1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
/*
* Microsoft RLE decoder
* Copyright (C) 2008 Konstantin Shishkov
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* MS RLE decoder based on decoder by Mike Melanson and my own for TSCC
* For more information about the MS RLE format, visit:
* http://www.multimedia.cx/msrle.txt
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "msrledec.h"
static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
GetByteContext *gb)
{
unsigned char rle_code;
unsigned char extra_byte, odd_pixel;
unsigned char stream_byte;
unsigned int pixel_ptr = 0;
int row_dec = pic->linesize[0];
int row_ptr = (avctx->height - 1) * row_dec;
int frame_size = row_dec * avctx->height;
int i;
while (row_ptr >= 0) {
if (bytestream2_get_bytes_left(gb) <= 0) {
av_log(avctx, AV_LOG_ERROR,
"MS RLE: bytestream overrun, %d rows left\n",
row_ptr);
return AVERROR_INVALIDDATA;
}
rle_code = stream_byte = bytestream2_get_byteu(gb);
if (rle_code == 0) {
/* fetch the next byte to see how to handle escape code */
stream_byte = bytestream2_get_byte(gb);
if (stream_byte == 0) {
/* line is done, goto the next one */
row_ptr -= row_dec;
pixel_ptr = 0;
} else if (stream_byte == 1) {
/* decode is done */
return 0;
} else if (stream_byte == 2) {
/* reposition frame decode coordinates */
stream_byte = bytestream2_get_byte(gb);
pixel_ptr += stream_byte;
stream_byte = bytestream2_get_byte(gb);
row_ptr -= stream_byte * row_dec;
} else {
// copy pixels from encoded stream
odd_pixel = stream_byte & 1;
rle_code = (stream_byte + 1) / 2;
extra_byte = rle_code & 0x01;
if (row_ptr + pixel_ptr + stream_byte > frame_size ||
bytestream2_get_bytes_left(gb) < rle_code) {
av_log(avctx, AV_LOG_ERROR,
"MS RLE: frame/stream ptr just went out of bounds (copy)\n");
return AVERROR_INVALIDDATA;
}
for (i = 0; i < rle_code; i++) {
if (pixel_ptr >= avctx->width)
break;
stream_byte = bytestream2_get_byteu(gb);
pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
pixel_ptr++;
if (i + 1 == rle_code && odd_pixel)
break;
if (pixel_ptr >= avctx->width)
break;
pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
pixel_ptr++;
}
// if the RLE code is odd, skip a byte in the stream
if (extra_byte)
bytestream2_skip(gb, 1);
}
} else {
// decode a run of data
if (row_ptr + pixel_ptr + stream_byte > frame_size) {
av_log(avctx, AV_LOG_ERROR,
"MS RLE: frame ptr just went out of bounds (run)\n");
return AVERROR_INVALIDDATA;
}
stream_byte = bytestream2_get_byte(gb);
for (i = 0; i < rle_code; i++) {
if (pixel_ptr >= avctx->width)
break;
if ((i & 1) == 0)
pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
else
pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
pixel_ptr++;
}
}
}
/* one last sanity check on the way out */
if (bytestream2_get_bytes_left(gb)) {
av_log(avctx, AV_LOG_ERROR,
"MS RLE: ended frame decode with %d bytes left over\n",
bytestream2_get_bytes_left(gb));
return AVERROR_INVALIDDATA;
}
return 0;
}
static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
int depth, GetByteContext *gb)
{
uint8_t *output, *output_end;
int p1, p2, line=avctx->height - 1, pos=0, i;
uint16_t pix16;
uint32_t pix32;
unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
output_end = pic->data[0] + avctx->height * pic->linesize[0];
while (bytestream2_get_bytes_left(gb) > 0) {
p1 = bytestream2_get_byteu(gb);
if(p1 == 0) { //Escape code
p2 = bytestream2_get_byte(gb);
if(p2 == 0) { //End-of-line
if (--line < 0) {
if (bytestream2_get_be16(gb) == 1) { // end-of-picture
return 0;
} else {
av_log(avctx, AV_LOG_ERROR,
"Next line is beyond picture bounds (%d bytes left)\n",
bytestream2_get_bytes_left(gb));
return AVERROR_INVALIDDATA;
}
}
output = pic->data[0] + line * pic->linesize[0];
pos = 0;
continue;
} else if(p2 == 1) { //End-of-picture
return 0;
} else if(p2 == 2) { //Skip
p1 = bytestream2_get_byte(gb);
p2 = bytestream2_get_byte(gb);
line -= p2;
pos += p1;
if (line < 0 || pos >= width){
av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
return -1;
}
output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
continue;
}
// Copy data
if ((pic->linesize[0] > 0 && output + p2 * (depth >> 3) > output_end) ||
(pic->linesize[0] < 0 && output + p2 * (depth >> 3) < output_end)) {
bytestream2_skip(gb, 2 * (depth >> 3));
continue;
} else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
return AVERROR_INVALIDDATA;
}
if ((depth == 8) || (depth == 24)) {
for(i = 0; i < p2 * (depth >> 3); i++) {
*output++ = bytestream2_get_byteu(gb);
}
// RLE8 copy is actually padded - and runs are not!
if(depth == 8 && (p2 & 1)) {
bytestream2_skip(gb, 1);
}
} else if (depth == 16) {
for(i = 0; i < p2; i++) {
*(uint16_t*)output = bytestream2_get_le16u(gb);
output += 2;
}
} else if (depth == 32) {
for(i = 0; i < p2; i++) {
*(uint32_t*)output = bytestream2_get_le32u(gb);
output += 4;
}
}
pos += p2;
} else { //run of pixels
uint8_t pix[3]; //original pixel
switch(depth){
case 8: pix[0] = bytestream2_get_byte(gb);
break;
case 16: pix16 = bytestream2_get_le16(gb);
break;
case 24: pix[0] = bytestream2_get_byte(gb);
pix[1] = bytestream2_get_byte(gb);
pix[2] = bytestream2_get_byte(gb);
break;
case 32: pix32 = bytestream2_get_le32(gb);
break;
}
if ((pic->linesize[0] > 0 && output + p1 * (depth >> 3) > output_end) ||
(pic->linesize[0] < 0 && output + p1 * (depth >> 3) < output_end))
continue;
for(i = 0; i < p1; i++) {
switch(depth){
case 8: *output++ = pix[0];
break;
case 16: *(uint16_t*)output = pix16;
output += 2;
break;
case 24: *output++ = pix[0];
*output++ = pix[1];
*output++ = pix[2];
break;
case 32: *(uint32_t*)output = pix32;
output += 4;
break;
}
}
pos += p1;
}
}
av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
return 0;
}
int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
int depth, GetByteContext *gb)
{
switch(depth){
case 4:
return msrle_decode_pal4(avctx, pic, gb);
case 8:
case 16:
case 24:
case 32:
return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
default:
av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
return -1;
}
}
|
