aboutsummaryrefslogtreecommitdiffhomepage
path: root/audio/chmap.c
blob: 254d9b38da3d3a6e2e7d87ef263b37accd497a43 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mpv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <assert.h>

#include "core/mp_msg.h"
#include "chmap.h"

// Names taken from libavutil/channel_layout.c (Not accessible by API.)
// Use of these names is hard-coded in some places (e.g. ao_alsa.c)
static const char *speaker_names[MP_SPEAKER_ID_COUNT][2] = {
    [MP_SPEAKER_ID_FL]          = {"fl",   "front left"},
    [MP_SPEAKER_ID_FR]          = {"fr",   "front right"},
    [MP_SPEAKER_ID_FC]          = {"fc",   "front center"},
    [MP_SPEAKER_ID_LFE]         = {"lfe",  "low frequency"},
    [MP_SPEAKER_ID_BL]          = {"bl",   "back left"},
    [MP_SPEAKER_ID_BR]          = {"br",   "back right"},
    [MP_SPEAKER_ID_FLC]         = {"flc",  "front left-of-center"},
    [MP_SPEAKER_ID_FRC]         = {"frc",  "front right-of-center"},
    [MP_SPEAKER_ID_BC]          = {"bc",   "back center"},
    [MP_SPEAKER_ID_SL]          = {"sl",   "side left"},
    [MP_SPEAKER_ID_SR]          = {"sr",   "side right"},
    [MP_SPEAKER_ID_TC]          = {"tc",   "top center"},
    [MP_SPEAKER_ID_TFL]         = {"tfl",  "top front left"},
    [MP_SPEAKER_ID_TFC]         = {"tfc",  "top front center"},
    [MP_SPEAKER_ID_TFR]         = {"tfr",  "top front right"},
    [MP_SPEAKER_ID_TBL]         = {"tbl",  "top back left"},
    [MP_SPEAKER_ID_TBC]         = {"tbc",  "top back center"},
    [MP_SPEAKER_ID_TBR]         = {"tbr",  "top back right"},
    [MP_SPEAKER_ID_DL]          = {"dl",   "downmix left"},
    [MP_SPEAKER_ID_DR]          = {"dr",   "downmix right"},
    [MP_SPEAKER_ID_WL]          = {"wl",   "wide left"},
    [MP_SPEAKER_ID_WR]          = {"wr",   "wide right"},
    [MP_SPEAKER_ID_SDL]         = {"sdl",  "surround direct left"},
    [MP_SPEAKER_ID_SDR]         = {"sdr",  "surround direct right"},
    [MP_SPEAKER_ID_LFE2]        = {"lfe2", "low frequency 2"},
};

// Names taken from libavutil/channel_layout.c (Not accessible by API.)
// Channel order corresponds to lavc/waveex, except for the alsa entries.
static const char *std_layout_names[][2] = {
    {"empty",           ""}, // not in lavc
    {"mono",            "fc"},
    {"stereo",          "fl-fr"},
    {"2.1",             "fl-fr-lfe"},
    {"3.0",             "fl-fr-fc"},
    {"3.0(back)",       "fl-fr-bc"},
    {"4.0",             "fl-fr-fc-bc"},
    {"quad",            "fl-fr-bl-br"},
    {"quad(side)",      "fl-fr-sl-sr"},
    {"3.1",             "fl-fr-fc-lfe"},
    {"5.0",             "fl-fr-fc-bl-br"},
    {"5.0(alsa)",       "fl-fr-bl-br-fc"}, // not in lavc
    {"5.0(side)",       "fl-fr-fc-sl-sr"},
    {"4.1",             "fl-fr-fc-lfe-bc"},
    {"4.1(alsa)",       "fl-fr-bl-br-lfe"}, // not in lavc
    {"5.1",             "fl-fr-fc-lfe-bl-br"},
    {"5.1(alsa)",       "fl-fr-bl-br-fc-lfe"}, // not in lavc
    {"5.1(side)",       "fl-fr-fc-lfe-sl-sr"},
    {"6.0",             "fl-fr-fc-bc-sl-sr"},
    {"6.0(front)",      "fl-fr-flc-frc-sl-sr"},
    {"hexagonal",       "fl-fr-fc-bl-br-bc"},
    {"6.1",             "fl-fr-fc-lfe-bc-sl-sr"},
    {"6.1(back)",       "fl-fr-fc-lfe-bl-br-bc"}, // lavc calls this "6.1" too
    {"6.1(front)",      "fl-fr-lfe-flc-frc-sl-sr"},
    {"7.0",             "fl-fr-fc-bl-br-sl-sr"},
    {"7.0(front)",      "fl-fr-fc-flc-frc-sl-sr"},
    {"7.1",             "fl-fr-fc-lfe-bl-br-sl-sr"},
    {"7.1(alsa)",       "fl-fr-bl-br-fc-lfe-sl-sr"}, // not in lavc
    {"7.1(wide)",       "fl-fr-fc-lfe-bl-br-flc-frc"},
    {"7.1(wide-side)",  "fl-fr-fc-lfe-flc-frc-sl-sr"},
    {"octagonal",       "fl-fr-fc-bl-br-bc-sl-sr"},
    {"downmix",         "dl-dr"},
    {0}
};

static const struct mp_chmap default_layouts[MP_NUM_CHANNELS + 1] = {
    {0},                                        // empty
    MP_CHMAP_INIT_MONO,                         // mono
    MP_CHMAP2(FL, FR),                          // stereo
    MP_CHMAP3(FL, FR, LFE),                     // 2.1
    MP_CHMAP4(FL, FR, FC, BC),                  // 4.0
    MP_CHMAP5(FL, FR, FC, BL,  BR),             // 5.0
    MP_CHMAP6(FL, FR, FC, LFE, BL, BR),         // 5.1
    MP_CHMAP7(FL, FR, FC, LFE, BC, SL, SR),     // 6.1
    MP_CHMAP8(FL, FR, FC, LFE, BL, BR, SL, SR), // 7.1
};

// The channel order was lavc/waveex, but differs from lavc for 5, 6 and 8
// channels. 3 and 7 channels were likely undefined (no ALSA support).
// I'm not sure about the 4 channel case: ALSA uses "quad", while the ffmpeg
// default layout is "4.0".
static const char *mplayer_layouts[MP_NUM_CHANNELS + 1] = {
    [1] = "mono",
    [2] = "stereo",
    [4] = "quad",
    [5] = "5.0(alsa)",
    [6] = "5.1(alsa)",
    [8] = "7.1(alsa)",
};

// Returns true if speakers are mapped uniquely, and there's at least 1 channel.
bool mp_chmap_is_valid(const struct mp_chmap *src)
{
    bool mapped[MP_SPEAKER_ID_COUNT] = {0};
    for (int n = 0; n < src->num; n++) {
        int sp = src->speaker[n];
        if (sp >= MP_SPEAKER_ID_COUNT || mapped[sp])
            return false;
        mapped[sp] = true;
    }
    return src->num > 0;
}

bool mp_chmap_is_empty(const struct mp_chmap *src)
{
    return src->num == 0;
}

// Return true if the channel map defines the number of the channels only, and
// the channels have to meaning associated with them.
bool mp_chmap_is_unknown(const struct mp_chmap *src)
{
    for (int n = 0; n < src->num; n++) {
        int speaker = src->speaker[n];
        if (speaker >= MP_SPEAKER_ID_UNKNOWN0 &&
            speaker <= MP_SPEAKER_ID_UNKNOWN_LAST)
            return true;
    }
    return false;
}

// Note: empty channel maps compare as equal. Invalid ones can equal too.
bool mp_chmap_equals(const struct mp_chmap *a, const struct mp_chmap *b)
{
    if (a->num != b->num)
        return false;
    for (int n = 0; n < a->num; n++) {
        if (a->speaker[n] != b->speaker[n])
            return false;
    }
    return true;
}

// Whether they use the same speakers (even if in different order).
bool mp_chmap_equals_reordered(const struct mp_chmap *a, const struct mp_chmap *b)
{
    struct mp_chmap t1 = *a, t2 = *b;
    mp_chmap_reorder_norm(&t1);
    mp_chmap_reorder_norm(&t2);
    return mp_chmap_equals(&t1, &t2);
}

bool mp_chmap_is_compatible(const struct mp_chmap *a, const struct mp_chmap *b)
{
    if (mp_chmap_equals(a, b))
        return true;
    if (a->num == b->num && (mp_chmap_is_unknown(a) || mp_chmap_is_unknown(b)))
        return true;
    return false;
}

bool mp_chmap_is_stereo(const struct mp_chmap *src)
{
    static const struct mp_chmap stereo = MP_CHMAP_INIT_STEREO;
    return mp_chmap_equals(src, &stereo);
}

static int comp_uint8(const void *a, const void *b)
{
    return *(const uint8_t *)a - *(const uint8_t *)b;
}

// Reorder channels to normal order, with monotonically increasing speaker IDs.
// We define this order as the same order used with waveex.
void mp_chmap_reorder_norm(struct mp_chmap *map)
{
    uint8_t *arr = &map->speaker[0];
    qsort(arr, map->num, 1, comp_uint8);
}

// Set *dst to a standard layout with the given number of channels.
// If the number of channels is invalid, an invalid map is set, and
// mp_chmap_is_valid(dst) will return false.
void mp_chmap_from_channels(struct mp_chmap *dst, int num_channels)
{
    if (num_channels < 0 || num_channels > MP_NUM_CHANNELS) {
        *dst = (struct mp_chmap) {0};
    } else {
        *dst = default_layouts[num_channels];
    }
}

// Try to do what mplayer/mplayer2/mpv did before channel layouts were
// introduced, i.e. get the old default channel order.
void mp_chmap_from_channels_alsa(struct mp_chmap *dst, int num_channels)
{
    if (num_channels < 0 || num_channels > MP_NUM_CHANNELS) {
        *dst = (struct mp_chmap) {0};
    } else {
        mp_chmap_from_str(dst, bstr0(mplayer_layouts[num_channels]));
        if (!dst->num)
            mp_chmap_from_channels(dst, num_channels);
    }
}

// Set *dst to an unknown layout for the given numbers of channels.
// If the number of channels is invalid, an invalid map is set, and
// mp_chmap_is_valid(dst) will return false.
void mp_chmap_set_unknown(struct mp_chmap *dst, int num_channels)
{
    if (num_channels < 0 || num_channels > MP_NUM_CHANNELS) {
        *dst = (struct mp_chmap) {0};
    } else {
        dst->num = num_channels;
        for (int n = 0; n < dst->num; n++)
            dst->speaker[n] = MP_SPEAKER_ID_UNKNOWN0 + n;
    }
}

// Return channel index of the given speaker, or -1.
static int mp_chmap_find_speaker(const struct mp_chmap *map, int speaker)
{
    for (int n = 0; n < map->num; n++) {
        if (map->speaker[n] == speaker)
            return n;
    }
    return -1;
}

static void mp_chmap_remove_speaker(struct mp_chmap *map, int speaker)
{
    int index = mp_chmap_find_speaker(map, speaker);
    if (index >= 0) {
        for (int n = index; n < map->num - 1; n++)
            map->speaker[n] = map->speaker[n + 1];
        map->num--;
    }
}

// Some decoders output additional, redundant channels, which are usually
// useless and will mess up proper audio output channel handling.
// map: channel map from which the channels should be removed
// requested: if not NULL, and if it contains any of the "useless" channels,
//            don't remove them (this is for convenience)
void mp_chmap_remove_useless_channels(struct mp_chmap *map,
                                      const struct mp_chmap *requested)
{
    if (requested &&
        mp_chmap_find_speaker(requested, MP_SPEAKER_ID_DL) >= 0)
        return;

    if (map->num > 2) {
        mp_chmap_remove_speaker(map, MP_SPEAKER_ID_DL);
        mp_chmap_remove_speaker(map, MP_SPEAKER_ID_DR);
    }
}

// Return the ffmpeg/libav channel layout as in <libavutil/channel_layout.h>.
// Warning: this ignores the order of the channels, and will return a channel
//          mask even if the order is different from libavcodec's.
uint64_t mp_chmap_to_lavc_unchecked(const struct mp_chmap *src)
{
    // lavc has no concept for unknown layouts yet, so pick a default
    struct mp_chmap t = *src;
    if (mp_chmap_is_unknown(&t))
        mp_chmap_from_channels(&t, t.num);
    uint64_t mask = 0;
    for (int n = 0; n < t.num; n++)
        mask |= 1ULL << t.speaker[n];
    return mask;
}

// Return the ffmpeg/libav channel layout as in <libavutil/channel_layout.h>.
// Returns 0 if the channel order doesn't match lavc's or if it's invalid.
uint64_t mp_chmap_to_lavc(const struct mp_chmap *src)
{
    if (!mp_chmap_is_lavc(src))
        return 0;
    return mp_chmap_to_lavc_unchecked(src);
}

// Set channel map from the ffmpeg/libav channel layout as in
// <libavutil/channel_layout.h>.
// If the number of channels exceed MP_NUM_CHANNELS, set dst to empty.
void mp_chmap_from_lavc(struct mp_chmap *dst, uint64_t src)
{
    dst->num = 0;
    for (int n = 0; n < 64; n++) {
        if (src & (1ULL << n)) {
            if (dst->num >= MP_NUM_CHANNELS) {
                dst->num = 0;
                return;
            }
            dst->speaker[dst->num] = n;
            dst->num++;
        }
    }
}

bool mp_chmap_is_lavc(const struct mp_chmap *src)
{
    if (!mp_chmap_is_valid(src))
        return false;
    if (mp_chmap_is_unknown(src))
        return true;
    // lavc's channel layout is a bit mask, and channels are always ordered
    // from LSB to MSB speaker bits, so speaker IDs have to increase.
    assert(src->num > 0);
    for (int n = 1; n < src->num; n++) {
        if (src->speaker[n - 1] >= src->speaker[n])
            return false;
    }
    for (int n = 0; n < src->num; n++) {
        if (src->speaker[n] >= 64)
            return false;
    }
    return true;
}

void mp_chmap_reorder_to_lavc(struct mp_chmap *map)
{
    if (!mp_chmap_is_valid(map))
        return;
    uint64_t mask = mp_chmap_to_lavc_unchecked(map);
    mp_chmap_from_lavc(map, mask);
}

// Get reordering array for from->to reordering. from->to must have the same set
// of speakers (i.e. same number and speaker IDs, just different order). Then,
// for each speaker n, dst[n] will be set such that:
//      to->speaker[dst[n]] = from->speaker[n]
// (dst[n] gives the source channel for destination channel n)
void mp_chmap_get_reorder(int dst[MP_NUM_CHANNELS], const struct mp_chmap *from,
                          const struct mp_chmap *to)
{
    assert(from->num == to->num);
    if (mp_chmap_is_unknown(from) || mp_chmap_is_unknown(to)) {
        for (int n = 0; n < from->num; n++)
            dst[n] = n;
        return;
    }
    // Same set of speakers required
    assert(mp_chmap_equals_reordered(from, to));
    for (int n = 0; n < from->num; n++) {
        int src = from->speaker[n];
        dst[n] = -1;
        for (int i = 0; i < to->num; i++) {
            if (src == to->speaker[i]) {
                dst[n] = i;
                break;
            }
        }
        assert(dst[n] != -1);
    }
    for (int n = 0; n < from->num; n++)
        assert(to->speaker[dst[n]] == from->speaker[n]);
}

// Returns something like "fl-fr-fc". If there's a standard layout in lavc
// order, return that, e.g. "3.0" instead of "fl-fr-fc".
// Unassigned but valid speakers get names like "sp28".
char *mp_chmap_to_str(const struct mp_chmap *src)
{
    char *res = talloc_strdup(NULL, "");

    if (mp_chmap_is_unknown(src))
        return talloc_asprintf_append_buffer(res, "unknown%d", src->num);

    for (int n = 0; n < src->num; n++) {
        int sp = src->speaker[n];
        const char *s = sp < MP_SPEAKER_ID_COUNT ? speaker_names[sp][0] : NULL;
        char buf[10];
        if (!s) {
            snprintf(buf, sizeof(buf), "sp%d", sp);
            s = buf;
        }
        res = talloc_asprintf_append_buffer(res, "%s%s", n > 0 ? "-" : "", s);
    }

    // To standard layout name
    for (int n = 0; std_layout_names[n][0]; n++) {
        if (res && strcmp(res, std_layout_names[n][1]) == 0) {
            talloc_free(res);
            res = talloc_strdup(NULL, std_layout_names[n][0]);
            break;
        }
    }

    return res;
}

// If src can be parsed as channel map (as produced by mp_chmap_to_str()),
// return true and set *dst. Otherwise, return false and don't change *dst.
// Note: call mp_chmap_is_valid() to test whether the returned map is valid
//       the map could be empty, or contain multiply mapped channels
bool mp_chmap_from_str(struct mp_chmap *dst, bstr src)
{
    // Single number corresponds to mp_chmap_from_channels()
    if (src.len > 0) {
        bstr t = src;
        bool unknown = bstr_eatstart0(&t, "unknown");
        bstr rest;
        long long count = bstrtoll(t, &rest, 10);
        if (rest.len == 0) {
            struct mp_chmap res;
            if (unknown) {
                mp_chmap_set_unknown(&res, count);
            } else {
                mp_chmap_from_channels(&res, count);
            }
            if (mp_chmap_is_valid(&res)) {
                *dst = res;
                return true;
            }
        }
    }

    // From standard layout name
    for (int n = 0; std_layout_names[n][0]; n++) {
        if (bstr_equals0(src, std_layout_names[n][0])) {
            src = bstr0(std_layout_names[n][1]);
            break;
        }
    }

    // Explicit speaker list (separated by "-")
    struct mp_chmap res = {0};
    while (src.len) {
        bstr s;
        bstr_split_tok(src, "-", &s, &src);
        int speaker = -1;
        for (int n = 0; n < MP_SPEAKER_ID_COUNT; n++) {
            const char *name = speaker_names[n][0];
            if (name && bstr_equals0(s, name)) {
                speaker = n;
                break;
            }
        }
        if (speaker < 0) {
            if (bstr_eatstart0(&s, "sp")) {
                long long sp = bstrtoll(s, &s, 0);
                if (s.len == 0 && sp >= 0 && sp < MP_SPEAKER_ID_COUNT)
                    speaker = sp;
            }
            if (speaker < 0)
                return false;
        }
        if (res.num >= MP_NUM_CHANNELS)
            return false;
        res.speaker[res.num] = speaker;
        res.num++;
    }

    *dst = res;
    return true;
}

void mp_chmap_print_help(int msgt, int msgl)
{
    mp_msg(msgt, msgl, "Speakers:\n");
    for (int n = 0; n < MP_SPEAKER_ID_COUNT; n++) {
        if (speaker_names[n][0])
            mp_msg(msgt, msgl, "    %-16s (%s)\n",
                   speaker_names[n][0], speaker_names[n][1]);
    }
    mp_msg(msgt, msgl, "Standard layouts:\n");
    for (int n = 0; std_layout_names[n][0]; n++) {
        mp_msg(msgt, msgl, "    %-16s (%s)\n",
               std_layout_names[n][0], std_layout_names[n][1]);
    }
    for (int n = 0; n < MP_NUM_CHANNELS; n++)
        mp_msg(msgt, msgl, "    unknown%d\n", n);
}