1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "avformat.h"
20 #include "internal.h"
21 #include "libavutil/intreadwrite.h"
22
23 #define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
24
sup_read_header(AVFormatContext * s)25 static int sup_read_header(AVFormatContext *s)
26 {
27 AVStream *st = avformat_new_stream(s, NULL);
28 if (!st)
29 return AVERROR(ENOMEM);
30 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
31 st->codecpar->codec_id = AV_CODEC_ID_HDMV_PGS_SUBTITLE;
32 avpriv_set_pts_info(st, 32, 1, 90000);
33
34 return 0;
35 }
36
sup_read_packet(AVFormatContext * s,AVPacket * pkt)37 static int sup_read_packet(AVFormatContext *s, AVPacket *pkt)
38 {
39 int64_t pts, dts, pos;
40 int ret;
41
42 pos = avio_tell(s->pb);
43
44 if (avio_rb16(s->pb) != SUP_PGS_MAGIC)
45 return avio_feof(s->pb) ? AVERROR_EOF : AVERROR_INVALIDDATA;
46
47 pts = avio_rb32(s->pb);
48 dts = avio_rb32(s->pb);
49
50 if ((ret = av_get_packet(s->pb, pkt, 3)) < 0)
51 return ret;
52
53 pkt->stream_index = 0;
54 pkt->flags |= AV_PKT_FLAG_KEY;
55 pkt->pos = pos;
56 pkt->pts = pts;
57 // Many files have DTS set to 0 for all packets, so assume 0 means unset.
58 pkt->dts = dts ? dts : AV_NOPTS_VALUE;
59
60 if (pkt->size >= 3) {
61 // The full packet size is stored as part of the packet.
62 size_t len = AV_RB16(pkt->data + 1);
63
64 if ((ret = av_append_packet(s->pb, pkt, len)) < 0)
65 return ret;
66 }
67
68 return 0;
69 }
70
sup_probe(const AVProbeData * p)71 static int sup_probe(const AVProbeData *p)
72 {
73 unsigned char *buf = p->buf;
74 size_t buf_size = p->buf_size;
75 int nb_packets;
76
77 for (nb_packets = 0; nb_packets < 10; nb_packets++) {
78 size_t full_packet_size;
79 if (buf_size < 10 + 3)
80 break;
81 if (AV_RB16(buf) != SUP_PGS_MAGIC)
82 return 0;
83 full_packet_size = AV_RB16(buf + 10 + 1) + 10 + 3;
84 if (buf_size < full_packet_size)
85 break;
86 buf += full_packet_size;
87 buf_size -= full_packet_size;
88 }
89 if (!nb_packets)
90 return 0;
91 if (nb_packets < 2)
92 return AVPROBE_SCORE_RETRY / 2;
93 if (nb_packets < 4)
94 return AVPROBE_SCORE_RETRY;
95 if (nb_packets < 10)
96 return AVPROBE_SCORE_EXTENSION;
97 return AVPROBE_SCORE_MAX;
98 }
99
100 AVInputFormat ff_sup_demuxer = {
101 .name = "sup",
102 .long_name = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
103 .extensions = "sup",
104 .mime_type = "application/x-pgs",
105 .read_probe = sup_probe,
106 .read_header = sup_read_header,
107 .read_packet = sup_read_packet,
108 .flags = AVFMT_GENERIC_INDEX,
109 };
110