| 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 | |
| 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->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| 31 | st->codec->codec_id = AV_CODEC_ID_HDMV_PGS_SUBTITLE; |
| 32 | avpriv_set_pts_info(st, 32, 1, 90000); |
| 33 | |
| 34 | return 0; |
| 35 | } |
| 36 | |
| 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 | |
| 71 | static int sup_probe(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 | }; |