964abc6d20fde8da4636ee22f8ff26a54b1b8ec2
2 * ASCII/ANSI art decoder
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * ASCII/ANSI art decoder
27 #include "libavutil/common.h"
28 #include "libavutil/lfg.h"
32 #define ATTR_BOLD 0x01 /**< Bold/Bright-foreground (mode 1) */
33 #define ATTR_FAINT 0x02 /**< Faint (mode 2) */
34 #define ATTR_UNDERLINE 0x08 /**< Underline (mode 4) */
35 #define ATTR_BLINK 0x10 /**< Blink/Bright-background (mode 5) */
36 #define ATTR_REVERSE 0x40 /**< Reverse (mode 7) */
37 #define ATTR_CONCEALED 0x80 /**< Concealed (mode 8) */
39 #define DEFAULT_FG_COLOR 7 /**< CGA color index */
40 #define DEFAULT_BG_COLOR 0
41 #define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
43 #define FONT_WIDTH 8 /**< Font width */
45 /** map ansi color index to cga palette index */
46 static const uint8_t ansi_to_cga
[16] = {
47 0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15
52 int x
; /**< x cursor position (pixels) */
53 int y
; /**< y cursor position (pixels) */
54 int sx
; /**< saved x cursor position (pixels) */
55 int sy
; /**< saved y cursor position (pixels) */
56 const uint8_t* font
; /**< font */
57 int font_height
; /**< font height */
58 int attributes
; /**< attribute flags */
59 int fg
; /**< foreground color */
60 int bg
; /**< background color */
62 /* ansi parser state machine */
70 int args
[MAX_NB_ARGS
];
71 int nb_args
; /**< number of arguments (may exceed MAX_NB_ARGS) */
74 static av_cold
int decode_init(AVCodecContext
*avctx
)
76 AnsiContext
*s
= avctx
->priv_data
;
77 avctx
->pix_fmt
= AV_PIX_FMT_PAL8
;
80 s
->font
= ff_vga16_font
;
82 s
->fg
= DEFAULT_FG_COLOR
;
83 s
->bg
= DEFAULT_BG_COLOR
;
85 if (!avctx
->width
|| !avctx
->height
)
86 avcodec_set_dimensions(avctx
, 80<<3, 25<<4);
91 static void hscroll(AVCodecContext
*avctx
)
93 AnsiContext
*s
= avctx
->priv_data
;
96 if (s
->y
< avctx
->height
- s
->font_height
) {
97 s
->y
+= s
->font_height
;
102 for (; i
< avctx
->height
- s
->font_height
; i
++)
103 memcpy(s
->frame
.data
[0] + i
* s
->frame
.linesize
[0],
104 s
->frame
.data
[0] + (i
+ s
->font_height
) * s
->frame
.linesize
[0],
106 for (; i
< avctx
->height
; i
++)
107 memset(s
->frame
.data
[0] + i
* s
->frame
.linesize
[0],
108 DEFAULT_BG_COLOR
, avctx
->width
);
111 static void erase_line(AVCodecContext
* avctx
, int xoffset
, int xlength
)
113 AnsiContext
*s
= avctx
->priv_data
;
115 for (i
= 0; i
< s
->font_height
; i
++)
116 memset(s
->frame
.data
[0] + (s
->y
+ i
)*s
->frame
.linesize
[0] + xoffset
,
117 DEFAULT_BG_COLOR
, xlength
);
120 static void erase_screen(AVCodecContext
*avctx
)
122 AnsiContext
*s
= avctx
->priv_data
;
124 for (i
= 0; i
< avctx
->height
; i
++)
125 memset(s
->frame
.data
[0] + i
* s
->frame
.linesize
[0], DEFAULT_BG_COLOR
, avctx
->width
);
130 * Draw character to screen
132 static void draw_char(AVCodecContext
*avctx
, int c
)
134 AnsiContext
*s
= avctx
->priv_data
;
138 if ((s
->attributes
& ATTR_BOLD
))
140 if ((s
->attributes
& ATTR_BLINK
))
142 if ((s
->attributes
& ATTR_REVERSE
))
144 if ((s
->attributes
& ATTR_CONCEALED
))
146 ff_draw_pc_font(s
->frame
.data
[0] + s
->y
* s
->frame
.linesize
[0] + s
->x
,
147 s
->frame
.linesize
[0], s
->font
, s
->font_height
, c
, fg
, bg
);
149 if (s
->x
>= avctx
->width
) {
156 * Execute ANSI escape code
157 * @return 0 on success, negative on error
159 static int execute_code(AVCodecContext
* avctx
, int c
)
161 AnsiContext
*s
= avctx
->priv_data
;
162 int ret
, i
, width
, height
;
164 case 'A': //Cursor Up
165 s
->y
= FFMAX(s
->y
- (s
->nb_args
> 0 ? s
->args
[0]*s
->font_height
: s
->font_height
), 0);
167 case 'B': //Cursor Down
168 s
->y
= FFMIN(s
->y
+ (s
->nb_args
> 0 ? s
->args
[0]*s
->font_height
: s
->font_height
), avctx
->height
- s
->font_height
);
170 case 'C': //Cursor Right
171 s
->x
= FFMIN(s
->x
+ (s
->nb_args
> 0 ? s
->args
[0]*FONT_WIDTH
: FONT_WIDTH
), avctx
->width
- FONT_WIDTH
);
173 case 'D': //Cursor Left
174 s
->x
= FFMAX(s
->x
- (s
->nb_args
> 0 ? s
->args
[0]*FONT_WIDTH
: FONT_WIDTH
), 0);
176 case 'H': //Cursor Position
177 case 'f': //Horizontal and Vertical Position
178 s
->y
= s
->nb_args
> 0 ?
av_clip((s
->args
[0] - 1)*s
->font_height
, 0, avctx
->height
- s
->font_height
) : 0;
179 s
->x
= s
->nb_args
> 1 ?
av_clip((s
->args
[1] - 1)*FONT_WIDTH
, 0, avctx
->width
- FONT_WIDTH
) : 0;
181 case 'h': //set creen mode
182 case 'l': //reset screen mode
184 s
->args
[0] = DEFAULT_SCREEN_MODE
;
186 case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
187 s
->font
= ff_cga_font
;
192 case 2: case 3: //640x400 (25 rows)
193 s
->font
= ff_vga16_font
;
198 case 6: case 14: //640x200 (25 rows)
199 s
->font
= ff_cga_font
;
204 case 7: //set line wrapping
206 case 15: case 16: //640x350 (43 rows)
207 s
->font
= ff_cga_font
;
212 case 17: case 18: //640x480 (60 rows)
213 s
->font
= ff_cga_font
;
219 av_log_ask_for_sample(avctx
, "unsupported screen mode\n");
221 if (width
!= avctx
->width
|| height
!= avctx
->height
) {
222 if (s
->frame
.data
[0])
223 avctx
->release_buffer(avctx
, &s
->frame
);
224 avcodec_set_dimensions(avctx
, width
, height
);
225 ret
= avctx
->get_buffer(avctx
, &s
->frame
);
227 av_log(avctx
, AV_LOG_ERROR
, "get_buffer() failed\n");
230 s
->frame
.pict_type
= AV_PICTURE_TYPE_I
;
231 s
->frame
.palette_has_changed
= 1;
232 memcpy(s
->frame
.data
[1], ff_cga_palette
, 16 * 4);
234 } else if (c
== 'l') {
238 case 'J': //Erase in Page
239 switch (s
->args
[0]) {
241 erase_line(avctx
, s
->x
, avctx
->width
- s
->x
);
242 if (s
->y
< avctx
->height
- s
->font_height
)
243 memset(s
->frame
.data
[0] + (s
->y
+ s
->font_height
)*s
->frame
.linesize
[0],
244 DEFAULT_BG_COLOR
, (avctx
->height
- s
->y
- s
->font_height
)*s
->frame
.linesize
[0]);
247 erase_line(avctx
, 0, s
->x
);
249 memset(s
->frame
.data
[0], DEFAULT_BG_COLOR
, s
->y
* s
->frame
.linesize
[0]);
255 case 'K': //Erase in Line
258 erase_line(avctx
, s
->x
, avctx
->width
- s
->x
);
261 erase_line(avctx
, 0, s
->x
);
264 erase_line(avctx
, 0, avctx
->width
);
267 case 'm': //Select Graphics Rendition
268 if (s
->nb_args
== 0) {
272 for (i
= 0; i
< FFMIN(s
->nb_args
, MAX_NB_ARGS
); i
++) {
276 s
->fg
= DEFAULT_FG_COLOR
;
277 s
->bg
= DEFAULT_BG_COLOR
;
278 } else if (m
== 1 || m
== 2 || m
== 4 || m
== 5 || m
== 7 || m
== 8) {
279 s
->attributes
|= 1 << (m
- 1);
280 } else if (m
>= 30 && m
<= 38) {
281 s
->fg
= ansi_to_cga
[m
- 30];
282 } else if (m
== 39) {
283 s
->fg
= ansi_to_cga
[DEFAULT_FG_COLOR
];
284 } else if (m
>= 40 && m
<= 47) {
285 s
->bg
= ansi_to_cga
[m
- 40];
286 } else if (m
== 49) {
287 s
->fg
= ansi_to_cga
[DEFAULT_BG_COLOR
];
289 av_log_ask_for_sample(avctx
, "unsupported rendition parameter\n");
293 case 'n': //Device Status Report
294 case 'R': //report current line and column
297 case 's': //Save Cursor Position
301 case 'u': //Restore Cursor Position
302 s
->x
= av_clip(s
->sx
, 0, avctx
->width
- FONT_WIDTH
);
303 s
->y
= av_clip(s
->sy
, 0, avctx
->height
- s
->font_height
);
306 av_log_ask_for_sample(avctx
, "unsupported escape code\n");
312 static int decode_frame(AVCodecContext
*avctx
,
313 void *data
, int *data_size
,
316 AnsiContext
*s
= avctx
->priv_data
;
317 uint8_t *buf
= avpkt
->data
;
318 int buf_size
= avpkt
->size
;
319 const uint8_t *buf_end
= buf
+buf_size
;
322 ret
= avctx
->reget_buffer(avctx
, &s
->frame
);
324 av_log(avctx
, AV_LOG_ERROR
, "get_buffer() failed\n");
327 s
->frame
.pict_type
= AV_PICTURE_TYPE_I
;
328 s
->frame
.palette_has_changed
= 1;
329 memcpy(s
->frame
.data
[1], ff_cga_palette
, 16 * 4);
331 while(buf
< buf_end
) {
341 s
->x
= FFMAX(s
->x
- 1, 0);
344 i
= s
->x
/ FONT_WIDTH
;
345 count
= ((i
+ 8) & ~7) - i
;
346 for (i
= 0; i
< count
; i
++)
347 draw_char(avctx
, ' ');
358 s
->state
= STATE_ESCAPE
;
361 draw_char(avctx
, buf
[0]);
366 s
->state
= STATE_CODE
;
370 s
->state
= STATE_NORMAL
;
371 draw_char(avctx
, 0x1B);
378 case '0': case '1': case '2': case '3': case '4':
379 case '5': case '6': case '7': case '8': case '9':
380 if (s
->nb_args
< MAX_NB_ARGS
)
381 s
->args
[s
->nb_args
] = s
->args
[s
->nb_args
] * 10 + buf
[0] - '0';
385 if (s
->nb_args
< MAX_NB_ARGS
)
386 s
->args
[s
->nb_args
] = 0;
389 s
->state
= STATE_MUSIC_PREAMBLE
;
395 if (s
->nb_args
> MAX_NB_ARGS
)
396 av_log(avctx
, AV_LOG_WARNING
, "args overflow (%i)\n", s
->nb_args
);
397 if (s
->nb_args
< MAX_NB_ARGS
&& s
->args
[s
->nb_args
])
399 if (execute_code(avctx
, buf
[0]) < 0)
401 s
->state
= STATE_NORMAL
;
404 case STATE_MUSIC_PREAMBLE
:
405 if (buf
[0] == 0x0E || buf
[0] == 0x1B)
406 s
->state
= STATE_NORMAL
;
407 /* ignore music data */
413 *data_size
= sizeof(AVFrame
);
414 *(AVFrame
*)data
= s
->frame
;
418 static av_cold
int decode_close(AVCodecContext
*avctx
)
420 AnsiContext
*s
= avctx
->priv_data
;
421 if (s
->frame
.data
[0])
422 avctx
->release_buffer(avctx
, &s
->frame
);
426 AVCodec ff_ansi_decoder
= {
428 .type
= AVMEDIA_TYPE_VIDEO
,
429 .id
= AV_CODEC_ID_ANSI
,
430 .priv_data_size
= sizeof(AnsiContext
),
432 .close
= decode_close
,
433 .decode
= decode_frame
,
434 .capabilities
= CODEC_CAP_DR1
,
435 .long_name
= NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),