mpv/sub/dec_sub.c

321 lines
9.0 KiB
C

/*
* 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 "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 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);
}
// 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;
}
sub->last_pkt_pts = pkt->pts;
if (pkt->new_segment) {
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->start = sub->end = 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;
}