Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / msrledec.c
1 /*
2 * Microsoft 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
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 "libavutil/intreadwrite.h"
30 #include "avcodec.h"
31 #include "msrledec.h"
32
33 static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
34 GetByteContext *gb)
35 {
36 unsigned char rle_code;
37 unsigned char extra_byte, odd_pixel;
38 unsigned char stream_byte;
39 unsigned int pixel_ptr = 0;
40 int row_dec = pic->linesize[0];
41 int row_ptr = (avctx->height - 1) * row_dec;
42 int frame_size = row_dec * avctx->height;
43 int i;
44
45 while (row_ptr >= 0) {
46 if (bytestream2_get_bytes_left(gb) <= 0) {
47 av_log(avctx, AV_LOG_ERROR,
48 "MS RLE: bytestream overrun, %d rows left\n",
49 row_ptr);
50 return AVERROR_INVALIDDATA;
51 }
52 rle_code = stream_byte = bytestream2_get_byteu(gb);
53 if (rle_code == 0) {
54 /* fetch the next byte to see how to handle escape code */
55 stream_byte = bytestream2_get_byte(gb);
56 if (stream_byte == 0) {
57 /* line is done, goto the next one */
58 row_ptr -= row_dec;
59 pixel_ptr = 0;
60 } else if (stream_byte == 1) {
61 /* decode is done */
62 return 0;
63 } else if (stream_byte == 2) {
64 /* reposition frame decode coordinates */
65 stream_byte = bytestream2_get_byte(gb);
66 pixel_ptr += stream_byte;
67 stream_byte = bytestream2_get_byte(gb);
68 row_ptr -= stream_byte * row_dec;
69 } else {
70 // copy pixels from encoded stream
71 odd_pixel = stream_byte & 1;
72 rle_code = (stream_byte + 1) / 2;
73 extra_byte = rle_code & 0x01;
74 if (row_ptr + pixel_ptr + stream_byte > frame_size ||
75 bytestream2_get_bytes_left(gb) < rle_code) {
76 av_log(avctx, AV_LOG_ERROR,
77 "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
78 return AVERROR_INVALIDDATA;
79 }
80
81 for (i = 0; i < rle_code; i++) {
82 if (pixel_ptr >= avctx->width)
83 break;
84 stream_byte = bytestream2_get_byteu(gb);
85 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
86 pixel_ptr++;
87 if (i + 1 == rle_code && odd_pixel)
88 break;
89 if (pixel_ptr >= avctx->width)
90 break;
91 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
92 pixel_ptr++;
93 }
94
95 // if the RLE code is odd, skip a byte in the stream
96 if (extra_byte)
97 bytestream2_skip(gb, 1);
98 }
99 } else {
100 // decode a run of data
101 if (row_ptr + pixel_ptr + stream_byte > frame_size) {
102 av_log(avctx, AV_LOG_ERROR,
103 "MS RLE: frame ptr just went out of bounds (run)\n");
104 return AVERROR_INVALIDDATA;
105 }
106 stream_byte = bytestream2_get_byte(gb);
107 for (i = 0; i < rle_code; i++) {
108 if (pixel_ptr >= avctx->width)
109 break;
110 if ((i & 1) == 0)
111 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
112 else
113 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
114 pixel_ptr++;
115 }
116 }
117 }
118
119 /* one last sanity check on the way out */
120 if (bytestream2_get_bytes_left(gb)) {
121 av_log(avctx, AV_LOG_ERROR,
122 "MS RLE: ended frame decode with %d bytes left over\n",
123 bytestream2_get_bytes_left(gb));
124 return AVERROR_INVALIDDATA;
125 }
126
127 return 0;
128 }
129
130
131 static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
132 int depth, GetByteContext *gb)
133 {
134 uint8_t *output, *output_end;
135 int p1, p2, line=avctx->height - 1, pos=0, i;
136 uint16_t pix16;
137 uint32_t pix32;
138 unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
139
140 output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
141 output_end = output + FFABS(pic->linesize[0]);
142
143 while (bytestream2_get_bytes_left(gb) > 0) {
144 p1 = bytestream2_get_byteu(gb);
145 if(p1 == 0) { //Escape code
146 p2 = bytestream2_get_byte(gb);
147 if(p2 == 0) { //End-of-line
148 if (--line < 0) {
149 if (bytestream2_get_be16(gb) == 1) { // end-of-picture
150 return 0;
151 } else {
152 av_log(avctx, AV_LOG_ERROR,
153 "Next line is beyond picture bounds (%d bytes left)\n",
154 bytestream2_get_bytes_left(gb));
155 return AVERROR_INVALIDDATA;
156 }
157 }
158 output = pic->data[0] + line * pic->linesize[0];
159 output_end = output + FFABS(pic->linesize[0]);
160 pos = 0;
161 continue;
162 } else if(p2 == 1) { //End-of-picture
163 return 0;
164 } else if(p2 == 2) { //Skip
165 p1 = bytestream2_get_byte(gb);
166 p2 = bytestream2_get_byte(gb);
167 line -= p2;
168 pos += p1;
169 if (line < 0 || pos >= width){
170 av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
171 return -1;
172 }
173 output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
174 output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]);
175 continue;
176 }
177 // Copy data
178 if (output + p2 * (depth >> 3) > output_end) {
179 bytestream2_skip(gb, 2 * (depth >> 3));
180 continue;
181 } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
182 av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
183 return AVERROR_INVALIDDATA;
184 }
185
186 if ((depth == 8) || (depth == 24)) {
187 bytestream2_get_bufferu(gb, output, p2 * (depth >> 3));
188 output += p2 * (depth >> 3);
189
190 // RLE8 copy is actually padded - and runs are not!
191 if(depth == 8 && (p2 & 1)) {
192 bytestream2_skip(gb, 1);
193 }
194 } else if (depth == 16) {
195 for(i = 0; i < p2; i++) {
196 *(uint16_t*)output = bytestream2_get_le16u(gb);
197 output += 2;
198 }
199 } else if (depth == 32) {
200 for(i = 0; i < p2; i++) {
201 *(uint32_t*)output = bytestream2_get_le32u(gb);
202 output += 4;
203 }
204 }
205 pos += p2;
206 } else { //run of pixels
207 uint8_t pix[3]; //original pixel
208 if (output + p1 * (depth >> 3) > output_end)
209 continue;
210
211 switch(depth){
212 case 8:
213 pix[0] = bytestream2_get_byte(gb);
214 memset(output, pix[0], p1);
215 output += p1;
216 break;
217 case 16:
218 pix16 = bytestream2_get_le16(gb);
219 for(i = 0; i < p1; i++) {
220 *(uint16_t*)output = pix16;
221 output += 2;
222 }
223 break;
224 case 24:
225 pix[0] = bytestream2_get_byte(gb);
226 pix[1] = bytestream2_get_byte(gb);
227 pix[2] = bytestream2_get_byte(gb);
228 for(i = 0; i < p1; i++) {
229 *output++ = pix[0];
230 *output++ = pix[1];
231 *output++ = pix[2];
232 }
233 break;
234 case 32:
235 pix32 = bytestream2_get_le32(gb);
236 for(i = 0; i < p1; i++) {
237 *(uint32_t*)output = pix32;
238 output += 4;
239 }
240 break;
241 }
242 pos += p1;
243 }
244 }
245
246 av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
247 return 0;
248 }
249
250
251 int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
252 int depth, GetByteContext *gb)
253 {
254 switch(depth){
255 case 4:
256 return msrle_decode_pal4(avctx, pic, gb);
257 case 8:
258 case 16:
259 case 24:
260 case 32:
261 return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
262 default:
263 av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
264 return -1;
265 }
266 }