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
|
/*
* Winnov WNV1 codec
* Copyright (c) 2005 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 libavcodec/wnv1.c
* Winnov WNV1 codec.
*/
#include "avcodec.h"
#include "bitstream.h"
typedef struct WNV1Context{
AVCodecContext *avctx;
AVFrame pic;
int shift;
GetBitContext gb;
} WNV1Context;
static const uint16_t code_tab[16][2]={
{0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3},
{0x000,1},
{0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8}
};
#define CODE_VLC_BITS 9
static VLC code_vlc;
/* returns modified base_value */
static inline int wnv1_get_code(WNV1Context *w, int base_value)
{
int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
if(v==15)
return ff_reverse[ get_bits(&w->gb, 8 - w->shift) ];
else
return base_value + ((v - 7)<<w->shift);
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
WNV1Context * const l = avctx->priv_data;
AVFrame * const p= (AVFrame*)&l->pic;
unsigned char *Y,*U,*V;
int i, j;
int prev_y = 0, prev_u = 0, prev_v = 0;
uint8_t *rbuf;
rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
if(!rbuf){
av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
return -1;
}
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference = 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
av_free(rbuf);
return -1;
}
p->key_frame = 1;
for(i=8; i<buf_size; i++)
rbuf[i]= ff_reverse[ buf[i] ];
init_get_bits(&l->gb, rbuf+8, (buf_size-8)*8);
if (buf[2] >> 4 == 6)
l->shift = 2;
else {
l->shift = 8 - (buf[2] >> 4);
if (l->shift > 4) {
av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4);
l->shift = 4;
}
if (l->shift < 1) {
av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4);
l->shift = 1;
}
}
Y = p->data[0];
U = p->data[1];
V = p->data[2];
for (j = 0; j < avctx->height; j++) {
for (i = 0; i < avctx->width / 2; i++) {
Y[i * 2] = wnv1_get_code(l, prev_y);
prev_u = U[i] = wnv1_get_code(l, prev_u);
prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
prev_v = V[i] = wnv1_get_code(l, prev_v);
}
Y += p->linesize[0];
U += p->linesize[1];
V += p->linesize[2];
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = l->pic;
av_free(rbuf);
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx){
WNV1Context * const l = avctx->priv_data;
l->avctx = avctx;
avctx->pix_fmt = PIX_FMT_YUV422P;
if(!code_vlc.table){
init_vlc(&code_vlc, CODE_VLC_BITS, 16,
&code_tab[0][1], 4, 2,
&code_tab[0][0], 4, 2, 1);
}
return 0;
}
AVCodec wnv1_decoder = {
"wnv1",
CODEC_TYPE_VIDEO,
CODEC_ID_WNV1,
sizeof(WNV1Context),
decode_init,
NULL,
NULL,
decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
};
|
