libavfilter/af_channelmap.c

   1 /*
   2  * Copyright (c) 2012 Google, Inc.
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; 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     AVFilterChannelLayouts *channel_layouts;
  61     char *mapping_str;
  62     char *channel_layout_str;
  63     uint64_t output_layout;
  64     struct ChannelMap map[MAX_CH];
  65     int nch;
  66     enum MappingMode mode;
  67 } ChannelMapContext;
  68
  69 #define OFFSET(x) offsetof(ChannelMapContext, x)
  70 #define A AV_OPT_FLAG_AUDIO_PARAM
  71 static const AVOption options[] = {
  72     { "map", "A comma-separated list of input channel numbers in output order.",
  73           OFFSET(mapping_str),        AV_OPT_TYPE_STRING, .flags = A },
  74     { "channel_layout", "Output channel layout.",
  75           OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, .flags = A },
  76     { NULL },
  77 };
  78
  79 static const AVClass channelmap_class = {
  80     .class_name = "channel map filter",
  81     .item_name  = av_default_item_name,
  82     .option     = options,
  83     .version    = LIBAVUTIL_VERSION_INT,
  84 };
  85
  86 static char* split(char *message, char delim) {
  87     char *next = strchr(message, delim);
  88     if (next)
  89       *next++ = '\0';
  90     return next;
  91 }
  92
  93 static int get_channel_idx(char **map, int *ch, char delim, int max_ch)
  94 {
  95     char *next = split(*map, delim);
  96     int len;
  97     int n = 0;
  98     if (!next && delim == '-')
  99         return AVERROR(EINVAL);
 100     len = strlen(*map);
 101     sscanf(*map, "%d%n", ch, &n);
 102     if (n != len)
 103         return AVERROR(EINVAL);
 104     if (*ch < 0 || *ch > max_ch)
 105         return AVERROR(EINVAL);
 106     *map = next;
 107     return 0;
 108 }
 109
 110 static int get_channel(char **map, uint64_t *ch, char delim)
 111 {
 112     char *next = split(*map, delim);
 113     if (!next && delim == '-')
 114         return AVERROR(EINVAL);
 115     *ch = av_get_channel_layout(*map);
 116     if (av_get_channel_layout_nb_channels(*ch) != 1)
 117         return AVERROR(EINVAL);
 118     *map = next;
 119     return 0;
 120 }
 121
 122 static av_cold int channelmap_init(AVFilterContext *ctx, const char *args)
 123 {
 124     ChannelMapContext *s = ctx->priv;
 125     int ret;
 126     char *mapping;
 127     int map_entries = 0;
 128     char buf[256];
 129     enum MappingMode mode;
 130     uint64_t out_ch_mask = 0;
 131     int i;
 132
 133     if (!args) {
 134         av_log(ctx, AV_LOG_ERROR, "No parameters supplied.\n");
 135         return AVERROR(EINVAL);
 136     }
 137
 138     s->class = &channelmap_class;
 139     av_opt_set_defaults(s);
 140
 141     if ((ret = av_set_options_string(s, args, "=", ":")) < 0) {
 142         av_log(ctx, AV_LOG_ERROR, "Error parsing options string '%s'.\n", args);
 143         return ret;
 144     }
 145
 146     mapping = s->mapping_str;
 147
 148     if (!mapping) {
 149         mode = MAP_NONE;
 150     } else {
 151         char *dash = strchr(mapping, '-');
 152         if (!dash) {  // short mapping
 153             if (av_isdigit(*mapping))
 154                 mode = MAP_ONE_INT;
 155             else
 156                 mode = MAP_ONE_STR;
 157         } else if (av_isdigit(*mapping)) {
 158             if (av_isdigit(*(dash+1)))
 159                 mode = MAP_PAIR_INT_INT;
 160             else
 161                 mode = MAP_PAIR_INT_STR;
 162         } else {
 163             if (av_isdigit(*(dash+1)))
 164                 mode = MAP_PAIR_STR_INT;
 165             else
 166                 mode = MAP_PAIR_STR_STR;
 167         }
 168     }
 169
 170     if (mode != MAP_NONE) {
 171         char *comma = mapping;
 172         map_entries = 1;
 173         while ((comma = strchr(comma, ','))) {
 174             if (*++comma)  // Allow trailing comma
 175                 map_entries++;
 176         }
 177     }
 178
 179     if (map_entries > MAX_CH) {
 180         av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n", map_entries);
 181         ret = AVERROR(EINVAL);
 182         goto fail;
 183     }
 184
 185     for (i = 0; i < map_entries; i++) {
 186         int in_ch_idx = -1, out_ch_idx = -1;
 187         uint64_t in_ch = 0, out_ch = 0;
 188         static const char err[] = "Failed to parse channel map\n";
 189         switch (mode) {
 190         case MAP_ONE_INT:
 191             if (get_channel_idx(&mapping, &in_ch_idx, ',', MAX_CH) < 0) {
 192                 ret = AVERROR(EINVAL);
 193                 av_log(ctx, AV_LOG_ERROR, err);
 194                 goto fail;
 195             }
 196             s->map[i].in_channel_idx  = in_ch_idx;
 197             s->map[i].out_channel_idx = i;
 198             break;
 199         case MAP_ONE_STR:
 200             if (!get_channel(&mapping, &in_ch, ',')) {
 201                 av_log(ctx, AV_LOG_ERROR, err);
 202                 ret = AVERROR(EINVAL);
 203                 goto fail;
 204             }
 205             s->map[i].in_channel      = in_ch;
 206             s->map[i].out_channel_idx = i;
 207             break;
 208         case MAP_PAIR_INT_INT:
 209             if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
 210                 get_channel_idx(&mapping, &out_ch_idx, ',', MAX_CH) < 0) {
 211                 av_log(ctx, AV_LOG_ERROR, err);
 212                 ret = AVERROR(EINVAL);
 213                 goto fail;
 214             }
 215             s->map[i].in_channel_idx  = in_ch_idx;
 216             s->map[i].out_channel_idx = out_ch_idx;
 217             break;
 218         case MAP_PAIR_INT_STR:
 219             if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
 220                 get_channel(&mapping, &out_ch, ',') < 0 ||
 221                 out_ch & out_ch_mask) {
 222                 av_log(ctx, AV_LOG_ERROR, err);
 223                 ret = AVERROR(EINVAL);
 224                 goto fail;
 225             }
 226             s->map[i].in_channel_idx  = in_ch_idx;
 227             s->map[i].out_channel     = out_ch;
 228             out_ch_mask |= out_ch;
 229             break;
 230         case MAP_PAIR_STR_INT:
 231             if (get_channel(&mapping, &in_ch, '-') < 0 ||
 232                 get_channel_idx(&mapping, &out_ch_idx, ',', MAX_CH) < 0) {
 233                 av_log(ctx, AV_LOG_ERROR, err);
 234                 ret = AVERROR(EINVAL);
 235                 goto fail;
 236             }
 237             s->map[i].in_channel      = in_ch;
 238             s->map[i].out_channel_idx = out_ch_idx;
 239             break;
 240         case MAP_PAIR_STR_STR:
 241             if (get_channel(&mapping, &in_ch, '-') < 0 ||
 242                 get_channel(&mapping, &out_ch, ',') < 0 ||
 243                 out_ch & out_ch_mask) {
 244                 av_log(ctx, AV_LOG_ERROR, err);
 245                 ret = AVERROR(EINVAL);
 246                 goto fail;
 247             }
 248             s->map[i].in_channel = in_ch;
 249             s->map[i].out_channel = out_ch;
 250             out_ch_mask |= out_ch;
 251             break;
 252         }
 253     }
 254     s->mode          = mode;
 255     s->nch           = map_entries;
 256     s->output_layout = out_ch_mask ? out_ch_mask :
 257                        av_get_default_channel_layout(map_entries);
 258
 259     if (s->channel_layout_str) {
 260         uint64_t fmt;
 261         if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
 262             av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout: '%s'.\n",
 263                    s->channel_layout_str);
 264             ret = AVERROR(EINVAL);
 265             goto fail;
 266         }
 267         if (mode == MAP_NONE) {
 268             int i;
 269             s->nch = av_get_channel_layout_nb_channels(fmt);
 270             for (i = 0; i < s->nch; i++) {
 271                 s->map[i].in_channel_idx  = i;
 272                 s->map[i].out_channel_idx = i;
 273             }
 274         } else if (out_ch_mask && out_ch_mask != fmt) {
 275             av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
 276             av_log(ctx, AV_LOG_ERROR,
 277                    "Output channel layout '%s' does not match the list of channel mapped: '%s'.\n",
 278                    s->channel_layout_str, buf);
 279             ret = AVERROR(EINVAL);
 280             goto fail;
 281         } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
 282             av_log(ctx, AV_LOG_ERROR,
 283                    "Output channel layout %s does not match the number of channels mapped %d.\n",
 284                    s->channel_layout_str, s->nch);
 285             ret = AVERROR(EINVAL);
 286             goto fail;
 287         }
 288         s->output_layout = fmt;
 289     }
 290     ff_add_channel_layout(&s->channel_layouts, s->output_layout);
 291
 292     if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
 293         for (i = 0; i < s->nch; i++) {
 294             s->map[i].out_channel_idx = av_get_channel_layout_channel_index(
 295                 s->output_layout, s->map[i].out_channel);
 296         }
 297     }
 298
 299 fail:
 300     av_opt_free(s);
 301     return ret;
 302 }
 303
 304 static int channelmap_query_formats(AVFilterContext *ctx)
 305 {
 306     ChannelMapContext *s = ctx->priv;
 307
 308     ff_set_common_formats(ctx, ff_planar_sample_fmts());
 309     ff_set_common_samplerates(ctx, ff_all_samplerates());
 310     ff_channel_layouts_ref(ff_all_channel_layouts(), &ctx->inputs[0]->out_channel_layouts);
 311     ff_channel_layouts_ref(s->channel_layouts,       &ctx->outputs[0]->in_channel_layouts);
 312
 313     return 0;
 314 }
 315
 316 static int channelmap_filter_frame(AVFilterLink *inlink, AVFrame *buf)
 317 {
 318     AVFilterContext  *ctx = inlink->dst;
 319     AVFilterLink *outlink = ctx->outputs[0];
 320     const ChannelMapContext *s = ctx->priv;
 321     const int nch_in = av_get_channel_layout_nb_channels(inlink->channel_layout);
 322     const int nch_out = s->nch;
 323     int ch;
 324     uint8_t *source_planes[MAX_CH];
 325
 326     memcpy(source_planes, buf->extended_data,
 327            nch_in * sizeof(source_planes[0]));
 328
 329     if (nch_out > nch_in) {
 330         if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
 331             uint8_t **new_extended_data =
 332                 av_mallocz(nch_out * sizeof(*buf->extended_data));
 333             if (!new_extended_data) {
 334                 av_frame_free(&buf);
 335                 return AVERROR(ENOMEM);
 336             }
 337             if (buf->extended_data == buf->data) {
 338                 buf->extended_data = new_extended_data;
 339             } else {
 340                 av_free(buf->extended_data);
 341                 buf->extended_data = new_extended_data;
 342             }
 343         } else if (buf->extended_data != buf->data) {
 344             av_free(buf->extended_data);
 345             buf->extended_data = buf->data;
 346         }
 347     }
 348
 349     for (ch = 0; ch < nch_out; ch++) {
 350         buf->extended_data[s->map[ch].out_channel_idx] =
 351             source_planes[s->map[ch].in_channel_idx];
 352     }
 353
 354     if (buf->data != buf->extended_data)
 355         memcpy(buf->data, buf->extended_data,
 356            FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
 357
 358     return ff_filter_frame(outlink, buf);
 359 }
 360
 361 static int channelmap_config_input(AVFilterLink *inlink)
 362 {
 363     AVFilterContext *ctx = inlink->dst;
 364     ChannelMapContext *s = ctx->priv;
 365     int i, err = 0;
 366     const char *channel_name;
 367     char layout_name[256];
 368
 369     if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
 370         for (i = 0; i < s->nch; i++) {
 371             s->map[i].in_channel_idx = av_get_channel_layout_channel_index(
 372                 inlink->channel_layout, s->map[i].in_channel);
 373             if (s->map[i].in_channel_idx < 0) {
 374                 channel_name = av_get_channel_name(s->map[i].in_channel);
 375                 av_get_channel_layout_string(layout_name, sizeof(layout_name),
 376                                              0, inlink->channel_layout);
 377                 av_log(ctx, AV_LOG_ERROR,
 378                        "input channel '%s' not available from input layout '%s'\n",
 379                        channel_name, layout_name);
 380                 err = AVERROR(EINVAL);
 381             }
 382         }
 383     }
 384
 385     return err;
 386 }
 387
 388 static const AVFilterPad avfilter_af_channelmap_inputs[] = {
 389     {
 390         .name           = "default",
 391         .type           = AVMEDIA_TYPE_AUDIO,
 392         .filter_frame   = channelmap_filter_frame,
 393         .config_props   = channelmap_config_input
 394     },
 395     { NULL }
 396 };
 397
 398 static const AVFilterPad avfilter_af_channelmap_outputs[] = {
 399     {
 400         .name = "default",
 401         .type = AVMEDIA_TYPE_AUDIO
 402     },
 403     { NULL }
 404 };
 405
 406 AVFilter avfilter_af_channelmap = {
 407     .name          = "channelmap",
 408     .description   = NULL_IF_CONFIG_SMALL("Remap audio channels."),
 409     .init          = channelmap_init,
 410     .query_formats = channelmap_query_formats,
 411     .priv_size     = sizeof(ChannelMapContext),
 412
 413     .inputs        = avfilter_af_channelmap_inputs,
 414     .outputs       = avfilter_af_channelmap_outputs,
 415 };