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 "libavutil/intreadwrite.h"
  25
  26 #define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
  27
  28 static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
  29 {
  30     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
  74 static 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
  87 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 };