return err;
379 }
380 
382  {
383  .name = "default",
384  .type = AVMEDIA_TYPE_AUDIO,
385  .filter_frame = channelmap_filter_frame,
386  .config_props = channelmap_config_input,
387  .needs_writable = 1,
388  },
389  { NULL }
390 };
391 
393  {
394  .name = "default",
395  .type = AVMEDIA_TYPE_AUDIO
396  },
397  { NULL }
398 };
399 
401  .name = "channelmap",
402  .description = NULL_IF_CONFIG_SMALL("Remap audio channels."),
403  .init = channelmap_init,
404  .query_formats = channelmap_query_formats,
405  .priv_size = sizeof(ChannelMapContext),
406  .priv_class = &channelmap_class,
407 
408  .inputs = avfilter_af_channelmap_inputs,
409  .outputs = avfilter_af_channelmap_outputs,
410 };