summaryrefslogtreecommitdiffstats
path: root/sub/dec_sub.c
blob: 11ab879211c0dccfaeeaf8a28fc5d47a99b9957e (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
/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <pthread.h>

#include "config.h"
#include "demux/demux.h"
#include "sd.h"
#include "dec_sub.h"
#include "options/options.h"
#include "common/global.h"
#include "common/msg.h"
#include "common/recorder.h"
#include "osdep/threads.h"

extern const struct sd_functions sd_ass;
extern const struct sd_functions sd_lavc;

static const struct sd_functions *const sd_list[] = {
    &sd_lavc,
#if HAVE_LIBASS
    &sd_ass,
#endif
    NULL
};

struct dec_sub {
    pthread_mutex_t lock;

    struct mp_log *log;
    struct mpv_global *global;
    struct MPOpts *opts;

    struct mp_recorder_sink *recorder_sink;

    struct attachment_list *attachments;

    struct sh_stream *sh;
    double last_pkt_pts;
    bool preload_attempted;

    struct mp_codec_params *codec;
    double start, end;

    double last_vo_pts;
    struct sd *sd;

    struct demux_packet *new_segment;
};

void sub_lock(struct dec_sub *sub)
{
    pthread_mutex_lock(&sub->lock);
}

void sub_unlock(struct dec_sub *sub)
{
    pthread_mutex_unlock(&sub->lock);
}

void sub_destroy(struct dec_sub *sub)
{
    if (!sub)
        return;
    sub_reset(sub);
    sub->sd->driver->uninit(sub->sd);
    talloc_free(sub->sd);
    pthread_mutex_destroy(&sub->lock);
    talloc_free(sub);
}

static struct sd *init_decoder(struct dec_sub *sub)
{
    for (int n = 0; sd_list[n]; n++) {
        const struct sd_functions *driver = sd_list[n];
        struct sd *sd = talloc(NULL, struct sd);
        *sd = (struct sd){
            .global = sub->global,
            .log = mp_log_new(sd, sub->log, driver->name),
            .opts = sub->opts,
            .driver = driver,
            .attachments = sub->attachments,
            .codec = sub->codec,
            .preload_ok = true,
        };

        if (sd->driver->init(sd) >= 0)
            return sd;

        talloc_free(sd);
    }

    MP_ERR(sub, "Could not find subtitle decoder for format '%s'.\n",
           sub->codec->codec);
    return NULL;
}

// Thread-safety of the returned object: all functions are thread-safe,
// except sub_get_bitmaps() and sub_get_text(). Decoder backends (sd_*)
// do not need to acquire locks.
// Ownership of attachments goes to the caller, and is released with
// talloc_free() (even on failure).
struct dec_sub *sub_create(struct mpv_global *global, struct sh_stream *sh,
                           struct attachment_list *attachments)
{
    assert(sh && sh->type == STREAM_SUB);

    struct dec_sub *sub = talloc(NULL, struct dec_sub);
    *sub = (struct dec_sub){
        .log = mp_log_new(sub, global->log, "sub"),
        .global = global,
        .opts = global->opts,
        .sh = sh,
        .codec = sh->codec,
        .attachments = talloc_steal(sub, attachments),
        .last_pkt_pts = MP_NOPTS_VALUE,
        .last_vo_pts = MP_NOPTS_VALUE,
        .start = MP_NOPTS_VALUE,
        .end = MP_NOPTS_VALUE,
    };
    mpthread_mutex_init_recursive(&sub->lock);

    sub->sd = init_decoder(sub);
    if (sub->sd)
        return sub;

    talloc_free(sub);
    return NULL;
}

// Called locked.
static void update_segment(struct dec_sub *sub)
{
    if (sub->new_segment && sub->last_vo_pts != MP_NOPTS_VALUE &&
        sub->last_vo_pts >= sub->new_segment->start)
    {
        MP_VERBOSE(sub, "Switch segment: %f at %f\n", sub->new_segment->start,
                   sub->last_vo_pts);

        sub->codec = sub->new_segment->codec;
        sub->start = sub->new_segment->start;
        sub->end = sub->new_segment->end;
        struct sd *new = init_decoder(sub);
        if (new) {
            sub->sd->driver->uninit(sub->sd);
            talloc_free(sub->sd);
            sub->sd = new;
        } else {
            // We'll just keep the current decoder, and feed it possibly
            // invalid data (not our fault if it crashes or something).
            MP_ERR(sub, "Can't change to new codec.\n");
        }
        sub->sd->driver->decode(sub->sd, sub->new_segment);
        talloc_free(sub->new_segment);
        sub->new_segment = NULL;
    }
}

bool sub_can_preload(struct dec_sub *sub)
{
    bool r;
    pthread_mutex_lock(&sub->lock);
    r = sub->sd->driver->accept_packets_in_advance && !sub->preload_attempted;
    pthread_mutex_unlock(&sub->lock);
    return r;
}

void sub_preload(struct dec_sub *sub)
{
    pthread_mutex_lock(&sub->lock);

    sub->preload_attempted = true;

    for (;;) {
        struct demux_packet *pkt = demux_read_packet(sub->sh);
        if (!pkt)
            break;
        sub->sd->driver->decode(sub->sd, pkt);
        talloc_free(pkt);
    }

    pthread_mutex_unlock(&sub->lock);
}

static bool is_new_segment(struct dec_sub *sub, struct demux_packet *p)
{
    return p->segmented &&
        (p->start != sub->start || p->end != sub->end || p->codec != sub->codec);
}

// Read packets from the demuxer stream passed to sub_create(). Return true if
// enough packets were read, false if the player should wait until the demuxer
// signals new packets available (and then should retry).
bool sub_read_packets(struct dec_sub *sub, double video_pts)
{
    bool r = true;
    pthread_mutex_lock(&sub->lock);
    while (1) {
        bool read_more = true;
        if (sub->sd->driver->accepts_packet)
            read_more = sub->sd->driver->accepts_packet(sub->sd, video_pts);

        if (!read_more)
            break;

        if (sub->new_segment && sub->new_segment->start < video_pts) {
            sub->last_vo_pts = video_pts;
            update_segment(sub);
        }

        if (sub->new_segment)
            break;

        struct demux_packet *pkt;
        int st = demux_read_packet_async(sub->sh, &pkt);
        // Note: "wait" (st==0) happens with non-interleaved streams only, and
        // then we should stop the playloop until a new enough packet has been
        // seen (or the subtitle decoder's queue is full). This does not happen
        // for interleaved subtitle streams, which never return "wait" when
        // reading.
        if (st <= 0) {
            r = st < 0 || (sub->last_pkt_pts != MP_NOPTS_VALUE &&
                           sub->last_pkt_pts > video_pts);
            break;
        }

        if (sub->recorder_sink)
            mp_recorder_feed_packet(sub->recorder_sink, pkt);

        sub->last_pkt_pts = pkt->pts;

        if (is_new_segment(sub, pkt)) {
            sub->new_segment = pkt;
            // Note that this can be delayed to a much later point in time.
            update_segment(sub);
            break;
        }

        if (!(sub->preload_attempted && sub->sd->preload_ok))
            sub->sd->driver->decode(sub->sd, pkt);

        talloc_free(pkt);
    }
    pthread_mutex_unlock(&sub->lock);
    return r;
}

// You must call sub_lock/sub_unlock if more than 1 thread access sub.
// The issue is that *res will contain decoder allocated data, which might
// be deallocated on the next decoder access.
void sub_get_bitmaps(struct dec_sub *sub, struct mp_osd_res dim, int format,
                     double pts, struct sub_bitmaps *res)
{
    struct MPOpts *opts = sub->opts;

    sub->last_vo_pts = pts;
    update_segment(sub);

    if (sub->end != MP_NOPTS_VALUE && pts >= sub->end)
        return;

    if (opts->sub_visibility && sub->sd->driver->get_bitmaps)
        sub->sd->driver->get_bitmaps(sub->sd, dim, format, pts, res);
}

// See sub_get_bitmaps() for locking requirements.
// It can be called unlocked too, but then only 1 thread must call this function
// at a time (unless exclusive access is guaranteed).
char *sub_get_text(struct dec_sub *sub, double pts)
{
    pthread_mutex_lock(&sub->lock);
    struct MPOpts *opts = sub->opts;
    char *text = NULL;

    sub->last_vo_pts = pts;
    update_segment(sub);

    if (opts->sub_visibility && sub->sd->driver->get_text)
        text = sub->sd->driver->get_text(sub->sd, pts);
    pthread_mutex_unlock(&sub->lock);
    return text;
}

void sub_reset(struct dec_sub *sub)
{
    pthread_mutex_lock(&sub->lock);
    if (sub->sd->driver->reset)
        sub->sd->driver->reset(sub->sd);
    sub->last_pkt_pts = MP_NOPTS_VALUE;
    sub->last_vo_pts = MP_NOPTS_VALUE;
    talloc_free(sub->new_segment);
    sub->new_segment = NULL;
    pthread_mutex_unlock(&sub->lock);
}

void sub_select(struct dec_sub *sub, bool selected)
{
    pthread_mutex_lock(&sub->lock);
    if (sub->sd->driver->select)
        sub->sd->driver->select(sub->sd, selected);
    pthread_mutex_unlock(&sub->lock);
}

int sub_control(struct dec_sub *sub, enum sd_ctrl cmd, void *arg)
{
    int r = CONTROL_UNKNOWN;
    pthread_mutex_lock(&sub->lock);
    if (sub->sd->driver->control)
        r = sub->sd->driver->control(sub->sd, cmd, arg);
    pthread_mutex_unlock(&sub->lock);
    return r;
}

void sub_set_recorder_sink(struct dec_sub *sub, struct mp_recorder_sink *sink)
{
    pthread_mutex_lock(&sub->lock);
    sub->recorder_sink = sink;
    pthread_mutex_unlock(&sub->lock);
}