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bmv.c
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1 /*
2  * Discworld II BMV demuxer
3  * Copyright (c) 2011 Konstantin Shishkov.
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
23 #include "avformat.h"
24 #include "internal.h"
25 
26 enum BMVFlags {
27  BMV_NOP = 0,
31 
32  BMV_AUDIO = 0x20,
33 };
34 
35 typedef struct BMVContext {
37  int size;
38  int get_next;
39  int64_t audio_pos;
40 } BMVContext;
41 
43 {
44  AVStream *st, *ast;
45  BMVContext *c = s->priv_data;
46 
47  st = avformat_new_stream(s, 0);
48  if (!st)
49  return AVERROR(ENOMEM);
52  st->codec->width = 640;
53  st->codec->height = 429;
55  avpriv_set_pts_info(st, 16, 1, 12);
56  ast = avformat_new_stream(s, 0);
57  if (!ast)
58  return AVERROR(ENOMEM);
61  ast->codec->channels = 2;
63  ast->codec->sample_rate = 22050;
64  avpriv_set_pts_info(ast, 16, 1, 22050);
65 
66  c->get_next = 1;
67  c->audio_pos = 0;
68  return 0;
69 }
70 
72 {
73  BMVContext *c = s->priv_data;
74  int type;
75  void *tmp;
76 
77  while (c->get_next) {
78  if (s->pb->eof_reached)
79  return AVERROR_EOF;
80  type = avio_r8(s->pb);
81  if (type == BMV_NOP)
82  continue;
83  if (type == BMV_END)
84  return AVERROR_EOF;
85  c->size = avio_rl24(s->pb);
86  if (!c->size)
87  return AVERROR_INVALIDDATA;
88  tmp = av_realloc(c->packet, c->size + 1);
89  if (!tmp)
90  return AVERROR(ENOMEM);
91  c->packet = tmp;
92  c->packet[0] = type;
93  if (avio_read(s->pb, c->packet + 1, c->size) != c->size)
94  return AVERROR(EIO);
95  if (type & BMV_AUDIO) {
96  int audio_size = c->packet[1] * 65 + 1;
97  if (audio_size >= c->size) {
98  av_log(s, AV_LOG_ERROR, "Reported audio size %d is bigger than packet size (%d)\n",
99  audio_size, c->size);
100  return AVERROR_INVALIDDATA;
101  }
102  if (av_new_packet(pkt, audio_size) < 0)
103  return AVERROR(ENOMEM);
104  memcpy(pkt->data, c->packet + 1, pkt->size);
105  pkt->stream_index = 1;
106  pkt->pts = c->audio_pos;
107  pkt->duration = c->packet[1] * 32;
108  c->audio_pos += pkt->duration;
109  c->get_next = 0;
110  return pkt->size;
111  } else
112  break;
113  }
114  if (av_new_packet(pkt, c->size + 1) < 0)
115  return AVERROR(ENOMEM);
116  pkt->stream_index = 0;
117  c->get_next = 1;
118  memcpy(pkt->data, c->packet, pkt->size);
119  return pkt->size;
120 }
121 
123 {
124  BMVContext *c = s->priv_data;
125 
126  av_freep(&c->packet);
127 
128  return 0;
129 }
130 
132  .name = "bmv",
133  .long_name = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
134  .priv_data_size = sizeof(BMVContext),
138  .extensions = "bmv",
139 };