2 * ASCII/ANSI art decoder
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
5 * This file is part of FFmpeg.
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.
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.
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
24 * ASCII/ANSI art decoder
27 #include "libavutil/common.h"
28 #include "libavutil/frame.h"
29 #include "libavutil/lfg.h"
30 #include "libavutil/xga_font_data.h"
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) */
42 #define DEFAULT_FG_COLOR 7 /**< CGA color index */
43 #define DEFAULT_BG_COLOR 0
44 #define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
46 #define FONT_WIDTH 8 /**< Font width */
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
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 */
66 /* ansi parser state machine */
74 int args
[MAX_NB_ARGS
];
75 int nb_args
; /**< number of arguments (may exceed MAX_NB_ARGS) */
78 static av_cold
int decode_init(AVCodecContext
*avctx
)
80 AnsiContext
*s
= avctx
->priv_data
;
81 avctx
->pix_fmt
= AV_PIX_FMT_PAL8
;
83 s
->frame
= av_frame_alloc();
85 return AVERROR(ENOMEM
);
88 s
->font
= avpriv_vga16_font
;
90 s
->fg
= DEFAULT_FG_COLOR
;
91 s
->bg
= DEFAULT_BG_COLOR
;
93 if (!avctx
->width
|| !avctx
->height
)
94 ff_set_dimensions(avctx
, 80 << 3, 25 << 4);
99 static void set_palette(uint32_t *pal
)
102 memcpy(pal
, ff_cga_palette
, 16 * 4);
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
);
114 static void hscroll(AVCodecContext
*avctx
)
116 AnsiContext
*s
= avctx
->priv_data
;
119 if (s
->y
<= avctx
->height
- 2*s
->font_height
) {
120 s
->y
+= s
->font_height
;
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],
129 for (; i
< avctx
->height
; i
++)
130 memset(s
->frame
->data
[0] + i
* s
->frame
->linesize
[0],
131 DEFAULT_BG_COLOR
, avctx
->width
);
134 static void erase_line(AVCodecContext
* avctx
, int xoffset
, int xlength
)
136 AnsiContext
*s
= avctx
->priv_data
;
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
);
143 static void erase_screen(AVCodecContext
*avctx
)
145 AnsiContext
*s
= avctx
->priv_data
;
147 for (i
= 0; i
< avctx
->height
; i
++)
148 memset(s
->frame
->data
[0] + i
* s
->frame
->linesize
[0], DEFAULT_BG_COLOR
, avctx
->width
);
153 * Draw character to screen
155 static void draw_char(AVCodecContext
*avctx
, int c
)
157 AnsiContext
*s
= avctx
->priv_data
;
161 if ((s
->attributes
& ATTR_BOLD
))
163 if ((s
->attributes
& ATTR_BLINK
))
165 if ((s
->attributes
& ATTR_REVERSE
))
167 if ((s
->attributes
& ATTR_CONCEALED
))
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
);
172 if (s
->x
> avctx
->width
- FONT_WIDTH
) {
179 * Execute ANSI escape code
180 * @return 0 on success, negative on error
182 static int execute_code(AVCodecContext
* avctx
, int c
)
184 AnsiContext
*s
= avctx
->priv_data
;
186 int width
= avctx
->width
;
187 int height
= avctx
->height
;
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);
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
);
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
);
199 case 'D': //Cursor Left
200 s
->x
= FFMAX(s
->x
- (s
->nb_args
> 0 ? s
->args
[0]*FONT_WIDTH
: FONT_WIDTH
), 0);
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;
207 case 'h': //set creen mode
208 case 'l': //reset screen mode
210 s
->args
[0] = DEFAULT_SCREEN_MODE
;
212 case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
213 s
->font
= avpriv_cga_font
;
218 case 2: case 3: //640x400 (25 rows)
219 s
->font
= avpriv_vga16_font
;
224 case 6: case 14: //640x200 (25 rows)
225 s
->font
= avpriv_cga_font
;
230 case 7: //set line wrapping
232 case 15: case 16: //640x350 (43 rows)
233 s
->font
= avpriv_cga_font
;
238 case 17: case 18: //640x480 (60 rows)
239 s
->font
= avpriv_cga_font
;
245 avpriv_request_sample(avctx
, "Unsupported screen mode");
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
);
254 if ((ret
= ff_get_buffer(avctx
, s
->frame
,
255 AV_GET_BUFFER_FLAG_REF
)) < 0)
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]);
261 } else if (c
== 'l') {
265 case 'J': //Erase in Page
266 switch (s
->args
[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]);
274 erase_line(avctx
, 0, s
->x
);
276 memset(s
->frame
->data
[0], DEFAULT_BG_COLOR
, s
->y
* s
->frame
->linesize
[0]);
282 case 'K': //Erase in Line
285 erase_line(avctx
, s
->x
, avctx
->width
- s
->x
);
288 erase_line(avctx
, 0, s
->x
);
291 erase_line(avctx
, 0, avctx
->width
);
294 case 'm': //Select Graphics Rendition
295 if (s
->nb_args
== 0) {
299 for (i
= 0; i
< FFMIN(s
->nb_args
, MAX_NB_ARGS
); i
++) {
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
;
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
;
321 } else if (m
== 49) {
322 s
->fg
= ansi_to_cga
[DEFAULT_BG_COLOR
];
324 avpriv_request_sample(avctx
, "Unsupported rendition parameter");
328 case 'n': //Device Status Report
329 case 'R': //report current line and column
332 case 's': //Save Cursor Position
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
);
341 avpriv_request_sample(avctx
, "Unknown escape code");
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
);
349 static int decode_frame(AVCodecContext
*avctx
,
350 void *data
, int *got_frame
,
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
;
359 if ((ret
= ff_reget_buffer(avctx
, s
->frame
)) < 0)
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
);
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
) {
375 while(buf
< buf_end
) {
385 s
->x
= FFMAX(s
->x
- 1, 0);
388 i
= s
->x
/ FONT_WIDTH
;
389 count
= ((i
+ 8) & ~7) - i
;
390 for (i
= 0; i
< count
; i
++)
391 draw_char(avctx
, ' ');
402 s
->state
= STATE_ESCAPE
;
405 draw_char(avctx
, buf
[0]);
410 s
->state
= STATE_CODE
;
414 s
->state
= STATE_NORMAL
;
415 draw_char(avctx
, 0x1B);
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';
428 if (s
->nb_args
< MAX_NB_ARGS
)
429 s
->args
[s
->nb_args
] = 0;
432 s
->state
= STATE_MUSIC_PREAMBLE
;
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)
442 if ((ret
= execute_code(avctx
, buf
[0])) < 0)
444 s
->state
= STATE_NORMAL
;
447 case STATE_MUSIC_PREAMBLE
:
448 if (buf
[0] == 0x0E || buf
[0] == 0x1B)
449 s
->state
= STATE_NORMAL
;
450 /* ignore music data */
457 if ((ret
= av_frame_ref(data
, s
->frame
)) < 0)
462 static av_cold
int decode_close(AVCodecContext
*avctx
)
464 AnsiContext
*s
= avctx
->priv_data
;
466 av_frame_free(&s
->frame
);
470 AVCodec ff_ansi_decoder
= {
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
),
477 .close
= decode_close
,
478 .decode
= decode_frame
,
479 .capabilities
= CODEC_CAP_DR1
,