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af_join.c
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1 /*
2  *
3  * This file is part of Libav.
4  *
5  * Libav is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * Libav is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with Libav; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 /**
21  * @file
22  * Audio join filter
23  *
24  * Join multiple audio inputs as different channels in
25  * a single output
26  */
27 
28 #include "libavutil/avassert.h"
30 #include "libavutil/common.h"
31 #include "libavutil/opt.h"
32 
33 #include "audio.h"
34 #include "avfilter.h"
35 #include "formats.h"
36 #include "internal.h"
37 
38 typedef struct ChannelMap {
39  int input; ///< input stream index
40  int in_channel_idx; ///< index of in_channel in the input stream data
41  uint64_t in_channel; ///< layout describing the input channel
42  uint64_t out_channel; ///< layout describing the output channel
43 } ChannelMap;
44 
45 typedef struct JoinContext {
46  const AVClass *class;
47 
48  int inputs;
49  char *map;
51  uint64_t channel_layout;
52 
55 
56  /**
57  * Temporary storage for input frames, until we get one on each input.
58  */
60 
61  /**
62  * Temporary storage for data pointers, for assembling the output buffer.
63  */
65 } JoinContext;
66 
67 /**
68  * To avoid copying the data from input buffers, this filter creates
69  * a custom output buffer that stores references to all inputs and
70  * unrefs them on free.
71  */
72 typedef struct JoinBufferPriv {
76 
77 #define OFFSET(x) offsetof(JoinContext, x)
78 #define A AV_OPT_FLAG_AUDIO_PARAM
79 #define F AV_OPT_FLAG_FILTERING_PARAM
80 static const AVOption join_options[] = {
81  { "inputs", "Number of input streams.", OFFSET(inputs), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, A|F },
82  { "channel_layout", "Channel layout of the "
83  "output stream.", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, A|F },
84  { "map", "A comma-separated list of channels maps in the format "
85  "'input_stream.input_channel-output_channel.",
86  OFFSET(map), AV_OPT_TYPE_STRING, .flags = A|F },
87  { NULL },
88 };
89 
90 static const AVClass join_class = {
91  .class_name = "join filter",
92  .item_name = av_default_item_name,
93  .option = join_options,
94  .version = LIBAVUTIL_VERSION_INT,
95 };
96 
98 {
99  AVFilterContext *ctx = link->dst;
100  JoinContext *s = ctx->priv;
101  int i;
102 
103  for (i = 0; i < ctx->nb_inputs; i++)
104  if (link == ctx->inputs[i])
105  break;
106  av_assert0(i < ctx->nb_inputs);
107  av_assert0(!s->input_frames[i]);
108  s->input_frames[i] = buf;
109 
110  return 0;
111 }
112 
113 static int parse_maps(AVFilterContext *ctx)
114 {
115  JoinContext *s = ctx->priv;
116  char *cur = s->map;
117 
118  while (cur && *cur) {
119  char *sep, *next, *p;
120  uint64_t in_channel = 0, out_channel = 0;
121  int input_idx, out_ch_idx, in_ch_idx;
122 
123  next = strchr(cur, ',');
124  if (next)
125  *next++ = 0;
126 
127  /* split the map into input and output parts */
128  if (!(sep = strchr(cur, '-'))) {
129  av_log(ctx, AV_LOG_ERROR, "Missing separator '-' in channel "
130  "map '%s'\n", cur);
131  return AVERROR(EINVAL);
132  }
133  *sep++ = 0;
134 
135 #define PARSE_CHANNEL(str, var, inout) \
136  if (!(var = av_get_channel_layout(str))) { \
137  av_log(ctx, AV_LOG_ERROR, "Invalid " inout " channel: %s.\n", str);\
138  return AVERROR(EINVAL); \
139  } \
140  if (av_get_channel_layout_nb_channels(var) != 1) { \
141  av_log(ctx, AV_LOG_ERROR, "Channel map describes more than one " \
142  inout " channel.\n"); \
143  return AVERROR(EINVAL); \
144  }
145 
146  /* parse output channel */
147  PARSE_CHANNEL(sep, out_channel, "output");
148  if (!(out_channel & s->channel_layout)) {
149  av_log(ctx, AV_LOG_ERROR, "Output channel '%s' is not present in "
150  "requested channel layout.\n", sep);
151  return AVERROR(EINVAL);
152  }
153 
155  out_channel);
156  if (s->channels[out_ch_idx].input >= 0) {
157  av_log(ctx, AV_LOG_ERROR, "Multiple maps for output channel "
158  "'%s'.\n", sep);
159  return AVERROR(EINVAL);
160  }
161 
162  /* parse input channel */
163  input_idx = strtol(cur, &cur, 0);
164  if (input_idx < 0 || input_idx >= s->inputs) {
165  av_log(ctx, AV_LOG_ERROR, "Invalid input stream index: %d.\n",
166  input_idx);
167  return AVERROR(EINVAL);
168  }
169 
170  if (*cur)
171  cur++;
172 
173  in_ch_idx = strtol(cur, &p, 0);
174  if (p == cur) {
175  /* channel specifier is not a number,
176  * try to parse as channel name */
177  PARSE_CHANNEL(cur, in_channel, "input");
178  }
179 
180  s->channels[out_ch_idx].input = input_idx;
181  if (in_channel)
182  s->channels[out_ch_idx].in_channel = in_channel;
183  else
184  s->channels[out_ch_idx].in_channel_idx = in_ch_idx;
185 
186  cur = next;
187  }
188  return 0;
189 }
190 
191 static int join_init(AVFilterContext *ctx, const char *args)
192 {
193  JoinContext *s = ctx->priv;
194  int ret, i;
195 
196  s->class = &join_class;
198  if ((ret = av_set_options_string(s, args, "=", ":")) < 0)
199  return ret;
200 
202  av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout '%s'.\n",
203  s->channel_layout_str);
204  ret = AVERROR(EINVAL);
205  goto fail;
206  }
207 
209  s->channels = av_mallocz(sizeof(*s->channels) * s->nb_channels);
210  s->data = av_mallocz(sizeof(*s->data) * s->nb_channels);
211  s->input_frames = av_mallocz(sizeof(*s->input_frames) * s->inputs);
212  if (!s->channels || !s->data || !s->input_frames) {
213  ret = AVERROR(ENOMEM);
214  goto fail;
215  }
216 
217  for (i = 0; i < s->nb_channels; i++) {
219  s->channels[i].input = -1;
220  }
221 
222  if ((ret = parse_maps(ctx)) < 0)
223  goto fail;
224 
225  for (i = 0; i < s->inputs; i++) {
226  char name[32];
227  AVFilterPad pad = { 0 };
228 
229  snprintf(name, sizeof(name), "input%d", i);
230  pad.type = AVMEDIA_TYPE_AUDIO;
231  pad.name = av_strdup(name);
233 
234  pad.needs_fifo = 1;
235 
236  ff_insert_inpad(ctx, i, &pad);
237  }
238 
239 fail:
240  av_opt_free(s);
241  return ret;
242 }
243 
244 static void join_uninit(AVFilterContext *ctx)
245 {
246  JoinContext *s = ctx->priv;
247  int i;
248 
249  for (i = 0; i < ctx->nb_inputs; i++) {
250  av_freep(&ctx->input_pads[i].name);
252  }
253 
254  av_freep(&s->channels);
255  av_freep(&s->data);
256  av_freep(&s->input_frames);
257 }
258 
260 {
261  JoinContext *s = ctx->priv;
263  int i;
264 
267 
268  for (i = 0; i < ctx->nb_inputs; i++)
270  &ctx->inputs[i]->out_channel_layouts);
271 
274 
275  return 0;
276 }
277 
279  uint64_t *inputs)
280 {
281  int i;
282 
283  for (i = 0; i < ctx->nb_inputs; i++) {
284  AVFilterLink *link = ctx->inputs[i];
285 
286  if (ch->out_channel & link->channel_layout &&
287  !(ch->out_channel & inputs[i])) {
288  ch->input = i;
289  ch->in_channel = ch->out_channel;
290  inputs[i] |= ch->out_channel;
291  return;
292  }
293  }
294 }
295 
297  uint64_t *inputs)
298 {
299  int i;
300 
301  for (i = 0; i < ctx->nb_inputs; i++) {
302  AVFilterLink *link = ctx->inputs[i];
303 
304  if ((inputs[i] & link->channel_layout) != link->channel_layout) {
305  uint64_t unused = link->channel_layout & ~inputs[i];
306 
307  ch->input = i;
309  inputs[i] |= ch->in_channel;
310  return;
311  }
312  }
313 }
314 
315 static int join_config_output(AVFilterLink *outlink)
316 {
317  AVFilterContext *ctx = outlink->src;
318  JoinContext *s = ctx->priv;
319  uint64_t *inputs; // nth element tracks which channels are used from nth input
320  int i, ret = 0;
321 
322  /* initialize inputs to user-specified mappings */
323  if (!(inputs = av_mallocz(sizeof(*inputs) * ctx->nb_inputs)))
324  return AVERROR(ENOMEM);
325  for (i = 0; i < s->nb_channels; i++) {
326  ChannelMap *ch = &s->channels[i];
327  AVFilterLink *inlink;
328 
329  if (ch->input < 0)
330  continue;
331 
332  inlink = ctx->inputs[ch->input];
333 
334  if (!ch->in_channel)
336  ch->in_channel_idx);
337 
338  if (!(ch->in_channel & inlink->channel_layout)) {
339  av_log(ctx, AV_LOG_ERROR, "Requested channel %s is not present in "
340  "input stream #%d.\n", av_get_channel_name(ch->in_channel),
341  ch->input);
342  ret = AVERROR(EINVAL);
343  goto fail;
344  }
345 
346  inputs[ch->input] |= ch->in_channel;
347  }
348 
349  /* guess channel maps when not explicitly defined */
350  /* first try unused matching channels */
351  for (i = 0; i < s->nb_channels; i++) {
352  ChannelMap *ch = &s->channels[i];
353 
354  if (ch->input < 0)
355  guess_map_matching(ctx, ch, inputs);
356  }
357 
358  /* if the above failed, try to find _any_ unused input channel */
359  for (i = 0; i < s->nb_channels; i++) {
360  ChannelMap *ch = &s->channels[i];
361 
362  if (ch->input < 0)
363  guess_map_any(ctx, ch, inputs);
364 
365  if (ch->input < 0) {
366  av_log(ctx, AV_LOG_ERROR, "Could not find input channel for "
367  "output channel '%s'.\n",
369  goto fail;
370  }
371 
373  ch->in_channel);
374  }
375 
376  /* print mappings */
377  av_log(ctx, AV_LOG_VERBOSE, "mappings: ");
378  for (i = 0; i < s->nb_channels; i++) {
379  ChannelMap *ch = &s->channels[i];
380  av_log(ctx, AV_LOG_VERBOSE, "%d.%s => %s ", ch->input,
383  }
384  av_log(ctx, AV_LOG_VERBOSE, "\n");
385 
386  for (i = 0; i < ctx->nb_inputs; i++) {
387  if (!inputs[i])
388  av_log(ctx, AV_LOG_WARNING, "No channels are used from input "
389  "stream %d.\n", i);
390  }
391 
392 fail:
393  av_freep(&inputs);
394  return ret;
395 }
396 
398 {
399  JoinBufferPriv *priv = buf->priv;
400 
401  if (priv) {
402  int i;
403 
404  for (i = 0; i < priv->nb_in_buffers; i++)
406 
407  av_freep(&priv->in_buffers);
408  av_freep(&buf->priv);
409  }
410 
411  if (buf->extended_data != buf->data)
412  av_freep(&buf->extended_data);
413  av_freep(&buf);
414 }
415 
416 static int join_request_frame(AVFilterLink *outlink)
417 {
418  AVFilterContext *ctx = outlink->src;
419  JoinContext *s = ctx->priv;
420  AVFilterBufferRef *buf;
421  JoinBufferPriv *priv;
422  int linesize = INT_MAX;
423  int perms = ~0;
424  int nb_samples = 0;
425  int i, j, ret;
426 
427  /* get a frame on each input */
428  for (i = 0; i < ctx->nb_inputs; i++) {
429  AVFilterLink *inlink = ctx->inputs[i];
430 
431  if (!s->input_frames[i] &&
432  (ret = ff_request_frame(inlink)) < 0)
433  return ret;
434 
435  /* request the same number of samples on all inputs */
436  if (i == 0) {
437  nb_samples = s->input_frames[0]->audio->nb_samples;
438 
439  for (j = 1; !i && j < ctx->nb_inputs; j++)
440  ctx->inputs[j]->request_samples = nb_samples;
441  }
442  }
443 
444  for (i = 0; i < s->nb_channels; i++) {
445  ChannelMap *ch = &s->channels[i];
446  AVFilterBufferRef *cur_buf = s->input_frames[ch->input];
447 
448  s->data[i] = cur_buf->extended_data[ch->in_channel_idx];
449  linesize = FFMIN(linesize, cur_buf->linesize[0]);
450  perms &= cur_buf->perms;
451  }
452 
453  av_assert0(nb_samples > 0);
454  buf = avfilter_get_audio_buffer_ref_from_arrays(s->data, linesize, perms,
455  nb_samples, outlink->format,
456  outlink->channel_layout);
457  if (!buf)
458  return AVERROR(ENOMEM);
459 
460  buf->buf->free = join_free_buffer;
461  buf->pts = s->input_frames[0]->pts;
462 
463  if (!(priv = av_mallocz(sizeof(*priv))))
464  goto fail;
465  if (!(priv->in_buffers = av_mallocz(sizeof(*priv->in_buffers) * ctx->nb_inputs)))
466  goto fail;
467 
468  for (i = 0; i < ctx->nb_inputs; i++)
469  priv->in_buffers[i] = s->input_frames[i];
470  priv->nb_in_buffers = ctx->nb_inputs;
471  buf->buf->priv = priv;
472 
473  ret = ff_filter_frame(outlink, buf);
474 
475  memset(s->input_frames, 0, sizeof(*s->input_frames) * ctx->nb_inputs);
476 
477  return ret;
478 
479 fail:
481  if (priv)
482  av_freep(&priv->in_buffers);
483  av_freep(&priv);
484  return AVERROR(ENOMEM);
485 }
486 
488  {
489  .name = "default",
490  .type = AVMEDIA_TYPE_AUDIO,
491  .config_props = join_config_output,
492  .request_frame = join_request_frame,
493  },
494  { NULL }
495 };
496 
498  .name = "join",
499  .description = NULL_IF_CONFIG_SMALL("Join multiple audio streams into "
500  "multi-channel output"),
501  .priv_size = sizeof(JoinContext),
502 
503  .init = join_init,
504  .uninit = join_uninit,
506 
507  .inputs = NULL,
508  .outputs = avfilter_af_join_outputs,
509  .priv_class = &join_class,
510 };