f44b8b6d1250a78ea41231991c9a09251d9dfed8
[libav.git] / libavcodec / msrledec.c
1 /*
2 * Micrsoft RLE Decoder
3 * Copyright (C) 2008 Konstantin Shishkov
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 msrledec.c
24 * MS RLE Decoder based on decoder by Mike Melanson and my own for TSCC
25 * For more information about the MS RLE format, visit:
26 * http://www.multimedia.cx/msrle.txt
27 */
28
29 #include "avcodec.h"
30
31 #define FETCH_NEXT_STREAM_BYTE() \
32 if (stream_ptr >= data_size) \
33 { \
34 av_log(avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
35 return -1; \
36 } \
37 stream_byte = data[stream_ptr++];
38
39 static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
40 const uint8_t *data, int data_size)
41 {
42 int stream_ptr = 0;
43 unsigned char rle_code;
44 unsigned char extra_byte, odd_pixel;
45 unsigned char stream_byte;
46 int pixel_ptr = 0;
47 int row_dec = pic->linesize[0];
48 int row_ptr = (avctx->height - 1) * row_dec;
49 int frame_size = row_dec * avctx->height;
50 int i;
51
52 while (row_ptr >= 0) {
53 FETCH_NEXT_STREAM_BYTE();
54 rle_code = stream_byte;
55 if (rle_code == 0) {
56 /* fetch the next byte to see how to handle escape code */
57 FETCH_NEXT_STREAM_BYTE();
58 if (stream_byte == 0) {
59 /* line is done, goto the next one */
60 row_ptr -= row_dec;
61 pixel_ptr = 0;
62 } else if (stream_byte == 1) {
63 /* decode is done */
64 return 0;
65 } else if (stream_byte == 2) {
66 /* reposition frame decode coordinates */
67 FETCH_NEXT_STREAM_BYTE();
68 pixel_ptr += stream_byte;
69 FETCH_NEXT_STREAM_BYTE();
70 row_ptr -= stream_byte * row_dec;
71 } else {
72 // copy pixels from encoded stream
73 odd_pixel = stream_byte & 1;
74 rle_code = (stream_byte + 1) / 2;
75 extra_byte = rle_code & 0x01;
76 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
77 (row_ptr < 0)) {
78 av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
79 return -1;
80 }
81
82 for (i = 0; i < rle_code; i++) {
83 if (pixel_ptr >= avctx->width)
84 break;
85 FETCH_NEXT_STREAM_BYTE();
86 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
87 pixel_ptr++;
88 if (i + 1 == rle_code && odd_pixel)
89 break;
90 if (pixel_ptr >= avctx->width)
91 break;
92 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
93 pixel_ptr++;
94 }
95
96 // if the RLE code is odd, skip a byte in the stream
97 if (extra_byte)
98 stream_ptr++;
99 }
100 } else {
101 // decode a run of data
102 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
103 (row_ptr < 0)) {
104 av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
105 return -1;
106 }
107 FETCH_NEXT_STREAM_BYTE();
108 for (i = 0; i < rle_code; i++) {
109 if (pixel_ptr >= avctx->width)
110 break;
111 if ((i & 1) == 0)
112 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
113 else
114 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
115 pixel_ptr++;
116 }
117 }
118 }
119
120 /* one last sanity check on the way out */
121 if (stream_ptr < data_size) {
122 av_log(avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
123 stream_ptr, data_size);
124 return -1;
125 }
126
127 return 0;
128 }
129
130
131 static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic, int depth,
132 const uint8_t *data, int srcsize)
133 {
134 uint8_t *output, *output_end;
135 const uint8_t* src = data;
136 int p1, p2, line=avctx->height, pos=0, i;
137 uint16_t pix16;
138 uint32_t pix32;
139
140 output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
141 output_end = pic->data[0] + (avctx->height) * pic->linesize[0];
142 while(src < data + srcsize) {
143 p1 = *src++;
144 if(p1 == 0) { //Escape code
145 p2 = *src++;
146 if(p2 == 0) { //End-of-line
147 output = pic->data[0] + (--line) * pic->linesize[0];
148 if (line < 0)
149 return -1;
150 pos = 0;
151 continue;
152 } else if(p2 == 1) { //End-of-picture
153 return 0;
154 } else if(p2 == 2) { //Skip
155 p1 = *src++;
156 p2 = *src++;
157 line -= p2;
158 if (line < 0)
159 return -1;
160 pos += p1;
161 output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
162 continue;
163 }
164 // Copy data
165 if (output + p2 * (depth >> 3) > output_end) {
166 src += p2 * (depth >> 3);
167 continue;
168 }
169 if ((depth == 8) || (depth == 24)) {
170 for(i = 0; i < p2 * (depth >> 3); i++) {
171 *output++ = *src++;
172 }
173 // RLE8 copy is actually padded - and runs are not!
174 if(depth == 8 && (p2 & 1)) {
175 src++;
176 }
177 } else if (depth == 16) {
178 for(i = 0; i < p2; i++) {
179 pix16 = AV_RL16(src);
180 src += 2;
181 *(uint16_t*)output = pix16;
182 output += 2;
183 }
184 } else if (depth == 32) {
185 for(i = 0; i < p2; i++) {
186 pix32 = AV_RL32(src);
187 src += 4;
188 *(uint32_t*)output = pix32;
189 output += 4;
190 }
191 }
192 pos += p2;
193 } else { //Run of pixels
194 int pix[4]; //original pixel
195 switch(depth){
196 case 8: pix[0] = *src++;
197 break;
198 case 16: pix16 = AV_RL16(src);
199 src += 2;
200 *(uint16_t*)pix = pix16;
201 break;
202 case 24: pix[0] = *src++;
203 pix[1] = *src++;
204 pix[2] = *src++;
205 break;
206 case 32: pix32 = AV_RL32(src);
207 src += 4;
208 *(uint32_t*)pix = pix32;
209 break;
210 }
211 if (output + p1 * (depth >> 3) > output_end)
212 continue;
213 for(i = 0; i < p1; i++) {
214 switch(depth){
215 case 8: *output++ = pix[0];
216 break;
217 case 16: *(uint16_t*)output = pix16;
218 output += 2;
219 break;
220 case 24: *output++ = pix[0];
221 *output++ = pix[1];
222 *output++ = pix[2];
223 break;
224 case 32: *(uint32_t*)output = pix32;
225 output += 4;
226 break;
227 }
228 }
229 pos += p1;
230 }
231 }
232
233 av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no End-of-picture code\n");
234 return 0;
235 }
236
237
238 int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic, int depth,
239 const uint8_t* data, int data_size)
240 {
241 switch(depth){
242 case 4:
243 return msrle_decode_pal4(avctx, pic, data, data_size);
244 case 8:
245 case 16:
246 case 24:
247 case 32:
248 return msrle_decode_8_16_24_32(avctx, pic, depth, data, data_size);
249 default:
250 av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
251 return -1;
252 }
253 }
254