FFmpeg  4.3.6
af_channelmap.c
Go to the documentation of this file.
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;
60  char *mapping_str;
62  uint64_t output_layout;
64  int nch;
67 
68 #define OFFSET(x) offsetof(ChannelMapContext, x)
69 #define A AV_OPT_FLAG_AUDIO_PARAM
70 #define F AV_OPT_FLAG_FILTERING_PARAM
71 static const AVOption channelmap_options[] = {
72  { "map", "A comma-separated list of input channel numbers in output order.",
73  OFFSET(mapping_str), AV_OPT_TYPE_STRING, .flags = A|F },
74  { "channel_layout", "Output channel layout.",
75  OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, .flags = A|F },
76  { NULL }
77 };
78 
79 AVFILTER_DEFINE_CLASS(channelmap);
80 
81 static char* split(char *message, char delim) {
82  char *next = strchr(message, delim);
83  if (next)
84  *next++ = '\0';
85  return next;
86 }
87 
88 static int get_channel_idx(char **map, int *ch, char delim, int max_ch)
89 {
90  char *next;
91  int len;
92  int n = 0;
93  if (!*map)
94  return AVERROR(EINVAL);
95  next = split(*map, delim);
96  if (!next && delim == '-')
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  }
153 
154  if (mode != MAP_NONE) {
155  char *sep = mapping;
156  map_entries = 1;
157  while ((sep = strchr(sep, separator))) {
158  if (*++sep) // Allow trailing comma
159  map_entries++;
160  }
161  }
162 
163  if (map_entries > MAX_CH) {
164  av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n", map_entries);
165  return AVERROR(EINVAL);
166  }
167 
168  for (i = 0; i < map_entries; i++) {
169  int in_ch_idx = -1, out_ch_idx = -1;
170  uint64_t in_ch = 0, out_ch = 0;
171  static const char err[] = "Failed to parse channel map\n";
172  switch (mode) {
173  case MAP_ONE_INT:
174  if (get_channel_idx(&mapping, &in_ch_idx, separator, MAX_CH) < 0) {
175  av_log(ctx, AV_LOG_ERROR, err);
176  return AVERROR(EINVAL);
177  }
178  s->map[i].in_channel_idx = in_ch_idx;
179  s->map[i].out_channel_idx = i;
180  break;
181  case MAP_ONE_STR:
182  if (get_channel(&mapping, &in_ch, separator) < 0) {
183  av_log(ctx, AV_LOG_ERROR, err);
184  return AVERROR(EINVAL);
185  }
186  s->map[i].in_channel = in_ch;
187  s->map[i].out_channel_idx = i;
188  break;
189  case MAP_PAIR_INT_INT:
190  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
191  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
192  av_log(ctx, AV_LOG_ERROR, err);
193  return AVERROR(EINVAL);
194  }
195  s->map[i].in_channel_idx = in_ch_idx;
196  s->map[i].out_channel_idx = out_ch_idx;
197  break;
198  case MAP_PAIR_INT_STR:
199  if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
200  get_channel(&mapping, &out_ch, separator) < 0 ||
201  out_ch & out_ch_mask) {
202  av_log(ctx, AV_LOG_ERROR, err);
203  return AVERROR(EINVAL);
204  }
205  s->map[i].in_channel_idx = in_ch_idx;
206  s->map[i].out_channel = out_ch;
207  out_ch_mask |= out_ch;
208  break;
209  case MAP_PAIR_STR_INT:
210  if (get_channel(&mapping, &in_ch, '-') < 0 ||
211  get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
212  av_log(ctx, AV_LOG_ERROR, err);
213  return AVERROR(EINVAL);
214  }
215  s->map[i].in_channel = in_ch;
216  s->map[i].out_channel_idx = out_ch_idx;
217  break;
218  case MAP_PAIR_STR_STR:
219  if (get_channel(&mapping, &in_ch, '-') < 0 ||
220  get_channel(&mapping, &out_ch, separator) < 0 ||
221  out_ch & out_ch_mask) {
222  av_log(ctx, AV_LOG_ERROR, err);
223  return AVERROR(EINVAL);
224  }
225  s->map[i].in_channel = in_ch;
226  s->map[i].out_channel = out_ch;
227  out_ch_mask |= out_ch;
228  break;
229  }
230  }
231  s->mode = mode;
232  s->nch = map_entries;
233  s->output_layout = out_ch_mask ? out_ch_mask :
234  av_get_default_channel_layout(map_entries);
235 
236  if (s->channel_layout_str) {
237  uint64_t fmt;
238  if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
239  av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout: '%s'.\n",
240  s->channel_layout_str);
241  return AVERROR(EINVAL);
242  }
243  if (mode == MAP_NONE) {
244  int i;
246  for (i = 0; i < s->nch; i++) {
247  s->map[i].in_channel_idx = i;
248  s->map[i].out_channel_idx = i;
249  }
250  } else if (out_ch_mask && out_ch_mask != fmt) {
251  av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
252  av_log(ctx, AV_LOG_ERROR,
253  "Output channel layout '%s' does not match the list of channel mapped: '%s'.\n",
254  s->channel_layout_str, buf);
255  return AVERROR(EINVAL);
256  } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
257  av_log(ctx, AV_LOG_ERROR,
258  "Output channel layout %s does not match the number of channels mapped %d.\n",
259  s->channel_layout_str, s->nch);
260  return AVERROR(EINVAL);
261  }
262  s->output_layout = fmt;
263  }
264  if (!s->output_layout) {
265  av_log(ctx, AV_LOG_ERROR, "Output channel layout is not set and "
266  "cannot be guessed from the maps.\n");
267  return AVERROR(EINVAL);
268  }
269 
270  if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
271  for (i = 0; i < s->nch; i++) {
273  s->output_layout, s->map[i].out_channel);
274  }
275  }
276 
277  return 0;
278 }
279 
281 {
282  ChannelMapContext *s = ctx->priv;
284  int ret;
285 
286  if ((ret = ff_set_common_formats (ctx, ff_planar_sample_fmts())) < 0 ||
287  (ret = ff_set_common_samplerates (ctx , ff_all_samplerates() )) < 0 ||
288  (ret = ff_add_channel_layout(&channel_layouts, s->output_layout)) < 0 ||
289  (ret = ff_channel_layouts_ref(channel_layouts,
290  &ctx->outputs[0]->in_channel_layouts)) < 0)
291  return ret;
292 
294  &ctx->inputs[0]->out_channel_layouts);
295 }
296 
298 {
299  AVFilterContext *ctx = inlink->dst;
300  AVFilterLink *outlink = ctx->outputs[0];
301  const ChannelMapContext *s = ctx->priv;
302  const int nch_in = inlink->channels;
303  const int nch_out = s->nch;
304  int ch;
305  uint8_t *source_planes[MAX_CH];
306 
307  memcpy(source_planes, buf->extended_data,
308  nch_in * sizeof(source_planes[0]));
309 
310  if (nch_out > nch_in) {
311  if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
312  uint8_t **new_extended_data =
313  av_mallocz_array(nch_out, sizeof(*buf->extended_data));
314  if (!new_extended_data) {
315  av_frame_free(&buf);
316  return AVERROR(ENOMEM);
317  }
318  if (buf->extended_data == buf->data) {
319  buf->extended_data = new_extended_data;
320  } else {
321  av_free(buf->extended_data);
322  buf->extended_data = new_extended_data;
323  }
324  } else if (buf->extended_data != buf->data) {
325  av_free(buf->extended_data);
326  buf->extended_data = buf->data;
327  }
328  }
329 
330  for (ch = 0; ch < nch_out; ch++) {
331  buf->extended_data[s->map[ch].out_channel_idx] =
332  source_planes[s->map[ch].in_channel_idx];
333  }
334 
335  if (buf->data != buf->extended_data)
336  memcpy(buf->data, buf->extended_data,
337  FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
338 
339  buf->channel_layout = outlink->channel_layout;
340  buf->channels = outlink->channels;
341 
342  return ff_filter_frame(outlink, buf);
343 }
344 
346 {
347  AVFilterContext *ctx = inlink->dst;
348  ChannelMapContext *s = ctx->priv;
349  int nb_channels = inlink->channels;
350  int i, err = 0;
351  const char *channel_name;
352  char layout_name[256];
353 
354  for (i = 0; i < s->nch; i++) {
355  struct ChannelMap *m = &s->map[i];
356 
357  if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
359  inlink->channel_layout, m->in_channel);
360  }
361 
362  if (m->in_channel_idx < 0 || m->in_channel_idx >= nb_channels) {
363  av_get_channel_layout_string(layout_name, sizeof(layout_name),
364  nb_channels, inlink->channel_layout);
365  if (m->in_channel) {
366  channel_name = av_get_channel_name(m->in_channel);
367  av_log(ctx, AV_LOG_ERROR,
368  "input channel '%s' not available from input layout '%s'\n",
369  channel_name, layout_name);
370  } else {
371  av_log(ctx, AV_LOG_ERROR,
372  "input channel #%d not available from input layout '%s'\n",
373  m->in_channel_idx, layout_name);
374  }
375  err = AVERROR(EINVAL);
376  }
377  }
378 
379  return err;
380 }
381 
383  {
384  .name = "default",
385  .type = AVMEDIA_TYPE_AUDIO,
386  .filter_frame = channelmap_filter_frame,
387  .config_props = channelmap_config_input,
388  .needs_writable = 1,
389  },
390  { NULL }
391 };
392 
394  {
395  .name = "default",
396  .type = AVMEDIA_TYPE_AUDIO
397  },
398  { NULL }
399 };
400 
402  .name = "channelmap",
403  .description = NULL_IF_CONFIG_SMALL("Remap audio channels."),
404  .init = channelmap_init,
405  .query_formats = channelmap_query_formats,
406  .priv_size = sizeof(ChannelMapContext),
407  .priv_class = &channelmap_class,
408  .inputs = avfilter_af_channelmap_inputs,
409  .outputs = avfilter_af_channelmap_outputs,
410 };
#define NULL
Definition: coverity.c:32
AVFILTER_DEFINE_CLASS(channelmap)
static av_const int av_isdigit(int c)
Locale-independent conversion of ASCII isdigit.
Definition: avstring.h:206
uint64_t in_channel
layout describing the input channel
Definition: af_channelmap.c:41
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
AVOption.
Definition: opt.h:246
#define OFFSET(x)
Definition: af_channelmap.c:68
Main libavfilter public API header.
AVFilter ff_af_channelmap
uint64_t output_layout
Definition: af_channelmap.c:62
static const AVOption channelmap_options[]
Definition: af_channelmap.c:71
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
const char * name
Pad name.
Definition: internal.h:60
uint64_t av_get_channel_layout(const char *name)
Return a channel layout id that matches name, or 0 if no match is found.
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:346
int ff_channel_layouts_ref(AVFilterChannelLayouts *f, AVFilterChannelLayouts **ref)
Add *ref as a new reference to f.
Definition: formats.c:479
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1075
uint8_t
#define av_cold
Definition: attributes.h:88
AVOptions.
enum MappingMode mode
Definition: af_channelmap.c:65
static int channelmap_filter_frame(AVFilterLink *inlink, AVFrame *buf)
char * channel_layout_str
Definition: af_channelmap.c:61
static int channelmap_query_formats(AVFilterContext *ctx)
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:54
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:605
int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout)
Definition: formats.c:356
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:188
void * priv
private data for use by the filter
Definition: avfilter.h:353
#define A
Definition: af_channelmap.c:69
static char * split(char *message, char delim)
Definition: af_channelmap.c:81
MappingMode
Definition: af_channelmap.c:47
uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:477
int channels
number of audio channels, only used for audio.
Definition: frame.h:606
audio channel layout utility functions
#define FFMIN(a, b)
Definition: common.h:96
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
AVFilterFormats * ff_planar_sample_fmts(void)
Construct a formats list containing all planar sample formats.
Definition: formats.c:426
static const AVFilterPad inputs[]
Definition: af_acontrast.c:193
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
#define FF_ARRAY_ELEMS(a)
int in_channel_idx
index of in_channel in the input stream data
Definition: af_channelmap.c:43
A list of supported channel layouts.
Definition: formats.h:85
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
Return a description of a channel layout.
struct ChannelMap map[MAX_CH]
Definition: af_channelmap.c:63
static const uint16_t channel_layouts[7]
Definition: dca_lbr.c:113
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
uint64_t out_channel
layout describing the output channel
Definition: af_channelmap.c:42
const char * name
Filter name.
Definition: avfilter.h:148
const VDPAUPixFmtMap * map
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
int av_get_channel_layout_channel_index(uint64_t channel_layout, uint64_t channel)
Get the index of a channel in channel_layout.
AVFilterFormats * ff_all_samplerates(void)
Definition: formats.c:439
static int channelmap_config_input(AVFilterLink *inlink)
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
static const AVFilterPad avfilter_af_channelmap_inputs[]
static int get_channel_idx(char **map, int *ch, char delim, int max_ch)
Definition: af_channelmap.c:88
#define MAX_CH
Definition: af_channelmap.c:57
common internal and external API header
#define F
Definition: af_channelmap.c:70
#define av_free(p)
const char * av_get_channel_name(uint64_t channel)
Get the name of a given channel.
int len
static int get_channel(char **map, uint64_t *ch, char delim)
An instance of a filter.
Definition: avfilter.h:338
int64_t av_get_default_channel_layout(int nb_channels)
Return default channel layout for a given number of channels.
static av_cold int channelmap_init(AVFilterContext *ctx)
static const AVFilterPad avfilter_af_channelmap_outputs[]
int nb_channels
int out_channel_idx
Definition: af_channelmap.c:44
internal API functions
AVFilterChannelLayouts * ff_all_channel_counts(void)
Construct an AVFilterChannelLayouts coding for any channel layout, with known or unknown disposition...
Definition: formats.c:454
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:347
mode
Use these values in ebur128_init (or&#39;ed).
Definition: ebur128.h:83
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:593
void * av_mallocz_array(size_t nmemb, size_t size)
Allocate a memory block for an array with av_mallocz().
Definition: mem.c:190