2 * Microsoft RLE decoder
3 * Copyright (C) 2008 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
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
29 #include "libavutil/intreadwrite.h"
33 static int msrle_decode_pal4(AVCodecContext
*avctx
, AVPicture
*pic
,
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
;
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",
50 return AVERROR_INVALIDDATA
;
52 rle_code
= stream_byte
= bytestream2_get_byteu(gb
);
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 */
60 } else if (stream_byte
== 1) {
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
;
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
;
81 for (i
= 0; i
< rle_code
; i
++) {
82 if (pixel_ptr
>= avctx
->width
)
84 stream_byte
= bytestream2_get_byteu(gb
);
85 pic
->data
[0][row_ptr
+ pixel_ptr
] = stream_byte
>> 4;
87 if (i
+ 1 == rle_code
&& odd_pixel
)
89 if (pixel_ptr
>= avctx
->width
)
91 pic
->data
[0][row_ptr
+ pixel_ptr
] = stream_byte
& 0x0F;
95 // if the RLE code is odd, skip a byte in the stream
97 bytestream2_skip(gb
, 1);
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
;
106 stream_byte
= bytestream2_get_byte(gb
);
107 for (i
= 0; i
< rle_code
; i
++) {
108 if (pixel_ptr
>= avctx
->width
)
111 pic
->data
[0][row_ptr
+ pixel_ptr
] = stream_byte
>> 4;
113 pic
->data
[0][row_ptr
+ pixel_ptr
] = stream_byte
& 0x0F;
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
;
131 static int msrle_decode_8_16_24_32(AVCodecContext
*avctx
, AVPicture
*pic
,
132 int depth
, GetByteContext
*gb
)
134 uint8_t *output
, *output_end
;
135 int p1
, p2
, line
=avctx
->height
- 1, pos
=0, i
;
138 unsigned int width
= FFABS(pic
->linesize
[0]) / (depth
>> 3);
140 output
= pic
->data
[0] + (avctx
->height
- 1) * pic
->linesize
[0];
141 output_end
= output
+ FFABS(pic
->linesize
[0]);
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
149 if (bytestream2_get_be16(gb
) == 1) { // end-of-picture
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
;
158 output
= pic
->data
[0] + line
* pic
->linesize
[0];
159 output_end
= output
+ FFABS(pic
->linesize
[0]);
162 } else if(p2
== 1) { //End-of-picture
164 } else if(p2
== 2) { //Skip
165 p1
= bytestream2_get_byte(gb
);
166 p2
= bytestream2_get_byte(gb
);
169 if (line
< 0 || pos
>= width
){
170 av_log(avctx
, AV_LOG_ERROR
, "Skip beyond picture bounds\n");
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]);
178 if (output
+ p2
* (depth
>> 3) > output_end
) {
179 bytestream2_skip(gb
, 2 * (depth
>> 3));
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
;
186 if ((depth
== 8) || (depth
== 24)) {
187 bytestream2_get_bufferu(gb
, output
, p2
* (depth
>> 3));
188 output
+= p2
* (depth
>> 3);
190 // RLE8 copy is actually padded - and runs are not!
191 if(depth
== 8 && (p2
& 1)) {
192 bytestream2_skip(gb
, 1);
194 } else if (depth
== 16) {
195 for(i
= 0; i
< p2
; i
++) {
196 *(uint16_t*)output
= bytestream2_get_le16u(gb
);
199 } else if (depth
== 32) {
200 for(i
= 0; i
< p2
; i
++) {
201 *(uint32_t*)output
= bytestream2_get_le32u(gb
);
206 } else { //run of pixels
207 uint8_t pix
[3]; //original pixel
208 if (output
+ p1
* (depth
>> 3) > output_end
)
213 pix
[0] = bytestream2_get_byte(gb
);
214 memset(output
, pix
[0], p1
);
218 pix16
= bytestream2_get_le16(gb
);
219 for(i
= 0; i
< p1
; i
++) {
220 *(uint16_t*)output
= pix16
;
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
++) {
235 pix32
= bytestream2_get_le32(gb
);
236 for(i
= 0; i
< p1
; i
++) {
237 *(uint32_t*)output
= pix32
;
246 av_log(avctx
, AV_LOG_WARNING
, "MS RLE warning: no end-of-picture code\n");
251 int ff_msrle_decode(AVCodecContext
*avctx
, AVPicture
*pic
,
252 int depth
, GetByteContext
*gb
)
256 return msrle_decode_pal4(avctx
, pic
, gb
);
261 return msrle_decode_8_16_24_32(avctx
, pic
, depth
, gb
);
263 av_log(avctx
, AV_LOG_ERROR
, "Unknown depth %d\n", depth
);