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[libav.git] / libavcodec / msrle.c
1 /*
2 * Micrsoft RLE Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 /**
21 * @file msrle.c
22 * MS RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
23 * For more information about the MS RLE format, visit:
24 * http://www.pcisys.net/~melanson/codecs/
25 *
26 * The MS RLE decoder outputs PAL8 colorspace data.
27 *
28 * Note that this decoder expects the palette colors from the end of the
29 * BITMAPINFO header passed through palctrl.
30 */
31
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36
37 #include "common.h"
38 #include "avcodec.h"
39 #include "dsputil.h"
40
41 typedef struct MsrleContext {
42 AVCodecContext *avctx;
43 AVFrame frame;
44
45 unsigned char *buf;
46 int size;
47
48 } MsrleContext;
49
50 #define FETCH_NEXT_STREAM_BYTE() \
51 if (stream_ptr >= s->size) \
52 { \
53 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
54 return; \
55 } \
56 stream_byte = s->buf[stream_ptr++];
57
58 static void msrle_decode_pal4(MsrleContext *s)
59 {
60 int stream_ptr = 0;
61 unsigned char rle_code;
62 unsigned char extra_byte, odd_pixel;
63 unsigned char stream_byte;
64 int pixel_ptr = 0;
65 int row_dec = s->frame.linesize[0];
66 int row_ptr = (s->avctx->height - 1) * row_dec;
67 int frame_size = row_dec * s->avctx->height;
68 int i;
69
70 /* make the palette available */
71 memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
72 if (s->avctx->palctrl->palette_changed) {
73 s->frame.palette_has_changed = 1;
74 s->avctx->palctrl->palette_changed = 0;
75 }
76
77 while (row_ptr >= 0) {
78 FETCH_NEXT_STREAM_BYTE();
79 rle_code = stream_byte;
80 if (rle_code == 0) {
81 /* fetch the next byte to see how to handle escape code */
82 FETCH_NEXT_STREAM_BYTE();
83 if (stream_byte == 0) {
84 /* line is done, goto the next one */
85 row_ptr -= row_dec;
86 pixel_ptr = 0;
87 } else if (stream_byte == 1) {
88 /* decode is done */
89 return;
90 } else if (stream_byte == 2) {
91 /* reposition frame decode coordinates */
92 FETCH_NEXT_STREAM_BYTE();
93 pixel_ptr += stream_byte;
94 FETCH_NEXT_STREAM_BYTE();
95 row_ptr -= stream_byte * row_dec;
96 } else {
97 // copy pixels from encoded stream
98 odd_pixel = stream_byte & 1;
99 rle_code = (stream_byte + 1) / 2;
100 extra_byte = rle_code & 0x01;
101 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
102 (row_ptr < 0)) {
103 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
104 return;
105 }
106
107 for (i = 0; i < rle_code; i++) {
108 if (pixel_ptr >= s->avctx->width)
109 break;
110 FETCH_NEXT_STREAM_BYTE();
111 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
112 pixel_ptr++;
113 if (i + 1 == rle_code && odd_pixel)
114 break;
115 if (pixel_ptr >= s->avctx->width)
116 break;
117 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
118 pixel_ptr++;
119 }
120
121 // if the RLE code is odd, skip a byte in the stream
122 if (extra_byte)
123 stream_ptr++;
124 }
125 } else {
126 // decode a run of data
127 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
128 (row_ptr < 0)) {
129 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
130 return;
131 }
132 FETCH_NEXT_STREAM_BYTE();
133 for (i = 0; i < rle_code; i++) {
134 if (pixel_ptr >= s->avctx->width)
135 break;
136 if ((i & 1) == 0)
137 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
138 else
139 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
140 pixel_ptr++;
141 }
142 }
143 }
144
145 /* one last sanity check on the way out */
146 if (stream_ptr < s->size)
147 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
148 stream_ptr, s->size);
149 }
150
151
152
153 static void msrle_decode_pal8(MsrleContext *s)
154 {
155 int stream_ptr = 0;
156 unsigned char rle_code;
157 unsigned char extra_byte;
158 unsigned char stream_byte;
159 int pixel_ptr = 0;
160 int row_dec = s->frame.linesize[0];
161 int row_ptr = (s->avctx->height - 1) * row_dec;
162 int frame_size = row_dec * s->avctx->height;
163
164 /* make the palette available */
165 memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
166 if (s->avctx->palctrl->palette_changed) {
167 s->frame.palette_has_changed = 1;
168 s->avctx->palctrl->palette_changed = 0;
169 }
170
171 while (row_ptr >= 0) {
172 FETCH_NEXT_STREAM_BYTE();
173 rle_code = stream_byte;
174 if (rle_code == 0) {
175 /* fetch the next byte to see how to handle escape code */
176 FETCH_NEXT_STREAM_BYTE();
177 if (stream_byte == 0) {
178 /* line is done, goto the next one */
179 row_ptr -= row_dec;
180 pixel_ptr = 0;
181 } else if (stream_byte == 1) {
182 /* decode is done */
183 return;
184 } else if (stream_byte == 2) {
185 /* reposition frame decode coordinates */
186 FETCH_NEXT_STREAM_BYTE();
187 pixel_ptr += stream_byte;
188 FETCH_NEXT_STREAM_BYTE();
189 row_ptr -= stream_byte * row_dec;
190 } else {
191 /* copy pixels from encoded stream */
192 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
193 (row_ptr < 0)) {
194 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
195 return;
196 }
197
198 rle_code = stream_byte;
199 extra_byte = stream_byte & 0x01;
200 if (stream_ptr + rle_code + extra_byte > s->size) {
201 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (2)\n");
202 return;
203 }
204
205 while (rle_code--) {
206 FETCH_NEXT_STREAM_BYTE();
207 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
208 pixel_ptr++;
209 }
210
211 /* if the RLE code is odd, skip a byte in the stream */
212 if (extra_byte)
213 stream_ptr++;
214 }
215 } else {
216 /* decode a run of data */
217 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
218 (row_ptr < 0)) {
219 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (2)\n");
220 return;
221 }
222
223 FETCH_NEXT_STREAM_BYTE();
224
225 while(rle_code--) {
226 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
227 pixel_ptr++;
228 }
229 }
230 }
231
232 /* one last sanity check on the way out */
233 if (stream_ptr < s->size)
234 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
235 stream_ptr, s->size);
236 }
237
238 static int msrle_decode_init(AVCodecContext *avctx)
239 {
240 MsrleContext *s = (MsrleContext *)avctx->priv_data;
241
242 s->avctx = avctx;
243
244 avctx->pix_fmt = PIX_FMT_PAL8;
245 avctx->has_b_frames = 0;
246 s->frame.data[0] = NULL;
247
248 return 0;
249 }
250
251 static int msrle_decode_frame(AVCodecContext *avctx,
252 void *data, int *data_size,
253 uint8_t *buf, int buf_size)
254 {
255 MsrleContext *s = (MsrleContext *)avctx->priv_data;
256
257 /* no supplementary picture */
258 if (buf_size == 0)
259 return 0;
260
261 s->buf = buf;
262 s->size = buf_size;
263
264 s->frame.reference = 1;
265 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
266 if (avctx->reget_buffer(avctx, &s->frame)) {
267 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
268 return -1;
269 }
270
271 switch (avctx->bits_per_sample) {
272 case 8:
273 msrle_decode_pal8(s);
274 break;
275 case 4:
276 msrle_decode_pal4(s);
277 break;
278 default:
279 av_log(avctx, AV_LOG_ERROR, "Don't know how to decode depth %u.\n",
280 avctx->bits_per_sample);
281 }
282
283 *data_size = sizeof(AVFrame);
284 *(AVFrame*)data = s->frame;
285
286 /* report that the buffer was completely consumed */
287 return buf_size;
288 }
289
290 static int msrle_decode_end(AVCodecContext *avctx)
291 {
292 MsrleContext *s = (MsrleContext *)avctx->priv_data;
293
294 /* release the last frame */
295 if (s->frame.data[0])
296 avctx->release_buffer(avctx, &s->frame);
297
298 return 0;
299 }
300
301 AVCodec msrle_decoder = {
302 "msrle",
303 CODEC_TYPE_VIDEO,
304 CODEC_ID_MSRLE,
305 sizeof(MsrleContext),
306 msrle_decode_init,
307 NULL,
308 msrle_decode_end,
309 msrle_decode_frame,
310 CODEC_CAP_DR1,
311 };