ansi: fix possible use of uninitialized variables
[libav.git] / libavcodec / ansi.c
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1/*
2 * ASCII/ANSI art decoder
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
4 *
2912e87a 5 * This file is part of Libav.
beaa963c 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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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
1d9c2dc8 27#include "libavutil/common.h"
759001c5 28#include "libavutil/frame.h"
625bac78 29#include "libavutil/lfg.h"
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30#include "avcodec.h"
31#include "cga_data.h"
594d4d5d 32#include "internal.h"
beaa963c 33
a20df858
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34#define ATTR_BOLD 0x01 /**< Bold/Bright-foreground (mode 1) */
35#define ATTR_FAINT 0x02 /**< Faint (mode 2) */
36#define ATTR_UNDERLINE 0x08 /**< Underline (mode 4) */
37#define ATTR_BLINK 0x10 /**< Blink/Bright-background (mode 5) */
38#define ATTR_REVERSE 0x40 /**< Reverse (mode 7) */
39#define ATTR_CONCEALED 0x80 /**< Concealed (mode 8) */
beaa963c 40
a20df858 41#define DEFAULT_FG_COLOR 7 /**< CGA color index */
beaa963c 42#define DEFAULT_BG_COLOR 0
a20df858 43#define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
beaa963c 44
a20df858 45#define FONT_WIDTH 8 /**< Font width */
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46
47/** map ansi color index to cga palette index */
48static 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
52typedef struct {
759001c5 53 AVFrame *frame;
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54 int x; /**< x cursor position (pixels) */
55 int y; /**< y cursor position (pixels) */
56 int sx; /**< saved x cursor position (pixels) */
57 int sy; /**< saved y cursor position (pixels) */
58 const uint8_t* font; /**< font */
59 int font_height; /**< font height */
60 int attributes; /**< attribute flags */
61 int fg; /**< foreground color */
62 int bg; /**< background color */
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63
64 /* ansi parser state machine */
65 enum {
66 STATE_NORMAL = 0,
67 STATE_ESCAPE,
68 STATE_CODE,
69 STATE_MUSIC_PREAMBLE
70 } state;
71#define MAX_NB_ARGS 4
72 int args[MAX_NB_ARGS];
a20df858 73 int nb_args; /**< number of arguments (may exceed MAX_NB_ARGS) */
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74} AnsiContext;
75
76static av_cold int decode_init(AVCodecContext *avctx)
77{
78 AnsiContext *s = avctx->priv_data;
716d413c 79 avctx->pix_fmt = AV_PIX_FMT_PAL8;
beaa963c 80
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81 s->frame = av_frame_alloc();
82 if (!s->frame)
83 return AVERROR(ENOMEM);
84
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85 /* defaults */
86 s->font = ff_vga16_font;
87 s->font_height = 16;
88 s->fg = DEFAULT_FG_COLOR;
89 s->bg = DEFAULT_BG_COLOR;
90
91 if (!avctx->width || !avctx->height)
78780c8b 92 ff_set_dimensions(avctx, 80 << 3, 25 << 4);
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93
94 return 0;
95}
96
97static void hscroll(AVCodecContext *avctx)
98{
99 AnsiContext *s = avctx->priv_data;
100 int i;
101
102 if (s->y < avctx->height - s->font_height) {
103 s->y += s->font_height;
104 return;
105 }
106
107 i = 0;
108 for (; i < avctx->height - s->font_height; i++)
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109 memcpy(s->frame->data[0] + i * s->frame->linesize[0],
110 s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0],
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111 avctx->width);
112 for (; i < avctx->height; i++)
759001c5 113 memset(s->frame->data[0] + i * s->frame->linesize[0],
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114 DEFAULT_BG_COLOR, avctx->width);
115}
116
117static void erase_line(AVCodecContext * avctx, int xoffset, int xlength)
118{
119 AnsiContext *s = avctx->priv_data;
120 int i;
121 for (i = 0; i < s->font_height; i++)
759001c5 122 memset(s->frame->data[0] + (s->y + i)*s->frame->linesize[0] + xoffset,
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123 DEFAULT_BG_COLOR, xlength);
124}
125
126static void erase_screen(AVCodecContext *avctx)
127{
128 AnsiContext *s = avctx->priv_data;
129 int i;
130 for (i = 0; i < avctx->height; i++)
759001c5 131 memset(s->frame->data[0] + i * s->frame->linesize[0], DEFAULT_BG_COLOR, avctx->width);
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132 s->x = s->y = 0;
133}
134
135/**
136 * Draw character to screen
137 */
138static void draw_char(AVCodecContext *avctx, int c)
139{
140 AnsiContext *s = avctx->priv_data;
141 int fg = s->fg;
142 int bg = s->bg;
143
144 if ((s->attributes & ATTR_BOLD))
145 fg += 8;
146 if ((s->attributes & ATTR_BLINK))
147 bg += 8;
148 if ((s->attributes & ATTR_REVERSE))
149 FFSWAP(int, fg, bg);
150 if ((s->attributes & ATTR_CONCEALED))
151 fg = bg;
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152 ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
153 s->frame->linesize[0], s->font, s->font_height, c, fg, bg);
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154 s->x += FONT_WIDTH;
155 if (s->x >= avctx->width) {
156 s->x = 0;
157 hscroll(avctx);
158 }
159}
160
161/**
162 * Execute ANSI escape code
3d85acc8 163 * @return 0 on success, negative on error
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164 */
165static int execute_code(AVCodecContext * avctx, int c)
166{
167 AnsiContext *s = avctx->priv_data;
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168 int ret, i;
169 int width = 0;
170 int height = 0;
171
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172 switch(c) {
173 case 'A': //Cursor Up
174 s->y = FFMAX(s->y - (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), 0);
175 break;
176 case 'B': //Cursor Down
177 s->y = FFMIN(s->y + (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), avctx->height - s->font_height);
178 break;
179 case 'C': //Cursor Right
180 s->x = FFMIN(s->x + (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), avctx->width - FONT_WIDTH);
181 break;
182 case 'D': //Cursor Left
183 s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0);
184 break;
185 case 'H': //Cursor Position
186 case 'f': //Horizontal and Vertical Position
187 s->y = s->nb_args > 0 ? av_clip((s->args[0] - 1)*s->font_height, 0, avctx->height - s->font_height) : 0;
188 s->x = s->nb_args > 1 ? av_clip((s->args[1] - 1)*FONT_WIDTH, 0, avctx->width - FONT_WIDTH) : 0;
189 break;
190 case 'h': //set creen mode
191 case 'l': //reset screen mode
192 if (s->nb_args < 2)
193 s->args[0] = DEFAULT_SCREEN_MODE;
194 switch(s->args[0]) {
195 case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
196 s->font = ff_cga_font;
197 s->font_height = 8;
198 width = 40<<3;
199 height = 25<<3;
200 break;
201 case 2: case 3: //640x400 (25 rows)
202 s->font = ff_vga16_font;
203 s->font_height = 16;
204 width = 80<<3;
205 height = 25<<4;
206 break;
207 case 6: case 14: //640x200 (25 rows)
208 s->font = ff_cga_font;
209 s->font_height = 8;
210 width = 80<<3;
211 height = 25<<3;
212 break;
213 case 7: //set line wrapping
214 break;
215 case 15: case 16: //640x350 (43 rows)
216 s->font = ff_cga_font;
217 s->font_height = 8;
218 width = 80<<3;
219 height = 43<<3;
220 break;
221 case 17: case 18: //640x480 (60 rows)
222 s->font = ff_cga_font;
223 s->font_height = 8;
224 width = 80<<3;
225 height = 60<<4;
226 break;
227 default:
6d97484d 228 avpriv_request_sample(avctx, "Unsupported screen mode");
beaa963c 229 }
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230 if (width != 0 && height != 0 &&
231 (width != avctx->width || height != avctx->height)) {
759001c5 232 av_frame_unref(s->frame);
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233 ret = ff_set_dimensions(avctx, width, height);
234 if (ret < 0)
235 return ret;
759001c5 236 ret = ff_get_buffer(avctx, s->frame, AV_GET_BUFFER_FLAG_REF);
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237 if (ret < 0) {
238 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
239 return ret;
240 }
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241 s->frame->pict_type = AV_PICTURE_TYPE_I;
242 s->frame->palette_has_changed = 1;
243 memcpy(s->frame->data[1], ff_cga_palette, 16 * 4);
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244 erase_screen(avctx);
245 } else if (c == 'l') {
246 erase_screen(avctx);
247 }
248 break;
249 case 'J': //Erase in Page
250 switch (s->args[0]) {
251 case 0:
252 erase_line(avctx, s->x, avctx->width - s->x);
253 if (s->y < avctx->height - s->font_height)
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254 memset(s->frame->data[0] + (s->y + s->font_height)*s->frame->linesize[0],
255 DEFAULT_BG_COLOR, (avctx->height - s->y - s->font_height)*s->frame->linesize[0]);
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256 break;
257 case 1:
258 erase_line(avctx, 0, s->x);
259 if (s->y > 0)
759001c5 260 memset(s->frame->data[0], DEFAULT_BG_COLOR, s->y * s->frame->linesize[0]);
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261 break;
262 case 2:
263 erase_screen(avctx);
264 }
265 break;
266 case 'K': //Erase in Line
267 switch(s->args[0]) {
268 case 0:
269 erase_line(avctx, s->x, avctx->width - s->x);
270 break;
271 case 1:
272 erase_line(avctx, 0, s->x);
273 break;
274 case 2:
275 erase_line(avctx, 0, avctx->width);
276 }
277 break;
278 case 'm': //Select Graphics Rendition
279 if (s->nb_args == 0) {
280 s->nb_args = 1;
281 s->args[0] = 0;
282 }
283 for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) {
284 int m = s->args[i];
285 if (m == 0) {
286 s->attributes = 0;
287 s->fg = DEFAULT_FG_COLOR;
288 s->bg = DEFAULT_BG_COLOR;
289 } else if (m == 1 || m == 2 || m == 4 || m == 5 || m == 7 || m == 8) {
290 s->attributes |= 1 << (m - 1);
291 } else if (m >= 30 && m <= 38) {
292 s->fg = ansi_to_cga[m - 30];
293 } else if (m == 39) {
294 s->fg = ansi_to_cga[DEFAULT_FG_COLOR];
295 } else if (m >= 40 && m <= 47) {
296 s->bg = ansi_to_cga[m - 40];
297 } else if (m == 49) {
298 s->fg = ansi_to_cga[DEFAULT_BG_COLOR];
299 } else {
6d97484d 300 avpriv_request_sample(avctx, "Unsupported rendition parameter");
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301 }
302 }
303 break;
304 case 'n': //Device Status Report
305 case 'R': //report current line and column
306 /* ignore */
307 break;
308 case 's': //Save Cursor Position
309 s->sx = s->x;
310 s->sy = s->y;
311 break;
312 case 'u': //Restore Cursor Position
313 s->x = av_clip(s->sx, 0, avctx->width - FONT_WIDTH);
314 s->y = av_clip(s->sy, 0, avctx->height - s->font_height);
315 break;
316 default:
6d97484d 317 avpriv_request_sample(avctx, "Unknown escape code");
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318 break;
319 }
320 return 0;
321}
322
323static int decode_frame(AVCodecContext *avctx,
df9b9567 324 void *data, int *got_frame,
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325 AVPacket *avpkt)
326{
327 AnsiContext *s = avctx->priv_data;
328 uint8_t *buf = avpkt->data;
329 int buf_size = avpkt->size;
330 const uint8_t *buf_end = buf+buf_size;
331 int ret, i, count;
332
759001c5 333 ret = ff_reget_buffer(avctx, s->frame);
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334 if (ret < 0){
335 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
336 return ret;
337 }
99e36ddd 338 if (!avctx->frame_number) {
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339 memset(s->frame->data[0], 0, avctx->height * FFABS(s->frame->linesize[0]));
340 memset(s->frame->data[1], 0, AVPALETTE_SIZE);
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341 }
342
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343 s->frame->pict_type = AV_PICTURE_TYPE_I;
344 s->frame->palette_has_changed = 1;
345 memcpy(s->frame->data[1], ff_cga_palette, 16 * 4);
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346
347 while(buf < buf_end) {
348 switch(s->state) {
349 case STATE_NORMAL:
350 switch (buf[0]) {
351 case 0x00: //NUL
352 case 0x07: //BEL
353 case 0x1A: //SUB
354 /* ignore */
355 break;
356 case 0x08: //BS
357 s->x = FFMAX(s->x - 1, 0);
358 break;
359 case 0x09: //HT
360 i = s->x / FONT_WIDTH;
361 count = ((i + 8) & ~7) - i;
362 for (i = 0; i < count; i++)
363 draw_char(avctx, ' ');
364 break;
365 case 0x0A: //LF
366 hscroll(avctx);
367 case 0x0D: //CR
368 s->x = 0;
369 break;
370 case 0x0C: //FF
371 erase_screen(avctx);
372 break;
373 case 0x1B: //ESC
374 s->state = STATE_ESCAPE;
375 break;
376 default:
377 draw_char(avctx, buf[0]);
378 }
379 break;
380 case STATE_ESCAPE:
381 if (buf[0] == '[') {
382 s->state = STATE_CODE;
383 s->nb_args = 0;
384 s->args[0] = 0;
385 } else {
386 s->state = STATE_NORMAL;
387 draw_char(avctx, 0x1B);
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388 continue;
389 }
390 break;
391 case STATE_CODE:
392 switch(buf[0]) {
393 case '0': case '1': case '2': case '3': case '4':
394 case '5': case '6': case '7': case '8': case '9':
395 if (s->nb_args < MAX_NB_ARGS)
396 s->args[s->nb_args] = s->args[s->nb_args] * 10 + buf[0] - '0';
397 break;
398 case ';':
399 s->nb_args++;
400 if (s->nb_args < MAX_NB_ARGS)
401 s->args[s->nb_args] = 0;
402 break;
403 case 'M':
404 s->state = STATE_MUSIC_PREAMBLE;
405 break;
406 case '=': case '?':
407 /* ignore */
408 break;
409 default:
410 if (s->nb_args > MAX_NB_ARGS)
411 av_log(avctx, AV_LOG_WARNING, "args overflow (%i)\n", s->nb_args);
412 if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args])
413 s->nb_args++;
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414 if ((ret = execute_code(avctx, buf[0])) < 0)
415 return ret;
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416 s->state = STATE_NORMAL;
417 }
418 break;
419 case STATE_MUSIC_PREAMBLE:
420 if (buf[0] == 0x0E || buf[0] == 0x1B)
421 s->state = STATE_NORMAL;
422 /* ignore music data */
423 break;
424 }
425 buf++;
426 }
427
df9b9567 428 *got_frame = 1;
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429 if ((ret = av_frame_ref(data, s->frame)) < 0)
430 return ret;
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431 return buf_size;
432}
433
434static av_cold int decode_close(AVCodecContext *avctx)
435{
436 AnsiContext *s = avctx->priv_data;
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437
438 av_frame_free(&s->frame);
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439 return 0;
440}
441
d36beb3f 442AVCodec ff_ansi_decoder = {
beaa963c 443 .name = "ansi",
b2bed932 444 .long_name = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),
b9f9e59a 445 .type = AVMEDIA_TYPE_VIDEO,
36ef5369 446 .id = AV_CODEC_ID_ANSI,
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447 .priv_data_size = sizeof(AnsiContext),
448 .init = decode_init,
449 .close = decode_close,
450 .decode = decode_frame,
451 .capabilities = CODEC_CAP_DR1,
beaa963c 452};