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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 
22 #include "libavutil/channel_layout.h"
23 #include "avformat.h"
24 #include "internal.h"
25 
26 enum BMVFlags {
27     BMV_NOP = 0,
28     BMV_END,
29     BMV_DELTA,
30     BMV_INTRA,
31 
32     BMV_AUDIO   = 0x20,
33 };
34 
35 typedef struct BMVContext {
36     uint8_t *packet;
37     int      size;
38     int      get_next;
39     int64_t  audio_pos;
40 } BMVContext;
41 
bmv_read_header(AVFormatContext * s)42 static int bmv_read_header(AVFormatContext *s)
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);
50     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
51     st->codecpar->codec_id   = AV_CODEC_ID_BMV_VIDEO;
52     st->codecpar->width      = 640;
53     st->codecpar->height     = 429;
54     st->codecpar->format     = AV_PIX_FMT_PAL8;
55     avpriv_set_pts_info(st, 16, 1, 12);
56     ast = avformat_new_stream(s, 0);
57     if (!ast)
58         return AVERROR(ENOMEM);
59     ast->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
60     ast->codecpar->codec_id        = AV_CODEC_ID_BMV_AUDIO;
61     ast->codecpar->channels        = 2;
62     ast->codecpar->channel_layout  = AV_CH_LAYOUT_STEREO;
63     ast->codecpar->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 
bmv_read_packet(AVFormatContext * s,AVPacket * pkt)71 static int bmv_read_packet(AVFormatContext *s, AVPacket *pkt)
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 ((err = av_new_packet(pkt, audio_size)) < 0)
100                 return err;
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 ((err = av_new_packet(pkt, c->size + 1)) < 0)
112         return err;
113     pkt->stream_index = 0;
114     c->get_next = 1;
115     memcpy(pkt->data, c->packet, pkt->size);
116     return pkt->size;
117 }
118 
bmv_read_close(AVFormatContext * s)119 static int bmv_read_close(AVFormatContext *s)
120 {
121     BMVContext *c = s->priv_data;
122 
123     av_freep(&c->packet);
124 
125     return 0;
126 }
127 
128 AVInputFormat ff_bmv_demuxer = {
129     .name           = "bmv",
130     .long_name      = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
131     .priv_data_size = sizeof(BMVContext),
132     .read_header    = bmv_read_header,
133     .read_packet    = bmv_read_packet,
134     .read_close     = bmv_read_close,
135     .extensions     = "bmv",
136 };
137