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"
29 #include "libavutil/channel_layout.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;
43 int in_channel_idx;
44 int out_channel_idx;
45 };
46
47 enum MappingMode {
48 MAP_NONE,
49 MAP_ONE_INT,
50 MAP_ONE_STR,
51 MAP_PAIR_INT_INT,
52 MAP_PAIR_INT_STR,
53 MAP_PAIR_STR_INT,
54 MAP_PAIR_STR_STR
55 };
56
57 #define MAX_CH 64
58 typedef struct ChannelMapContext {
59 const AVClass *class;
60 char *mapping_str;
61 char *channel_layout_str;
62 uint64_t output_layout;
63 struct ChannelMap map[MAX_CH];
64 int nch;
65 enum MappingMode mode;
66 } ChannelMapContext;
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
split(char * message,char delim)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
get_channel_idx(char ** map,int * ch,char delim,int max_ch)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
get_channel(char ** map,uint64_t * ch,char delim)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
channelmap_init(AVFilterContext * ctx)120 static av_cold int channelmap_init(AVFilterContext *ctx)
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;
245 s->nch = av_get_channel_layout_nb_channels(fmt);
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++) {
272 s->map[i].out_channel_idx = av_get_channel_layout_channel_index(
273 s->output_layout, s->map[i].out_channel);
274 }
275 }
276
277 return 0;
278 }
279
channelmap_query_formats(AVFilterContext * ctx)280 static int channelmap_query_formats(AVFilterContext *ctx)
281 {
282 ChannelMapContext *s = ctx->priv;
283 AVFilterChannelLayouts *channel_layouts = NULL;
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]->incfg.channel_layouts)) < 0)
291 return ret;
292
293 return ff_channel_layouts_ref(ff_all_channel_counts(),
294 &ctx->inputs[0]->outcfg.channel_layouts);
295 }
296
channelmap_filter_frame(AVFilterLink * inlink,AVFrame * buf)297 static int channelmap_filter_frame(AVFilterLink *inlink, AVFrame *buf)
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
channelmap_config_input(AVFilterLink * inlink)345 static int channelmap_config_input(AVFilterLink *inlink)
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) {
358 m->in_channel_idx = av_get_channel_layout_channel_index(
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
382 static const AVFilterPad avfilter_af_channelmap_inputs[] = {
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
393 static const AVFilterPad avfilter_af_channelmap_outputs[] = {
394 {
395 .name = "default",
396 .type = AVMEDIA_TYPE_AUDIO
397 },
398 { NULL }
399 };
400
401 AVFilter ff_af_channelmap = {
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 };
411