xref: /third_party/ffmpeg/libavformat/supenc.c (revision cabdff1a)
1/*
2 * SUP muxer
3 * Copyright (c) 2014 Petri Hintukainen <phintuka@users.sourceforge.net>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avformat.h"
23#include "internal.h"
24#include "libavutil/intreadwrite.h"
25
26#define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
27
28static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
29{
30    const uint8_t *data = pkt->data;
31    size_t size = pkt->size;
32    uint32_t pts = 0, dts = 0;
33
34    if (pkt->pts != AV_NOPTS_VALUE) {
35        pts = pkt->pts;
36    }
37    if (pkt->dts != AV_NOPTS_VALUE) {
38        dts = pkt->dts;
39    }
40
41    /*
42      Split frame to segments.
43      mkvmerge stores multiple segments in one frame.
44    */
45    while (size > 2) {
46        size_t len = AV_RB16(data + 1) + 3;
47
48        if (len > size) {
49            av_log(s, AV_LOG_ERROR, "Not enough data, skipping %"SIZE_SPECIFIER" bytes\n",
50                   size);
51            return AVERROR_INVALIDDATA;
52        }
53
54        /* header */
55        avio_wb16(s->pb, SUP_PGS_MAGIC);
56        avio_wb32(s->pb, pts);
57        avio_wb32(s->pb, dts);
58
59        avio_write(s->pb, data, len);
60
61        data += len;
62        size -= len;
63    }
64
65    if (size > 0) {
66        av_log(s, AV_LOG_ERROR, "Skipping %"SIZE_SPECIFIER" bytes after last segment in frame\n",
67               size);
68        return AVERROR_INVALIDDATA;
69    }
70
71    return 0;
72}
73
74static int sup_write_header(AVFormatContext *s)
75{
76    if (s->nb_streams != 1) {
77        av_log(s, AV_LOG_ERROR, "%s files have exactly one stream\n",
78               s->oformat->name);
79        return AVERROR(EINVAL);
80    }
81
82    avpriv_set_pts_info(s->streams[0], 32, 1, 90000);
83
84    return 0;
85}
86
87const AVOutputFormat ff_sup_muxer = {
88    .name           = "sup",
89    .long_name      = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
90    .extensions     = "sup",
91    .mime_type      = "application/x-pgs",
92    .subtitle_codec = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
93    .write_header   = sup_write_header,
94    .write_packet   = sup_write_packet,
95    .flags          = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
96};
97