FFmpeg/libavformat/subtitles.c
Clément Bœsch d948893dbd lavf/subtitles: add some SMIL helpers.
This is needed for SAMI and RealText demuxers.
2012-06-29 20:20:02 +02:00

146 lines
3.9 KiB
C

/*
* Copyright (c) 2012 Clément Bœsch
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "subtitles.h"
#include "libavutil/avstring.h"
AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
const uint8_t *event, int len, int merge)
{
AVPacket *subs, *sub;
if (merge && q->nb_subs > 0) {
/* merge with previous event */
int old_len;
sub = &q->subs[q->nb_subs - 1];
old_len = sub->size;
if (av_grow_packet(sub, len) < 0)
return NULL;
memcpy(sub->data + old_len, event, len);
} else {
/* new event */
if (q->nb_subs >= INT_MAX/sizeof(*q->subs) - 1)
return NULL;
subs = av_fast_realloc(q->subs, &q->allocated_size,
(q->nb_subs + 1) * sizeof(*q->subs));
if (!subs)
return NULL;
q->subs = subs;
sub = &subs[q->nb_subs++];
if (av_new_packet(sub, len) < 0)
return NULL;
sub->destruct = NULL;
sub->flags |= AV_PKT_FLAG_KEY;
sub->pts = sub->dts = 0;
memcpy(sub->data, event, len);
}
return sub;
}
static int cmp_pkt_sub(const void *a, const void *b)
{
const AVPacket *s1 = a;
const AVPacket *s2 = b;
if (s1->pts == s2->pts) {
if (s1->pos == s2->pos)
return 0;
return s1->pos > s2->pos ? 1 : -1;
}
return s1->pts > s2->pts ? 1 : -1;
}
void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q)
{
int i;
qsort(q->subs, q->nb_subs, sizeof(*q->subs), cmp_pkt_sub);
for (i = 0; i < q->nb_subs; i++)
if (q->subs[i].duration == -1 && i < q->nb_subs - 1)
q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts;
}
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
{
AVPacket *sub = q->subs + q->current_sub_idx;
if (q->current_sub_idx == q->nb_subs)
return AVERROR_EOF;
*pkt = *sub;
pkt->dts = pkt->pts;
q->current_sub_idx++;
return 0;
}
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
{
int i;
for (i = 0; i < q->nb_subs; i++)
av_destruct_packet(&q->subs[i]);
av_freep(&q->subs);
q->nb_subs = q->allocated_size = q->current_sub_idx = 0;
}
int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c)
{
int i = 0;
char end_chr;
if (!*c) // cached char?
*c = avio_r8(pb);
if (!*c)
return 0;
end_chr = *c == '<' ? '>' : '<';
do {
av_bprint_chars(buf, *c, 1);
*c = avio_r8(pb);
i++;
} while (*c != end_chr && *c);
if (end_chr == '>') {
av_bprint_chars(buf, '>', 1);
*c = 0;
}
return i;
}
const char *ff_smil_get_attr_ptr(const char *s, const char *attr)
{
int in_quotes = 0;
const int len = strlen(attr);
while (*s) {
while (*s) {
if (!in_quotes && isspace(*s))
break;
in_quotes ^= *s == '"'; // XXX: support escaping?
s++;
}
while (isspace(*s))
s++;
if (!av_strncasecmp(s, attr, len) && s[len] == '=')
return s + len + 1 + (s[len + 1] == '"');
}
return NULL;
}