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2ba45a60 DM |
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 | ||
f6fa7814 DM |
93 | if (!avctx->width || !avctx->height) { |
94 | int ret = ff_set_dimensions(avctx, 80 << 3, 25 << 4); | |
95 | if (ret < 0) | |
96 | return ret; | |
97 | } | |
2ba45a60 DM |
98 | return 0; |
99 | } | |
100 | ||
101 | static void set_palette(uint32_t *pal) | |
102 | { | |
103 | int r, g, b; | |
104 | memcpy(pal, ff_cga_palette, 16 * 4); | |
105 | pal += 16; | |
106 | #define COLOR(x) ((x) * 40 + 55) | |
107 | for (r = 0; r < 6; r++) | |
108 | for (g = 0; g < 6; g++) | |
109 | for (b = 0; b < 6; b++) | |
110 | *pal++ = 0xFF000000 | (COLOR(r) << 16) | (COLOR(g) << 8) | COLOR(b); | |
111 | #define GRAY(x) ((x) * 10 + 8) | |
112 | for (g = 0; g < 24; g++) | |
113 | *pal++ = 0xFF000000 | (GRAY(g) << 16) | (GRAY(g) << 8) | GRAY(g); | |
114 | } | |
115 | ||
116 | static void hscroll(AVCodecContext *avctx) | |
117 | { | |
118 | AnsiContext *s = avctx->priv_data; | |
119 | int i; | |
120 | ||
121 | if (s->y <= avctx->height - 2*s->font_height) { | |
122 | s->y += s->font_height; | |
123 | return; | |
124 | } | |
125 | ||
126 | i = 0; | |
127 | for (; i < avctx->height - s->font_height; i++) | |
128 | memcpy(s->frame->data[0] + i * s->frame->linesize[0], | |
129 | s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0], | |
130 | avctx->width); | |
131 | for (; i < avctx->height; i++) | |
132 | memset(s->frame->data[0] + i * s->frame->linesize[0], | |
133 | DEFAULT_BG_COLOR, avctx->width); | |
134 | } | |
135 | ||
136 | static void erase_line(AVCodecContext * avctx, int xoffset, int xlength) | |
137 | { | |
138 | AnsiContext *s = avctx->priv_data; | |
139 | int i; | |
140 | for (i = 0; i < s->font_height; i++) | |
141 | memset(s->frame->data[0] + (s->y + i)*s->frame->linesize[0] + xoffset, | |
142 | DEFAULT_BG_COLOR, xlength); | |
143 | } | |
144 | ||
145 | static void erase_screen(AVCodecContext *avctx) | |
146 | { | |
147 | AnsiContext *s = avctx->priv_data; | |
148 | int i; | |
149 | for (i = 0; i < avctx->height; i++) | |
150 | memset(s->frame->data[0] + i * s->frame->linesize[0], DEFAULT_BG_COLOR, avctx->width); | |
151 | s->x = s->y = 0; | |
152 | } | |
153 | ||
154 | /** | |
155 | * Draw character to screen | |
156 | */ | |
157 | static void draw_char(AVCodecContext *avctx, int c) | |
158 | { | |
159 | AnsiContext *s = avctx->priv_data; | |
160 | int fg = s->fg; | |
161 | int bg = s->bg; | |
162 | ||
163 | if ((s->attributes & ATTR_BOLD)) | |
164 | fg += 8; | |
165 | if ((s->attributes & ATTR_BLINK)) | |
166 | bg += 8; | |
167 | if ((s->attributes & ATTR_REVERSE)) | |
168 | FFSWAP(int, fg, bg); | |
169 | if ((s->attributes & ATTR_CONCEALED)) | |
170 | fg = bg; | |
171 | ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x, | |
172 | s->frame->linesize[0], s->font, s->font_height, c, fg, bg); | |
173 | s->x += FONT_WIDTH; | |
174 | if (s->x > avctx->width - FONT_WIDTH) { | |
175 | s->x = 0; | |
176 | hscroll(avctx); | |
177 | } | |
178 | } | |
179 | ||
180 | /** | |
181 | * Execute ANSI escape code | |
182 | * @return 0 on success, negative on error | |
183 | */ | |
184 | static int execute_code(AVCodecContext * avctx, int c) | |
185 | { | |
186 | AnsiContext *s = avctx->priv_data; | |
187 | int ret, i; | |
188 | int width = avctx->width; | |
189 | int height = avctx->height; | |
190 | ||
191 | switch(c) { | |
192 | case 'A': //Cursor Up | |
193 | s->y = FFMAX(s->y - (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), 0); | |
194 | break; | |
195 | case 'B': //Cursor Down | |
196 | s->y = FFMIN(s->y + (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), avctx->height - s->font_height); | |
197 | break; | |
198 | case 'C': //Cursor Right | |
199 | s->x = FFMIN(s->x + (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), avctx->width - FONT_WIDTH); | |
200 | break; | |
201 | case 'D': //Cursor Left | |
202 | s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0); | |
203 | break; | |
204 | case 'H': //Cursor Position | |
205 | case 'f': //Horizontal and Vertical Position | |
206 | s->y = s->nb_args > 0 ? av_clip((s->args[0] - 1)*s->font_height, 0, avctx->height - s->font_height) : 0; | |
207 | s->x = s->nb_args > 1 ? av_clip((s->args[1] - 1)*FONT_WIDTH, 0, avctx->width - FONT_WIDTH) : 0; | |
208 | break; | |
209 | case 'h': //set creen mode | |
210 | case 'l': //reset screen mode | |
211 | if (s->nb_args < 2) | |
212 | s->args[0] = DEFAULT_SCREEN_MODE; | |
213 | switch(s->args[0]) { | |
214 | case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows) | |
215 | s->font = avpriv_cga_font; | |
216 | s->font_height = 8; | |
217 | width = 40<<3; | |
218 | height = 25<<3; | |
219 | break; | |
220 | case 2: case 3: //640x400 (25 rows) | |
221 | s->font = avpriv_vga16_font; | |
222 | s->font_height = 16; | |
223 | width = 80<<3; | |
224 | height = 25<<4; | |
225 | break; | |
226 | case 6: case 14: //640x200 (25 rows) | |
227 | s->font = avpriv_cga_font; | |
228 | s->font_height = 8; | |
229 | width = 80<<3; | |
230 | height = 25<<3; | |
231 | break; | |
232 | case 7: //set line wrapping | |
233 | break; | |
234 | case 15: case 16: //640x350 (43 rows) | |
235 | s->font = avpriv_cga_font; | |
236 | s->font_height = 8; | |
237 | width = 80<<3; | |
238 | height = 43<<3; | |
239 | break; | |
240 | case 17: case 18: //640x480 (60 rows) | |
241 | s->font = avpriv_cga_font; | |
242 | s->font_height = 8; | |
243 | width = 80<<3; | |
244 | height = 60<<4; | |
245 | break; | |
246 | default: | |
247 | avpriv_request_sample(avctx, "Unsupported screen mode"); | |
248 | } | |
249 | s->x = av_clip(s->x, 0, width - FONT_WIDTH); | |
250 | s->y = av_clip(s->y, 0, height - s->font_height); | |
251 | if (width != avctx->width || height != avctx->height) { | |
252 | av_frame_unref(s->frame); | |
253 | ret = ff_set_dimensions(avctx, width, height); | |
254 | if (ret < 0) | |
255 | return ret; | |
256 | if ((ret = ff_get_buffer(avctx, s->frame, | |
257 | AV_GET_BUFFER_FLAG_REF)) < 0) | |
258 | return ret; | |
259 | s->frame->pict_type = AV_PICTURE_TYPE_I; | |
260 | s->frame->palette_has_changed = 1; | |
261 | set_palette((uint32_t *)s->frame->data[1]); | |
262 | erase_screen(avctx); | |
263 | } else if (c == 'l') { | |
264 | erase_screen(avctx); | |
265 | } | |
266 | break; | |
267 | case 'J': //Erase in Page | |
268 | switch (s->args[0]) { | |
269 | case 0: | |
270 | erase_line(avctx, s->x, avctx->width - s->x); | |
271 | if (s->y < avctx->height - s->font_height) | |
272 | memset(s->frame->data[0] + (s->y + s->font_height)*s->frame->linesize[0], | |
273 | DEFAULT_BG_COLOR, (avctx->height - s->y - s->font_height)*s->frame->linesize[0]); | |
274 | break; | |
275 | case 1: | |
276 | erase_line(avctx, 0, s->x); | |
277 | if (s->y > 0) | |
278 | memset(s->frame->data[0], DEFAULT_BG_COLOR, s->y * s->frame->linesize[0]); | |
279 | break; | |
280 | case 2: | |
281 | erase_screen(avctx); | |
282 | } | |
283 | break; | |
284 | case 'K': //Erase in Line | |
285 | switch(s->args[0]) { | |
286 | case 0: | |
287 | erase_line(avctx, s->x, avctx->width - s->x); | |
288 | break; | |
289 | case 1: | |
290 | erase_line(avctx, 0, s->x); | |
291 | break; | |
292 | case 2: | |
293 | erase_line(avctx, 0, avctx->width); | |
294 | } | |
295 | break; | |
296 | case 'm': //Select Graphics Rendition | |
297 | if (s->nb_args == 0) { | |
298 | s->nb_args = 1; | |
299 | s->args[0] = 0; | |
300 | } | |
301 | for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) { | |
302 | int m = s->args[i]; | |
303 | if (m == 0) { | |
304 | s->attributes = 0; | |
305 | s->fg = DEFAULT_FG_COLOR; | |
306 | s->bg = DEFAULT_BG_COLOR; | |
307 | } else if (m == 1 || m == 2 || m == 4 || m == 5 || m == 7 || m == 8) { | |
308 | s->attributes |= 1 << (m - 1); | |
309 | } else if (m >= 30 && m <= 37) { | |
310 | s->fg = ansi_to_cga[m - 30]; | |
311 | } else if (m == 38 && 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->fg = index < 16 ? ansi_to_cga[index] : index; | |
314 | i += 2; | |
315 | } else if (m == 39) { | |
316 | s->fg = ansi_to_cga[DEFAULT_FG_COLOR]; | |
317 | } else if (m >= 40 && m <= 47) { | |
318 | s->bg = ansi_to_cga[m - 40]; | |
319 | } else if (m == 48 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) { | |
320 | int index = s->args[i + 2]; | |
321 | s->bg = index < 16 ? ansi_to_cga[index] : index; | |
322 | i += 2; | |
323 | } else if (m == 49) { | |
324 | s->fg = ansi_to_cga[DEFAULT_BG_COLOR]; | |
325 | } else { | |
326 | avpriv_request_sample(avctx, "Unsupported rendition parameter"); | |
327 | } | |
328 | } | |
329 | break; | |
330 | case 'n': //Device Status Report | |
331 | case 'R': //report current line and column | |
332 | /* ignore */ | |
333 | break; | |
334 | case 's': //Save Cursor Position | |
335 | s->sx = s->x; | |
336 | s->sy = s->y; | |
337 | break; | |
338 | case 'u': //Restore Cursor Position | |
339 | s->x = av_clip(s->sx, 0, avctx->width - FONT_WIDTH); | |
340 | s->y = av_clip(s->sy, 0, avctx->height - s->font_height); | |
341 | break; | |
342 | default: | |
343 | avpriv_request_sample(avctx, "Unknown escape code"); | |
344 | break; | |
345 | } | |
346 | s->x = av_clip(s->x, 0, avctx->width - FONT_WIDTH); | |
347 | s->y = av_clip(s->y, 0, avctx->height - s->font_height); | |
348 | return 0; | |
349 | } | |
350 | ||
351 | static int decode_frame(AVCodecContext *avctx, | |
352 | void *data, int *got_frame, | |
353 | AVPacket *avpkt) | |
354 | { | |
355 | AnsiContext *s = avctx->priv_data; | |
356 | uint8_t *buf = avpkt->data; | |
357 | int buf_size = avpkt->size; | |
358 | const uint8_t *buf_end = buf+buf_size; | |
359 | int ret, i, count; | |
360 | ||
361 | if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) | |
362 | return ret; | |
363 | if (!avctx->frame_number) { | |
364 | for (i=0; i<avctx->height; i++) | |
365 | memset(s->frame->data[0]+ i*s->frame->linesize[0], 0, avctx->width); | |
366 | memset(s->frame->data[1], 0, AVPALETTE_SIZE); | |
367 | } | |
368 | ||
369 | s->frame->pict_type = AV_PICTURE_TYPE_I; | |
370 | s->frame->palette_has_changed = 1; | |
371 | set_palette((uint32_t *)s->frame->data[1]); | |
372 | if (!s->first_frame) { | |
373 | erase_screen(avctx); | |
374 | s->first_frame = 1; | |
375 | } | |
376 | ||
377 | while(buf < buf_end) { | |
378 | switch(s->state) { | |
379 | case STATE_NORMAL: | |
380 | switch (buf[0]) { | |
381 | case 0x00: //NUL | |
382 | case 0x07: //BEL | |
383 | case 0x1A: //SUB | |
384 | /* ignore */ | |
385 | break; | |
386 | case 0x08: //BS | |
387 | s->x = FFMAX(s->x - 1, 0); | |
388 | break; | |
389 | case 0x09: //HT | |
390 | i = s->x / FONT_WIDTH; | |
391 | count = ((i + 8) & ~7) - i; | |
392 | for (i = 0; i < count; i++) | |
393 | draw_char(avctx, ' '); | |
394 | break; | |
395 | case 0x0A: //LF | |
396 | hscroll(avctx); | |
397 | case 0x0D: //CR | |
398 | s->x = 0; | |
399 | break; | |
400 | case 0x0C: //FF | |
401 | erase_screen(avctx); | |
402 | break; | |
403 | case 0x1B: //ESC | |
404 | s->state = STATE_ESCAPE; | |
405 | break; | |
406 | default: | |
407 | draw_char(avctx, buf[0]); | |
408 | } | |
409 | break; | |
410 | case STATE_ESCAPE: | |
411 | if (buf[0] == '[') { | |
412 | s->state = STATE_CODE; | |
413 | s->nb_args = 0; | |
414 | s->args[0] = -1; | |
415 | } else { | |
416 | s->state = STATE_NORMAL; | |
417 | draw_char(avctx, 0x1B); | |
418 | continue; | |
419 | } | |
420 | break; | |
421 | case STATE_CODE: | |
422 | switch(buf[0]) { | |
423 | case '0': case '1': case '2': case '3': case '4': | |
424 | case '5': case '6': case '7': case '8': case '9': | |
425 | if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] < 6553) | |
426 | s->args[s->nb_args] = FFMAX(s->args[s->nb_args], 0) * 10 + buf[0] - '0'; | |
427 | break; | |
428 | case ';': | |
429 | s->nb_args++; | |
430 | if (s->nb_args < MAX_NB_ARGS) | |
431 | s->args[s->nb_args] = 0; | |
432 | break; | |
433 | case 'M': | |
434 | s->state = STATE_MUSIC_PREAMBLE; | |
435 | break; | |
436 | case '=': case '?': | |
437 | /* ignore */ | |
438 | break; | |
439 | default: | |
440 | if (s->nb_args > MAX_NB_ARGS) | |
441 | av_log(avctx, AV_LOG_WARNING, "args overflow (%i)\n", s->nb_args); | |
442 | if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] >= 0) | |
443 | s->nb_args++; | |
444 | if ((ret = execute_code(avctx, buf[0])) < 0) | |
445 | return ret; | |
446 | s->state = STATE_NORMAL; | |
447 | } | |
448 | break; | |
449 | case STATE_MUSIC_PREAMBLE: | |
450 | if (buf[0] == 0x0E || buf[0] == 0x1B) | |
451 | s->state = STATE_NORMAL; | |
452 | /* ignore music data */ | |
453 | break; | |
454 | } | |
455 | buf++; | |
456 | } | |
457 | ||
458 | *got_frame = 1; | |
459 | if ((ret = av_frame_ref(data, s->frame)) < 0) | |
460 | return ret; | |
461 | return buf_size; | |
462 | } | |
463 | ||
464 | static av_cold int decode_close(AVCodecContext *avctx) | |
465 | { | |
466 | AnsiContext *s = avctx->priv_data; | |
467 | ||
468 | av_frame_free(&s->frame); | |
469 | return 0; | |
470 | } | |
471 | ||
472 | AVCodec ff_ansi_decoder = { | |
473 | .name = "ansi", | |
474 | .long_name = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"), | |
475 | .type = AVMEDIA_TYPE_VIDEO, | |
476 | .id = AV_CODEC_ID_ANSI, | |
477 | .priv_data_size = sizeof(AnsiContext), | |
478 | .init = decode_init, | |
479 | .close = decode_close, | |
480 | .decode = decode_frame, | |
481 | .capabilities = CODEC_CAP_DR1, | |
482 | }; |