2 * Copyright (c) 2012 Google, Inc.
4 * This file is part of FFmpeg.
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.
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.
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
23 * audio channel mapping filter
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"
58 typedef struct ChannelMapContext {
60 AVFilterChannelLayouts *channel_layouts;
62 char *channel_layout_str;
63 uint64_t output_layout;
64 struct ChannelMap map[MAX_CH];
66 enum MappingMode mode;
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 },
80 AVFILTER_DEFINE_CLASS(channelmap);
82 static char* split(char *message, char delim) {
83 char *next = strchr(message, delim);
89 static int get_channel_idx(char **map, int *ch, char delim, int max_ch)
95 return AVERROR(EINVAL);
96 next = split(*map, delim);
97 if (!next && delim == '-')
98 return AVERROR(EINVAL);
100 sscanf(*map, "%d%n", ch, &n);
102 return AVERROR(EINVAL);
103 if (*ch < 0 || *ch > max_ch)
104 return AVERROR(EINVAL);
109 static int get_channel(char **map, uint64_t *ch, char delim)
111 char *next = split(*map, delim);
112 if (!next && delim == '-')
113 return AVERROR(EINVAL);
114 *ch = av_get_channel_layout(*map);
115 if (av_get_channel_layout_nb_channels(*ch) != 1)
116 return AVERROR(EINVAL);
121 static av_cold int channelmap_init(AVFilterContext *ctx)
123 ChannelMapContext *s = ctx->priv;
124 char *mapping, separator = '|';
127 enum MappingMode mode;
128 uint64_t out_ch_mask = 0;
131 mapping = s->mapping_str;
136 char *dash = strchr(mapping, '-');
137 if (!dash) { // short mapping
138 if (av_isdigit(*mapping))
142 } else if (av_isdigit(*mapping)) {
143 if (av_isdigit(*(dash+1)))
144 mode = MAP_PAIR_INT_INT;
146 mode = MAP_PAIR_INT_STR;
148 if (av_isdigit(*(dash+1)))
149 mode = MAP_PAIR_STR_INT;
151 mode = MAP_PAIR_STR_STR;
153 #if FF_API_OLD_FILTER_OPTS
154 if (strchr(mapping, ',')) {
155 av_log(ctx, AV_LOG_WARNING, "This syntax is deprecated, use "
156 "'|' to separate the mappings.\n");
162 if (mode != MAP_NONE) {
165 while ((sep = strchr(sep, separator))) {
166 if (*++sep) // Allow trailing comma
171 if (map_entries > MAX_CH) {
172 av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n", map_entries);
173 return AVERROR(EINVAL);
176 for (i = 0; i < map_entries; i++) {
177 int in_ch_idx = -1, out_ch_idx = -1;
178 uint64_t in_ch = 0, out_ch = 0;
179 static const char err[] = "Failed to parse channel map\n";
182 if (get_channel_idx(&mapping, &in_ch_idx, separator, MAX_CH) < 0) {
183 av_log(ctx, AV_LOG_ERROR, err);
184 return AVERROR(EINVAL);
186 s->map[i].in_channel_idx = in_ch_idx;
187 s->map[i].out_channel_idx = i;
190 if (get_channel(&mapping, &in_ch, separator) < 0) {
191 av_log(ctx, AV_LOG_ERROR, err);
192 return AVERROR(EINVAL);
194 s->map[i].in_channel = in_ch;
195 s->map[i].out_channel_idx = i;
197 case MAP_PAIR_INT_INT:
198 if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
199 get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
200 av_log(ctx, AV_LOG_ERROR, err);
201 return AVERROR(EINVAL);
203 s->map[i].in_channel_idx = in_ch_idx;
204 s->map[i].out_channel_idx = out_ch_idx;
206 case MAP_PAIR_INT_STR:
207 if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
208 get_channel(&mapping, &out_ch, separator) < 0 ||
209 out_ch & out_ch_mask) {
210 av_log(ctx, AV_LOG_ERROR, err);
211 return AVERROR(EINVAL);
213 s->map[i].in_channel_idx = in_ch_idx;
214 s->map[i].out_channel = out_ch;
215 out_ch_mask |= out_ch;
217 case MAP_PAIR_STR_INT:
218 if (get_channel(&mapping, &in_ch, '-') < 0 ||
219 get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
220 av_log(ctx, AV_LOG_ERROR, err);
221 return AVERROR(EINVAL);
223 s->map[i].in_channel = in_ch;
224 s->map[i].out_channel_idx = out_ch_idx;
226 case MAP_PAIR_STR_STR:
227 if (get_channel(&mapping, &in_ch, '-') < 0 ||
228 get_channel(&mapping, &out_ch, separator) < 0 ||
229 out_ch & out_ch_mask) {
230 av_log(ctx, AV_LOG_ERROR, err);
231 return AVERROR(EINVAL);
233 s->map[i].in_channel = in_ch;
234 s->map[i].out_channel = out_ch;
235 out_ch_mask |= out_ch;
240 s->nch = map_entries;
241 s->output_layout = out_ch_mask ? out_ch_mask :
242 av_get_default_channel_layout(map_entries);
244 if (s->channel_layout_str) {
246 if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
247 av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout: '%s'.\n",
248 s->channel_layout_str);
249 return AVERROR(EINVAL);
251 if (mode == MAP_NONE) {
253 s->nch = av_get_channel_layout_nb_channels(fmt);
254 for (i = 0; i < s->nch; i++) {
255 s->map[i].in_channel_idx = i;
256 s->map[i].out_channel_idx = i;
258 } else if (out_ch_mask && out_ch_mask != fmt) {
259 av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
260 av_log(ctx, AV_LOG_ERROR,
261 "Output channel layout '%s' does not match the list of channel mapped: '%s'.\n",
262 s->channel_layout_str, buf);
263 return AVERROR(EINVAL);
264 } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
265 av_log(ctx, AV_LOG_ERROR,
266 "Output channel layout %s does not match the number of channels mapped %d.\n",
267 s->channel_layout_str, s->nch);
268 return AVERROR(EINVAL);
270 s->output_layout = fmt;
272 if (!s->output_layout) {
273 av_log(ctx, AV_LOG_ERROR, "Output channel layout is not set and "
274 "cannot be guessed from the maps.\n");
275 return AVERROR(EINVAL);
278 ff_add_channel_layout(&s->channel_layouts, s->output_layout);
280 if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
281 for (i = 0; i < s->nch; i++) {
282 s->map[i].out_channel_idx = av_get_channel_layout_channel_index(
283 s->output_layout, s->map[i].out_channel);
290 static int channelmap_query_formats(AVFilterContext *ctx)
292 ChannelMapContext *s = ctx->priv;
293 AVFilterChannelLayouts *layouts;
295 ff_set_common_formats(ctx, ff_planar_sample_fmts());
296 ff_set_common_samplerates(ctx, ff_all_samplerates());
298 layouts = ff_all_channel_layouts();
300 return AVERROR(ENOMEM);
302 ff_channel_layouts_ref(layouts, &ctx->inputs[0]->out_channel_layouts);
303 ff_channel_layouts_ref(s->channel_layouts, &ctx->outputs[0]->in_channel_layouts);
308 static int channelmap_filter_frame(AVFilterLink *inlink, AVFrame *buf)
310 AVFilterContext *ctx = inlink->dst;
311 AVFilterLink *outlink = ctx->outputs[0];
312 const ChannelMapContext *s = ctx->priv;
313 const int nch_in = av_get_channel_layout_nb_channels(inlink->channel_layout);
314 const int nch_out = s->nch;
316 uint8_t *source_planes[MAX_CH];
318 memcpy(source_planes, buf->extended_data,
319 nch_in * sizeof(source_planes[0]));
321 if (nch_out > nch_in) {
322 if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
323 uint8_t **new_extended_data =
324 av_mallocz_array(nch_out, sizeof(*buf->extended_data));
325 if (!new_extended_data) {
327 return AVERROR(ENOMEM);
329 if (buf->extended_data == buf->data) {
330 buf->extended_data = new_extended_data;
332 av_free(buf->extended_data);
333 buf->extended_data = new_extended_data;
335 } else if (buf->extended_data != buf->data) {
336 av_free(buf->extended_data);
337 buf->extended_data = buf->data;
341 for (ch = 0; ch < nch_out; ch++) {
342 buf->extended_data[s->map[ch].out_channel_idx] =
343 source_planes[s->map[ch].in_channel_idx];
346 if (buf->data != buf->extended_data)
347 memcpy(buf->data, buf->extended_data,
348 FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
350 buf->channel_layout = outlink->channel_layout;
351 av_frame_set_channels(buf, outlink->channels);
353 return ff_filter_frame(outlink, buf);
356 static int channelmap_config_input(AVFilterLink *inlink)
358 AVFilterContext *ctx = inlink->dst;
359 ChannelMapContext *s = ctx->priv;
360 int nb_channels = av_get_channel_layout_nb_channels(inlink->channel_layout);
362 const char *channel_name;
363 char layout_name[256];
365 for (i = 0; i < s->nch; i++) {
366 struct ChannelMap *m = &s->map[i];
368 if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
369 m->in_channel_idx = av_get_channel_layout_channel_index(
370 inlink->channel_layout, m->in_channel);
373 if (m->in_channel_idx < 0 || m->in_channel_idx >= nb_channels) {
374 av_get_channel_layout_string(layout_name, sizeof(layout_name),
375 0, inlink->channel_layout);
377 channel_name = av_get_channel_name(m->in_channel);
378 av_log(ctx, AV_LOG_ERROR,
379 "input channel '%s' not available from input layout '%s'\n",
380 channel_name, layout_name);
382 av_log(ctx, AV_LOG_ERROR,
383 "input channel #%d not available from input layout '%s'\n",
384 m->in_channel_idx, layout_name);
386 err = AVERROR(EINVAL);
393 static const AVFilterPad avfilter_af_channelmap_inputs[] = {
396 .type = AVMEDIA_TYPE_AUDIO,
397 .filter_frame = channelmap_filter_frame,
398 .config_props = channelmap_config_input,
404 static const AVFilterPad avfilter_af_channelmap_outputs[] = {
407 .type = AVMEDIA_TYPE_AUDIO
412 AVFilter ff_af_channelmap = {
413 .name = "channelmap",
414 .description = NULL_IF_CONFIG_SMALL("Remap audio channels."),
415 .init = channelmap_init,
416 .query_formats = channelmap_query_formats,
417 .priv_size = sizeof(ChannelMapContext),
418 .priv_class = &channelmap_class,
419 .inputs = avfilter_af_channelmap_inputs,
420 .outputs = avfilter_af_channelmap_outputs,