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
|
/*
* Brute Force & Ignorance (BFI) video decoder
* Copyright (c) 2008 Sisir Koppaka
*
* 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
* @brief Brute Force & Ignorance (.bfi) video decoder
* @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
* @see http://wiki.multimedia.cx/index.php?title=BFI
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
typedef struct BFIContext {
AVCodecContext *avctx;
uint8_t *dst;
uint32_t pal[256];
} BFIContext;
static av_cold int bfi_decode_init(AVCodecContext *avctx)
{
BFIContext *bfi = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
bfi->dst = av_mallocz(avctx->width * avctx->height);
return 0;
}
static int bfi_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
AVFrame *frame = data;
GetByteContext g;
int buf_size = avpkt->size;
BFIContext *bfi = avctx->priv_data;
uint8_t *dst = bfi->dst;
uint8_t *src, *dst_offset, colour1, colour2;
uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
uint32_t *pal;
int i, j, ret, height = avctx->height;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
bytestream2_init(&g, avpkt->data, buf_size);
/* Set frame parameters and palette, if necessary */
if (!avctx->frame_number) {
frame->pict_type = AV_PICTURE_TYPE_I;
frame->key_frame = 1;
/* Setting the palette */
if (avctx->extradata_size > 768) {
av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
return AVERROR_INVALIDDATA;
}
pal = (uint32_t *)frame->data[1];
for (i = 0; i < avctx->extradata_size / 3; i++) {
int shift = 16;
*pal = 0xFFU << 24;
for (j = 0; j < 3; j++, shift -= 8)
*pal += ((avctx->extradata[i * 3 + j] << 2) |
(avctx->extradata[i * 3 + j] >> 4)) << shift;
pal++;
}
memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
frame->palette_has_changed = 1;
} else {
frame->pict_type = AV_PICTURE_TYPE_P;
frame->key_frame = 0;
frame->palette_has_changed = 0;
memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
}
bytestream2_skip(&g, 4); // Unpacked size, not required.
while (dst != frame_end) {
static const uint8_t lentab[4] = { 0, 2, 0, 1 };
unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
unsigned int code = byte >> 6;
unsigned int length = byte & ~0xC0;
if (!bytestream2_get_bytes_left(&g)) {
av_log(avctx, AV_LOG_ERROR,
"Input resolution larger than actual frame.\n");
return AVERROR_INVALIDDATA;
}
/* Get length and offset (if required) */
if (length == 0) {
if (code == 1) {
length = bytestream2_get_byte(&g);
offset = bytestream2_get_le16(&g);
} else {
length = bytestream2_get_le16(&g);
if (code == 2 && length == 0)
break;
}
} else {
if (code == 1)
offset = bytestream2_get_byte(&g);
}
/* Do boundary check */
if (dst + (length << lentab[code]) > frame_end)
break;
switch (code) {
case 0: // normal chain
if (length >= bytestream2_get_bytes_left(&g)) {
av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
return AVERROR_INVALIDDATA;
}
bytestream2_get_buffer(&g, dst, length);
dst += length;
break;
case 1: // back chain
dst_offset = dst - offset;
length *= 4; // Convert dwords to bytes.
if (dst_offset < bfi->dst)
break;
while (length--)
*dst++ = *dst_offset++;
break;
case 2: // skip chain
dst += length;
break;
case 3: // fill chain
colour1 = bytestream2_get_byte(&g);
colour2 = bytestream2_get_byte(&g);
while (length--) {
*dst++ = colour1;
*dst++ = colour2;
}
break;
}
}
src = bfi->dst;
dst = frame->data[0];
while (height--) {
memcpy(dst, src, avctx->width);
src += avctx->width;
dst += frame->linesize[0];
}
*got_frame = 1;
return buf_size;
}
static av_cold int bfi_decode_close(AVCodecContext *avctx)
{
BFIContext *bfi = avctx->priv_data;
av_free(bfi->dst);
return 0;
}
AVCodec ff_bfi_decoder = {
.name = "bfi",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_BFI,
.priv_data_size = sizeof(BFIContext),
.init = bfi_decode_init,
.close = bfi_decode_close,
.decode = bfi_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
};
|
