FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/mm.c
Date: 2025-11-01 17:46:10
Exec Total Coverage
Lines: 73 88 83.0%
Functions: 3 3 100.0%
Branches: 34 58 58.6%
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1 /*
2 * American Laser Games MM Format Demuxer
3 * Copyright (c) 2006 Peter Ross
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 /**
23 * @file
24 * American Laser Games MM Format Demuxer
25 * by Peter Ross (pross@xvid.org)
26 *
27 * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
28 * including Mad Dog McCree and Crime Patrol.
29 *
30 * Technical details here:
31 * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
32 */
33
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/intreadwrite.h"
36 #include "avformat.h"
37 #include "avio_internal.h"
38 #include "demux.h"
39 #include "internal.h"
40
41 #define MM_PREAMBLE_SIZE 6
42
43 #define MM_TYPE_HEADER 0x0
44 #define MM_TYPE_RAW 0x2
45 #define MM_TYPE_INTER 0x5
46 #define MM_TYPE_INTRA 0x8
47 #define MM_TYPE_INTRA_HH 0xc
48 #define MM_TYPE_INTER_HH 0xd
49 #define MM_TYPE_INTRA_HHV 0xe
50 #define MM_TYPE_INTER_HHV 0xf
51 #define MM_TYPE_AUDIO2 0x14
52 #define MM_TYPE_AUDIO 0x15
53 #define MM_TYPE_PALETTE 0x31
54
55 #define MM_HEADER_LEN_V 0x16 /* video only */
56 #define MM_HEADER_LEN_AV 0x18 /* video + audio */
57 #define MM_HEADER_LEN_AV2 0x1a
58
59 #define MM_PALETTE_COUNT 128
60 #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
61
62 7282 static int probe(const AVProbeData *p)
63 {
64 int len, type, fps, w, h;
65
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 7282 if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
66 ✗ return 0;
67 /* the first chunk is always the header */
68
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 7282 if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
69 5850 return 0;
70 1432 len = AV_RL32(&p->buf[2]);
71
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 1432 if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV && len != MM_HEADER_LEN_AV2)
72 1431 return 0;
73 1 fps = AV_RL16(&p->buf[8]);
74 1 w = AV_RL16(&p->buf[12]);
75 1 h = AV_RL16(&p->buf[14]);
76
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 1 if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
77 ✗ return 0;
78 1 type = AV_RL16(&p->buf[len]);
79
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 1 if (!type || type > 0x31)
80 ✗ return 0;
81
82 /* only return half certainty since this check is a bit sketchy */
83 1 return AVPROBE_SCORE_EXTENSION;
84 }
85
86 1 static int read_header(AVFormatContext *s)
87 {
88 1 AVIOContext *pb = s->pb;
89 AVStream *st;
90
91 unsigned int type, length;
92 unsigned int frame_rate, width, height;
93
94 1 type = avio_rl16(pb);
95 1 length = avio_rl32(pb);
96
97
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 1 if (type != MM_TYPE_HEADER || length < 10)
98 ✗ return AVERROR_INVALIDDATA;
99
100 /* read header */
101 1 avio_rl16(pb); /* total number of chunks */
102 1 frame_rate = avio_rl16(pb);
103 1 avio_rl16(pb); /* ibm-pc video bios mode */
104 1 width = avio_rl16(pb);
105 1 height = avio_rl16(pb);
106 1 avio_skip(pb, length - 10); /* unknown data */
107
108 /* video stream */
109 1 st = avformat_new_stream(s, NULL);
110
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 1 if (!st)
111 ✗ return AVERROR(ENOMEM);
112 1 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
113 1 st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
114 1 st->codecpar->codec_tag = 0; /* no fourcc */
115 1 st->codecpar->width = width;
116 1 st->codecpar->height = height;
117 1 avpriv_set_pts_info(st, 64, 1, frame_rate);
118
119 /* audio stream */
120
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 1 if (length >= MM_HEADER_LEN_AV) {
121 1 st = avformat_new_stream(s, NULL);
122
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 1 if (!st)
123 ✗ return AVERROR(ENOMEM);
124 1 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
125 1 st->codecpar->codec_tag = 0; /* no fourcc */
126 1 st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
127 1 st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
128 1 st->codecpar->sample_rate = 8000;
129 1 avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
130 }
131
132 1 return 0;
133 }
134
135 100 static int read_packet(AVFormatContext *s,
136 AVPacket *pkt)
137 {
138 100 AVIOContext *pb = s->pb;
139 unsigned char preamble[MM_PREAMBLE_SIZE];
140 unsigned int type, length;
141 100 int64_t pos = avio_tell(pb);
142 int ret;
143
144 while (1) {
145
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 100 if (avio_feof(pb))
146 ✗ return AVERROR_EOF;
147
148 100 ret = ffio_read_size(pb, preamble, MM_PREAMBLE_SIZE);
149
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 100 if (ret < 0)
150 1 return ret;
151
152 99 type = AV_RL16(&preamble[0]);
153 99 length = AV_RL16(&preamble[2]);
154
155
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 99 switch (type) {
156 32 case MM_TYPE_RAW :
157 case MM_TYPE_PALETTE :
158 case MM_TYPE_INTER :
159 case MM_TYPE_INTRA :
160 case MM_TYPE_INTRA_HH :
161 case MM_TYPE_INTER_HH :
162 case MM_TYPE_INTRA_HHV :
163 case MM_TYPE_INTER_HHV :
164 /* output preamble + data */
165
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 32 if ((ret = av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) < 0)
166 ✗ return ret;
167 32 memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
168 32 ret = ffio_read_size(pb, pkt->data + MM_PREAMBLE_SIZE, length);
169
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 32 if (ret < 0)
170 ✗ return ret;
171 32 pkt->size = length + MM_PREAMBLE_SIZE;
172 32 pkt->stream_index = 0;
173
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 32 if (type!=MM_TYPE_PALETTE)
174 31 pkt->duration = 1;
175
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 32 if (type == MM_TYPE_RAW ||
176 type == MM_TYPE_INTRA)
177 31 pkt->flags |= AV_PKT_FLAG_KEY;
178 32 pkt->pos = pos;
179 32 return 0;
180
181 67 case MM_TYPE_AUDIO :
182
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 67 if (s->nb_streams < 2)
183 ✗ return AVERROR_INVALIDDATA;
184
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 67 if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
185 ✗ return ret;
186 67 pkt->stream_index = 1;
187 67 pkt->duration = length;
188 67 pkt->pos = pos;
189 67 return 0;
190
191 ✗ default :
192 ✗ av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
193 /* fallthrough */
194 ✗ case MM_TYPE_AUDIO2 :
195 ✗ avio_skip(pb, length);
196 }
197 }
198 }
199
200 const FFInputFormat ff_mm_demuxer = {
201 .p.name = "mm",
202 .p.long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
203 .p.flags = AVFMT_GENERIC_INDEX,
204 .read_probe = probe,
205 .read_header = read_header,
206 .read_packet = read_packet,
207 };
208