f8adcddd3a734c8035138afebd5bfc7e041971f5
[libav.git] / libavcodec / mmvideo.c
1 /*
2 * American Laser Games MM Video Decoder
3 * Copyright (c) 2006,2008 Peter Ross
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 int palette[AVPALETTE_COUNT];
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
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
71 s->frame = av_frame_alloc();
72 if (!s->frame)
73 return AVERROR(ENOMEM);
74
75 return 0;
76 }
77
78 static int 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] = bytestream2_get_be24(&s->gb);
85 s->palette[i+128] = s->palette[i]<<2;
86 }
87
88 return 0;
89 }
90
91 /**
92 * @param half_horiz Half horizontal resolution (0 or 1)
93 * @param half_vert Half vertical resolution (0 or 1)
94 */
95 static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
96 {
97 int x = 0, y = 0;
98
99 while (bytestream2_get_bytes_left(&s->gb) > 0) {
100 int run_length, color;
101
102 if (y >= s->avctx->height)
103 return 0;
104
105 color = bytestream2_get_byte(&s->gb);
106 if (color & 0x80) {
107 run_length = 1;
108 }else{
109 run_length = (color & 0x7f) + 2;
110 color = bytestream2_get_byte(&s->gb);
111 }
112
113 if (half_horiz)
114 run_length *=2;
115
116 if (color) {
117 memset(s->frame->data[0] + y*s->frame->linesize[0] + x, color, run_length);
118 if (half_vert)
119 memset(s->frame->data[0] + (y+1)*s->frame->linesize[0] + x, color, run_length);
120 }
121 x+= run_length;
122
123 if (x >= s->avctx->width) {
124 x=0;
125 y += 1 + half_vert;
126 }
127 }
128
129 return 0;
130 }
131
132 /*
133 * @param half_horiz Half horizontal resolution (0 or 1)
134 * @param half_vert Half vertical resolution (0 or 1)
135 */
136 static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
137 {
138 int data_off = bytestream2_get_le16(&s->gb);
139 int y = 0;
140 GetByteContext data_ptr;
141
142 if (bytestream2_get_bytes_left(&s->gb) < data_off)
143 return AVERROR_INVALIDDATA;
144
145 bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
146 while (s->gb.buffer < data_ptr.buffer_start) {
147 int i, j;
148 int length = bytestream2_get_byte(&s->gb);
149 int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
150 length &= 0x7F;
151
152 if (length==0) {
153 y += x;
154 continue;
155 }
156
157 if (y + half_vert >= s->avctx->height)
158 return 0;
159
160 for(i=0; i<length; i++) {
161 int replace_array = bytestream2_get_byte(&s->gb);
162 for(j=0; j<8; j++) {
163 int replace = (replace_array >> (7-j)) & 1;
164 if (x + half_horiz >= s->avctx->width)
165 return AVERROR_INVALIDDATA;
166 if (replace) {
167 int color = bytestream2_get_byte(&data_ptr);
168 s->frame->data[0][y*s->frame->linesize[0] + x] = color;
169 if (half_horiz)
170 s->frame->data[0][y*s->frame->linesize[0] + x + 1] = color;
171 if (half_vert) {
172 s->frame->data[0][(y+1)*s->frame->linesize[0] + x] = color;
173 if (half_horiz)
174 s->frame->data[0][(y+1)*s->frame->linesize[0] + x + 1] = color;
175 }
176 }
177 x += 1 + half_horiz;
178 }
179 }
180
181 y += 1 + half_vert;
182 }
183
184 return 0;
185 }
186
187 static int mm_decode_frame(AVCodecContext *avctx,
188 void *data, int *got_frame,
189 AVPacket *avpkt)
190 {
191 const uint8_t *buf = avpkt->data;
192 int buf_size = avpkt->size;
193 MmContext *s = avctx->priv_data;
194 int type, res;
195
196 if (buf_size < MM_PREAMBLE_SIZE)
197 return AVERROR_INVALIDDATA;
198 type = AV_RL16(&buf[0]);
199 buf += MM_PREAMBLE_SIZE;
200 buf_size -= MM_PREAMBLE_SIZE;
201 bytestream2_init(&s->gb, buf, buf_size);
202
203 if ((res = ff_reget_buffer(avctx, s->frame)) < 0) {
204 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
205 return res;
206 }
207
208 switch(type) {
209 case MM_TYPE_PALETTE : res = mm_decode_pal(s); return buf_size;
210 case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
211 case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
212 case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
213 case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
214 case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
215 case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
216 default:
217 res = AVERROR_INVALIDDATA;
218 break;
219 }
220 if (res < 0)
221 return res;
222
223 memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
224
225 if ((res = av_frame_ref(data, s->frame)) < 0)
226 return res;
227
228 *got_frame = 1;
229
230 return buf_size;
231 }
232
233 static av_cold int mm_decode_end(AVCodecContext *avctx)
234 {
235 MmContext *s = avctx->priv_data;
236
237 av_frame_free(&s->frame);
238
239 return 0;
240 }
241
242 AVCodec ff_mmvideo_decoder = {
243 .name = "mmvideo",
244 .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
245 .type = AVMEDIA_TYPE_VIDEO,
246 .id = AV_CODEC_ID_MMVIDEO,
247 .priv_data_size = sizeof(MmContext),
248 .init = mm_decode_init,
249 .close = mm_decode_end,
250 .decode = mm_decode_frame,
251 .capabilities = AV_CODEC_CAP_DR1,
252 };