FFmpeg
Main Page
Related Pages
Modules
Namespaces
Data Structures
Files
Examples
File List
Globals
•
All
Data Structures
Namespaces
Files
Functions
Variables
Typedefs
Enumerations
Enumerator
Macros
Groups
Pages
libavcodec
ansi.c
Go to the documentation of this file.
1
/*
2
* ASCII/ANSI art decoder
3
* Copyright (c) 2010 Peter Ross <pross@xvid.org>
4
*
5
* This file is part of FFmpeg.
6
*
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.
11
*
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.
16
*
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
20
*/
21
22
/**
23
* @file
24
* ASCII/ANSI art decoder
25
*/
26
27
#include "
libavutil/common.h
"
28
#include "
libavutil/frame.h
"
29
#include "
libavutil/lfg.h
"
30
#include "
libavutil/xga_font_data.h
"
31
#include "
avcodec.h
"
32
#include "
cga_data.h
"
33
#include "
internal.h
"
34
35
#define ATTR_BOLD 0x01
/**< Bold/Bright-foreground (mode 1) */
36
#define ATTR_FAINT 0x02
/**< Faint (mode 2) */
37
#define ATTR_UNDERLINE 0x08
/**< Underline (mode 4) */
38
#define ATTR_BLINK 0x10
/**< Blink/Bright-background (mode 5) */
39
#define ATTR_REVERSE 0x40
/**< Reverse (mode 7) */
40
#define ATTR_CONCEALED 0x80
/**< Concealed (mode 8) */
41
42
#define DEFAULT_FG_COLOR 7
/**< CGA color index */
43
#define DEFAULT_BG_COLOR 0
44
#define DEFAULT_SCREEN_MODE 3
/**< 80x25 */
45
46
#define FONT_WIDTH 8
/**< Font width */
47
48
/** map ansi color index to cga palette index */
49
static
const
uint8_t
ansi_to_cga
[16] = {
50
0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15
51
};
52
53
typedef
struct
{
54
AVFrame
*
frame
;
55
int
x
;
/**< x cursor position (pixels) */
56
int
y
;
/**< y cursor position (pixels) */
57
int
sx
;
/**< saved x cursor position (pixels) */
58
int
sy
;
/**< saved y cursor position (pixels) */
59
const
uint8_t
*
font
;
/**< font */
60
int
font_height
;
/**< font height */
61
int
attributes
;
/**< attribute flags */
62
int
fg
;
/**< foreground color */
63
int
bg
;
/**< background color */
64
int
first_frame
;
65
66
/* ansi parser state machine */
67
enum
{
68
STATE_NORMAL = 0,
69
STATE_ESCAPE
,
70
STATE_CODE
,
71
STATE_MUSIC_PREAMBLE
72
}
state
;
73
#define MAX_NB_ARGS 4
74
int
args
[
MAX_NB_ARGS
];
75
int
nb_args
;
/**< number of arguments (may exceed MAX_NB_ARGS) */
76
}
AnsiContext
;
77
78
static
av_cold
int
decode_init
(
AVCodecContext
*avctx)
79
{
80
AnsiContext
*
s
= avctx->
priv_data
;
81
avctx->
pix_fmt
=
AV_PIX_FMT_PAL8
;
82
83
s->
frame
=
av_frame_alloc
();
84
if
(!s->
frame
)
85
return
AVERROR
(ENOMEM);
86
87
/* defaults */
88
s->
font
=
avpriv_vga16_font
;
89
s->
font_height
= 16;
90
s->
fg
=
DEFAULT_FG_COLOR
;
91
s->
bg
=
DEFAULT_BG_COLOR
;
92
93
if
(!avctx->
width
|| !avctx->
height
)
94
ff_set_dimensions
(avctx, 80 << 3, 25 << 4);
95
96
return
0;
97
}
98
99
static
void
set_palette
(uint32_t *pal)
100
{
101
int
r
,
g
,
b
;
102
memcpy(pal,
ff_cga_palette
, 16 * 4);
103
pal += 16;
104
#define COLOR(x) ((x) * 40 + 55)
105
for
(r = 0; r < 6; r++)
106
for
(g = 0; g < 6; g++)
107
for
(b = 0; b < 6; b++)
108
*pal++ = 0xFF000000 | (
COLOR
(r) << 16) | (
COLOR
(g) << 8) |
COLOR
(b);
109
#define GRAY(x) ((x) * 10 + 8)
110
for
(g = 0; g < 24; g++)
111
*pal++ = 0xFF000000 | (
GRAY
(g) << 16) | (
GRAY
(g) << 8) |
GRAY
(g);
112
}
113
114
static
void
hscroll
(
AVCodecContext
*avctx)
115
{
116
AnsiContext
*
s
= avctx->
priv_data
;
117
int
i;
118
119
if
(s->
y
<= avctx->
height
- 2*s->
font_height
) {
120
s->
y
+= s->
font_height
;
121
return
;
122
}
123
124
i = 0;
125
for
(; i < avctx->
height
- s->
font_height
; i++)
126
memcpy(s->
frame
->
data
[0] + i * s->
frame
->
linesize
[0],
127
s->
frame
->
data
[0] + (i + s->
font_height
) * s->
frame
->
linesize
[0],
128
avctx->
width
);
129
for
(; i < avctx->
height
; i++)
130
memset(s->
frame
->
data
[0] + i * s->
frame
->
linesize
[0],
131
DEFAULT_BG_COLOR
, avctx->
width
);
132
}
133
134
static
void
erase_line
(
AVCodecContext
* avctx,
int
xoffset,
int
xlength)
135
{
136
AnsiContext
*
s
= avctx->
priv_data
;
137
int
i;
138
for
(i = 0; i < s->
font_height
; i++)
139
memset(s->
frame
->
data
[0] + (s->
y
+ i)*s->
frame
->
linesize
[0] + xoffset,
140
DEFAULT_BG_COLOR
, xlength);
141
}
142
143
static
void
erase_screen
(
AVCodecContext
*avctx)
144
{
145
AnsiContext
*
s
= avctx->
priv_data
;
146
int
i;
147
for
(i = 0; i < avctx->
height
; i++)
148
memset(s->
frame
->
data
[0] + i * s->
frame
->
linesize
[0],
DEFAULT_BG_COLOR
, avctx->
width
);
149
s->
x
= s->
y
= 0;
150
}
151
152
/**
153
* Draw character to screen
154
*/
155
static
void
draw_char
(
AVCodecContext
*avctx,
int
c
)
156
{
157
AnsiContext
*
s
= avctx->
priv_data
;
158
int
fg = s->
fg
;
159
int
bg = s->
bg
;
160
161
if
((s->
attributes
&
ATTR_BOLD
))
162
fg += 8;
163
if
((s->
attributes
&
ATTR_BLINK
))
164
bg += 8;
165
if
((s->
attributes
&
ATTR_REVERSE
))
166
FFSWAP
(
int
, fg, bg);
167
if
((s->
attributes
&
ATTR_CONCEALED
))
168
fg = bg;
169
ff_draw_pc_font
(s->
frame
->
data
[0] + s->
y
* s->
frame
->
linesize
[0] + s->
x
,
170
s->
frame
->
linesize
[0], s->
font
, s->
font_height
, c, fg, bg);
171
s->
x
+=
FONT_WIDTH
;
172
if
(s->
x
> avctx->
width
-
FONT_WIDTH
) {
173
s->
x
= 0;
174
hscroll
(avctx);
175
}
176
}
177
178
/**
179
* Execute ANSI escape code
180
* @return 0 on success, negative on error
181
*/
182
static
int
execute_code
(
AVCodecContext
* avctx,
int
c
)
183
{
184
AnsiContext
*
s
= avctx->
priv_data
;
185
int
ret
, i;
186
int
width
= avctx->
width
;
187
int
height
= avctx->
height
;
188
189
switch
(c) {
190
case
'A'
:
//Cursor Up
191
s->
y
=
FFMAX
(s->
y
- (s->
nb_args
> 0 ? s->
args
[0]*s->
font_height
: s->
font_height
), 0);
192
break
;
193
case
'B'
:
//Cursor Down
194
s->
y
=
FFMIN
(s->
y
+ (s->
nb_args
> 0 ? s->
args
[0]*s->
font_height
: s->
font_height
), avctx->
height
- s->
font_height
);
195
break
;
196
case
'C'
:
//Cursor Right
197
s->
x
=
FFMIN
(s->
x
+ (s->
nb_args
> 0 ? s->
args
[0]*
FONT_WIDTH
:
FONT_WIDTH
), avctx->
width
- FONT_WIDTH);
198
break
;
199
case
'D'
:
//Cursor Left
200
s->
x
=
FFMAX
(s->
x
- (s->
nb_args
> 0 ? s->
args
[0]*FONT_WIDTH : FONT_WIDTH), 0);
201
break
;
202
case
'H'
:
//Cursor Position
203
case
'f'
:
//Horizontal and Vertical Position
204
s->
y
= s->
nb_args
> 0 ? av_clip((s->
args
[0] - 1)*s->
font_height
, 0, avctx->
height
- s->
font_height
) : 0;
205
s->
x
= s->
nb_args
> 1 ? av_clip((s->
args
[1] - 1)*FONT_WIDTH, 0, avctx->
width
- FONT_WIDTH) : 0;
206
break
;
207
case
'h'
:
//set creen mode
208
case
'l'
:
//reset screen mode
209
if
(s->
nb_args
< 2)
210
s->
args
[0] =
DEFAULT_SCREEN_MODE
;
211
switch
(s->
args
[0]) {
212
case
0:
case
1:
case
4:
case
5:
case
13:
case
19:
//320x200 (25 rows)
213
s->
font
=
avpriv_cga_font
;
214
s->
font_height
= 8;
215
width = 40<<3;
216
height = 25<<3;
217
break
;
218
case
2:
case
3:
//640x400 (25 rows)
219
s->
font
=
avpriv_vga16_font
;
220
s->
font_height
= 16;
221
width = 80<<3;
222
height = 25<<4;
223
break
;
224
case
6:
case
14:
//640x200 (25 rows)
225
s->
font
=
avpriv_cga_font
;
226
s->
font_height
= 8;
227
width = 80<<3;
228
height = 25<<3;
229
break
;
230
case
7:
//set line wrapping
231
break
;
232
case
15:
case
16:
//640x350 (43 rows)
233
s->
font
=
avpriv_cga_font
;
234
s->
font_height
= 8;
235
width = 80<<3;
236
height = 43<<3;
237
break
;
238
case
17:
case
18:
//640x480 (60 rows)
239
s->
font
=
avpriv_cga_font
;
240
s->
font_height
= 8;
241
width = 80<<3;
242
height = 60<<4;
243
break
;
244
default
:
245
avpriv_request_sample
(avctx,
"Unsupported screen mode"
);
246
}
247
s->
x
= av_clip(s->
x
, 0, width - FONT_WIDTH);
248
s->
y
= av_clip(s->
y
, 0, height - s->
font_height
);
249
if
(width != avctx->
width
|| height != avctx->
height
) {
250
av_frame_unref
(s->
frame
);
251
ret =
ff_set_dimensions
(avctx, width, height);
252
if
(ret < 0)
253
return
ret
;
254
if
((ret =
ff_get_buffer
(avctx, s->
frame
,
255
AV_GET_BUFFER_FLAG_REF
)) < 0)
256
return
ret
;
257
s->
frame
->
pict_type
=
AV_PICTURE_TYPE_I
;
258
s->
frame
->
palette_has_changed
= 1;
259
set_palette
((uint32_t *)s->
frame
->
data
[1]);
260
erase_screen
(avctx);
261
}
else
if
(c ==
'l'
) {
262
erase_screen
(avctx);
263
}
264
break
;
265
case
'J'
:
//Erase in Page
266
switch
(s->
args
[0]) {
267
case
0:
268
erase_line
(avctx, s->
x
, avctx->
width
- s->
x
);
269
if
(s->
y
< avctx->
height
- s->
font_height
)
270
memset(s->
frame
->
data
[0] + (s->
y
+ s->
font_height
)*s->
frame
->
linesize
[0],
271
DEFAULT_BG_COLOR
, (avctx->
height
- s->
y
- s->
font_height
)*s->
frame
->
linesize
[0]);
272
break
;
273
case
1:
274
erase_line
(avctx, 0, s->
x
);
275
if
(s->
y
> 0)
276
memset(s->
frame
->
data
[0],
DEFAULT_BG_COLOR
, s->
y
* s->
frame
->
linesize
[0]);
277
break
;
278
case
2:
279
erase_screen
(avctx);
280
}
281
break
;
282
case
'K'
:
//Erase in Line
283
switch
(s->
args
[0]) {
284
case
0:
285
erase_line
(avctx, s->
x
, avctx->
width
- s->
x
);
286
break
;
287
case
1:
288
erase_line
(avctx, 0, s->
x
);
289
break
;
290
case
2:
291
erase_line
(avctx, 0, avctx->
width
);
292
}
293
break
;
294
case
'm'
:
//Select Graphics Rendition
295
if
(s->
nb_args
== 0) {
296
s->
nb_args
= 1;
297
s->
args
[0] = 0;
298
}
299
for
(i = 0; i <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
); i++) {
300
int
m
= s->
args
[i];
301
if
(m == 0) {
302
s->
attributes
= 0;
303
s->
fg
=
DEFAULT_FG_COLOR
;
304
s->
bg
=
DEFAULT_BG_COLOR
;
305
}
else
if
(m == 1 || m == 2 || m == 4 || m == 5 || m == 7 || m == 8) {
306
s->
attributes
|= 1 << (m - 1);
307
}
else
if
(m >= 30 && m <= 37) {
308
s->
fg
=
ansi_to_cga
[m - 30];
309
}
else
if
(m == 38 && i + 2 <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
) && s->
args
[i + 1] == 5 && s->
args
[i + 2] < 256) {
310
int
index
= s->
args
[i + 2];
311
s->
fg
= index < 16 ?
ansi_to_cga
[
index
] :
index
;
312
i += 2;
313
}
else
if
(m == 39) {
314
s->
fg
=
ansi_to_cga
[
DEFAULT_FG_COLOR
];
315
}
else
if
(m >= 40 && m <= 47) {
316
s->
bg
=
ansi_to_cga
[m - 40];
317
}
else
if
(m == 48 && i + 2 <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
) && s->
args
[i + 1] == 5 && s->
args
[i + 2] < 256) {
318
int
index
= s->
args
[i + 2];
319
s->
bg
= index < 16 ?
ansi_to_cga
[
index
] :
index
;
320
i += 2;
321
}
else
if
(m == 49) {
322
s->
fg
=
ansi_to_cga
[
DEFAULT_BG_COLOR
];
323
}
else
{
324
avpriv_request_sample
(avctx,
"Unsupported rendition parameter"
);
325
}
326
}
327
break
;
328
case
'n'
:
//Device Status Report
329
case
'R'
:
//report current line and column
330
/* ignore */
331
break
;
332
case
's'
:
//Save Cursor Position
333
s->
sx
= s->
x
;
334
s->
sy
= s->
y
;
335
break
;
336
case
'u'
:
//Restore Cursor Position
337
s->
x
= av_clip(s->
sx
, 0, avctx->
width
- FONT_WIDTH);
338
s->
y
= av_clip(s->
sy
, 0, avctx->
height
- s->
font_height
);
339
break
;
340
default
:
341
avpriv_request_sample
(avctx,
"Unknown escape code"
);
342
break
;
343
}
344
s->
x
= av_clip(s->
x
, 0, avctx->
width
-
FONT_WIDTH
);
345
s->
y
= av_clip(s->
y
, 0, avctx->
height
- s->
font_height
);
346
return
0;
347
}
348
349
static
int
decode_frame
(
AVCodecContext
*avctx,
350
void
*
data
,
int
*got_frame,
351
AVPacket
*avpkt)
352
{
353
AnsiContext
*
s
= avctx->
priv_data
;
354
uint8_t
*
buf
= avpkt->
data
;
355
int
buf_size = avpkt->
size
;
356
const
uint8_t
*buf_end = buf+buf_size;
357
int
ret
, i,
count
;
358
359
if
((ret =
ff_reget_buffer
(avctx, s->
frame
)) < 0)
360
return
ret
;
361
if
(!avctx->
frame_number
) {
362
for
(i=0; i<avctx->
height
; i++)
363
memset(s->
frame
->
data
[0]+ i*s->
frame
->
linesize
[0], 0, avctx->
width
);
364
memset(s->
frame
->
data
[1], 0,
AVPALETTE_SIZE
);
365
}
366
367
s->
frame
->
pict_type
=
AV_PICTURE_TYPE_I
;
368
s->
frame
->
palette_has_changed
= 1;
369
set_palette
((uint32_t *)s->
frame
->
data
[1]);
370
if
(!s->
first_frame
) {
371
erase_screen
(avctx);
372
s->
first_frame
= 1;
373
}
374
375
while
(buf < buf_end) {
376
switch
(s->
state
) {
377
case
STATE_NORMAL:
378
switch
(buf[0]) {
379
case
0x00:
//NUL
380
case
0x07:
//BEL
381
case
0x1A:
//SUB
382
/* ignore */
383
break
;
384
case
0x08:
//BS
385
s->
x
=
FFMAX
(s->
x
- 1, 0);
386
break
;
387
case
0x09:
//HT
388
i = s->
x
/
FONT_WIDTH
;
389
count = ((i + 8) & ~7) - i;
390
for
(i = 0; i <
count
; i++)
391
draw_char
(avctx,
' '
);
392
break
;
393
case
0x0A:
//LF
394
hscroll
(avctx);
395
case
0x0D:
//CR
396
s->
x
= 0;
397
break
;
398
case
0x0C:
//FF
399
erase_screen
(avctx);
400
break
;
401
case
0x1B:
//ESC
402
s->
state
= STATE_ESCAPE;
403
break
;
404
default
:
405
draw_char
(avctx, buf[0]);
406
}
407
break
;
408
case
STATE_ESCAPE:
409
if
(buf[0] ==
'['
) {
410
s->
state
= STATE_CODE;
411
s->
nb_args
= 0;
412
s->
args
[0] = -1;
413
}
else
{
414
s->
state
= STATE_NORMAL;
415
draw_char
(avctx, 0x1B);
416
continue
;
417
}
418
break
;
419
case
STATE_CODE:
420
switch
(buf[0]) {
421
case
'0'
:
case
'1'
:
case
'2'
:
case
'3'
:
case
'4'
:
422
case
'5'
:
case
'6'
:
case
'7'
:
case
'8'
:
case
'9'
:
423
if
(s->
nb_args
<
MAX_NB_ARGS
&& s->
args
[s->
nb_args
] < 6553)
424
s->
args
[s->
nb_args
] =
FFMAX
(s->
args
[s->
nb_args
], 0) * 10 + buf[0] -
'0'
;
425
break
;
426
case
';'
:
427
s->
nb_args
++;
428
if
(s->
nb_args
<
MAX_NB_ARGS
)
429
s->
args
[s->
nb_args
] = 0;
430
break
;
431
case
'M'
:
432
s->
state
= STATE_MUSIC_PREAMBLE;
433
break
;
434
case
'='
:
case
'?'
:
435
/* ignore */
436
break
;
437
default
:
438
if
(s->
nb_args
>
MAX_NB_ARGS
)
439
av_log
(avctx,
AV_LOG_WARNING
,
"args overflow (%i)\n"
, s->
nb_args
);
440
if
(s->
nb_args
<
MAX_NB_ARGS
&& s->
args
[s->
nb_args
] >= 0)
441
s->
nb_args
++;
442
if
((ret =
execute_code
(avctx, buf[0])) < 0)
443
return
ret
;
444
s->
state
= STATE_NORMAL;
445
}
446
break
;
447
case
STATE_MUSIC_PREAMBLE:
448
if
(buf[0] == 0x0E || buf[0] == 0x1B)
449
s->
state
= STATE_NORMAL;
450
/* ignore music data */
451
break
;
452
}
453
buf++;
454
}
455
456
*got_frame = 1;
457
if
((ret =
av_frame_ref
(data, s->
frame
)) < 0)
458
return
ret
;
459
return
buf_size;
460
}
461
462
static
av_cold
int
decode_close
(
AVCodecContext
*avctx)
463
{
464
AnsiContext
*
s
= avctx->
priv_data
;
465
466
av_frame_free
(&s->
frame
);
467
return
0;
468
}
469
470
AVCodec
ff_ansi_decoder
= {
471
.
name
=
"ansi"
,
472
.long_name =
NULL_IF_CONFIG_SMALL
(
"ASCII/ANSI art"
),
473
.type =
AVMEDIA_TYPE_VIDEO
,
474
.id =
AV_CODEC_ID_ANSI
,
475
.priv_data_size =
sizeof
(
AnsiContext
),
476
.
init
=
decode_init
,
477
.
close
=
decode_close
,
478
.
decode
=
decode_frame
,
479
.capabilities =
CODEC_CAP_DR1
,
480
};
Generated on Sun Jul 20 2014 23:05:43 for FFmpeg by
1.8.2