1/*
2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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 layout utility functions
24 */
25
26#include <stdint.h>
27#include <stdlib.h>
28#include <string.h>
29
30#include "avassert.h"
31#include "channel_layout.h"
32#include "bprint.h"
33#include "common.h"
34#include "error.h"
35#include "macros.h"
36#include "opt.h"
37
38#define CHAN_IS_AMBI(x) ((x) >= AV_CHAN_AMBISONIC_BASE &&\
39                         (x) <= AV_CHAN_AMBISONIC_END)
40
41struct channel_name {
42    const char *name;
43    const char *description;
44};
45
46static const struct channel_name channel_names[] = {
47    [AV_CHAN_FRONT_LEFT           ] = { "FL",        "front left"            },
48    [AV_CHAN_FRONT_RIGHT          ] = { "FR",        "front right"           },
49    [AV_CHAN_FRONT_CENTER         ] = { "FC",        "front center"          },
50    [AV_CHAN_LOW_FREQUENCY        ] = { "LFE",       "low frequency"         },
51    [AV_CHAN_BACK_LEFT            ] = { "BL",        "back left"             },
52    [AV_CHAN_BACK_RIGHT           ] = { "BR",        "back right"            },
53    [AV_CHAN_FRONT_LEFT_OF_CENTER ] = { "FLC",       "front left-of-center"  },
54    [AV_CHAN_FRONT_RIGHT_OF_CENTER] = { "FRC",       "front right-of-center" },
55    [AV_CHAN_BACK_CENTER          ] = { "BC",        "back center"           },
56    [AV_CHAN_SIDE_LEFT            ] = { "SL",        "side left"             },
57    [AV_CHAN_SIDE_RIGHT           ] = { "SR",        "side right"            },
58    [AV_CHAN_TOP_CENTER           ] = { "TC",        "top center"            },
59    [AV_CHAN_TOP_FRONT_LEFT       ] = { "TFL",       "top front left"        },
60    [AV_CHAN_TOP_FRONT_CENTER     ] = { "TFC",       "top front center"      },
61    [AV_CHAN_TOP_FRONT_RIGHT      ] = { "TFR",       "top front right"       },
62    [AV_CHAN_TOP_BACK_LEFT        ] = { "TBL",       "top back left"         },
63    [AV_CHAN_TOP_BACK_CENTER      ] = { "TBC",       "top back center"       },
64    [AV_CHAN_TOP_BACK_RIGHT       ] = { "TBR",       "top back right"        },
65    [AV_CHAN_STEREO_LEFT          ] = { "DL",        "downmix left"          },
66    [AV_CHAN_STEREO_RIGHT         ] = { "DR",        "downmix right"         },
67    [AV_CHAN_WIDE_LEFT            ] = { "WL",        "wide left"             },
68    [AV_CHAN_WIDE_RIGHT           ] = { "WR",        "wide right"            },
69    [AV_CHAN_SURROUND_DIRECT_LEFT ] = { "SDL",       "surround direct left"  },
70    [AV_CHAN_SURROUND_DIRECT_RIGHT] = { "SDR",       "surround direct right" },
71    [AV_CHAN_LOW_FREQUENCY_2      ] = { "LFE2",      "low frequency 2"       },
72    [AV_CHAN_TOP_SIDE_LEFT        ] = { "TSL",       "top side left"         },
73    [AV_CHAN_TOP_SIDE_RIGHT       ] = { "TSR",       "top side right"        },
74    [AV_CHAN_BOTTOM_FRONT_CENTER  ] = { "BFC",       "bottom front center"   },
75    [AV_CHAN_BOTTOM_FRONT_LEFT    ] = { "BFL",       "bottom front left"     },
76    [AV_CHAN_BOTTOM_FRONT_RIGHT   ] = { "BFR",       "bottom front right"    },
77};
78
79static const char *get_channel_name(enum AVChannel channel_id)
80{
81    if ((unsigned) channel_id >= FF_ARRAY_ELEMS(channel_names) ||
82        !channel_names[channel_id].name)
83        return NULL;
84    return channel_names[channel_id].name;
85}
86
87void av_channel_name_bprint(AVBPrint *bp, enum AVChannel channel_id)
88{
89    if (channel_id >= AV_CHAN_AMBISONIC_BASE &&
90        channel_id <= AV_CHAN_AMBISONIC_END)
91        av_bprintf(bp, "AMBI%d", channel_id - AV_CHAN_AMBISONIC_BASE);
92    else if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names) &&
93             channel_names[channel_id].name)
94        av_bprintf(bp, "%s", channel_names[channel_id].name);
95    else if (channel_id == AV_CHAN_NONE)
96        av_bprintf(bp, "NONE");
97    else
98        av_bprintf(bp, "USR%d", channel_id);
99}
100
101int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel_id)
102{
103    AVBPrint bp;
104
105    if (!buf && buf_size)
106        return AVERROR(EINVAL);
107
108    av_bprint_init_for_buffer(&bp, buf, buf_size);
109    av_channel_name_bprint(&bp, channel_id);
110
111    return bp.len;
112}
113
114void av_channel_description_bprint(AVBPrint *bp, enum AVChannel channel_id)
115{
116    if (channel_id >= AV_CHAN_AMBISONIC_BASE &&
117        channel_id <= AV_CHAN_AMBISONIC_END)
118        av_bprintf(bp, "ambisonic ACN %d", channel_id - AV_CHAN_AMBISONIC_BASE);
119    else if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names) &&
120             channel_names[channel_id].description)
121        av_bprintf(bp, "%s", channel_names[channel_id].description);
122    else if (channel_id == AV_CHAN_NONE)
123        av_bprintf(bp, "none");
124    else
125        av_bprintf(bp, "user %d", channel_id);
126}
127
128int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel_id)
129{
130    AVBPrint bp;
131
132    if (!buf && buf_size)
133        return AVERROR(EINVAL);
134
135    av_bprint_init_for_buffer(&bp, buf, buf_size);
136    av_channel_description_bprint(&bp, channel_id);
137
138    return bp.len;
139}
140
141enum AVChannel av_channel_from_string(const char *str)
142{
143    int i;
144    char *endptr = (char *)str;
145    enum AVChannel id = AV_CHAN_NONE;
146
147    if (!strncmp(str, "AMBI", 4)) {
148        i = strtol(str + 4, NULL, 0);
149        if (i < 0 || i > AV_CHAN_AMBISONIC_END - AV_CHAN_AMBISONIC_BASE)
150            return AV_CHAN_NONE;
151        return AV_CHAN_AMBISONIC_BASE + i;
152    }
153
154    for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
155        if (channel_names[i].name && !strcmp(str, channel_names[i].name))
156            return i;
157    }
158    if (!strncmp(str, "USR", 3)) {
159        const char *p = str + 3;
160        id = strtol(p, &endptr, 0);
161    }
162    if (id >= 0 && !*endptr)
163        return id;
164
165    return AV_CHAN_NONE;
166}
167
168struct channel_layout_name {
169    const char *name;
170    AVChannelLayout layout;
171};
172
173static const struct channel_layout_name channel_layout_map[] = {
174    { "mono",           AV_CHANNEL_LAYOUT_MONO                },
175    { "stereo",         AV_CHANNEL_LAYOUT_STEREO              },
176    { "2.1",            AV_CHANNEL_LAYOUT_2POINT1             },
177    { "3.0",            AV_CHANNEL_LAYOUT_SURROUND            },
178    { "3.0(back)",      AV_CHANNEL_LAYOUT_2_1                 },
179    { "4.0",            AV_CHANNEL_LAYOUT_4POINT0             },
180    { "quad",           AV_CHANNEL_LAYOUT_QUAD                },
181    { "quad(side)",     AV_CHANNEL_LAYOUT_2_2                 },
182    { "3.1",            AV_CHANNEL_LAYOUT_3POINT1             },
183    { "5.0",            AV_CHANNEL_LAYOUT_5POINT0_BACK        },
184    { "5.0(side)",      AV_CHANNEL_LAYOUT_5POINT0             },
185    { "4.1",            AV_CHANNEL_LAYOUT_4POINT1             },
186    { "5.1",            AV_CHANNEL_LAYOUT_5POINT1_BACK        },
187    { "5.1(side)",      AV_CHANNEL_LAYOUT_5POINT1             },
188    { "6.0",            AV_CHANNEL_LAYOUT_6POINT0             },
189    { "6.0(front)",     AV_CHANNEL_LAYOUT_6POINT0_FRONT       },
190    { "hexagonal",      AV_CHANNEL_LAYOUT_HEXAGONAL           },
191    { "6.1",            AV_CHANNEL_LAYOUT_6POINT1             },
192    { "6.1(back)",      AV_CHANNEL_LAYOUT_6POINT1_BACK        },
193    { "6.1(front)",     AV_CHANNEL_LAYOUT_6POINT1_FRONT       },
194    { "7.0",            AV_CHANNEL_LAYOUT_7POINT0             },
195    { "7.0(front)",     AV_CHANNEL_LAYOUT_7POINT0_FRONT       },
196    { "7.1",            AV_CHANNEL_LAYOUT_7POINT1             },
197    { "7.1(wide)",      AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK   },
198    { "7.1(wide-side)", AV_CHANNEL_LAYOUT_7POINT1_WIDE        },
199    { "octagonal",      AV_CHANNEL_LAYOUT_OCTAGONAL           },
200    { "hexadecagonal",  AV_CHANNEL_LAYOUT_HEXADECAGONAL       },
201    { "downmix",        AV_CHANNEL_LAYOUT_STEREO_DOWNMIX,     },
202    { "22.2",           AV_CHANNEL_LAYOUT_22POINT2,           },
203};
204
205#if FF_API_OLD_CHANNEL_LAYOUT
206FF_DISABLE_DEPRECATION_WARNINGS
207static uint64_t get_channel_layout_single(const char *name, int name_len)
208{
209    int i;
210    char *end;
211    int64_t layout;
212
213    for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
214        if (strlen(channel_layout_map[i].name) == name_len &&
215            !memcmp(channel_layout_map[i].name, name, name_len))
216            return channel_layout_map[i].layout.u.mask;
217    }
218    for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
219        if (channel_names[i].name &&
220            strlen(channel_names[i].name) == name_len &&
221            !memcmp(channel_names[i].name, name, name_len))
222            return (int64_t)1 << i;
223
224    errno = 0;
225    i = strtol(name, &end, 10);
226
227    if (!errno && (end + 1 - name == name_len && *end  == 'c'))
228        return av_get_default_channel_layout(i);
229
230    errno = 0;
231    layout = strtoll(name, &end, 0);
232    if (!errno && end - name == name_len)
233        return FFMAX(layout, 0);
234    return 0;
235}
236
237uint64_t av_get_channel_layout(const char *name)
238{
239    const char *n, *e;
240    const char *name_end = name + strlen(name);
241    int64_t layout = 0, layout_single;
242
243    for (n = name; n < name_end; n = e + 1) {
244        for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
245        layout_single = get_channel_layout_single(n, e - n);
246        if (!layout_single)
247            return 0;
248        layout |= layout_single;
249    }
250    return layout;
251}
252
253int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels)
254{
255    int nb = 0;
256    char *end;
257    uint64_t layout = av_get_channel_layout(name);
258
259    if (layout) {
260        *channel_layout = layout;
261        *nb_channels = av_get_channel_layout_nb_channels(layout);
262        return 0;
263    }
264
265    nb = strtol(name, &end, 10);
266    if (!errno && *end  == 'C' && *(end + 1) == '\0' && nb > 0 && nb < 64) {
267        *channel_layout = 0;
268        *nb_channels = nb;
269        return 0;
270    }
271
272    return AVERROR(EINVAL);
273}
274
275void av_bprint_channel_layout(struct AVBPrint *bp,
276                              int nb_channels, uint64_t channel_layout)
277{
278    int i;
279
280    if (nb_channels <= 0)
281        nb_channels = av_get_channel_layout_nb_channels(channel_layout);
282
283    for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
284        if (nb_channels    == channel_layout_map[i].layout.nb_channels &&
285            channel_layout == channel_layout_map[i].layout.u.mask) {
286            av_bprintf(bp, "%s", channel_layout_map[i].name);
287            return;
288        }
289
290    av_bprintf(bp, "%d channels", nb_channels);
291    if (channel_layout) {
292        int i, ch;
293        av_bprintf(bp, " (");
294        for (i = 0, ch = 0; i < 64; i++) {
295            if ((channel_layout & (UINT64_C(1) << i))) {
296                const char *name = get_channel_name(i);
297                if (name) {
298                    if (ch > 0)
299                        av_bprintf(bp, "+");
300                    av_bprintf(bp, "%s", name);
301                }
302                ch++;
303            }
304        }
305        av_bprintf(bp, ")");
306    }
307}
308
309void av_get_channel_layout_string(char *buf, int buf_size,
310                                  int nb_channels, uint64_t channel_layout)
311{
312    AVBPrint bp;
313
314    av_bprint_init_for_buffer(&bp, buf, buf_size);
315    av_bprint_channel_layout(&bp, nb_channels, channel_layout);
316}
317
318int av_get_channel_layout_nb_channels(uint64_t channel_layout)
319{
320    return av_popcount64(channel_layout);
321}
322
323int64_t av_get_default_channel_layout(int nb_channels) {
324    int i;
325    for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
326        if (nb_channels == channel_layout_map[i].layout.nb_channels)
327            return channel_layout_map[i].layout.u.mask;
328    return 0;
329}
330
331int av_get_channel_layout_channel_index(uint64_t channel_layout,
332                                        uint64_t channel)
333{
334    if (!(channel_layout & channel) ||
335        av_get_channel_layout_nb_channels(channel) != 1)
336        return AVERROR(EINVAL);
337    channel_layout &= channel - 1;
338    return av_get_channel_layout_nb_channels(channel_layout);
339}
340
341const char *av_get_channel_name(uint64_t channel)
342{
343    int i;
344    if (av_get_channel_layout_nb_channels(channel) != 1)
345        return NULL;
346    for (i = 0; i < 64; i++)
347        if ((1ULL<<i) & channel)
348            return get_channel_name(i);
349    return NULL;
350}
351
352const char *av_get_channel_description(uint64_t channel)
353{
354    int i;
355    if (av_get_channel_layout_nb_channels(channel) != 1)
356        return NULL;
357    for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
358        if ((1ULL<<i) & channel)
359            return channel_names[i].description;
360    return NULL;
361}
362
363uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
364{
365    int i;
366
367    if (av_get_channel_layout_nb_channels(channel_layout) <= index)
368        return 0;
369
370    for (i = 0; i < 64; i++) {
371        if ((1ULL << i) & channel_layout && !index--)
372            return 1ULL << i;
373    }
374    return 0;
375}
376
377int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
378                                   const char **name)
379{
380    if (index >= FF_ARRAY_ELEMS(channel_layout_map))
381        return AVERROR_EOF;
382    if (layout) *layout = channel_layout_map[index].layout.u.mask;
383    if (name)   *name   = channel_layout_map[index].name;
384    return 0;
385}
386FF_ENABLE_DEPRECATION_WARNINGS
387#endif
388
389int av_channel_layout_from_mask(AVChannelLayout *channel_layout,
390                                uint64_t mask)
391{
392    if (!mask)
393        return AVERROR(EINVAL);
394
395    channel_layout->order       = AV_CHANNEL_ORDER_NATIVE;
396    channel_layout->nb_channels = av_popcount64(mask);
397    channel_layout->u.mask      = mask;
398
399    return 0;
400}
401
402int av_channel_layout_from_string(AVChannelLayout *channel_layout,
403                                  const char *str)
404{
405    int i;
406    int channels = 0, nb_channels = 0, native = 1;
407    enum AVChannel highest_channel = AV_CHAN_NONE;
408    const char *dup;
409    char *chlist, *end;
410    uint64_t mask = 0;
411
412    /* channel layout names */
413    for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
414        if (channel_layout_map[i].name && !strcmp(str, channel_layout_map[i].name)) {
415            *channel_layout = channel_layout_map[i].layout;
416            return 0;
417        }
418    }
419
420    /* ambisonic */
421    if (!strncmp(str, "ambisonic ", 10)) {
422        const char *p = str + 10;
423        char *endptr;
424        AVChannelLayout extra = {0};
425        int order;
426
427        order = strtol(p, &endptr, 0);
428        if (order < 0 || order + 1  > INT_MAX / (order + 1) ||
429            (*endptr && *endptr != '+'))
430            return AVERROR(EINVAL);
431
432        channel_layout->order       = AV_CHANNEL_ORDER_AMBISONIC;
433        channel_layout->nb_channels = (order + 1) * (order + 1);
434
435        if (*endptr) {
436            int ret = av_channel_layout_from_string(&extra, endptr + 1);
437            if (ret < 0)
438                return ret;
439            if (extra.nb_channels >= INT_MAX - channel_layout->nb_channels) {
440                av_channel_layout_uninit(&extra);
441                return AVERROR(EINVAL);
442            }
443
444            if (extra.order == AV_CHANNEL_ORDER_NATIVE) {
445                channel_layout->u.mask = extra.u.mask;
446            } else {
447                channel_layout->order = AV_CHANNEL_ORDER_CUSTOM;
448                channel_layout->u.map =
449                    av_calloc(channel_layout->nb_channels + extra.nb_channels,
450                              sizeof(*channel_layout->u.map));
451                if (!channel_layout->u.map) {
452                    av_channel_layout_uninit(&extra);
453                    return AVERROR(ENOMEM);
454                }
455
456                for (i = 0; i < channel_layout->nb_channels; i++)
457                    channel_layout->u.map[i].id = AV_CHAN_AMBISONIC_BASE + i;
458                for (i = 0; i < extra.nb_channels; i++) {
459                    enum AVChannel ch = av_channel_layout_channel_from_index(&extra, i);
460                    if (CHAN_IS_AMBI(ch)) {
461                        av_channel_layout_uninit(&extra);
462                        return AVERROR(EINVAL);
463                    }
464                    channel_layout->u.map[channel_layout->nb_channels + i].id = ch;
465                    if (extra.order == AV_CHANNEL_ORDER_CUSTOM &&
466                        extra.u.map[i].name[0])
467                        av_strlcpy(channel_layout->u.map[channel_layout->nb_channels + i].name,
468                                   extra.u.map[i].name,
469                                   sizeof(channel_layout->u.map[channel_layout->nb_channels + i].name));
470                }
471            }
472            channel_layout->nb_channels += extra.nb_channels;
473            av_channel_layout_uninit(&extra);
474        }
475
476        return 0;
477    }
478
479    chlist = av_strdup(str);
480    if (!chlist)
481        return AVERROR(ENOMEM);
482
483    /* channel names */
484    av_sscanf(str, "%d channels (%[^)]", &nb_channels, chlist);
485    end = strchr(str, ')');
486
487    dup = chlist;
488    while (*dup) {
489        char *channel, *chname;
490        int ret = av_opt_get_key_value(&dup, "@", "+", AV_OPT_FLAG_IMPLICIT_KEY, &channel, &chname);
491        if (ret < 0) {
492            av_free(chlist);
493            return ret;
494        }
495        if (*dup)
496            dup++; // skip separator
497        if (channel && !*channel)
498            av_freep(&channel);
499        for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
500            if (channel_names[i].name && !strcmp(channel ? channel : chname, channel_names[i].name)) {
501                if (channel || i < highest_channel || mask & (1ULL << i))
502                    native = 0; // Not a native layout, use a custom one
503                highest_channel = i;
504                mask |= 1ULL << i;
505                break;
506            }
507        }
508
509        if (!channel && i >= FF_ARRAY_ELEMS(channel_names)) {
510            char *endptr = chname;
511            enum AVChannel id = AV_CHAN_NONE;
512
513            if (!strncmp(chname, "USR", 3)) {
514                const char *p = chname + 3;
515                id = strtol(p, &endptr, 0);
516            }
517            if (id < 0 || *endptr) {
518                native = 0; // Unknown channel name
519                channels = 0;
520                mask = 0;
521                av_free(chname);
522                break;
523            }
524            if (id > 63)
525                native = 0; // Not a native layout, use a custom one
526            else {
527                if (id < highest_channel || mask & (1ULL << id))
528                    native = 0; // Not a native layout, use a custom one
529                highest_channel = id;
530                mask |= 1ULL << id;
531            }
532        }
533        channels++;
534        av_free(channel);
535        av_free(chname);
536    }
537
538    if (mask && native) {
539        av_free(chlist);
540        if (nb_channels && ((nb_channels != channels) || (!end || *++end)))
541            return AVERROR(EINVAL);
542        av_channel_layout_from_mask(channel_layout, mask);
543        return 0;
544    }
545
546    /* custom layout of channel names */
547    if (channels && !native) {
548        int idx = 0;
549
550        if (nb_channels && ((nb_channels != channels) || (!end || *++end))) {
551            av_free(chlist);
552            return AVERROR(EINVAL);
553        }
554
555        channel_layout->u.map = av_calloc(channels, sizeof(*channel_layout->u.map));
556        if (!channel_layout->u.map) {
557            av_free(chlist);
558            return AVERROR(ENOMEM);
559        }
560
561        channel_layout->order = AV_CHANNEL_ORDER_CUSTOM;
562        channel_layout->nb_channels = channels;
563
564        dup = chlist;
565        while (*dup) {
566            char *channel, *chname;
567            int ret = av_opt_get_key_value(&dup, "@", "+", AV_OPT_FLAG_IMPLICIT_KEY, &channel, &chname);
568            if (ret < 0) {
569                av_freep(&channel_layout->u.map);
570                av_free(chlist);
571                return ret;
572            }
573            if (*dup)
574                dup++; // skip separator
575            for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
576                if (channel_names[i].name && !strcmp(channel ? channel : chname, channel_names[i].name)) {
577                    channel_layout->u.map[idx].id = i;
578                    if (channel)
579                        av_strlcpy(channel_layout->u.map[idx].name, chname, sizeof(channel_layout->u.map[idx].name));
580                    idx++;
581                    break;
582                }
583            }
584            if (i >= FF_ARRAY_ELEMS(channel_names)) {
585                const char *p = (channel ? channel : chname) + 3;
586                channel_layout->u.map[idx].id = strtol(p, NULL, 0);
587                if (channel)
588                    av_strlcpy(channel_layout->u.map[idx].name, chname, sizeof(channel_layout->u.map[idx].name));
589                idx++;
590            }
591            av_free(channel);
592            av_free(chname);
593        }
594        av_free(chlist);
595
596        return 0;
597    }
598    av_freep(&chlist);
599
600    errno = 0;
601    mask = strtoull(str, &end, 0);
602
603    /* channel layout mask */
604    if (!errno && !*end && !strchr(str, '-') && mask) {
605        av_channel_layout_from_mask(channel_layout, mask);
606        return 0;
607    }
608
609    errno = 0;
610    channels = strtol(str, &end, 10);
611
612    /* number of channels */
613    if (!errno && !strcmp(end, "c") && channels > 0) {
614        av_channel_layout_default(channel_layout, channels);
615        if (channel_layout->order == AV_CHANNEL_ORDER_NATIVE)
616            return 0;
617    }
618
619    /* number of unordered channels */
620    if (!errno && (!strcmp(end, "C") || !strcmp(end, " channels"))
621        && channels > 0) {
622        channel_layout->order = AV_CHANNEL_ORDER_UNSPEC;
623        channel_layout->nb_channels = channels;
624        return 0;
625    }
626
627    return AVERROR(EINVAL);
628}
629
630void av_channel_layout_uninit(AVChannelLayout *channel_layout)
631{
632    if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM)
633        av_freep(&channel_layout->u.map);
634    memset(channel_layout, 0, sizeof(*channel_layout));
635}
636
637int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
638{
639    av_channel_layout_uninit(dst);
640    *dst = *src;
641    if (src->order == AV_CHANNEL_ORDER_CUSTOM) {
642        dst->u.map = av_malloc_array(src->nb_channels, sizeof(*dst->u.map));
643        if (!dst->u.map)
644            return AVERROR(ENOMEM);
645        memcpy(dst->u.map, src->u.map, src->nb_channels * sizeof(*src->u.map));
646    }
647    return 0;
648}
649
650/**
651 * If the layout is n-th order standard-order ambisonic, with optional
652 * extra non-diegetic channels at the end, return the order.
653 * Return a negative error code otherwise.
654 */
655static int ambisonic_order(const AVChannelLayout *channel_layout)
656{
657    int i, highest_ambi, order;
658
659    highest_ambi = -1;
660    if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC)
661        highest_ambi = channel_layout->nb_channels - av_popcount64(channel_layout->u.mask) - 1;
662    else {
663        const AVChannelCustom *map = channel_layout->u.map;
664        av_assert0(channel_layout->order == AV_CHANNEL_ORDER_CUSTOM);
665
666        for (i = 0; i < channel_layout->nb_channels; i++) {
667            int is_ambi = CHAN_IS_AMBI(map[i].id);
668
669            /* ambisonic following non-ambisonic */
670            if (i > 0 && is_ambi && !CHAN_IS_AMBI(map[i - 1].id))
671                return AVERROR(EINVAL);
672
673            /* non-default ordering */
674            if (is_ambi && map[i].id - AV_CHAN_AMBISONIC_BASE != i)
675                return AVERROR(EINVAL);
676
677            if (CHAN_IS_AMBI(map[i].id))
678                highest_ambi = i;
679        }
680    }
681    /* no ambisonic channels*/
682    if (highest_ambi < 0)
683        return AVERROR(EINVAL);
684
685    order = floor(sqrt(highest_ambi));
686    /* incomplete order - some harmonics are missing */
687    if ((order + 1) * (order + 1) != highest_ambi + 1)
688        return AVERROR(EINVAL);
689
690    return order;
691}
692
693/**
694 * If the custom layout is n-th order standard-order ambisonic, with optional
695 * extra non-diegetic channels at the end, write its string description in bp.
696 * Return a negative error code otherwise.
697 */
698static int try_describe_ambisonic(AVBPrint *bp, const AVChannelLayout *channel_layout)
699{
700    int nb_ambi_channels;
701    int order = ambisonic_order(channel_layout);
702    if (order < 0)
703        return order;
704
705    av_bprintf(bp, "ambisonic %d", order);
706
707    /* extra channels present */
708    nb_ambi_channels = (order + 1) * (order + 1);
709    if (nb_ambi_channels < channel_layout->nb_channels) {
710        AVChannelLayout extra = { 0 };
711
712        if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC) {
713            extra.order       = AV_CHANNEL_ORDER_NATIVE;
714            extra.nb_channels = av_popcount64(channel_layout->u.mask);
715            extra.u.mask      = channel_layout->u.mask;
716        } else {
717            extra.order       = AV_CHANNEL_ORDER_CUSTOM;
718            extra.nb_channels = channel_layout->nb_channels - nb_ambi_channels;
719            extra.u.map       = channel_layout->u.map + nb_ambi_channels;
720        }
721
722        av_bprint_chars(bp, '+', 1);
723        av_channel_layout_describe_bprint(&extra, bp);
724        /* Not calling uninit here on extra because we don't own the u.map pointer */
725    }
726
727    return 0;
728}
729
730int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
731                                      AVBPrint *bp)
732{
733    int i;
734
735    switch (channel_layout->order) {
736    case AV_CHANNEL_ORDER_NATIVE:
737        for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
738            if (channel_layout->u.mask == channel_layout_map[i].layout.u.mask) {
739                av_bprintf(bp, "%s", channel_layout_map[i].name);
740                return 0;
741            }
742        // fall-through
743    case AV_CHANNEL_ORDER_CUSTOM:
744        if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM) {
745            int res = try_describe_ambisonic(bp, channel_layout);
746            if (res >= 0)
747                return 0;
748        }
749        if (channel_layout->nb_channels)
750            av_bprintf(bp, "%d channels (", channel_layout->nb_channels);
751        for (i = 0; i < channel_layout->nb_channels; i++) {
752            enum AVChannel ch = av_channel_layout_channel_from_index(channel_layout, i);
753
754            if (i)
755                av_bprintf(bp, "+");
756            av_channel_name_bprint(bp, ch);
757            if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM &&
758                channel_layout->u.map[i].name[0])
759                av_bprintf(bp, "@%s", channel_layout->u.map[i].name);
760        }
761        if (channel_layout->nb_channels) {
762            av_bprintf(bp, ")");
763            return 0;
764        }
765        // fall-through
766    case AV_CHANNEL_ORDER_UNSPEC:
767        av_bprintf(bp, "%d channels", channel_layout->nb_channels);
768        return 0;
769    case AV_CHANNEL_ORDER_AMBISONIC:
770        return try_describe_ambisonic(bp, channel_layout);
771    default:
772        return AVERROR(EINVAL);
773    }
774}
775
776int av_channel_layout_describe(const AVChannelLayout *channel_layout,
777                               char *buf, size_t buf_size)
778{
779    AVBPrint bp;
780    int ret;
781
782    if (!buf && buf_size)
783        return AVERROR(EINVAL);
784
785    av_bprint_init_for_buffer(&bp, buf, buf_size);
786    ret = av_channel_layout_describe_bprint(channel_layout, &bp);
787    if (ret < 0)
788        return ret;
789
790    return bp.len;
791}
792
793enum AVChannel
794av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout,
795                                     unsigned int idx)
796{
797    int i;
798
799    if (idx >= channel_layout->nb_channels)
800        return AV_CHAN_NONE;
801
802    switch (channel_layout->order) {
803    case AV_CHANNEL_ORDER_CUSTOM:
804        return channel_layout->u.map[idx].id;
805    case AV_CHANNEL_ORDER_AMBISONIC: {
806        int ambi_channels = channel_layout->nb_channels - av_popcount64(channel_layout->u.mask);
807        if (idx < ambi_channels)
808            return AV_CHAN_AMBISONIC_BASE + idx;
809        idx -= ambi_channels;
810        }
811    // fall-through
812    case AV_CHANNEL_ORDER_NATIVE:
813        for (i = 0; i < 64; i++) {
814            if ((1ULL << i) & channel_layout->u.mask && !idx--)
815                return i;
816        }
817    default:
818        return AV_CHAN_NONE;
819    }
820}
821
822enum AVChannel
823av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout,
824                                      const char *str)
825{
826    int index = av_channel_layout_index_from_string(channel_layout, str);
827
828    if (index < 0)
829        return AV_CHAN_NONE;
830
831    return av_channel_layout_channel_from_index(channel_layout, index);
832}
833
834int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
835                                         enum AVChannel channel)
836{
837    int i;
838
839    if (channel == AV_CHAN_NONE)
840        return AVERROR(EINVAL);
841
842    switch (channel_layout->order) {
843    case AV_CHANNEL_ORDER_CUSTOM:
844        for (i = 0; i < channel_layout->nb_channels; i++)
845            if (channel_layout->u.map[i].id == channel)
846                return i;
847        return AVERROR(EINVAL);
848    case AV_CHANNEL_ORDER_AMBISONIC:
849    case AV_CHANNEL_ORDER_NATIVE: {
850        uint64_t mask = channel_layout->u.mask;
851        int ambi_channels = channel_layout->nb_channels - av_popcount64(mask);
852        if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC &&
853            channel >= AV_CHAN_AMBISONIC_BASE) {
854            if (channel - AV_CHAN_AMBISONIC_BASE >= ambi_channels)
855                return AVERROR(EINVAL);
856            return channel - AV_CHAN_AMBISONIC_BASE;
857        }
858        if ((unsigned)channel > 63 || !(mask & (1ULL << channel)))
859            return AVERROR(EINVAL);
860        mask &= (1ULL << channel) - 1;
861        return av_popcount64(mask) + ambi_channels;
862        }
863    default:
864        return AVERROR(EINVAL);
865    }
866}
867
868int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
869                                        const char *str)
870{
871    char *chname;
872    enum AVChannel ch = AV_CHAN_NONE;
873
874    switch (channel_layout->order) {
875    case AV_CHANNEL_ORDER_CUSTOM:
876        chname = strstr(str, "@");
877        if (chname) {
878            char buf[16];
879            chname++;
880            av_strlcpy(buf, str, FFMIN(sizeof(buf), chname - str));
881            if (!*chname)
882                chname = NULL;
883            ch = av_channel_from_string(buf);
884            if (ch == AV_CHAN_NONE && *buf)
885                return AVERROR(EINVAL);
886        }
887        for (int i = 0; chname && i < channel_layout->nb_channels; i++) {
888            if (!strcmp(chname, channel_layout->u.map[i].name) &&
889                (ch == AV_CHAN_NONE || ch == channel_layout->u.map[i].id))
890                return i;
891        }
892        // fall-through
893    case AV_CHANNEL_ORDER_AMBISONIC:
894    case AV_CHANNEL_ORDER_NATIVE:
895        ch = av_channel_from_string(str);
896        if (ch == AV_CHAN_NONE)
897            return AVERROR(EINVAL);
898        return av_channel_layout_index_from_channel(channel_layout, ch);
899    }
900
901    return AVERROR(EINVAL);
902}
903
904int av_channel_layout_check(const AVChannelLayout *channel_layout)
905{
906    if (channel_layout->nb_channels <= 0)
907        return 0;
908
909    switch (channel_layout->order) {
910    case AV_CHANNEL_ORDER_NATIVE:
911        return av_popcount64(channel_layout->u.mask) == channel_layout->nb_channels;
912    case AV_CHANNEL_ORDER_CUSTOM:
913        if (!channel_layout->u.map)
914            return 0;
915        for (int i = 0; i < channel_layout->nb_channels; i++) {
916            if (channel_layout->u.map[i].id == AV_CHAN_NONE)
917                return 0;
918        }
919        return 1;
920    case AV_CHANNEL_ORDER_AMBISONIC:
921        /* If non-diegetic channels are present, ensure they are taken into account */
922        return av_popcount64(channel_layout->u.mask) < channel_layout->nb_channels;
923    case AV_CHANNEL_ORDER_UNSPEC:
924        return 1;
925    default:
926        return 0;
927    }
928}
929
930int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1)
931{
932    int i;
933
934    /* different channel counts -> not equal */
935    if (chl->nb_channels != chl1->nb_channels)
936        return 1;
937
938    /* if only one is unspecified -> not equal */
939    if ((chl->order  == AV_CHANNEL_ORDER_UNSPEC) !=
940        (chl1->order == AV_CHANNEL_ORDER_UNSPEC))
941        return 1;
942    /* both are unspecified -> equal */
943    else if (chl->order == AV_CHANNEL_ORDER_UNSPEC)
944        return 0;
945
946    /* can compare masks directly */
947    if ((chl->order == AV_CHANNEL_ORDER_NATIVE ||
948         chl->order == AV_CHANNEL_ORDER_AMBISONIC) &&
949        chl->order == chl1->order)
950        return chl->u.mask != chl1->u.mask;
951
952    /* compare channel by channel */
953    for (i = 0; i < chl->nb_channels; i++)
954        if (av_channel_layout_channel_from_index(chl,  i) !=
955            av_channel_layout_channel_from_index(chl1, i))
956            return 1;
957    return 0;
958}
959
960void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
961{
962    int i;
963    for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
964        if (nb_channels == channel_layout_map[i].layout.nb_channels) {
965            *ch_layout = channel_layout_map[i].layout;
966            return;
967        }
968
969    ch_layout->order       = AV_CHANNEL_ORDER_UNSPEC;
970    ch_layout->nb_channels = nb_channels;
971}
972
973const AVChannelLayout *av_channel_layout_standard(void **opaque)
974{
975    uintptr_t i = (uintptr_t)*opaque;
976    const AVChannelLayout *ch_layout = NULL;
977
978    if (i < FF_ARRAY_ELEMS(channel_layout_map)) {
979        ch_layout = &channel_layout_map[i].layout;
980        *opaque = (void*)(i + 1);
981    }
982
983    return ch_layout;
984}
985
986uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
987                                  uint64_t mask)
988{
989    uint64_t ret = 0;
990    int i;
991
992    switch (channel_layout->order) {
993    case AV_CHANNEL_ORDER_NATIVE:
994    case AV_CHANNEL_ORDER_AMBISONIC:
995        return channel_layout->u.mask & mask;
996    case AV_CHANNEL_ORDER_CUSTOM:
997        for (i = 0; i < 64; i++)
998            if (mask & (1ULL << i) && av_channel_layout_index_from_channel(channel_layout, i) >= 0)
999                ret |= (1ULL << i);
1000        break;
1001    }
1002
1003    return ret;
1004}
1005