libavformat/oggparsedirac.c

   1 /*
   2  * Copyright (C) 2008  David Conrad
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "libavcodec/get_bits.h"
  22 #include "libavcodec/dirac.h"
  23 #include "avformat.h"
  24 #include "internal.h"
  25 #include "oggdec.h"
  26
  27 static int dirac_header(AVFormatContext *s, int idx)
  28 {
  29     struct ogg *ogg = s->priv_data;
  30     struct ogg_stream *os = ogg->streams + idx;
  31     AVStream *st = s->streams[idx];
  32     dirac_source_params source;
  33     GetBitContext gb;
  34
  35     // already parsed the header
  36     if (st->codec->codec_id == AV_CODEC_ID_DIRAC)
  37         return 0;
  38
  39     init_get_bits(&gb, os->buf + os->pstart + 13, (os->psize - 13) * 8);
  40     if (avpriv_dirac_parse_sequence_header(st->codec, &gb, &source) < 0)
  41         return -1;
  42
  43     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
  44     st->codec->codec_id = AV_CODEC_ID_DIRAC;
  45     // dirac in ogg always stores timestamps as though the video were interlaced
  46     avpriv_set_pts_info(st, 64, st->codec->time_base.num, 2*st->codec->time_base.den);
  47     return 1;
  48 }
  49
  50 // various undocument things: granule is signed (only for dirac!)
  51 static uint64_t dirac_gptopts(AVFormatContext *s, int idx, uint64_t granule,
  52                               int64_t *dts_out)
  53 {
  54     int64_t gp = granule;
  55     struct ogg *ogg = s->priv_data;
  56     struct ogg_stream *os = ogg->streams + idx;
  57
  58     unsigned dist  = ((gp >> 14) & 0xff00) | (gp & 0xff);
  59     int64_t  dts   = (gp >> 31);
  60     int64_t  pts   = dts + ((gp >> 9) & 0x1fff);
  61
  62     if (!dist)
  63         os->pflags |= AV_PKT_FLAG_KEY;
  64
  65     if (dts_out)
  66         *dts_out = dts;
  67
  68     return pts;
  69 }
  70
  71 static int old_dirac_header(AVFormatContext *s, int idx)
  72 {
  73     struct ogg *ogg = s->priv_data;
  74     struct ogg_stream *os = ogg->streams + idx;
  75     AVStream *st = s->streams[idx];
  76     uint8_t *buf = os->buf + os->pstart;
  77
  78     if (buf[0] != 'K')
  79         return 0;
  80
  81     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
  82     st->codec->codec_id = AV_CODEC_ID_DIRAC;
  83     avpriv_set_pts_info(st, 64, AV_RB32(buf+12), AV_RB32(buf+8));
  84     return 1;
  85 }
  86
  87 static uint64_t old_dirac_gptopts(AVFormatContext *s, int idx, uint64_t gp,
  88                                   int64_t *dts)
  89 {
  90     struct ogg *ogg = s->priv_data;
  91     struct ogg_stream *os = ogg->streams + idx;
  92     uint64_t iframe = gp >> 30;
  93     uint64_t pframe = gp & 0x3fffffff;
  94
  95     if (!pframe)
  96         os->pflags |= AV_PKT_FLAG_KEY;
  97
  98     return iframe + pframe;
  99 }
 100
 101 const struct ogg_codec ff_dirac_codec = {
 102     .magic = "BBCD\0",
 103     .magicsize = 5,
 104     .header = dirac_header,
 105     .gptopts = dirac_gptopts,
 106     .granule_is_start = 1,
 107     .nb_header = 1,
 108 };
 109
 110 const struct ogg_codec ff_old_dirac_codec = {
 111     .magic = "KW-DIRAC",
 112     .magicsize = 8,
 113     .header = old_dirac_header,
 114     .gptopts = old_dirac_gptopts,
 115     .granule_is_start = 1,
 116     .nb_header = 1,
 117 };