FFmpeg
1.2.4
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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
27
#include "libavutil/common.h"
28
#include "libavutil/lfg.h"
29
#include "
libavutil/xga_font_data.h
"
30
#include "
avcodec.h
"
31
#include "
cga_data.h
"
32
#include "
internal.h
"
33
34
#define ATTR_BOLD 0x01
35
#define ATTR_FAINT 0x02
36
#define ATTR_UNDERLINE 0x08
37
#define ATTR_BLINK 0x10
38
#define ATTR_REVERSE 0x40
39
#define ATTR_CONCEALED 0x80
41
#define DEFAULT_FG_COLOR 7
42
#define DEFAULT_BG_COLOR 0
43
#define DEFAULT_SCREEN_MODE 3
45
#define FONT_WIDTH 8
48
static const uint8_t ansi_to_cga[16] = {
49
0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15
50
};
51
52
typedef
struct
{
53
AVFrame
frame
;
54
int
x
;
55
int
y
;
56
int
sx
;
57
int
sy
;
58
const
uint8_t
*
font
;
59
int
font_height
;
60
int
attributes
;
61
int
fg
;
62
int
bg
;
63
int
first_frame
;
64
65
/* ansi parser state machine */
66
enum
{
67
STATE_NORMAL = 0,
68
STATE_ESCAPE
,
69
STATE_CODE
,
70
STATE_MUSIC_PREAMBLE
71
}
state
;
72
#define MAX_NB_ARGS 4
73
int
args[
MAX_NB_ARGS
];
74
int
nb_args
;
75
}
AnsiContext
;
76
77
static
av_cold
int
decode_init
(
AVCodecContext
*avctx)
78
{
79
AnsiContext
*s = avctx->
priv_data
;
80
avctx->
pix_fmt
=
AV_PIX_FMT_PAL8
;
81
82
/* defaults */
83
s->
font
=
avpriv_vga16_font
;
84
s->
font_height
= 16;
85
s->
fg
=
DEFAULT_FG_COLOR
;
86
s->
bg
=
DEFAULT_BG_COLOR
;
87
88
avcodec_get_frame_defaults
(&s->
frame
);
89
if
(!avctx->
width
|| !avctx->
height
)
90
avcodec_set_dimensions
(avctx, 80<<3, 25<<4);
91
92
return
0;
93
}
94
95
static
void
set_palette
(uint32_t *pal)
96
{
97
int
r
,
g
,
b
;
98
memcpy(pal,
ff_cga_palette
, 16 * 4);
99
pal += 16;
100
#define COLOR(x) ((x) * 40 + 55)
101
for
(r = 0; r < 6; r++)
102
for
(g = 0; g < 6; g++)
103
for
(b = 0; b < 6; b++)
104
*pal++ = 0xFF000000 | (
COLOR
(r) << 16) | (
COLOR
(g) << 8) |
COLOR
(b);
105
#define GRAY(x) ((x) * 10 + 8)
106
for
(g = 0; g < 24; g++)
107
*pal++ = 0xFF000000 | (
GRAY
(g) << 16) | (
GRAY
(g) << 8) |
GRAY
(g);
108
}
109
110
static
void
hscroll
(
AVCodecContext
*avctx)
111
{
112
AnsiContext
*s = avctx->
priv_data
;
113
int
i;
114
115
if
(s->
y
< avctx->
height
- s->
font_height
) {
116
s->
y
+= s->
font_height
;
117
return
;
118
}
119
120
i = 0;
121
for
(; i < avctx->
height
- s->
font_height
; i++)
122
memcpy(s->
frame
.
data
[0] + i * s->
frame
.
linesize
[0],
123
s->
frame
.
data
[0] + (i + s->
font_height
) * s->
frame
.
linesize
[0],
124
avctx->
width
);
125
for
(; i < avctx->
height
; i++)
126
memset(s->
frame
.
data
[0] + i * s->
frame
.
linesize
[0],
127
DEFAULT_BG_COLOR
, avctx->
width
);
128
}
129
130
static
void
erase_line
(
AVCodecContext
* avctx,
int
xoffset,
int
xlength)
131
{
132
AnsiContext
*s = avctx->
priv_data
;
133
int
i;
134
for
(i = 0; i < s->
font_height
; i++)
135
memset(s->
frame
.
data
[0] + (s->
y
+ i)*s->
frame
.
linesize
[0] + xoffset,
136
DEFAULT_BG_COLOR
, xlength);
137
}
138
139
static
void
erase_screen
(
AVCodecContext
*avctx)
140
{
141
AnsiContext
*s = avctx->
priv_data
;
142
int
i;
143
for
(i = 0; i < avctx->
height
; i++)
144
memset(s->
frame
.
data
[0] + i * s->
frame
.
linesize
[0],
DEFAULT_BG_COLOR
, avctx->
width
);
145
s->
x
= s->
y
= 0;
146
}
147
151
static
void
draw_char
(
AVCodecContext
*avctx,
int
c
)
152
{
153
AnsiContext
*s = avctx->
priv_data
;
154
int
fg = s->
fg
;
155
int
bg = s->
bg
;
156
157
if
((s->
attributes
&
ATTR_BOLD
))
158
fg += 8;
159
if
((s->
attributes
&
ATTR_BLINK
))
160
bg += 8;
161
if
((s->
attributes
&
ATTR_REVERSE
))
162
FFSWAP
(
int
, fg, bg);
163
if
((s->
attributes
&
ATTR_CONCEALED
))
164
fg = bg;
165
ff_draw_pc_font
(s->
frame
.
data
[0] + s->
y
* s->
frame
.
linesize
[0] + s->
x
,
166
s->
frame
.
linesize
[0], s->
font
, s->
font_height
, c, fg, bg);
167
s->
x
+=
FONT_WIDTH
;
168
if
(s->
x
>= avctx->
width
) {
169
s->
x
= 0;
170
hscroll
(avctx);
171
}
172
}
173
178
static
int
execute_code
(
AVCodecContext
* avctx,
int
c
)
179
{
180
AnsiContext
*s = avctx->
priv_data
;
181
int
ret, i,
width
,
height
;
182
switch
(c) {
183
case
'A'
:
//Cursor Up
184
s->
y
=
FFMAX
(s->
y
- (s->
nb_args
> 0 ? s->
args
[0]*s->
font_height
: s->
font_height
), 0);
185
break
;
186
case
'B'
:
//Cursor Down
187
s->
y
=
FFMIN
(s->
y
+ (s->
nb_args
> 0 ? s->
args
[0]*s->
font_height
: s->
font_height
), avctx->
height
- s->
font_height
);
188
break
;
189
case
'C'
:
//Cursor Right
190
s->
x
=
FFMIN
(s->
x
+ (s->
nb_args
> 0 ? s->
args
[0]*
FONT_WIDTH
:
FONT_WIDTH
), avctx->
width
- FONT_WIDTH);
191
break
;
192
case
'D'
:
//Cursor Left
193
s->
x
=
FFMAX
(s->
x
- (s->
nb_args
> 0 ? s->
args
[0]*FONT_WIDTH : FONT_WIDTH), 0);
194
break
;
195
case
'H'
:
//Cursor Position
196
case
'f'
:
//Horizontal and Vertical Position
197
s->
y
= s->
nb_args
> 0 ? av_clip((s->
args
[0] - 1)*s->
font_height
, 0, avctx->
height
- s->
font_height
) : 0;
198
s->
x
= s->
nb_args
> 1 ? av_clip((s->
args
[1] - 1)*FONT_WIDTH, 0, avctx->
width
- FONT_WIDTH) : 0;
199
break
;
200
case
'h'
:
//set creen mode
201
case
'l'
:
//reset screen mode
202
if
(s->
nb_args
< 2)
203
s->
args
[0] =
DEFAULT_SCREEN_MODE
;
204
width = avctx->
width
;
205
height = avctx->
height
;
206
switch
(s->
args
[0]) {
207
case
0:
case
1:
case
4:
case
5:
case
13:
case
19:
//320x200 (25 rows)
208
s->
font
=
avpriv_cga_font
;
209
s->
font_height
= 8;
210
width = 40<<3;
211
height = 25<<3;
212
break
;
213
case
2:
case
3:
//640x400 (25 rows)
214
s->
font
=
avpriv_vga16_font
;
215
s->
font_height
= 16;
216
width = 80<<3;
217
height = 25<<4;
218
break
;
219
case
6:
case
14:
//640x200 (25 rows)
220
s->
font
=
avpriv_cga_font
;
221
s->
font_height
= 8;
222
width = 80<<3;
223
height = 25<<3;
224
break
;
225
case
7:
//set line wrapping
226
break
;
227
case
15:
case
16:
//640x350 (43 rows)
228
s->
font
=
avpriv_cga_font
;
229
s->
font_height
= 8;
230
width = 80<<3;
231
height = 43<<3;
232
break
;
233
case
17:
case
18:
//640x480 (60 rows)
234
s->
font
=
avpriv_cga_font
;
235
s->
font_height
= 8;
236
width = 80<<3;
237
height = 60<<4;
238
break
;
239
default
:
240
av_log_ask_for_sample
(avctx,
"unsupported screen mode\n"
);
241
}
242
if
(width != avctx->
width
|| height != avctx->
height
) {
243
if
(s->
frame
.
data
[0])
244
avctx->
release_buffer
(avctx, &s->
frame
);
245
avcodec_set_dimensions
(avctx, width, height);
246
ret =
ff_get_buffer
(avctx, &s->
frame
);
247
if
(ret < 0) {
248
av_log
(avctx,
AV_LOG_ERROR
,
"get_buffer() failed\n"
);
249
return
ret;
250
}
251
s->
frame
.
pict_type
=
AV_PICTURE_TYPE_I
;
252
s->
frame
.
palette_has_changed
= 1;
253
set_palette
((uint32_t *)s->
frame
.
data
[1]);
254
erase_screen
(avctx);
255
}
else
if
(c ==
'l'
) {
256
erase_screen
(avctx);
257
}
258
break
;
259
case
'J'
:
//Erase in Page
260
switch
(s->
args
[0]) {
261
case
0:
262
erase_line
(avctx, s->
x
, avctx->
width
- s->
x
);
263
if
(s->
y
< avctx->
height
- s->
font_height
)
264
memset(s->
frame
.
data
[0] + (s->
y
+ s->
font_height
)*s->
frame
.
linesize
[0],
265
DEFAULT_BG_COLOR
, (avctx->
height
- s->
y
- s->
font_height
)*s->
frame
.
linesize
[0]);
266
break
;
267
case
1:
268
erase_line
(avctx, 0, s->
x
);
269
if
(s->
y
> 0)
270
memset(s->
frame
.
data
[0],
DEFAULT_BG_COLOR
, s->
y
* s->
frame
.
linesize
[0]);
271
break
;
272
case
2:
273
erase_screen
(avctx);
274
}
275
break
;
276
case
'K'
:
//Erase in Line
277
switch
(s->
args
[0]) {
278
case
0:
279
erase_line
(avctx, s->
x
, avctx->
width
- s->
x
);
280
break
;
281
case
1:
282
erase_line
(avctx, 0, s->
x
);
283
break
;
284
case
2:
285
erase_line
(avctx, 0, avctx->
width
);
286
}
287
break
;
288
case
'm'
:
//Select Graphics Rendition
289
if
(s->
nb_args
== 0) {
290
s->
nb_args
= 1;
291
s->
args
[0] = 0;
292
}
293
for
(i = 0; i <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
); i++) {
294
int
m
= s->
args
[i];
295
if
(m == 0) {
296
s->
attributes
= 0;
297
s->
fg
=
DEFAULT_FG_COLOR
;
298
s->
bg
=
DEFAULT_BG_COLOR
;
299
}
else
if
(m == 1 || m == 2 || m == 4 || m == 5 || m == 7 || m == 8) {
300
s->
attributes
|= 1 << (m - 1);
301
}
else
if
(m >= 30 && m <= 37) {
302
s->
fg
=
ansi_to_cga
[m - 30];
303
}
else
if
(m == 38 && i + 2 <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
) && s->
args
[i + 1] == 5 && s->
args
[i + 2] < 256) {
304
int
index
= s->
args
[i + 2];
305
s->
fg
= index < 16 ?
ansi_to_cga
[
index
] :
index
;
306
i += 2;
307
}
else
if
(m == 39) {
308
s->
fg
=
ansi_to_cga
[
DEFAULT_FG_COLOR
];
309
}
else
if
(m >= 40 && m <= 47) {
310
s->
bg
=
ansi_to_cga
[m - 40];
311
}
else
if
(m == 48 && i + 2 <
FFMIN
(s->
nb_args
,
MAX_NB_ARGS
) && s->
args
[i + 1] == 5 && s->
args
[i + 2] < 256) {
312
int
index
= s->
args
[i + 2];
313
s->
bg
= index < 16 ?
ansi_to_cga
[
index
] :
index
;
314
i += 2;
315
}
else
if
(m == 49) {
316
s->
fg
=
ansi_to_cga
[
DEFAULT_BG_COLOR
];
317
}
else
{
318
av_log_ask_for_sample
(avctx,
"unsupported rendition parameter\n"
);
319
}
320
}
321
break
;
322
case
'n'
:
//Device Status Report
323
case
'R'
:
//report current line and column
324
/* ignore */
325
break
;
326
case
's'
:
//Save Cursor Position
327
s->
sx
= s->
x
;
328
s->
sy
= s->
y
;
329
break
;
330
case
'u'
:
//Restore Cursor Position
331
s->
x
= av_clip(s->
sx
, 0, avctx->
width
- FONT_WIDTH);
332
s->
y
= av_clip(s->
sy
, 0, avctx->
height
- s->
font_height
);
333
break
;
334
default
:
335
av_log_ask_for_sample
(avctx,
"unsupported escape code\n"
);
336
break
;
337
}
338
return
0;
339
}
340
341
static
int
decode_frame
(
AVCodecContext
*avctx,
342
void
*
data
,
int
*got_frame,
343
AVPacket
*avpkt)
344
{
345
AnsiContext
*s = avctx->
priv_data
;
346
uint8_t
*buf = avpkt->
data
;
347
int
buf_size = avpkt->
size
;
348
const
uint8_t
*buf_end = buf+buf_size;
349
int
ret, i, count;
350
351
ret = avctx->
reget_buffer
(avctx, &s->
frame
);
352
if
(ret < 0){
353
av_log
(avctx,
AV_LOG_ERROR
,
"get_buffer() failed\n"
);
354
return
ret;
355
}
356
if
(!avctx->
frame_number
) {
357
for
(i=0; i<avctx->
height
; i++)
358
memset(s->
frame
.
data
[0]+ i*s->
frame
.
linesize
[0], 0, avctx->
width
);
359
memset(s->
frame
.
data
[1], 0,
AVPALETTE_SIZE
);
360
}
361
362
s->
frame
.
pict_type
=
AV_PICTURE_TYPE_I
;
363
s->
frame
.
palette_has_changed
= 1;
364
set_palette
((uint32_t *)s->
frame
.
data
[1]);
365
if
(!s->
first_frame
) {
366
erase_screen
(avctx);
367
s->
first_frame
= 1;
368
}
369
370
while
(buf < buf_end) {
371
switch
(s->
state
) {
372
case
STATE_NORMAL:
373
switch
(buf[0]) {
374
case
0x00:
//NUL
375
case
0x07:
//BEL
376
case
0x1A:
//SUB
377
/* ignore */
378
break
;
379
case
0x08:
//BS
380
s->
x
=
FFMAX
(s->
x
- 1, 0);
381
break
;
382
case
0x09:
//HT
383
i = s->
x
/
FONT_WIDTH
;
384
count = ((i + 8) & ~7) - i;
385
for
(i = 0; i < count; i++)
386
draw_char
(avctx,
' '
);
387
break
;
388
case
0x0A:
//LF
389
hscroll
(avctx);
390
case
0x0D:
//CR
391
s->
x
= 0;
392
break
;
393
case
0x0C:
//FF
394
erase_screen
(avctx);
395
break
;
396
case
0x1B:
//ESC
397
s->
state
= STATE_ESCAPE;
398
break
;
399
default
:
400
draw_char
(avctx, buf[0]);
401
}
402
break
;
403
case
STATE_ESCAPE:
404
if
(buf[0] ==
'['
) {
405
s->
state
= STATE_CODE;
406
s->
nb_args
= 0;
407
s->
args
[0] = -1;
408
}
else
{
409
s->
state
= STATE_NORMAL;
410
draw_char
(avctx, 0x1B);
411
continue
;
412
}
413
break
;
414
case
STATE_CODE:
415
switch
(buf[0]) {
416
case
'0'
:
case
'1'
:
case
'2'
:
case
'3'
:
case
'4'
:
417
case
'5'
:
case
'6'
:
case
'7'
:
case
'8'
:
case
'9'
:
418
if
(s->
nb_args
<
MAX_NB_ARGS
)
419
s->
args
[s->
nb_args
] =
FFMAX
(s->
args
[s->
nb_args
], 0) * 10 + buf[0] -
'0'
;
420
break
;
421
case
';'
:
422
s->
nb_args
++;
423
if
(s->
nb_args
<
MAX_NB_ARGS
)
424
s->
args
[s->
nb_args
] = 0;
425
break
;
426
case
'M'
:
427
s->
state
= STATE_MUSIC_PREAMBLE;
428
break
;
429
case
'='
:
case
'?'
:
430
/* ignore */
431
break
;
432
default
:
433
if
(s->
nb_args
>
MAX_NB_ARGS
)
434
av_log
(avctx,
AV_LOG_WARNING
,
"args overflow (%i)\n"
, s->
nb_args
);
435
if
(s->
nb_args
<
MAX_NB_ARGS
&& s->
args
[s->
nb_args
] >= 0)
436
s->
nb_args
++;
437
if
((ret =
execute_code
(avctx, buf[0])) < 0)
438
return
ret;
439
s->
state
= STATE_NORMAL;
440
}
441
break
;
442
case
STATE_MUSIC_PREAMBLE:
443
if
(buf[0] == 0x0E || buf[0] == 0x1B)
444
s->
state
= STATE_NORMAL;
445
/* ignore music data */
446
break
;
447
}
448
buf++;
449
}
450
451
*got_frame = 1;
452
*(
AVFrame
*)data = s->
frame
;
453
return
buf_size;
454
}
455
456
static
av_cold
int
decode_close
(
AVCodecContext
*avctx)
457
{
458
AnsiContext
*s = avctx->
priv_data
;
459
if
(s->
frame
.
data
[0])
460
avctx->
release_buffer
(avctx, &s->
frame
);
461
return
0;
462
}
463
464
AVCodec
ff_ansi_decoder
= {
465
.
name
=
"ansi"
,
466
.type =
AVMEDIA_TYPE_VIDEO
,
467
.id =
AV_CODEC_ID_ANSI
,
468
.priv_data_size =
sizeof
(
AnsiContext
),
469
.
init
=
decode_init
,
470
.
close
=
decode_close
,
471
.
decode
=
decode_frame
,
472
.capabilities =
CODEC_CAP_DR1
,
473
.long_name =
NULL_IF_CONFIG_SMALL
(
"ASCII/ANSI art"
),
474
};
Generated on Fri Nov 29 2013 19:14:56 for FFmpeg by
1.8.1.2