FFmpeg
bintext.c
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1 /*
2  * Binary text decoder
3  * eXtended BINary text (XBIN) decoder
4  * iCEDraw File decoder
5  * Copyright (c) 2010 Peter Ross (pross@xvid.org)
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /**
25  * @file
26  * Binary text decoder
27  * eXtended BINary text (XBIN) decoder
28  * iCEDraw File decoder
29  */
30 
31 #include "libavutil/intreadwrite.h"
33 #include "avcodec.h"
34 #include "cga_data.h"
35 #include "bintext.h"
36 #include "internal.h"
37 
38 #define FONT_WIDTH 8
39 
40 typedef struct XbinContext {
42  int palette[16];
43  int flags;
45  const uint8_t *font;
46  int x, y;
47 } XbinContext;
48 
50 {
51  XbinContext *s = avctx->priv_data;
52  uint8_t *p;
53  int i;
54 
55  avctx->pix_fmt = AV_PIX_FMT_PAL8;
56  p = avctx->extradata;
57  if (p) {
58  s->font_height = p[0];
59  s->flags = p[1];
60  p += 2;
61  if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
62  + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
63  av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
64  return AVERROR_INVALIDDATA;
65  }
66  } else {
67  s->font_height = 8;
68  s->flags = 0;
69  }
70 
71  if ((s->flags & BINTEXT_PALETTE)) {
72  for (i = 0; i < 16; i++) {
73  s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
74  p += 3;
75  }
76  } else {
77  for (i = 0; i < 16; i++)
78  s->palette[i] = 0xFF000000 | ff_cga_palette[i];
79  }
80 
81  if ((s->flags & BINTEXT_FONT)) {
82  s->font = p;
83  } else {
84  switch(s->font_height) {
85  default:
86  av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
87  s->font_height = 8;
88  case 8:
89  s->font = avpriv_cga_font;
90  break;
91  case 16:
93  break;
94  }
95  }
96  if (avctx->width < FONT_WIDTH || avctx->height < s->font_height)
97  return AVERROR_INVALIDDATA;
98 
99  return 0;
100 }
101 
102 #define DEFAULT_BG_COLOR 0
103 av_unused static void hscroll(AVCodecContext *avctx)
104 {
105  XbinContext *s = avctx->priv_data;
106  if (s->y < avctx->height - s->font_height) {
107  s->y += s->font_height;
108  } else {
109  memmove(s->frame->data[0], s->frame->data[0] + s->font_height*s->frame->linesize[0],
110  (avctx->height - s->font_height)*s->frame->linesize[0]);
111  memset(s->frame->data[0] + (avctx->height - s->font_height)*s->frame->linesize[0],
113  }
114 }
115 
116 /**
117  * Draw character to screen
118  */
119 static void draw_char(AVCodecContext *avctx, int c, int a)
120 {
121  XbinContext *s = avctx->priv_data;
122  if (s->y > avctx->height - s->font_height)
123  return;
124  ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
125  s->frame->linesize[0], s->font, s->font_height, c,
126  a & 0x0F, a >> 4);
127  s->x += FONT_WIDTH;
128  if (s->x > avctx->width - FONT_WIDTH) {
129  s->x = 0;
130  s->y += s->font_height;
131  }
132 }
133 
134 static int decode_frame(AVCodecContext *avctx,
135  void *data, int *got_frame,
136  AVPacket *avpkt)
137 {
138  XbinContext *s = avctx->priv_data;
139  const uint8_t *buf = avpkt->data;
140  int buf_size = avpkt->size;
141  const uint8_t *buf_end = buf+buf_size;
142  int ret;
143 
144  if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
145  return AVERROR_INVALIDDATA;
146 
147  s->frame = data;
148  s->x = s->y = 0;
149  if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
150  return ret;
152  s->frame->palette_has_changed = 1;
153  memcpy(s->frame->data[1], s->palette, 16 * 4);
154 
155  if (avctx->codec_id == AV_CODEC_ID_XBIN) {
156  while (buf + 2 < buf_end) {
157  int i,c,a;
158  int type = *buf >> 6;
159  int count = (*buf & 0x3F) + 1;
160  buf++;
161  switch (type) {
162  case 0: //no compression
163  for (i = 0; i < count && buf + 1 < buf_end; i++) {
164  draw_char(avctx, buf[0], buf[1]);
165  buf += 2;
166  }
167  break;
168  case 1: //character compression
169  c = *buf++;
170  for (i = 0; i < count && buf < buf_end; i++)
171  draw_char(avctx, c, *buf++);
172  break;
173  case 2: //attribute compression
174  a = *buf++;
175  for (i = 0; i < count && buf < buf_end; i++)
176  draw_char(avctx, *buf++, a);
177  break;
178  case 3: //character/attribute compression
179  c = *buf++;
180  a = *buf++;
181  for (i = 0; i < count && buf < buf_end; i++)
182  draw_char(avctx, c, a);
183  break;
184  }
185  }
186  } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
187  while (buf + 2 < buf_end) {
188  if (AV_RL16(buf) == 1) {
189  int i;
190  if (buf + 6 > buf_end)
191  break;
192  for (i = 0; i < buf[2]; i++)
193  draw_char(avctx, buf[4], buf[5]);
194  buf += 6;
195  } else {
196  draw_char(avctx, buf[0], buf[1]);
197  buf += 2;
198  }
199  }
200  } else {
201  while (buf + 1 < buf_end) {
202  draw_char(avctx, buf[0], buf[1]);
203  buf += 2;
204  }
205  }
206 
207  *got_frame = 1;
208  return buf_size;
209 }
210 
211 #if CONFIG_BINTEXT_DECODER
213  .name = "bintext",
214  .long_name = NULL_IF_CONFIG_SMALL("Binary text"),
215  .type = AVMEDIA_TYPE_VIDEO,
216  .id = AV_CODEC_ID_BINTEXT,
217  .priv_data_size = sizeof(XbinContext),
218  .init = decode_init,
219  .decode = decode_frame,
220  .capabilities = AV_CODEC_CAP_DR1,
221 };
222 #endif
223 #if CONFIG_XBIN_DECODER
225  .name = "xbin",
226  .long_name = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
227  .type = AVMEDIA_TYPE_VIDEO,
228  .id = AV_CODEC_ID_XBIN,
229  .priv_data_size = sizeof(XbinContext),
230  .init = decode_init,
231  .decode = decode_frame,
232  .capabilities = AV_CODEC_CAP_DR1,
233 };
234 #endif
235 #if CONFIG_IDF_DECODER
237  .name = "idf",
238  .long_name = NULL_IF_CONFIG_SMALL("iCEDraw text"),
239  .type = AVMEDIA_TYPE_VIDEO,
240  .id = AV_CODEC_ID_IDF,
241  .priv_data_size = sizeof(XbinContext),
242  .init = decode_init,
243  .decode = decode_frame,
244  .capabilities = AV_CODEC_CAP_DR1,
245 };
246 #endif
Binary text decoder.
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:268
const uint8_t * font
Definition: bintext.c:45
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
AVCodec ff_bintext_decoder
int flags
Definition: bintext.c:43
int size
Definition: avcodec.h:1469
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1766
GLint GLenum type
Definition: opengl_enc.c:105
const uint8_t avpriv_vga16_font[4096]
static av_unused void hscroll(AVCodecContext *avctx)
Definition: bintext.c:103
AVCodec.
Definition: avcodec.h:3468
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
static av_cold int decode_init(AVCodecContext *avctx)
Definition: bintext.c:49
uint8_t
#define av_cold
Definition: attributes.h:82
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
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
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1657
uint8_t * data
Definition: avcodec.h:1468
CGA/EGA/VGA ROM data.
#define av_log(a,...)
#define BINTEXT_PALETTE
Definition: bintext.h:34
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
const uint8_t avpriv_cga_font[2048]
Definition: xga_font_data.c:29
#define DEFAULT_BG_COLOR
Definition: bintext.c:102
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * name
Name of the codec implementation.
Definition: avcodec.h:3475
GLsizei count
Definition: opengl_enc.c:109
int palette[16]
Definition: bintext.c:42
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:351
int width
picture width / height.
Definition: avcodec.h:1729
static void draw_char(AVCodecContext *avctx, int c, int a)
Draw character to screen.
Definition: bintext.c:119
int font_height
Definition: bintext.c:44
#define FONT_WIDTH
Definition: bintext.c:38
#define s(width, name)
Definition: cbs_vp9.c:257
AVCodec ff_idf_decoder
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
Libavcodec external API header.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
enum AVCodecID codec_id
Definition: avcodec.h:1566
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:299
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: bintext.c:134
main external API structure.
Definition: avcodec.h:1556
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1919
void * buf
Definition: avisynth_c.h:690
int extradata_size
Definition: avcodec.h:1658
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:425
AVFrame * frame
Definition: bintext.c:41
const uint32_t ff_cga_palette[16]
Definition: cga_data.c:30
AVCodec ff_xbin_decoder
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:282
common internal api header.
void * priv_data
Definition: avcodec.h:1583
#define BINTEXT_FONT
Definition: bintext.h:35
This structure stores compressed data.
Definition: avcodec.h:1445
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:972
CGA/EGA/VGA ROM font data.
#define av_unused
Definition: attributes.h:125