libavformat/supenc.c

   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 "mux.h"
  25 #include "libavutil/intreadwrite.h"
  26
  27 #define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
  28
  29 static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
  30 {
  31     const uint8_t *data = pkt->data;
  32     size_t size = pkt->size;
  33     uint32_t pts = 0, dts = 0;
  34
  35     if (pkt->pts != AV_NOPTS_VALUE) {
  36         pts = pkt->pts;
  37     }
  38     if (pkt->dts != AV_NOPTS_VALUE) {
  39         dts = pkt->dts;
  40     }
  41
  42     /*
  43       Split frame to segments.
  44       mkvmerge stores multiple segments in one frame.
  45     */
  46     while (size > 2) {
  47         size_t len = AV_RB16(data + 1) + 3;
  48
  49         if (len > size) {
  50             av_log(s, AV_LOG_ERROR, "Not enough data, skipping %"SIZE_SPECIFIER" bytes\n",
  51                    size);
  52             return AVERROR_INVALIDDATA;
  53         }
  54
  55         /* header */
  56         avio_wb16(s->pb, SUP_PGS_MAGIC);
  57         avio_wb32(s->pb, pts);
  58         avio_wb32(s->pb, dts);
  59
  60         avio_write(s->pb, data, len);
  61
  62         data += len;
  63         size -= len;
  64     }
  65
  66     if (size > 0) {
  67         av_log(s, AV_LOG_ERROR, "Skipping %"SIZE_SPECIFIER" bytes after last segment in frame\n",
  68                size);
  69         return AVERROR_INVALIDDATA;
  70     }
  71
  72     return 0;
  73 }
  74
  75 static av_cold int sup_init(AVFormatContext *s)
  76 {
  77     avpriv_set_pts_info(s->streams[0], 32, 1, 90000);
  78
  79     return 0;
  80 }
  81
  82 const FFOutputFormat ff_sup_muxer = {
  83     .p.name           = "sup",
  84     .p.long_name      = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
  85     .p.extensions     = "sup",
  86     .p.mime_type      = "application/x-pgs",
  87     .p.video_codec    = AV_CODEC_ID_NONE,
  88     .p.audio_codec    = AV_CODEC_ID_NONE,
  89     .p.subtitle_codec = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
  90     .p.flags          = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
  91     .flags_internal   = FF_OFMT_FLAG_MAX_ONE_OF_EACH,
  92     .init             = sup_init,
  93     .write_packet   = sup_write_packet,
  94 };