16x8 MV vissualization by (Wolfgang Hesseler <qv at multimediaware dot com>)
[libav.git] / libavcodec / msrle.c
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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
875efafa 29 * BITMAPINFO header passed through palctrl.
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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
41typedef struct MsrleContext {
42 AVCodecContext *avctx;
43 AVFrame frame;
44 AVFrame prev_frame;
45
46 unsigned char *buf;
47 int size;
48
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49} MsrleContext;
50
51#define FETCH_NEXT_STREAM_BYTE() \
52 if (stream_ptr >= s->size) \
53 { \
9b879566 54 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
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55 return; \
56 } \
57 stream_byte = s->buf[stream_ptr++];
58
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59static void msrle_decode_pal4(MsrleContext *s)
60{
61 int stream_ptr = 0;
62 unsigned char rle_code;
63 unsigned char extra_byte, odd_pixel;
64 unsigned char stream_byte;
65 int pixel_ptr = 0;
66 int row_dec = s->frame.linesize[0];
67 int row_ptr = (s->avctx->height - 1) * row_dec;
68 int frame_size = row_dec * s->avctx->height;
69 int i;
70
71 /* make the palette available */
72 memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
73 if (s->avctx->palctrl->palette_changed) {
74 s->frame.palette_has_changed = 1;
75 s->avctx->palctrl->palette_changed = 0;
76 }
77
78 while (row_ptr >= 0) {
79 FETCH_NEXT_STREAM_BYTE();
80 rle_code = stream_byte;
81 if (rle_code == 0) {
82 /* fetch the next byte to see how to handle escape code */
83 FETCH_NEXT_STREAM_BYTE();
84 if (stream_byte == 0) {
85 /* line is done, goto the next one */
86 row_ptr -= row_dec;
87 pixel_ptr = 0;
88 } else if (stream_byte == 1) {
89 /* decode is done */
90 return;
91 } else if (stream_byte == 2) {
92 /* reposition frame decode coordinates */
93 FETCH_NEXT_STREAM_BYTE();
94 pixel_ptr += stream_byte;
95 FETCH_NEXT_STREAM_BYTE();
96 row_ptr -= stream_byte * row_dec;
97 } else {
98 // copy pixels from encoded stream
99 odd_pixel = stream_byte & 1;
100 rle_code = (stream_byte + 1) / 2;
101 extra_byte = rle_code & 0x01;
102 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
103 (row_ptr < 0)) {
104 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
105 return;
106 }
107
108 for (i = 0; i < rle_code; i++) {
109 if (pixel_ptr >= s->avctx->width)
110 break;
111 FETCH_NEXT_STREAM_BYTE();
112 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
113 pixel_ptr++;
114 if (i + 1 == rle_code && odd_pixel)
115 break;
116 if (pixel_ptr >= s->avctx->width)
117 break;
118 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
119 pixel_ptr++;
120 }
121
122 // if the RLE code is odd, skip a byte in the stream
123 if (extra_byte)
124 stream_ptr++;
125 }
126 } else {
127 // decode a run of data
128 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
129 (row_ptr < 0)) {
130 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
131 return;
132 }
133 FETCH_NEXT_STREAM_BYTE();
134 for (i = 0; i < rle_code; i++) {
135 if (pixel_ptr >= s->avctx->width)
136 break;
137 if ((i & 1) == 0)
138 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
139 else
140 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
141 pixel_ptr++;
142 }
143 }
144 }
145
146 /* one last sanity check on the way out */
147 if (stream_ptr < s->size)
148 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
149 stream_ptr, s->size);
150}
151
152
153
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154static void msrle_decode_pal8(MsrleContext *s)
155{
156 int stream_ptr = 0;
157 unsigned char rle_code;
158 unsigned char extra_byte;
159 unsigned char stream_byte;
160 int pixel_ptr = 0;
161 int row_dec = s->frame.linesize[0];
162 int row_ptr = (s->avctx->height - 1) * row_dec;
163 int frame_size = row_dec * s->avctx->height;
164
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165 /* make the palette available */
166 memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
167 if (s->avctx->palctrl->palette_changed) {
168 s->frame.palette_has_changed = 1;
169 s->avctx->palctrl->palette_changed = 0;
170 }
171
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172 while (row_ptr >= 0) {
173 FETCH_NEXT_STREAM_BYTE();
174 rle_code = stream_byte;
175 if (rle_code == 0) {
176 /* fetch the next byte to see how to handle escape code */
177 FETCH_NEXT_STREAM_BYTE();
178 if (stream_byte == 0) {
179 /* line is done, goto the next one */
180 row_ptr -= row_dec;
181 pixel_ptr = 0;
182 } else if (stream_byte == 1) {
183 /* decode is done */
184 return;
185 } else if (stream_byte == 2) {
186 /* reposition frame decode coordinates */
187 FETCH_NEXT_STREAM_BYTE();
188 pixel_ptr += stream_byte;
189 FETCH_NEXT_STREAM_BYTE();
190 row_ptr -= stream_byte * row_dec;
191 } else {
192 /* copy pixels from encoded stream */
193 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
194 (row_ptr < 0)) {
9b879566 195 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
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196 return;
197 }
198
199 rle_code = stream_byte;
200 extra_byte = stream_byte & 0x01;
201 if (stream_ptr + rle_code + extra_byte > s->size) {
9b879566 202 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (2)\n");
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203 return;
204 }
205
206 while (rle_code--) {
207 FETCH_NEXT_STREAM_BYTE();
208 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
209 pixel_ptr++;
210 }
211
212 /* if the RLE code is odd, skip a byte in the stream */
213 if (extra_byte)
214 stream_ptr++;
215 }
216 } else {
217 /* decode a run of data */
218 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
219 (row_ptr < 0)) {
9b879566 220 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (2)\n");
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221 return;
222 }
223
224 FETCH_NEXT_STREAM_BYTE();
225
226 while(rle_code--) {
227 s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
228 pixel_ptr++;
229 }
230 }
231 }
232
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233 /* one last sanity check on the way out */
234 if (stream_ptr < s->size)
9b879566 235 av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
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236 stream_ptr, s->size);
237}
238
239static int msrle_decode_init(AVCodecContext *avctx)
240{
241 MsrleContext *s = (MsrleContext *)avctx->priv_data;
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242
243 s->avctx = avctx;
244
245 avctx->pix_fmt = PIX_FMT_PAL8;
246 avctx->has_b_frames = 0;
247 s->frame.data[0] = s->prev_frame.data[0] = NULL;
248
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249 return 0;
250}
251
252static int msrle_decode_frame(AVCodecContext *avctx,
253 void *data, int *data_size,
254 uint8_t *buf, int buf_size)
255{
256 MsrleContext *s = (MsrleContext *)avctx->priv_data;
257
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258 /* no supplementary picture */
259 if (buf_size == 0)
260 return 0;
261
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262 s->buf = buf;
263 s->size = buf_size;
264
04939fb7 265 s->frame.reference = 1;
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266 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE;
267 if (avctx->cr_available)
268 s->frame.buffer_hints |= FF_BUFFER_HINTS_REUSABLE;
269 else
270 s->frame.buffer_hints |= FF_BUFFER_HINTS_READABLE;
2fdf638b 271 if (avctx->get_buffer(avctx, &s->frame)) {
9b879566 272 av_log(avctx, AV_LOG_ERROR, " MS RLE: get_buffer() failed\n");
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273 return -1;
274 }
275
875efafa 276 if (s->prev_frame.data[0] && (s->frame.linesize[0] != s->prev_frame.linesize[0]))
9b879566 277 av_log(avctx, AV_LOG_ERROR, " MS RLE: Buffer linesize changed: current %u, previous %u.\n"
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278 " Expect wrong image and/or crash!\n",
279 s->frame.linesize[0], s->prev_frame.linesize[0]);
280
2fdf638b 281 /* grossly inefficient, but...oh well */
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282 if (s->prev_frame.data[0] != NULL)
283 memcpy(s->frame.data[0], s->prev_frame.data[0],
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284 s->frame.linesize[0] * s->avctx->height);
285
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286 switch (avctx->bits_per_sample) {
287 case 8:
288 msrle_decode_pal8(s);
289 break;
290 case 4:
291 msrle_decode_pal4(s);
292 break;
293 default:
294 av_log(avctx, AV_LOG_ERROR, "Don't know how to decode depth %u.\n",
295 avctx->bits_per_sample);
296 }
2fdf638b 297
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298 if (s->prev_frame.data[0])
299 avctx->release_buffer(avctx, &s->prev_frame);
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300
301 /* shuffle frames */
e02c251e 302 if (!avctx->cr_available)
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303 s->prev_frame = s->frame;
304
305 *data_size = sizeof(AVFrame);
306 *(AVFrame*)data = s->frame;
307
308 /* report that the buffer was completely consumed */
309 return buf_size;
310}
311
312static int msrle_decode_end(AVCodecContext *avctx)
313{
314 MsrleContext *s = (MsrleContext *)avctx->priv_data;
315
316 /* release the last frame */
317 if (s->prev_frame.data[0])
318 avctx->release_buffer(avctx, &s->prev_frame);
319
320 return 0;
321}
322
323AVCodec msrle_decoder = {
324 "msrle",
325 CODEC_TYPE_VIDEO,
326 CODEC_ID_MSRLE,
327 sizeof(MsrleContext),
328 msrle_decode_init,
329 NULL,
330 msrle_decode_end,
331 msrle_decode_frame,
e02c251e 332 CODEC_CAP_DR1 | CODEC_CAP_CR,
2fdf638b 333};