FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/mm.c
Date: 2022-12-05 03:11:11
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 "internal.h"
38
39 #define MM_PREAMBLE_SIZE 6
40
41 #define MM_TYPE_HEADER 0x0
42 #define MM_TYPE_INTER 0x5
43 #define MM_TYPE_INTRA 0x8
44 #define MM_TYPE_INTRA_HH 0xc
45 #define MM_TYPE_INTER_HH 0xd
46 #define MM_TYPE_INTRA_HHV 0xe
47 #define MM_TYPE_INTER_HHV 0xf
48 #define MM_TYPE_AUDIO 0x15
49 #define MM_TYPE_PALETTE 0x31
50
51 #define MM_HEADER_LEN_V 0x16 /* video only */
52 #define MM_HEADER_LEN_AV 0x18 /* video + audio */
53
54 #define MM_PALETTE_COUNT 128
55 #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
56
57 typedef struct MmDemuxContext {
58 unsigned int audio_pts, video_pts;
59 } MmDemuxContext;
60
61 6782 static int probe(const AVProbeData *p)
62 {
63 int len, type, fps, w, h;
64
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6782 if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
65 return 0;
66 /* the first chunk is always the header */
67
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6782 if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
68 5521 return 0;
69 1261 len = AV_RL32(&p->buf[2]);
70
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1261 if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
71 1260 return 0;
72 1 fps = AV_RL16(&p->buf[8]);
73 1 w = AV_RL16(&p->buf[12]);
74 1 h = AV_RL16(&p->buf[14]);
75
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1 if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
76 return 0;
77 1 type = AV_RL16(&p->buf[len]);
78
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1 if (!type || type > 0x31)
79 return 0;
80
81 /* only return half certainty since this check is a bit sketchy */
82 1 return AVPROBE_SCORE_EXTENSION;
83 }
84
85 1 static int read_header(AVFormatContext *s)
86 {
87 1 MmDemuxContext *mm = s->priv_data;
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)
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 mm->audio_pts = 0;
133 1 mm->video_pts = 0;
134 1 return 0;
135 }
136
137 100 static int read_packet(AVFormatContext *s,
138 AVPacket *pkt)
139 {
140 100 MmDemuxContext *mm = s->priv_data;
141 100 AVIOContext *pb = s->pb;
142 unsigned char preamble[MM_PREAMBLE_SIZE];
143 unsigned int type, length;
144 int ret;
145
146 while(1) {
147
148
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100 if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
149 1 return AVERROR(EIO);
150 }
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_PALETTE :
157 case MM_TYPE_INTER :
158 case MM_TYPE_INTRA :
159 case MM_TYPE_INTRA_HH :
160 case MM_TYPE_INTER_HH :
161 case MM_TYPE_INTRA_HHV :
162 case MM_TYPE_INTER_HHV :
163 /* output preamble + data */
164
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32 if ((ret = av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) < 0)
165 return ret;
166 32 memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
167
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32 if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
168 return AVERROR(EIO);
169 32 pkt->size = length + MM_PREAMBLE_SIZE;
170 32 pkt->stream_index = 0;
171 32 pkt->pts = mm->video_pts;
172
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32 if (type!=MM_TYPE_PALETTE)
173 31 mm->video_pts++;
174 32 return 0;
175
176 67 case MM_TYPE_AUDIO :
177
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67 if (s->nb_streams < 2)
178 return AVERROR_INVALIDDATA;
179
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67 if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
180 return ret;
181 67 pkt->stream_index = 1;
182 67 pkt->pts = mm->audio_pts++;
183 67 return 0;
184
185 default :
186 av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
187 avio_skip(pb, length);
188 }
189 }
190 }
191
192 const AVInputFormat ff_mm_demuxer = {
193 .name = "mm",
194 .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
195 .priv_data_size = sizeof(MmDemuxContext),
196 .read_probe = probe,
197 .read_header = read_header,
198 .read_packet = read_packet,
199 };
200