FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/mmvideo.c
Date: 2021-09-22 05:58:22
Exec Total Coverage
Lines: 56 108 51.9%
Branches: 25 68 36.8%

Line Branch Exec Source
1 /*
2 * American Laser Games MM Video Decoder
3 * Copyright (c) 2006,2008 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 Video Decoder
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/intreadwrite.h"
35 #include "avcodec.h"
36 #include "bytestream.h"
37 #include "internal.h"
38
39 #define MM_PREAMBLE_SIZE 6
40
41 #define MM_TYPE_INTER 0x5
42 #define MM_TYPE_INTRA 0x8
43 #define MM_TYPE_INTRA_HH 0xc
44 #define MM_TYPE_INTER_HH 0xd
45 #define MM_TYPE_INTRA_HHV 0xe
46 #define MM_TYPE_INTER_HHV 0xf
47 #define MM_TYPE_PALETTE 0x31
48
49 typedef struct MmContext {
50 AVCodecContext *avctx;
51 AVFrame *frame;
52 unsigned int palette[AVPALETTE_COUNT];
53 GetByteContext gb;
54 } MmContext;
55
56 2 static av_cold int mm_decode_init(AVCodecContext *avctx)
57 {
58 2 MmContext *s = avctx->priv_data;
59
60 2 s->avctx = avctx;
61
62 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
63
64
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2 if (!avctx->width || !avctx->height ||
65
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2 (avctx->width & 1) || (avctx->height & 1)) {
66 av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
67 avctx->width, avctx->height);
68 return AVERROR(EINVAL);
69 }
70
71 2 s->frame = av_frame_alloc();
72
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2 if (!s->frame)
73 return AVERROR(ENOMEM);
74
75 2 return 0;
76 }
77
78 1 static void mm_decode_pal(MmContext *s)
79 {
80 int i;
81
82 1 bytestream2_skip(&s->gb, 4);
83
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129 for (i = 0; i < 128; i++) {
84 128 s->palette[i] = 0xFFU << 24 | bytestream2_get_be24(&s->gb);
85 128 s->palette[i+128] = s->palette[i]<<2;
86 }
87 1 }
88
89 /**
90 * @param half_horiz Half horizontal resolution (0 or 1)
91 * @param half_vert Half vertical resolution (0 or 1)
92 */
93 31 static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
94 {
95 31 int x = 0, y = 0;
96
97
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168603 while (bytestream2_get_bytes_left(&s->gb) > 0) {
98 int run_length, color;
99
100
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168572 if (y >= s->avctx->height)
101 return 0;
102
103 168572 color = bytestream2_get_byte(&s->gb);
104
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168572 if (color & 0x80) {
105 92018 run_length = 1;
106 }else{
107 76554 run_length = (color & 0x7f) + 2;
108 76554 color = bytestream2_get_byte(&s->gb);
109 }
110
111
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168572 if (half_horiz)
112 run_length *=2;
113
114
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168572 if (run_length > s->avctx->width - x)
115 return AVERROR_INVALIDDATA;
116
117
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168572 if (color) {
118 147172 memset(s->frame->data[0] + y*s->frame->linesize[0] + x, color, run_length);
119
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147172 if (half_vert && y + half_vert < s->avctx->height)
120 memset(s->frame->data[0] + (y+1)*s->frame->linesize[0] + x, color, run_length);
121 }
122 168572 x+= run_length;
123
124
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168572 if (x >= s->avctx->width) {
125 4960 x=0;
126 4960 y += 1 + half_vert;
127 }
128 }
129
130 31 return 0;
131 }
132
133 /**
134 * @param half_horiz Half horizontal resolution (0 or 1)
135 * @param half_vert Half vertical resolution (0 or 1)
136 */
137 static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
138 {
139 int data_off = bytestream2_get_le16(&s->gb);
140 int y = 0;
141 GetByteContext data_ptr;
142
143 if (bytestream2_get_bytes_left(&s->gb) < data_off)
144 return AVERROR_INVALIDDATA;
145
146 bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
147 while (s->gb.buffer < data_ptr.buffer_start) {
148 int i, j;
149 int length = bytestream2_get_byte(&s->gb);
150 int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
151 length &= 0x7F;
152
153 if (length==0) {
154 y += x;
155 continue;
156 }
157
158 if (y + half_vert >= s->avctx->height)
159 return 0;
160
161 for(i=0; i<length; i++) {
162 int replace_array = bytestream2_get_byte(&s->gb);
163 for(j=0; j<8; j++) {
164 int replace = (replace_array >> (7-j)) & 1;
165 if (x + half_horiz >= s->avctx->width)
166 return AVERROR_INVALIDDATA;
167 if (replace) {
168 int color = bytestream2_get_byte(&data_ptr);
169 s->frame->data[0][y*s->frame->linesize[0] + x] = color;
170 if (half_horiz)
171 s->frame->data[0][y*s->frame->linesize[0] + x + 1] = color;
172 if (half_vert) {
173 s->frame->data[0][(y+1)*s->frame->linesize[0] + x] = color;
174 if (half_horiz)
175 s->frame->data[0][(y+1)*s->frame->linesize[0] + x + 1] = color;
176 }
177 }
178 x += 1 + half_horiz;
179 }
180 }
181
182 y += 1 + half_vert;
183 }
184
185 return 0;
186 }
187
188 32 static int mm_decode_frame(AVCodecContext *avctx,
189 void *data, int *got_frame,
190 AVPacket *avpkt)
191 {
192 32 const uint8_t *buf = avpkt->data;
193 32 int buf_size = avpkt->size;
194 32 MmContext *s = avctx->priv_data;
195 int type, res;
196
197
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32 if (buf_size < MM_PREAMBLE_SIZE)
198 return AVERROR_INVALIDDATA;
199 32 type = AV_RL16(&buf[0]);
200 32 buf += MM_PREAMBLE_SIZE;
201 32 buf_size -= MM_PREAMBLE_SIZE;
202 32 bytestream2_init(&s->gb, buf, buf_size);
203
204
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32 if ((res = ff_reget_buffer(avctx, s->frame, 0)) < 0)
205 return res;
206
207
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32 switch(type) {
208 1 case MM_TYPE_PALETTE : mm_decode_pal(s); return avpkt->size;
209 31 case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
210 case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
211 case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
212 case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
213 case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
214 case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
215 default:
216 res = AVERROR_INVALIDDATA;
217 break;
218 }
219
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31 if (res < 0)
220 return res;
221
222 31 memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
223
224
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31 if ((res = av_frame_ref(data, s->frame)) < 0)
225 return res;
226
227 31 *got_frame = 1;
228
229 31 return avpkt->size;
230 }
231
232 2 static av_cold int mm_decode_end(AVCodecContext *avctx)
233 {
234 2 MmContext *s = avctx->priv_data;
235
236 2 av_frame_free(&s->frame);
237
238 2 return 0;
239 }
240
241 const AVCodec ff_mmvideo_decoder = {
242 .name = "mmvideo",
243 .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
244 .type = AVMEDIA_TYPE_VIDEO,
245 .id = AV_CODEC_ID_MMVIDEO,
246 .priv_data_size = sizeof(MmContext),
247 .init = mm_decode_init,
248 .close = mm_decode_end,
249 .decode = mm_decode_frame,
250 .capabilities = AV_CODEC_CAP_DR1,
251 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
252 };
253