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af_join.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /**
20  * @file
21  * Audio join filter
22  *
23  * Join multiple audio inputs as different channels in
24  * a single output
25  */
26 
27 #include "libavutil/avassert.h"
29 #include "libavutil/common.h"
30 #include "libavutil/opt.h"
31 
32 #include "audio.h"
33 #include "avfilter.h"
34 #include "formats.h"
35 #include "internal.h"
36 
37 typedef struct ChannelMap {
38  int input; ///< input stream index
39  int in_channel_idx; ///< index of in_channel in the input stream data
40  uint64_t in_channel; ///< layout describing the input channel
41  uint64_t out_channel; ///< layout describing the output channel
42 } ChannelMap;
43 
44 typedef struct JoinContext {
45  const AVClass *class;
46 
47  int inputs;
48  char *map;
50  uint64_t channel_layout;
51 
54 
55  /**
56  * Temporary storage for input frames, until we get one on each input.
57  */
59 
60  /**
61  * Temporary storage for buffer references, for assembling the output frame.
62  */
64 } JoinContext;
65 
66 #define OFFSET(x) offsetof(JoinContext, x)
67 #define A AV_OPT_FLAG_AUDIO_PARAM
68 #define F AV_OPT_FLAG_FILTERING_PARAM
69 static const AVOption join_options[] = {
70  { "inputs", "Number of input streams.", OFFSET(inputs), AV_OPT_TYPE_INT, { .i64 = 2 }, 1, INT_MAX, A|F },
71  { "channel_layout", "Channel layout of the "
72  "output stream.", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, A|F },
73  { "map", "A comma-separated list of channels maps in the format "
74  "'input_stream.input_channel-output_channel.",
75  OFFSET(map), AV_OPT_TYPE_STRING, .flags = A|F },
76  { NULL }
77 };
78 
80 
82 {
83  AVFilterContext *ctx = link->dst;
84  JoinContext *s = ctx->priv;
85  int i;
86 
87  for (i = 0; i < ctx->nb_inputs; i++)
88  if (link == ctx->inputs[i])
89  break;
90  av_assert0(i < ctx->nb_inputs);
91  av_assert0(!s->input_frames[i]);
92  s->input_frames[i] = frame;
93 
94  return 0;
95 }
96 
97 static int parse_maps(AVFilterContext *ctx)
98 {
99  JoinContext *s = ctx->priv;
100  char separator = '|';
101  char *cur = s->map;
102 
103 #if FF_API_OLD_FILTER_OPTS
104  if (cur && strchr(cur, ',')) {
105  av_log(ctx, AV_LOG_WARNING, "This syntax is deprecated, use '|' to "
106  "separate the mappings.\n");
107  separator = ',';
108  }
109 #endif
110 
111  while (cur && *cur) {
112  char *sep, *next, *p;
113  uint64_t in_channel = 0, out_channel = 0;
114  int input_idx, out_ch_idx, in_ch_idx;
115 
116  next = strchr(cur, separator);
117  if (next)
118  *next++ = 0;
119 
120  /* split the map into input and output parts */
121  if (!(sep = strchr(cur, '-'))) {
122  av_log(ctx, AV_LOG_ERROR, "Missing separator '-' in channel "
123  "map '%s'\n", cur);
124  return AVERROR(EINVAL);
125  }
126  *sep++ = 0;
127 
128 #define PARSE_CHANNEL(str, var, inout) \
129  if (!(var = av_get_channel_layout(str))) { \
130  av_log(ctx, AV_LOG_ERROR, "Invalid " inout " channel: %s.\n", str);\
131  return AVERROR(EINVAL); \
132  } \
133  if (av_get_channel_layout_nb_channels(var) != 1) { \
134  av_log(ctx, AV_LOG_ERROR, "Channel map describes more than one " \
135  inout " channel.\n"); \
136  return AVERROR(EINVAL); \
137  }
138 
139  /* parse output channel */
140  PARSE_CHANNEL(sep, out_channel, "output");
141  if (!(out_channel & s->channel_layout)) {
142  av_log(ctx, AV_LOG_ERROR, "Output channel '%s' is not present in "
143  "requested channel layout.\n", sep);
144  return AVERROR(EINVAL);
145  }
146 
148  out_channel);
149  if (s->channels[out_ch_idx].input >= 0) {
150  av_log(ctx, AV_LOG_ERROR, "Multiple maps for output channel "
151  "'%s'.\n", sep);
152  return AVERROR(EINVAL);
153  }
154 
155  /* parse input channel */
156  input_idx = strtol(cur, &cur, 0);
157  if (input_idx < 0 || input_idx >= s->inputs) {
158  av_log(ctx, AV_LOG_ERROR, "Invalid input stream index: %d.\n",
159  input_idx);
160  return AVERROR(EINVAL);
161  }
162 
163  if (*cur)
164  cur++;
165 
166  in_ch_idx = strtol(cur, &p, 0);
167  if (p == cur) {
168  /* channel specifier is not a number,
169  * try to parse as channel name */
170  PARSE_CHANNEL(cur, in_channel, "input");
171  }
172 
173  s->channels[out_ch_idx].input = input_idx;
174  if (in_channel)
175  s->channels[out_ch_idx].in_channel = in_channel;
176  else
177  s->channels[out_ch_idx].in_channel_idx = in_ch_idx;
178 
179  cur = next;
180  }
181  return 0;
182 }
183 
185 {
186  JoinContext *s = ctx->priv;
187  int ret, i;
188 
190  av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout '%s'.\n",
191  s->channel_layout_str);
192  return AVERROR(EINVAL);
193  }
194 
196  s->channels = av_mallocz(sizeof(*s->channels) * s->nb_channels);
197  s->buffers = av_mallocz(sizeof(*s->buffers) * s->nb_channels);
198  s->input_frames = av_mallocz(sizeof(*s->input_frames) * s->inputs);
199  if (!s->channels || !s->buffers|| !s->input_frames)
200  return AVERROR(ENOMEM);
201 
202  for (i = 0; i < s->nb_channels; i++) {
204  s->channels[i].input = -1;
205  }
206 
207  if ((ret = parse_maps(ctx)) < 0)
208  return ret;
209 
210  for (i = 0; i < s->inputs; i++) {
211  char name[32];
212  AVFilterPad pad = { 0 };
213 
214  snprintf(name, sizeof(name), "input%d", i);
215  pad.type = AVMEDIA_TYPE_AUDIO;
216  pad.name = av_strdup(name);
218 
219  pad.needs_fifo = 1;
220 
221  ff_insert_inpad(ctx, i, &pad);
222  }
223 
224  return 0;
225 }
226 
228 {
229  JoinContext *s = ctx->priv;
230  int i;
231 
232  for (i = 0; i < ctx->nb_inputs; i++) {
233  av_freep(&ctx->input_pads[i].name);
234  av_frame_free(&s->input_frames[i]);
235  }
236 
237  av_freep(&s->channels);
238  av_freep(&s->buffers);
239  av_freep(&s->input_frames);
240 }
241 
243 {
244  JoinContext *s = ctx->priv;
246  int i;
247 
250 
251  for (i = 0; i < ctx->nb_inputs; i++)
253  &ctx->inputs[i]->out_channel_layouts);
254 
257 
258  return 0;
259 }
260 
262  uint64_t *inputs)
263 {
264  int i;
265 
266  for (i = 0; i < ctx->nb_inputs; i++) {
267  AVFilterLink *link = ctx->inputs[i];
268 
269  if (ch->out_channel & link->channel_layout &&
270  !(ch->out_channel & inputs[i])) {
271  ch->input = i;
272  ch->in_channel = ch->out_channel;
273  inputs[i] |= ch->out_channel;
274  return;
275  }
276  }
277 }
278 
280  uint64_t *inputs)
281 {
282  int i;
283 
284  for (i = 0; i < ctx->nb_inputs; i++) {
285  AVFilterLink *link = ctx->inputs[i];
286 
287  if ((inputs[i] & link->channel_layout) != link->channel_layout) {
288  uint64_t unused = link->channel_layout & ~inputs[i];
289 
290  ch->input = i;
292  inputs[i] |= ch->in_channel;
293  return;
294  }
295  }
296 }
297 
298 static int join_config_output(AVFilterLink *outlink)
299 {
300  AVFilterContext *ctx = outlink->src;
301  JoinContext *s = ctx->priv;
302  uint64_t *inputs; // nth element tracks which channels are used from nth input
303  int i, ret = 0;
304 
305  /* initialize inputs to user-specified mappings */
306  if (!(inputs = av_mallocz(sizeof(*inputs) * ctx->nb_inputs)))
307  return AVERROR(ENOMEM);
308  for (i = 0; i < s->nb_channels; i++) {
309  ChannelMap *ch = &s->channels[i];
310  AVFilterLink *inlink;
311 
312  if (ch->input < 0)
313  continue;
314 
315  inlink = ctx->inputs[ch->input];
316 
317  if (!ch->in_channel)
319  ch->in_channel_idx);
320 
321  if (!(ch->in_channel & inlink->channel_layout)) {
322  av_log(ctx, AV_LOG_ERROR, "Requested channel %s is not present in "
323  "input stream #%d.\n", av_get_channel_name(ch->in_channel),
324  ch->input);
325  ret = AVERROR(EINVAL);
326  goto fail;
327  }
328 
329  inputs[ch->input] |= ch->in_channel;
330  }
331 
332  /* guess channel maps when not explicitly defined */
333  /* first try unused matching channels */
334  for (i = 0; i < s->nb_channels; i++) {
335  ChannelMap *ch = &s->channels[i];
336 
337  if (ch->input < 0)
338  guess_map_matching(ctx, ch, inputs);
339  }
340 
341  /* if the above failed, try to find _any_ unused input channel */
342  for (i = 0; i < s->nb_channels; i++) {
343  ChannelMap *ch = &s->channels[i];
344 
345  if (ch->input < 0)
346  guess_map_any(ctx, ch, inputs);
347 
348  if (ch->input < 0) {
349  av_log(ctx, AV_LOG_ERROR, "Could not find input channel for "
350  "output channel '%s'.\n",
352  goto fail;
353  }
354 
356  ch->in_channel);
357  }
358 
359  /* print mappings */
360  av_log(ctx, AV_LOG_VERBOSE, "mappings: ");
361  for (i = 0; i < s->nb_channels; i++) {
362  ChannelMap *ch = &s->channels[i];
363  av_log(ctx, AV_LOG_VERBOSE, "%d.%s => %s ", ch->input,
366  }
367  av_log(ctx, AV_LOG_VERBOSE, "\n");
368 
369  for (i = 0; i < ctx->nb_inputs; i++) {
370  if (!inputs[i])
371  av_log(ctx, AV_LOG_WARNING, "No channels are used from input "
372  "stream %d.\n", i);
373  }
374 
375 fail:
376  av_freep(&inputs);
377  return ret;
378 }
379 
380 static int join_request_frame(AVFilterLink *outlink)
381 {
382  AVFilterContext *ctx = outlink->src;
383  JoinContext *s = ctx->priv;
384  AVFrame *frame;
385  int linesize = INT_MAX;
386  int nb_samples = 0;
387  int nb_buffers = 0;
388  int i, j, ret;
389 
390  /* get a frame on each input */
391  for (i = 0; i < ctx->nb_inputs; i++) {
392  AVFilterLink *inlink = ctx->inputs[i];
393 
394  if (!s->input_frames[i] &&
395  (ret = ff_request_frame(inlink)) < 0)
396  return ret;
397 
398  /* request the same number of samples on all inputs */
399  if (i == 0) {
400  nb_samples = s->input_frames[0]->nb_samples;
401 
402  for (j = 1; !i && j < ctx->nb_inputs; j++)
403  ctx->inputs[j]->request_samples = nb_samples;
404  }
405  }
406 
407  /* setup the output frame */
408  frame = av_frame_alloc();
409  if (!frame)
410  return AVERROR(ENOMEM);
411  if (s->nb_channels > FF_ARRAY_ELEMS(frame->data)) {
412  frame->extended_data = av_mallocz(s->nb_channels *
413  sizeof(*frame->extended_data));
414  if (!frame->extended_data) {
415  ret = AVERROR(ENOMEM);
416  goto fail;
417  }
418  }
419 
420  /* copy the data pointers */
421  for (i = 0; i < s->nb_channels; i++) {
422  ChannelMap *ch = &s->channels[i];
423  AVFrame *cur = s->input_frames[ch->input];
424  AVBufferRef *buf;
425 
426  frame->extended_data[i] = cur->extended_data[ch->in_channel_idx];
427  linesize = FFMIN(linesize, cur->linesize[0]);
428 
429  /* add the buffer where this plan is stored to the list if it's
430  * not already there */
432  if (!buf) {
433  ret = AVERROR(EINVAL);
434  goto fail;
435  }
436  for (j = 0; j < nb_buffers; j++)
437  if (s->buffers[j]->buffer == buf->buffer)
438  break;
439  if (j == i)
440  s->buffers[nb_buffers++] = buf;
441  }
442 
443  /* create references to the buffers we copied to output */
444  if (nb_buffers > FF_ARRAY_ELEMS(frame->buf)) {
445  frame->nb_extended_buf = nb_buffers - FF_ARRAY_ELEMS(frame->buf);
446  frame->extended_buf = av_mallocz(sizeof(*frame->extended_buf) *
447  frame->nb_extended_buf);
448  if (!frame->extended_buf) {
449  frame->nb_extended_buf = 0;
450  ret = AVERROR(ENOMEM);
451  goto fail;
452  }
453  }
454  for (i = 0; i < FFMIN(FF_ARRAY_ELEMS(frame->buf), nb_buffers); i++) {
455  frame->buf[i] = av_buffer_ref(s->buffers[i]);
456  if (!frame->buf[i]) {
457  ret = AVERROR(ENOMEM);
458  goto fail;
459  }
460  }
461  for (i = 0; i < frame->nb_extended_buf; i++) {
462  frame->extended_buf[i] = av_buffer_ref(s->buffers[i +
463  FF_ARRAY_ELEMS(frame->buf)]);
464  if (!frame->extended_buf[i]) {
465  ret = AVERROR(ENOMEM);
466  goto fail;
467  }
468  }
469 
470  frame->nb_samples = nb_samples;
471  frame->channel_layout = outlink->channel_layout;
472  av_frame_set_channels(frame, outlink->channels);
473  frame->sample_rate = outlink->sample_rate;
474  frame->format = outlink->format;
475  frame->pts = s->input_frames[0]->pts;
476  frame->linesize[0] = linesize;
477  if (frame->data != frame->extended_data) {
478  memcpy(frame->data, frame->extended_data, sizeof(*frame->data) *
479  FFMIN(FF_ARRAY_ELEMS(frame->data), s->nb_channels));
480  }
481 
482  ret = ff_filter_frame(outlink, frame);
483 
484  for (i = 0; i < ctx->nb_inputs; i++)
485  av_frame_free(&s->input_frames[i]);
486 
487  return ret;
488 
489 fail:
490  av_frame_free(&frame);
491  return ret;
492 }
493 
495  {
496  .name = "default",
497  .type = AVMEDIA_TYPE_AUDIO,
498  .config_props = join_config_output,
499  .request_frame = join_request_frame,
500  },
501  { NULL }
502 };
503 
505  .name = "join",
506  .description = NULL_IF_CONFIG_SMALL("Join multiple audio streams into "
507  "multi-channel output."),
508  .priv_size = sizeof(JoinContext),
509  .priv_class = &join_class,
510  .init = join_init,
511  .uninit = join_uninit,
513  .inputs = NULL,
514  .outputs = avfilter_af_join_outputs,
516 };