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2ba45a60 DM |
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; | |
f6fa7814 | 52 | unsigned int palette[AVPALETTE_COUNT]; |
2ba45a60 DM |
53 | GetByteContext gb; |
54 | } MmContext; | |
55 | ||
56 | static av_cold int mm_decode_init(AVCodecContext *avctx) | |
57 | { | |
58 | MmContext *s = avctx->priv_data; | |
59 | ||
60 | s->avctx = avctx; | |
61 | ||
62 | avctx->pix_fmt = AV_PIX_FMT_PAL8; | |
63 | ||
092a9121 DM |
64 | if (!avctx->width || !avctx->height || |
65 | (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 | ||
2ba45a60 DM |
71 | s->frame = av_frame_alloc(); |
72 | if (!s->frame) | |
73 | return AVERROR(ENOMEM); | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | static void mm_decode_pal(MmContext *s) | |
79 | { | |
80 | int i; | |
81 | ||
82 | bytestream2_skip(&s->gb, 4); | |
83 | for (i = 0; i < 128; i++) { | |
84 | s->palette[i] = 0xFFU << 24 | bytestream2_get_be24(&s->gb); | |
85 | s->palette[i+128] = s->palette[i]<<2; | |
86 | } | |
87 | } | |
88 | ||
89 | /** | |
90 | * @param half_horiz Half horizontal resolution (0 or 1) | |
91 | * @param half_vert Half vertical resolution (0 or 1) | |
92 | */ | |
93 | static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert) | |
94 | { | |
95 | int x = 0, y = 0; | |
96 | ||
97 | while (bytestream2_get_bytes_left(&s->gb) > 0) { | |
98 | int run_length, color; | |
99 | ||
100 | if (y >= s->avctx->height) | |
101 | return 0; | |
102 | ||
103 | color = bytestream2_get_byte(&s->gb); | |
104 | if (color & 0x80) { | |
105 | run_length = 1; | |
106 | }else{ | |
107 | run_length = (color & 0x7f) + 2; | |
108 | color = bytestream2_get_byte(&s->gb); | |
109 | } | |
110 | ||
111 | if (half_horiz) | |
112 | run_length *=2; | |
113 | ||
114 | if (run_length > s->avctx->width - x) | |
115 | return AVERROR_INVALIDDATA; | |
116 | ||
117 | if (color) { | |
118 | memset(s->frame->data[0] + y*s->frame->linesize[0] + x, color, run_length); | |
119 | 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 | x+= run_length; | |
123 | ||
124 | if (x >= s->avctx->width) { | |
125 | x=0; | |
126 | y += 1 + half_vert; | |
127 | } | |
128 | } | |
129 | ||
130 | 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 | static int mm_decode_frame(AVCodecContext *avctx, | |
189 | void *data, int *got_frame, | |
190 | AVPacket *avpkt) | |
191 | { | |
192 | const uint8_t *buf = avpkt->data; | |
193 | int buf_size = avpkt->size; | |
194 | MmContext *s = avctx->priv_data; | |
195 | int type, res; | |
196 | ||
197 | if (buf_size < MM_PREAMBLE_SIZE) | |
198 | return AVERROR_INVALIDDATA; | |
199 | type = AV_RL16(&buf[0]); | |
200 | buf += MM_PREAMBLE_SIZE; | |
201 | buf_size -= MM_PREAMBLE_SIZE; | |
202 | bytestream2_init(&s->gb, buf, buf_size); | |
203 | ||
204 | if ((res = ff_reget_buffer(avctx, s->frame)) < 0) | |
205 | return res; | |
206 | ||
207 | switch(type) { | |
208 | case MM_TYPE_PALETTE : mm_decode_pal(s); return avpkt->size; | |
209 | 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 | if (res < 0) | |
220 | return res; | |
221 | ||
222 | memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE); | |
223 | ||
224 | if ((res = av_frame_ref(data, s->frame)) < 0) | |
225 | return res; | |
226 | ||
227 | *got_frame = 1; | |
228 | ||
229 | return avpkt->size; | |
230 | } | |
231 | ||
232 | static av_cold int mm_decode_end(AVCodecContext *avctx) | |
233 | { | |
234 | MmContext *s = avctx->priv_data; | |
235 | ||
236 | av_frame_free(&s->frame); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | 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 = CODEC_CAP_DR1, | |
251 | }; |