FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/mm.c
Date: 2024-03-29 01:21:52
Exec Total Coverage
Lines: 70 83 84.3%
Functions: 3 3 100.0%
Branches: 28 47 59.6%

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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 "demux.h"
38 #include "internal.h"
39
40 #define MM_PREAMBLE_SIZE 6
41
42 #define MM_TYPE_HEADER 0x0
43 #define MM_TYPE_INTER 0x5
44 #define MM_TYPE_INTRA 0x8
45 #define MM_TYPE_INTRA_HH 0xc
46 #define MM_TYPE_INTER_HH 0xd
47 #define MM_TYPE_INTRA_HHV 0xe
48 #define MM_TYPE_INTER_HHV 0xf
49 #define MM_TYPE_AUDIO 0x15
50 #define MM_TYPE_PALETTE 0x31
51
52 #define MM_HEADER_LEN_V 0x16 /* video only */
53 #define MM_HEADER_LEN_AV 0x18 /* video + audio */
54
55 #define MM_PALETTE_COUNT 128
56 #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
57
58 typedef struct MmDemuxContext {
59 unsigned int audio_pts, video_pts;
60 } MmDemuxContext;
61
62 7124 static int probe(const AVProbeData *p)
63 {
64 int len, type, fps, w, h;
65
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7124 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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7124 if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
69 5750 return 0;
70 1374 len = AV_RL32(&p->buf[2]);
71
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1374 if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
72 1373 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 MmDemuxContext *mm = s->priv_data;
89 1 AVIOContext *pb = s->pb;
90 AVStream *st;
91
92 unsigned int type, length;
93 unsigned int frame_rate, width, height;
94
95 1 type = avio_rl16(pb);
96 1 length = avio_rl32(pb);
97
98
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1 if (type != MM_TYPE_HEADER)
99 return AVERROR_INVALIDDATA;
100
101 /* read header */
102 1 avio_rl16(pb); /* total number of chunks */
103 1 frame_rate = avio_rl16(pb);
104 1 avio_rl16(pb); /* ibm-pc video bios mode */
105 1 width = avio_rl16(pb);
106 1 height = avio_rl16(pb);
107 1 avio_skip(pb, length - 10); /* unknown data */
108
109 /* video stream */
110 1 st = avformat_new_stream(s, NULL);
111
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1 if (!st)
112 return AVERROR(ENOMEM);
113 1 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
114 1 st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
115 1 st->codecpar->codec_tag = 0; /* no fourcc */
116 1 st->codecpar->width = width;
117 1 st->codecpar->height = height;
118 1 avpriv_set_pts_info(st, 64, 1, frame_rate);
119
120 /* audio stream */
121
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1 if (length == MM_HEADER_LEN_AV) {
122 1 st = avformat_new_stream(s, NULL);
123
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1 if (!st)
124 return AVERROR(ENOMEM);
125 1 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
126 1 st->codecpar->codec_tag = 0; /* no fourcc */
127 1 st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
128 1 st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
129 1 st->codecpar->sample_rate = 8000;
130 1 avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
131 }
132
133 1 mm->audio_pts = 0;
134 1 mm->video_pts = 0;
135 1 return 0;
136 }
137
138 100 static int read_packet(AVFormatContext *s,
139 AVPacket *pkt)
140 {
141 100 MmDemuxContext *mm = s->priv_data;
142 100 AVIOContext *pb = s->pb;
143 unsigned char preamble[MM_PREAMBLE_SIZE];
144 unsigned int type, length;
145 int ret;
146
147 while(1) {
148
149
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100 if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
150 1 return AVERROR(EIO);
151 }
152
153 99 type = AV_RL16(&preamble[0]);
154 99 length = AV_RL16(&preamble[2]);
155
156
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99 switch(type) {
157 32 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
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32 if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
169 return AVERROR(EIO);
170 32 pkt->size = length + MM_PREAMBLE_SIZE;
171 32 pkt->stream_index = 0;
172 32 pkt->pts = mm->video_pts;
173
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32 if (type!=MM_TYPE_PALETTE)
174 31 mm->video_pts++;
175 32 return 0;
176
177 67 case MM_TYPE_AUDIO :
178
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67 if (s->nb_streams < 2)
179 return AVERROR_INVALIDDATA;
180
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67 if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
181 return ret;
182 67 pkt->stream_index = 1;
183 67 pkt->pts = mm->audio_pts++;
184 67 return 0;
185
186 default :
187 av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
188 avio_skip(pb, length);
189 }
190 }
191 }
192
193 const FFInputFormat ff_mm_demuxer = {
194 .p.name = "mm",
195 .p.long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
196 .priv_data_size = sizeof(MmDemuxContext),
197 .read_probe = probe,
198 .read_header = read_header,
199 .read_packet = read_packet,
200 };
201