ffmpeg/libavformat/mpsubdec.c

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2012-12-28 00:38:50 +00:00
/*
* 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
*/
/**
* @file
* MPlayer subtitles format demuxer
*/
#include "avformat.h"
#include "internal.h"
#include "subtitles.h"
typedef struct {
FFDemuxSubtitlesQueue q;
} MPSubContext;
static int mpsub_probe(AVProbeData *p)
{
const char *ptr = p->buf;
const char *ptr_end = p->buf + p->buf_size;
while (ptr < ptr_end) {
int n;
if (!memcmp(ptr, "FORMAT=TIME", 11) ||
sscanf(ptr, "FORMAT=%d", &n) == 1)
return AVPROBE_SCORE_MAX/2;
ptr += strcspn(ptr, "\n") + 1;
}
return 0;
}
static int mpsub_read_header(AVFormatContext *s)
{
MPSubContext *mpsub = s->priv_data;
AVStream *st;
AVBPrint buf;
AVRational pts_info = (AVRational){ 100, 1 }; // ts based by default
int res = 0;
float multiplier = 100.0;
float current_pts = 0;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
while (!url_feof(s->pb)) {
char line[1024];
float start, duration;
int fps, len = ff_get_line(s->pb, line, sizeof(line));
if (!len)
break;
line[strcspn(line, "\r\n")] = 0;
if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) {
/* frame based timing */
pts_info = (AVRational){ fps, 1 };
multiplier = 1.0;
} else if (sscanf(line, "%f %f", &start, &duration) == 2) {
AVPacket *sub;
const int64_t pos = avio_tell(s->pb);
ff_subtitles_read_chunk(s->pb, &buf);
if (buf.len) {
sub = ff_subtitles_queue_insert(&mpsub->q, buf.str, buf.len, 0);
if (!sub) {
res = AVERROR(ENOMEM);
goto end;
}
sub->pts = (int64_t)(current_pts + start*multiplier);
sub->duration = (int)(duration * multiplier);
current_pts += (start + duration) * multiplier;
sub->pos = pos;
}
}
}
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = AV_CODEC_ID_TEXT;
ff_subtitles_queue_finalize(&mpsub->q);
end:
av_bprint_finalize(&buf, NULL);
return res;
}
static int mpsub_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MPSubContext *mpsub = s->priv_data;
return ff_subtitles_queue_read_packet(&mpsub->q, pkt);
}
static int mpsub_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
MPSubContext *mpsub = s->priv_data;
return ff_subtitles_queue_seek(&mpsub->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
static int mpsub_read_close(AVFormatContext *s)
{
MPSubContext *mpsub = s->priv_data;
ff_subtitles_queue_clean(&mpsub->q);
return 0;
}
AVInputFormat ff_mpsub_demuxer = {
.name = "mpsub",
.long_name = NULL_IF_CONFIG_SMALL("MPlayer subtitles"),
.priv_data_size = sizeof(MPSubContext),
.read_probe = mpsub_probe,
.read_header = mpsub_read_header,
.read_packet = mpsub_read_packet,
.read_seek2 = mpsub_read_seek,
.read_close = mpsub_read_close,
.extensions = "sub",
};