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[libav.git] / libavcodec / ansi.c
1 /*
2 * ASCII/ANSI art decoder
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
4 *
5 * This file is part of Libav.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * ASCII/ANSI art decoder
25 */
26
27 #include "libavutil/common.h"
28 #include "libavutil/lfg.h"
29 #include "avcodec.h"
30 #include "cga_data.h"
31
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) */
38
39 #define DEFAULT_FG_COLOR 7 /**< CGA color index */
40 #define DEFAULT_BG_COLOR 0
41 #define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
42
43 #define FONT_WIDTH 8 /**< Font width */
44
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
48 };
49
50 typedef struct {
51 AVFrame frame;
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 */
61
62 /* ansi parser state machine */
63 enum {
64 STATE_NORMAL = 0,
65 STATE_ESCAPE,
66 STATE_CODE,
67 STATE_MUSIC_PREAMBLE
68 } state;
69 #define MAX_NB_ARGS 4
70 int args[MAX_NB_ARGS];
71 int nb_args; /**< number of arguments (may exceed MAX_NB_ARGS) */
72 } AnsiContext;
73
74 static av_cold int decode_init(AVCodecContext *avctx)
75 {
76 AnsiContext *s = avctx->priv_data;
77 avctx->pix_fmt = AV_PIX_FMT_PAL8;
78
79 /* defaults */
80 s->font = ff_vga16_font;
81 s->font_height = 16;
82 s->fg = DEFAULT_FG_COLOR;
83 s->bg = DEFAULT_BG_COLOR;
84
85 if (!avctx->width || !avctx->height)
86 avcodec_set_dimensions(avctx, 80<<3, 25<<4);
87
88 return 0;
89 }
90
91 static void hscroll(AVCodecContext *avctx)
92 {
93 AnsiContext *s = avctx->priv_data;
94 int i;
95
96 if (s->y < avctx->height - s->font_height) {
97 s->y += s->font_height;
98 return;
99 }
100
101 i = 0;
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],
105 avctx->width);
106 for (; i < avctx->height; i++)
107 memset(s->frame.data[0] + i * s->frame.linesize[0],
108 DEFAULT_BG_COLOR, avctx->width);
109 }
110
111 static void erase_line(AVCodecContext * avctx, int xoffset, int xlength)
112 {
113 AnsiContext *s = avctx->priv_data;
114 int i;
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);
118 }
119
120 static void erase_screen(AVCodecContext *avctx)
121 {
122 AnsiContext *s = avctx->priv_data;
123 int i;
124 for (i = 0; i < avctx->height; i++)
125 memset(s->frame.data[0] + i * s->frame.linesize[0], DEFAULT_BG_COLOR, avctx->width);
126 s->x = s->y = 0;
127 }
128
129 /**
130 * Draw character to screen
131 */
132 static void draw_char(AVCodecContext *avctx, int c)
133 {
134 AnsiContext *s = avctx->priv_data;
135 int fg = s->fg;
136 int bg = s->bg;
137
138 if ((s->attributes & ATTR_BOLD))
139 fg += 8;
140 if ((s->attributes & ATTR_BLINK))
141 bg += 8;
142 if ((s->attributes & ATTR_REVERSE))
143 FFSWAP(int, fg, bg);
144 if ((s->attributes & ATTR_CONCEALED))
145 fg = bg;
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);
148 s->x += FONT_WIDTH;
149 if (s->x >= avctx->width) {
150 s->x = 0;
151 hscroll(avctx);
152 }
153 }
154
155 /**
156 * Execute ANSI escape code
157 * @return 0 on success, negative on error
158 */
159 static int execute_code(AVCodecContext * avctx, int c)
160 {
161 AnsiContext *s = avctx->priv_data;
162 int ret, i, width, height;
163 switch(c) {
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);
166 break;
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);
169 break;
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);
172 break;
173 case 'D': //Cursor Left
174 s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0);
175 break;
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;
180 break;
181 case 'h': //set creen mode
182 case 'l': //reset screen mode
183 if (s->nb_args < 2)
184 s->args[0] = DEFAULT_SCREEN_MODE;
185 switch(s->args[0]) {
186 case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
187 s->font = ff_cga_font;
188 s->font_height = 8;
189 width = 40<<3;
190 height = 25<<3;
191 break;
192 case 2: case 3: //640x400 (25 rows)
193 s->font = ff_vga16_font;
194 s->font_height = 16;
195 width = 80<<3;
196 height = 25<<4;
197 break;
198 case 6: case 14: //640x200 (25 rows)
199 s->font = ff_cga_font;
200 s->font_height = 8;
201 width = 80<<3;
202 height = 25<<3;
203 break;
204 case 7: //set line wrapping
205 break;
206 case 15: case 16: //640x350 (43 rows)
207 s->font = ff_cga_font;
208 s->font_height = 8;
209 width = 80<<3;
210 height = 43<<3;
211 break;
212 case 17: case 18: //640x480 (60 rows)
213 s->font = ff_cga_font;
214 s->font_height = 8;
215 width = 80<<3;
216 height = 60<<4;
217 break;
218 default:
219 av_log_ask_for_sample(avctx, "unsupported screen mode\n");
220 }
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);
226 if (ret < 0) {
227 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
228 return ret;
229 }
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);
233 erase_screen(avctx);
234 } else if (c == 'l') {
235 erase_screen(avctx);
236 }
237 break;
238 case 'J': //Erase in Page
239 switch (s->args[0]) {
240 case 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]);
245 break;
246 case 1:
247 erase_line(avctx, 0, s->x);
248 if (s->y > 0)
249 memset(s->frame.data[0], DEFAULT_BG_COLOR, s->y * s->frame.linesize[0]);
250 break;
251 case 2:
252 erase_screen(avctx);
253 }
254 break;
255 case 'K': //Erase in Line
256 switch(s->args[0]) {
257 case 0:
258 erase_line(avctx, s->x, avctx->width - s->x);
259 break;
260 case 1:
261 erase_line(avctx, 0, s->x);
262 break;
263 case 2:
264 erase_line(avctx, 0, avctx->width);
265 }
266 break;
267 case 'm': //Select Graphics Rendition
268 if (s->nb_args == 0) {
269 s->nb_args = 1;
270 s->args[0] = 0;
271 }
272 for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) {
273 int m = s->args[i];
274 if (m == 0) {
275 s->attributes = 0;
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];
288 } else {
289 av_log_ask_for_sample(avctx, "unsupported rendition parameter\n");
290 }
291 }
292 break;
293 case 'n': //Device Status Report
294 case 'R': //report current line and column
295 /* ignore */
296 break;
297 case 's': //Save Cursor Position
298 s->sx = s->x;
299 s->sy = s->y;
300 break;
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);
304 break;
305 default:
306 av_log_ask_for_sample(avctx, "unsupported escape code\n");
307 break;
308 }
309 return 0;
310 }
311
312 static int decode_frame(AVCodecContext *avctx,
313 void *data, int *data_size,
314 AVPacket *avpkt)
315 {
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;
320 int ret, i, count;
321
322 ret = avctx->reget_buffer(avctx, &s->frame);
323 if (ret < 0){
324 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
325 return ret;
326 }
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);
330
331 while(buf < buf_end) {
332 switch(s->state) {
333 case STATE_NORMAL:
334 switch (buf[0]) {
335 case 0x00: //NUL
336 case 0x07: //BEL
337 case 0x1A: //SUB
338 /* ignore */
339 break;
340 case 0x08: //BS
341 s->x = FFMAX(s->x - 1, 0);
342 break;
343 case 0x09: //HT
344 i = s->x / FONT_WIDTH;
345 count = ((i + 8) & ~7) - i;
346 for (i = 0; i < count; i++)
347 draw_char(avctx, ' ');
348 break;
349 case 0x0A: //LF
350 hscroll(avctx);
351 case 0x0D: //CR
352 s->x = 0;
353 break;
354 case 0x0C: //FF
355 erase_screen(avctx);
356 break;
357 case 0x1B: //ESC
358 s->state = STATE_ESCAPE;
359 break;
360 default:
361 draw_char(avctx, buf[0]);
362 }
363 break;
364 case STATE_ESCAPE:
365 if (buf[0] == '[') {
366 s->state = STATE_CODE;
367 s->nb_args = 0;
368 s->args[0] = 0;
369 } else {
370 s->state = STATE_NORMAL;
371 draw_char(avctx, 0x1B);
372 return -1;
373 continue;
374 }
375 break;
376 case STATE_CODE:
377 switch(buf[0]) {
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';
382 break;
383 case ';':
384 s->nb_args++;
385 if (s->nb_args < MAX_NB_ARGS)
386 s->args[s->nb_args] = 0;
387 break;
388 case 'M':
389 s->state = STATE_MUSIC_PREAMBLE;
390 break;
391 case '=': case '?':
392 /* ignore */
393 break;
394 default:
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])
398 s->nb_args++;
399 if (execute_code(avctx, buf[0]) < 0)
400 return -1;
401 s->state = STATE_NORMAL;
402 }
403 break;
404 case STATE_MUSIC_PREAMBLE:
405 if (buf[0] == 0x0E || buf[0] == 0x1B)
406 s->state = STATE_NORMAL;
407 /* ignore music data */
408 break;
409 }
410 buf++;
411 }
412
413 *data_size = sizeof(AVFrame);
414 *(AVFrame*)data = s->frame;
415 return buf_size;
416 }
417
418 static av_cold int decode_close(AVCodecContext *avctx)
419 {
420 AnsiContext *s = avctx->priv_data;
421 if (s->frame.data[0])
422 avctx->release_buffer(avctx, &s->frame);
423 return 0;
424 }
425
426 AVCodec ff_ansi_decoder = {
427 .name = "ansi",
428 .type = AVMEDIA_TYPE_VIDEO,
429 .id = AV_CODEC_ID_ANSI,
430 .priv_data_size = sizeof(AnsiContext),
431 .init = decode_init,
432 .close = decode_close,
433 .decode = decode_frame,
434 .capabilities = CODEC_CAP_DR1,
435 .long_name = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),
436 };
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