aac5773f
 hucm
功能基本完成，接口待打磨
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/*
* 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 "internal.h"
#include "libavutil/intreadwrite.h"
#define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
static int sup_read_header(AVFormatContext *s)
{
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = AV_CODEC_ID_HDMV_PGS_SUBTITLE;
avpriv_set_pts_info(st, 32, 1, 90000);
return 0;
}
static int sup_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int64_t pts, dts, pos;
int ret;
pos = avio_tell(s->pb);
if (avio_rb16(s->pb) != SUP_PGS_MAGIC)
return avio_feof(s->pb) ? AVERROR_EOF : AVERROR_INVALIDDATA;
pts = avio_rb32(s->pb);
dts = avio_rb32(s->pb);
if ((ret = av_get_packet(s->pb, pkt, 3)) < 0)
return ret;
pkt->stream_index = 0;
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->pos = pos;
pkt->pts = pts;
// Many files have DTS set to 0 for all packets, so assume 0 means unset.
pkt->dts = dts ? dts : AV_NOPTS_VALUE;
if (pkt->size >= 3) {
// The full packet size is stored as part of the packet.
size_t len = AV_RB16(pkt->data + 1);
if ((ret = av_append_packet(s->pb, pkt, len)) < 0)
return ret;
}
return 0;
}
static int sup_probe(const AVProbeData *p)
{
unsigned char *buf = p->buf;
size_t buf_size = p->buf_size;
int nb_packets;
for (nb_packets = 0; nb_packets < 10; nb_packets++) {
size_t full_packet_size;
if (buf_size < 10 + 3)
break;
if (AV_RB16(buf) != SUP_PGS_MAGIC)
return 0;
full_packet_size = AV_RB16(buf + 10 + 1) + 10 + 3;
if (buf_size < full_packet_size)
break;
buf += full_packet_size;
buf_size -= full_packet_size;
}
if (!nb_packets)
return 0;
if (nb_packets < 2)
return AVPROBE_SCORE_RETRY / 2;
if (nb_packets < 4)
return AVPROBE_SCORE_RETRY;
if (nb_packets < 10)
return AVPROBE_SCORE_EXTENSION;
return AVPROBE_SCORE_MAX;
}
AVInputFormat ff_sup_demuxer = {
.name = "sup",
.long_name = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
.extensions = "sup",
.mime_type = "application/x-pgs",
.read_probe = sup_probe,
.read_header = sup_read_header,
.read_packet = sup_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};
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