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
|
/*
* Autodesc RLE Decoder
* Copyright (C) 2005 the ffmpeg project
*
* 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 aasc.c
* Autodesc RLE Video Decoder by Konstantin Shishkov
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"
#include "avcodec.h"
#include "dsputil.h"
typedef struct AascContext {
AVCodecContext *avctx;
AVFrame frame;
} AascContext;
#define FETCH_NEXT_STREAM_BYTE() \
if (stream_ptr >= buf_size) \
{ \
av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (fetch)\n"); \
break; \
} \
stream_byte = buf[stream_ptr++];
static int aasc_decode_init(AVCodecContext *avctx)
{
AascContext *s = (AascContext *)avctx->priv_data;
s->avctx = avctx;
avctx->pix_fmt = PIX_FMT_BGR24;
avctx->has_b_frames = 0;
s->frame.data[0] = NULL;
return 0;
}
static int aasc_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
AascContext *s = (AascContext *)avctx->priv_data;
int stream_ptr = 4;
unsigned char rle_code;
unsigned char stream_byte;
int pixel_ptr = 0;
int row_dec, row_ptr;
int frame_size;
int i;
s->frame.reference = 1;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, &s->frame)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
row_dec = s->frame.linesize[0];
row_ptr = (s->avctx->height - 1) * row_dec;
frame_size = row_dec * s->avctx->height;
while (row_ptr >= 0) {
FETCH_NEXT_STREAM_BYTE();
rle_code = stream_byte;
if (rle_code == 0) {
/* fetch the next byte to see how to handle escape code */
FETCH_NEXT_STREAM_BYTE();
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 */
break;
} else if (stream_byte == 2) {
/* reposition frame decode coordinates */
FETCH_NEXT_STREAM_BYTE();
pixel_ptr += stream_byte;
FETCH_NEXT_STREAM_BYTE();
row_ptr -= stream_byte * row_dec;
} else {
/* copy pixels from encoded stream */
if ((pixel_ptr + stream_byte > avctx->width * 3) ||
(row_ptr < 0)) {
av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (copy1)\n");
break;
}
rle_code = stream_byte;
if (stream_ptr + rle_code > buf_size) {
av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (copy2)\n");
break;
}
for (i = 0; i < rle_code; i++) {
FETCH_NEXT_STREAM_BYTE();
s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
pixel_ptr++;
}
if (rle_code & 1)
stream_ptr++;
}
} else {
/* decode a run of data */
if ((pixel_ptr + rle_code > avctx->width * 3) ||
(row_ptr < 0)) {
av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (run1)\n");
break;
}
FETCH_NEXT_STREAM_BYTE();
while(rle_code--) {
s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
pixel_ptr++;
}
}
}
/* one last sanity check on the way out */
if (stream_ptr < buf_size)
av_log(s->avctx, AV_LOG_ERROR, " AASC: ended frame decode with bytes left over (%d < %d)\n",
stream_ptr, buf_size);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static int aasc_decode_end(AVCodecContext *avctx)
{
AascContext *s = (AascContext *)avctx->priv_data;
/* release the last frame */
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec aasc_decoder = {
"aasc",
CODEC_TYPE_VIDEO,
CODEC_ID_AASC,
sizeof(AascContext),
aasc_decode_init,
NULL,
aasc_decode_end,
aasc_decode_frame,
CODEC_CAP_DR1,
};
|
