FFmpeg
ansi.c
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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/attributes.h"
28 #include "libavutil/common.h"
29 #include "libavutil/frame.h"
30 #include "libavutil/xga_font_data.h"
31 #include "avcodec.h"
32 #include "cga_data.h"
33 #include "codec_internal.h"
34 #include "decode.h"
35 
36 #define ATTR_BOLD 0x01 /**< Bold/Bright-foreground (mode 1) */
37 #define ATTR_FAINT 0x02 /**< Faint (mode 2) */
38 #define ATTR_ITALICS 0x04 /**< Italics (mode 3) */
39 #define ATTR_UNDERLINE 0x08 /**< Underline (mode 4) */
40 #define ATTR_BLINK 0x10 /**< Blink/Bright-background (mode 5) */
41 #define ATTR_REVERSE 0x40 /**< Reverse (mode 7) */
42 #define ATTR_CONCEALED 0x80 /**< Concealed (mode 8) */
43 
44 #define DEFAULT_FG_COLOR 7 /**< CGA color index */
45 #define DEFAULT_BG_COLOR 0
46 #define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
47 
48 #define FONT_WIDTH 8 /**< Font width */
49 
50 /** map ansi color index to cga palette index */
51 static const uint8_t ansi_to_cga[16] = {
52  0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15
53 };
54 
55 typedef struct AnsiContext {
56  AVFrame *frame;
57  int x; /**< x cursor position (pixels) */
58  int y; /**< y cursor position (pixels) */
59  int sx; /**< saved x cursor position (pixels) */
60  int sy; /**< saved y cursor position (pixels) */
61  const uint8_t* font; /**< font */
62  int font_height; /**< font height */
63  int attributes; /**< attribute flags */
64  int fg; /**< foreground color */
65  int bg; /**< background color */
66  int first_frame;
67 
68  /* ansi parser state machine */
69  enum {
70  STATE_NORMAL = 0,
71  STATE_ESCAPE,
72  STATE_CODE,
73  STATE_MUSIC_PREAMBLE
74  } state;
75 #define MAX_NB_ARGS 4
76  int args[MAX_NB_ARGS];
77  int nb_args; /**< number of arguments (may exceed MAX_NB_ARGS) */
78 } AnsiContext;
79 
80 static av_cold int decode_init(AVCodecContext *avctx)
81 {
82  AnsiContext *s = avctx->priv_data;
83  avctx->pix_fmt = AV_PIX_FMT_PAL8;
84 
85  /* defaults */
86  s->font = avpriv_vga16_font_get();
87  s->font_height = 16;
88  s->fg = DEFAULT_FG_COLOR;
89  s->bg = DEFAULT_BG_COLOR;
90 
91  if (!avctx->width || !avctx->height) {
92  int ret = ff_set_dimensions(avctx, 80 << 3, 25 << 4);
93  if (ret < 0)
94  return ret;
95  } else if (avctx->width % FONT_WIDTH || avctx->height % s->font_height) {
96  av_log(avctx, AV_LOG_ERROR, "Invalid dimensions %d %d\n", avctx->width, avctx->height);
97  return AVERROR(EINVAL);
98  }
99 
100  s->frame = av_frame_alloc();
101  if (!s->frame)
102  return AVERROR(ENOMEM);
103 
104  return 0;
105 }
106 
107 static void set_palette(uint32_t *pal)
108 {
109  int r, g, b;
110  memcpy(pal, ff_cga_palette, 16 * 4);
111  pal += 16;
112 #define COLOR(x) ((x) * 40 + 55)
113  for (r = 0; r < 6; r++)
114  for (g = 0; g < 6; g++)
115  for (b = 0; b < 6; b++)
116  *pal++ = 0xFF000000 | (COLOR(r) << 16) | (COLOR(g) << 8) | COLOR(b);
117 #define GRAY(x) ((x) * 10 + 8)
118  for (g = 0; g < 24; g++)
119  *pal++ = 0xFF000000 | (GRAY(g) << 16) | (GRAY(g) << 8) | GRAY(g);
120 }
121 
122 static void hscroll(AVCodecContext *avctx)
123 {
124  AnsiContext *s = avctx->priv_data;
125  int i;
126 
127  if (s->y <= avctx->height - 2*s->font_height) {
128  s->y += s->font_height;
129  return;
130  }
131 
132  i = 0;
133  for (; i < avctx->height - s->font_height; i++)
134  memcpy(s->frame->data[0] + i * s->frame->linesize[0],
135  s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0],
136  avctx->width);
137  for (; i < avctx->height; i++)
138  memset(s->frame->data[0] + i * s->frame->linesize[0],
139  DEFAULT_BG_COLOR, avctx->width);
140 }
141 
142 static void erase_line(AVCodecContext * avctx, int xoffset, int xlength)
143 {
144  AnsiContext *s = avctx->priv_data;
145  int i;
146  for (i = 0; i < s->font_height; i++)
147  memset(s->frame->data[0] + (s->y + i)*s->frame->linesize[0] + xoffset,
148  DEFAULT_BG_COLOR, xlength);
149 }
150 
151 static void erase_screen(AVCodecContext *avctx)
152 {
153  AnsiContext *s = avctx->priv_data;
154  int i;
155  for (i = 0; i < avctx->height; i++)
156  memset(s->frame->data[0] + i * s->frame->linesize[0], DEFAULT_BG_COLOR, avctx->width);
157  s->x = s->y = 0;
158 }
159 
160 /**
161  * Draw character to screen
162  */
163 static void draw_char(AVCodecContext *avctx, int c)
164 {
165  AnsiContext *s = avctx->priv_data;
166  int fg = s->fg;
167  int bg = s->bg;
168 
169  if ((s->attributes & ATTR_BOLD))
170  fg += 8;
171  if ((s->attributes & ATTR_BLINK))
172  bg += 8;
173  if ((s->attributes & ATTR_REVERSE))
174  FFSWAP(int, fg, bg);
175  if ((s->attributes & ATTR_CONCEALED))
176  fg = bg;
177  ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
178  s->frame->linesize[0], s->font, s->font_height, c, fg, bg);
179  s->x += FONT_WIDTH;
180  if (s->x > avctx->width - FONT_WIDTH) {
181  s->x = 0;
182  hscroll(avctx);
183  }
184 }
185 
186 /**
187  * Execute ANSI escape code
188  * @return 0 on success, negative on error
189  */
190 static int execute_code(AVCodecContext * avctx, int c)
191 {
192  AnsiContext *s = avctx->priv_data;
193  int ret, i;
194  int width = avctx->width;
195  int height = avctx->height;
196 
197  switch(c) {
198  case 'A': //Cursor Up
199  s->y = FFMAX(s->y - (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), 0);
200  break;
201  case 'B': //Cursor Down
202  s->y = FFMIN(s->y + (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), avctx->height - s->font_height);
203  break;
204  case 'C': //Cursor Right
205  s->x = FFMIN(s->x + (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), avctx->width - FONT_WIDTH);
206  break;
207  case 'D': //Cursor Left
208  s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0);
209  break;
210  case 'H': //Cursor Position
211  case 'f': //Horizontal and Vertical Position
212  s->y = s->nb_args > 0 ? av_clip((s->args[0] - 1)*s->font_height, 0, avctx->height - s->font_height) : 0;
213  s->x = s->nb_args > 1 ? av_clip((s->args[1] - 1)*FONT_WIDTH, 0, avctx->width - FONT_WIDTH) : 0;
214  break;
215  case 'h': //set screen mode
216  case 'l': //reset screen mode
217  if (s->nb_args < 2)
218  s->args[0] = DEFAULT_SCREEN_MODE;
219  switch(s->args[0]) {
220  case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
221  s->font = avpriv_cga_font_get();
222  s->font_height = 8;
223  width = 40<<3;
224  height = 25<<3;
225  break;
226  case 2: case 3: //640x400 (25 rows)
227  s->font = avpriv_vga16_font_get();
228  s->font_height = 16;
229  width = 80<<3;
230  height = 25<<4;
231  break;
232  case 6: case 14: //640x200 (25 rows)
233  s->font = avpriv_cga_font_get();
234  s->font_height = 8;
235  width = 80<<3;
236  height = 25<<3;
237  break;
238  case 7: //set line wrapping
239  break;
240  case 15: case 16: //640x350 (43 rows)
241  s->font = avpriv_cga_font_get();
242  s->font_height = 8;
243  width = 80<<3;
244  height = 43<<3;
245  break;
246  case 17: case 18: //640x480 (60 rows)
247  s->font = avpriv_cga_font_get();
248  s->font_height = 8;
249  width = 80<<3;
250  height = 60<<4;
251  break;
252  default:
253  avpriv_request_sample(avctx, "Unsupported screen mode");
254  }
255  s->x = av_clip(s->x, 0, width - FONT_WIDTH);
256  s->y = av_clip(s->y, 0, height - s->font_height);
257  if (width != avctx->width || height != avctx->height) {
258  av_frame_unref(s->frame);
259  ret = ff_set_dimensions(avctx, width, height);
260  if (ret < 0)
261  return ret;
262  if ((ret = ff_get_buffer(avctx, s->frame,
263  AV_GET_BUFFER_FLAG_REF)) < 0)
264  return ret;
265  s->frame->pict_type = AV_PICTURE_TYPE_I;
266  set_palette((uint32_t *)s->frame->data[1]);
267  erase_screen(avctx);
268  } else if (c == 'l') {
269  erase_screen(avctx);
270  }
271  break;
272  case 'J': //Erase in Page
273  switch (s->args[0]) {
274  case 0:
275  erase_line(avctx, s->x, avctx->width - s->x);
276  if (s->y < avctx->height - s->font_height)
277  memset(s->frame->data[0] + (s->y + s->font_height)*s->frame->linesize[0],
278  DEFAULT_BG_COLOR, (avctx->height - s->y - s->font_height)*s->frame->linesize[0]);
279  break;
280  case 1:
281  erase_line(avctx, 0, s->x);
282  if (s->y > 0)
283  memset(s->frame->data[0], DEFAULT_BG_COLOR, s->y * s->frame->linesize[0]);
284  break;
285  case 2:
286  erase_screen(avctx);
287  }
288  break;
289  case 'K': //Erase in Line
290  switch(s->args[0]) {
291  case 0:
292  erase_line(avctx, s->x, avctx->width - s->x);
293  break;
294  case 1:
295  erase_line(avctx, 0, s->x);
296  break;
297  case 2:
298  erase_line(avctx, 0, avctx->width);
299  }
300  break;
301  case 'm': //Select Graphics Rendition
302  if (s->nb_args == 0) {
303  s->nb_args = 1;
304  s->args[0] = 0;
305  }
306  for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) {
307  int m = s->args[i];
308  if (m == 0) {
309  s->attributes = 0;
310  s->fg = DEFAULT_FG_COLOR;
311  s->bg = DEFAULT_BG_COLOR;
312  } else if (m == 1 || m == 2 || m == 3 || m == 4 || m == 5 || m == 7 || m == 8) {
313  s->attributes |= 1 << (m - 1);
314  } else if (m >= 30 && m <= 37) {
315  s->fg = ansi_to_cga[m - 30];
316  } else if (m == 38 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
317  int index = s->args[i + 2];
318  s->fg = index < 16 ? ansi_to_cga[index] : index;
319  i += 2;
320  } else if (m == 39) {
321  s->fg = ansi_to_cga[DEFAULT_FG_COLOR];
322  } else if (m >= 40 && m <= 47) {
323  s->bg = ansi_to_cga[m - 40];
324  } else if (m == 48 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
325  int index = s->args[i + 2];
326  s->bg = index < 16 ? ansi_to_cga[index] : index;
327  i += 2;
328  } else if (m == 49) {
329  s->bg = ansi_to_cga[DEFAULT_BG_COLOR];
330  } else {
331  avpriv_request_sample(avctx, "Unsupported rendition parameter");
332  }
333  }
334  break;
335  case 'n': //Device Status Report
336  case 'R': //report current line and column
337  /* ignore */
338  break;
339  case 's': //Save Cursor Position
340  s->sx = s->x;
341  s->sy = s->y;
342  break;
343  case 'u': //Restore Cursor Position
344  s->x = av_clip(s->sx, 0, avctx->width - FONT_WIDTH);
345  s->y = av_clip(s->sy, 0, avctx->height - s->font_height);
346  break;
347  default:
348  avpriv_request_sample(avctx, "Unknown escape code");
349  break;
350  }
351  s->x = av_clip(s->x, 0, avctx->width - FONT_WIDTH);
352  s->y = av_clip(s->y, 0, avctx->height - s->font_height);
353  return 0;
354 }
355 
356 static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
357  int *got_frame, AVPacket *avpkt)
358 {
359  AnsiContext *s = avctx->priv_data;
360  const uint8_t *buf = avpkt->data;
361  int buf_size = avpkt->size;
362  const uint8_t *buf_end = buf+buf_size;
363  int ret, i, count;
364 
365  if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
366  return ret;
367  if (!avctx->frame_num) {
368  for (i=0; i<avctx->height; i++)
369  memset(s->frame->data[0]+ i*s->frame->linesize[0], 0, avctx->width);
370  memset(s->frame->data[1], 0, AVPALETTE_SIZE);
371  }
372 
373  s->frame->pict_type = AV_PICTURE_TYPE_I;
374  set_palette((uint32_t *)s->frame->data[1]);
375  if (!s->first_frame) {
376  erase_screen(avctx);
377  s->first_frame = 1;
378  }
379 
380  while(buf < buf_end) {
381  switch(s->state) {
382  case STATE_NORMAL:
383  switch (buf[0]) {
384  case 0x00: //NUL
385  case 0x07: //BEL
386  case 0x1A: //SUB
387  /* ignore */
388  break;
389  case 0x08: //BS
390  s->x = FFMAX(s->x - 1, 0);
391  break;
392  case 0x09: //HT
393  i = s->x / FONT_WIDTH;
394  count = ((i + 8) & ~7) - i;
395  for (i = 0; i < count; i++)
396  draw_char(avctx, ' ');
397  break;
398  case 0x0A: //LF
399  hscroll(avctx);
400  av_fallthrough;
401  case 0x0D: //CR
402  s->x = 0;
403  break;
404  case 0x0C: //FF
405  erase_screen(avctx);
406  break;
407  case 0x1B: //ESC
408  s->state = STATE_ESCAPE;
409  break;
410  default:
411  draw_char(avctx, buf[0]);
412  }
413  break;
414  case STATE_ESCAPE:
415  if (buf[0] == '[') {
416  s->state = STATE_CODE;
417  s->nb_args = 0;
418  s->args[0] = -1;
419  } else {
420  s->state = STATE_NORMAL;
421  draw_char(avctx, 0x1B);
422  continue;
423  }
424  break;
425  case STATE_CODE:
426  switch(buf[0]) {
427  case '0': case '1': case '2': case '3': case '4':
428  case '5': case '6': case '7': case '8': case '9':
429  if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] < 6553)
430  s->args[s->nb_args] = FFMAX(s->args[s->nb_args], 0) * 10 + buf[0] - '0';
431  break;
432  case ';':
433  if (s->nb_args < MAX_NB_ARGS)
434  s->nb_args++;
435  if (s->nb_args < MAX_NB_ARGS)
436  s->args[s->nb_args] = 0;
437  break;
438  case 'M':
439  s->state = STATE_MUSIC_PREAMBLE;
440  break;
441  case '=': case '?':
442  /* ignore */
443  break;
444  default:
445  if (s->nb_args > MAX_NB_ARGS)
446  av_log(avctx, AV_LOG_WARNING, "args overflow (%i)\n", s->nb_args);
447  if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] >= 0)
448  s->nb_args++;
449  if ((ret = execute_code(avctx, buf[0])) < 0)
450  return ret;
451  s->state = STATE_NORMAL;
452  }
453  break;
454  case STATE_MUSIC_PREAMBLE:
455  if (buf[0] == 0x0E || buf[0] == 0x1B)
456  s->state = STATE_NORMAL;
457  /* ignore music data */
458  break;
459  }
460  buf++;
461  }
462 
463  *got_frame = 1;
464  if ((ret = av_frame_ref(rframe, s->frame)) < 0)
465  return ret;
466  return buf_size;
467 }
468 
469 static av_cold int decode_close(AVCodecContext *avctx)
470 {
471  AnsiContext *s = avctx->priv_data;
472 
473  av_frame_free(&s->frame);
474  return 0;
475 }
476 
477 static const FFCodecDefault ansi_defaults[] = {
478  { "max_pixels", "640*480" },
479  { NULL },
480 };
481 
482 const FFCodec ff_ansi_decoder = {
483  .p.name = "ansi",
484  CODEC_LONG_NAME("ASCII/ANSI art"),
485  .p.type = AVMEDIA_TYPE_VIDEO,
486  .p.id = AV_CODEC_ID_ANSI,
487  .priv_data_size = sizeof(AnsiContext),
488  .init = decode_init,
489  .close = decode_close,
490  FF_CODEC_DECODE_CB(decode_frame),
491  .p.capabilities = AV_CODEC_CAP_DR1,
492  .defaults = ansi_defaults,
493 };
AV_CODEC_ID_ANSI
@ AV_CODEC_ID_ANSI
Definition: codec_id.h:194
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:216
decode_close
static av_cold int decode_close(AVCodecContext *avctx)
Definition: ansi.c:469
av_clip
#define av_clip
Definition: common.h:100
r
const char * r
Definition: vf_curves.c:127
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
ff_cga_palette
const uint32_t ff_cga_palette[16]
Definition: cga_data.c:30
COLOR
#define COLOR(x)
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:64
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:435
AVPacket::data
uint8_t * data
Definition: packet.h:595
execute_code
static int execute_code(AVCodecContext *avctx, int c)
Execute ANSI escape code.
Definition: ansi.c:190
b
#define b
Definition: input.c:43
FFCodec
Definition: codec_internal.h:127
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AnsiContext
Definition: ansi.c:55
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Definition: utils.c:91
AnsiContext::font
const uint8_t * font
font
Definition: ansi.c:61
AnsiContext::STATE_CODE
@ STATE_CODE
Definition: ansi.c:72
avpriv_vga16_font_get
const uint8_t * avpriv_vga16_font_get(void)
Definition: xga_font_data.c:430
close
static av_cold void close(AVCodecParserContext *s)
Definition: apv_parser.c:197
AnsiContext::sy
int sy
saved y cursor position (pixels)
Definition: ansi.c:60
FFCodecDefault
Definition: codec_internal.h:97
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
AnsiContext::first_frame
int first_frame
Definition: ansi.c:66
AnsiContext::nb_args
int nb_args
number of arguments (may exceed MAX_NB_ARGS)
Definition: ansi.c:77
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:52
ff_draw_pc_font
void ff_draw_pc_font(uint8_t *dst, int linesize, const uint8_t *font, int font_height, int ch, int fg, int bg)
Draw CGA/EGA/VGA font to 8-bit pixel buffer.
Definition: cga_data.c:46
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:210
av_cold
#define av_cold
Definition: attributes.h:119
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:347
AnsiContext::y
int y
y cursor position (pixels)
Definition: ansi.c:58
s
#define s(width, name)
Definition: cbs_vp9.c:198
g
const char * g
Definition: vf_curves.c:128
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:411
AnsiContext::STATE_NORMAL
@ STATE_NORMAL
Definition: ansi.c:70
decode.h
draw_char
static void draw_char(AVCodecContext *avctx, int c)
Draw character to screen.
Definition: ansi.c:163
AnsiContext::STATE_MUSIC_PREAMBLE
@ STATE_MUSIC_PREAMBLE
Definition: ansi.c:73
ATTR_BLINK
#define ATTR_BLINK
Blink/Bright-background (mode 5)
Definition: ansi.c:40
av_fallthrough
#define av_fallthrough
Definition: attributes.h:67
ATTR_CONCEALED
#define ATTR_CONCEALED
Concealed (mode 8)
Definition: ansi.c:42
ATTR_BOLD
#define ATTR_BOLD
Bold/Bright-foreground (mode 1)
Definition: ansi.c:36
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:332
GRAY
#define GRAY(x)
NULL
#define NULL
Definition: coverity.c:32
DEFAULT_SCREEN_MODE
#define DEFAULT_SCREEN_MODE
80x25
Definition: ansi.c:46
ansi_defaults
static const FFCodecDefault ansi_defaults[]
Definition: ansi.c:477
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:278
index
int index
Definition: gxfenc.c:90
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AnsiContext::sx
int sx
saved x cursor position (pixels)
Definition: ansi.c:59
AnsiContext::attributes
int attributes
attribute flags
Definition: ansi.c:63
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1765
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:551
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:596
height
#define height
Definition: dsp.h:89
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:278
codec_internal.h
MAX_NB_ARGS
#define MAX_NB_ARGS
Definition: ansi.c:75
i
#define i(width, name, range_min, range_max)
Definition: cbs_h264.c:63
avpriv_cga_font_get
const uint8_t * avpriv_cga_font_get(void)
Definition: xga_font_data.c:163
hscroll
static void hscroll(AVCodecContext *avctx)
Definition: ansi.c:122
frame.h
cga_data.h
erase_line
static void erase_line(AVCodecContext *avctx, int xoffset, int xlength)
Definition: ansi.c:142
attributes.h
DEFAULT_FG_COLOR
#define DEFAULT_FG_COLOR
CGA color index.
Definition: ansi.c:44
xga_font_data.h
AnsiContext::frame
AVFrame * frame
Definition: ansi.c:56
AnsiContext::state
enum AnsiContext::@46 state
set_palette
static void set_palette(uint32_t *pal)
Definition: ansi.c:107
ATTR_REVERSE
#define ATTR_REVERSE
Reverse (mode 7)
Definition: ansi.c:41
DEFAULT_BG_COLOR
#define DEFAULT_BG_COLOR
Definition: ansi.c:45
common.h
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:496
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:179
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: ansi.c:356
AVCodecContext::height
int height
Definition: avcodec.h:600
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:639
AnsiContext::bg
int bg
background color
Definition: ansi.c:65
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:84
AVCodecContext::frame_num
int64_t frame_num
Frame counter, set by libavcodec.
Definition: avcodec.h:1890
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1894
ret
ret
Definition: filter_design.txt:187
FFSWAP
#define FFSWAP(type, a, b)
Definition: macros.h:52
FONT_WIDTH
#define FONT_WIDTH
Font width.
Definition: ansi.c:48
AnsiContext::fg
int fg
foreground color
Definition: ansi.c:64
AVCodecContext
main external API structure.
Definition: avcodec.h:439
ff_ansi_decoder
const FFCodec ff_ansi_decoder
Definition: ansi.c:482
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:37
AVPacket
This structure stores compressed data.
Definition: packet.h:572
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:466
AnsiContext::args
int args[MAX_NB_ARGS]
Definition: ansi.c:76
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:600
AnsiContext::x
int x
x cursor position (pixels)
Definition: ansi.c:57
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AnsiContext::font_height
int font_height
font height
Definition: ansi.c:62
width
#define width
Definition: dsp.h:89
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: ansi.c:80
erase_screen
static void erase_screen(AVCodecContext *avctx)
Definition: ansi.c:151
ansi_to_cga
static const uint8_t ansi_to_cga[16]
map ansi color index to cga palette index
Definition: ansi.c:51
AnsiContext::STATE_ESCAPE
@ STATE_ESCAPE
Definition: ansi.c:71
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