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
|
/*
* Copyright (c) 1990 James Ashton - Sydney University
* Copyright (c) 2012 Stefano Sabatini
*
* 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
* X-Face decoder, based on libcompface, by James Ashton.
*/
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "xface.h"
static int pop_integer(BigInt *b, const ProbRange *pranges)
{
uint8_t r;
int i;
/* extract the last byte into r, and shift right b by 8 bits */
ff_big_div(b, 0, &r);
i = 0;
while (r < pranges->offset || r >= pranges->range + pranges->offset) {
pranges++;
i++;
}
ff_big_mul(b, pranges->range);
ff_big_add(b, r - pranges->offset);
return i;
}
static void pop_greys(BigInt *b, char *bitmap, int w, int h)
{
if (w > 3) {
w /= 2;
h /= 2;
pop_greys(b, bitmap, w, h);
pop_greys(b, bitmap + w, w, h);
pop_greys(b, bitmap + XFACE_WIDTH * h, w, h);
pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h);
} else {
w = pop_integer(b, ff_xface_probranges_2x2);
if (w & 1) bitmap[0] = 1;
if (w & 2) bitmap[1] = 1;
if (w & 4) bitmap[XFACE_WIDTH] = 1;
if (w & 8) bitmap[XFACE_WIDTH + 1] = 1;
}
}
static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
{
switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) {
case XFACE_COLOR_WHITE:
return;
case XFACE_COLOR_BLACK:
pop_greys(b, bitmap, w, h);
return;
default:
w /= 2;
h /= 2;
level++;
decode_block(b, bitmap, w, h, level);
decode_block(b, bitmap + w, w, h, level);
decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level);
decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level);
return;
}
}
typedef struct XFaceContext {
AVFrame frame;
uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
} XFaceContext;
static av_cold int xface_decode_init(AVCodecContext *avctx)
{
XFaceContext *xface = avctx->priv_data;
avcodec_get_frame_defaults(&xface->frame);
if (avctx->width || avctx->height) {
if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
av_log(avctx, AV_LOG_ERROR,
"Size value %dx%d not supported, only accepts a size of %dx%d\n",
avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
return AVERROR(EINVAL);
}
}
avctx->width = XFACE_WIDTH;
avctx->height = XFACE_HEIGHT;
avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
return 0;
}
static av_cold int xface_decode_close(AVCodecContext *avctx)
{
XFaceContext *xface = avctx->priv_data;
if (xface->frame.data[0])
avctx->release_buffer(avctx, &xface->frame);
return 0;
}
static int xface_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
XFaceContext *xface = avctx->priv_data;
int ret, i, j, k;
uint8_t byte;
BigInt b = {0};
char *buf;
int64_t c;
if (xface->frame.data[0])
avctx->release_buffer(avctx, &xface->frame);
xface->frame.data[0] = NULL;
if ((ret = ff_get_buffer(avctx, &xface->frame)) < 0)
return ret;
xface->frame.reference = 0;
for (i = 0, k = 0; avpkt->data[i] && i < avpkt->size; i++) {
c = avpkt->data[i];
/* ignore invalid digits */
if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT)
continue;
if (++k > XFACE_MAX_DIGITS) {
av_log(avctx, AV_LOG_WARNING,
"Buffer is longer than expected, truncating at byte %d\n", i);
break;
}
ff_big_mul(&b, XFACE_PRINTS);
ff_big_add(&b, c - XFACE_FIRST_PRINT);
}
/* decode image and put it in bitmap */
memset(xface->bitmap, 0, XFACE_PIXELS);
buf = xface->bitmap;
decode_block(&b, buf, 16, 16, 0);
decode_block(&b, buf + 16, 16, 16, 0);
decode_block(&b, buf + 32, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0);
ff_xface_generate_face(xface->bitmap, xface->bitmap);
/* convert image from 1=black 0=white bitmap to MONOWHITE */
buf = xface->frame.data[0];
for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) {
byte += xface->bitmap[i];
if (k == 7) {
buf[j++] = byte;
byte = k = 0;
} else {
k++;
byte <<= 1;
}
if (j == XFACE_WIDTH/8) {
j = 0;
buf += xface->frame.linesize[0];
}
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = xface->frame;
return avpkt->size;
}
AVCodec ff_xface_decoder = {
.name = "xface",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_XFACE,
.priv_data_size = sizeof(XFaceContext),
.init = xface_decode_init,
.close = xface_decode_close,
.decode = xface_decode_frame,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
.long_name = NULL_IF_CONFIG_SMALL("X-face image"),
};
|
