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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 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 
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, err;
75 
76  while (c->get_next) {
77  if (s->pb->eof_reached)
78  return AVERROR_EOF;
79  type = avio_r8(s->pb);
80  if (type == BMV_NOP)
81  continue;
82  if (type == BMV_END)
83  return AVERROR_EOF;
84  c->size = avio_rl24(s->pb);
85  if (!c->size)
86  return AVERROR_INVALIDDATA;
87  if ((err = av_reallocp(&c->packet, c->size + 1)) < 0)
88  return err;
89  c->packet[0] = type;
90  if (avio_read(s->pb, c->packet + 1, c->size) != c->size)
91  return AVERROR(EIO);
92  if (type & BMV_AUDIO) {
93  int audio_size = c->packet[1] * 65 + 1;
94  if (audio_size >= c->size) {
95  av_log(s, AV_LOG_ERROR, "Reported audio size %d is bigger than packet size (%d)\n",
96  audio_size, c->size);
97  return AVERROR_INVALIDDATA;
98  }
99  if (av_new_packet(pkt, audio_size) < 0)
100  return AVERROR(ENOMEM);
101  memcpy(pkt->data, c->packet + 1, pkt->size);
102  pkt->stream_index = 1;
103  pkt->pts = c->audio_pos;
104  pkt->duration = c->packet[1] * 32;
105  c->audio_pos += pkt->duration;
106  c->get_next = 0;
107  return pkt->size;
108  } else
109  break;
110  }
111  if (av_new_packet(pkt, c->size + 1) < 0)
112  return AVERROR(ENOMEM);
113  pkt->stream_index = 0;
114  c->get_next = 1;
115  memcpy(pkt->data, c->packet, pkt->size);
116  return pkt->size;
117 }
118 
120 {
121  BMVContext *c = s->priv_data;
122 
123  av_freep(&c->packet);
124 
125  return 0;
126 }
127 
129  .name = "bmv",
130  .long_name = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
131  .priv_data_size = sizeof(BMVContext),
135  .extensions = "bmv",
136 };