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 "config_components.h"
32 
33 #include "libavutil/attributes.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/xga_font_data.h"
36 #include "avcodec.h"
37 #include "cga_data.h"
38 #include "bintext.h"
39 #include "codec_internal.h"
40 #include "decode.h"
41 
42 #define FONT_WIDTH 8
43 
44 typedef struct XbinContext {
45  AVFrame *frame;
46  int palette[16];
47  int flags;
48  int font_height;
49  const uint8_t *font;
50  int x, y;
51 } XbinContext;
52 
53 static av_cold int decode_init(AVCodecContext *avctx)
54 {
55  XbinContext *s = avctx->priv_data;
56  uint8_t *p;
57  int i;
58 
59  avctx->pix_fmt = AV_PIX_FMT_PAL8;
60  p = avctx->extradata;
61  if (p) {
62  s->font_height = p[0];
63  s->flags = p[1];
64  p += 2;
65  if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
66  + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
67  av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
68  return AVERROR_INVALIDDATA;
69  }
70  if (!s->font_height) {
71  av_log(avctx, AV_LOG_ERROR, "invalid font height\n");
72  return AVERROR_INVALIDDATA;
73  }
74  } else {
75  s->font_height = 8;
76  s->flags = 0;
77  }
78 
79  if ((s->flags & BINTEXT_PALETTE)) {
80  for (i = 0; i < 16; i++) {
81  s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
82  p += 3;
83  }
84  } else {
85  for (i = 0; i < 16; i++)
86  s->palette[i] = 0xFF000000 | ff_cga_palette[i];
87  }
88 
89  if ((s->flags & BINTEXT_FONT)) {
90  s->font = p;
91  } else {
92  switch(s->font_height) {
93  default:
94  av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
95  s->font_height = 8;
96  av_fallthrough;
97  case 8:
98  s->font = avpriv_cga_font_get();
99  break;
100  case 16:
101  s->font = avpriv_vga16_font_get();
102  break;
103  }
104  }
105  if (avctx->width < FONT_WIDTH || avctx->height < s->font_height) {
106  av_log(avctx, AV_LOG_ERROR, "Resolution too small for font.\n");
107  return AVERROR_INVALIDDATA;
108  }
109 
110  return 0;
111 }
112 
113 #define DEFAULT_BG_COLOR 0
114 av_unused static void hscroll(AVCodecContext *avctx)
115 {
116  XbinContext *s = avctx->priv_data;
117  if (s->y < avctx->height - s->font_height) {
118  s->y += s->font_height;
119  } else {
120  memmove(s->frame->data[0], s->frame->data[0] + s->font_height*s->frame->linesize[0],
121  (avctx->height - s->font_height)*s->frame->linesize[0]);
122  memset(s->frame->data[0] + (avctx->height - s->font_height)*s->frame->linesize[0],
123  DEFAULT_BG_COLOR, s->font_height * s->frame->linesize[0]);
124  }
125 }
126 
127 /**
128  * Draw character to screen
129  */
130 static void draw_char(AVCodecContext *avctx, int c, int a)
131 {
132  XbinContext *s = avctx->priv_data;
133  if (s->y > avctx->height - s->font_height)
134  return;
135  ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
136  s->frame->linesize[0], s->font, s->font_height, c,
137  a & 0x0F, a >> 4);
138  s->x += FONT_WIDTH;
139  if (s->x > avctx->width - FONT_WIDTH) {
140  s->x = 0;
141  s->y += s->font_height;
142  }
143 }
144 
145 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
146  int *got_frame, AVPacket *avpkt)
147 {
148  XbinContext *s = avctx->priv_data;
149  const uint8_t *buf = avpkt->data;
150  int buf_size = avpkt->size;
151  const uint8_t *buf_end = buf+buf_size;
152  int ret;
153 
154  if ((avctx->width / FONT_WIDTH) * (avctx->height / s->font_height) / 256 > buf_size)
155  return AVERROR_INVALIDDATA;
156 
157  s->frame = frame;
158  s->x = s->y = 0;
159  if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0)
160  return ret;
161  s->frame->pict_type = AV_PICTURE_TYPE_I;
162  memcpy(s->frame->data[1], s->palette, 16 * 4);
163 
164  if (avctx->codec_id == AV_CODEC_ID_XBIN) {
165  while (buf + 2 < buf_end) {
166  int i,c,a;
167  int type = *buf >> 6;
168  int count = (*buf & 0x3F) + 1;
169  buf++;
170  switch (type) {
171  case 0: //no compression
172  for (i = 0; i < count && buf + 1 < buf_end; i++) {
173  draw_char(avctx, buf[0], buf[1]);
174  buf += 2;
175  }
176  break;
177  case 1: //character compression
178  c = *buf++;
179  for (i = 0; i < count && buf < buf_end; i++)
180  draw_char(avctx, c, *buf++);
181  break;
182  case 2: //attribute compression
183  a = *buf++;
184  for (i = 0; i < count && buf < buf_end; i++)
185  draw_char(avctx, *buf++, a);
186  break;
187  case 3: //character/attribute compression
188  c = *buf++;
189  a = *buf++;
190  for (i = 0; i < count && buf < buf_end; i++)
191  draw_char(avctx, c, a);
192  break;
193  }
194  }
195  } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
196  while (buf + 2 < buf_end) {
197  if (AV_RL16(buf) == 1) {
198  int i;
199  if (buf + 6 > buf_end)
200  break;
201  for (i = 0; i < buf[2]; i++)
202  draw_char(avctx, buf[4], buf[5]);
203  buf += 6;
204  } else {
205  draw_char(avctx, buf[0], buf[1]);
206  buf += 2;
207  }
208  }
209  } else {
210  while (buf + 1 < buf_end) {
211  draw_char(avctx, buf[0], buf[1]);
212  buf += 2;
213  }
214  }
215 
216  *got_frame = 1;
217  return buf_size;
218 }
219 
220 #if CONFIG_BINTEXT_DECODER
221 const FFCodec ff_bintext_decoder = {
222  .p.name = "bintext",
223  CODEC_LONG_NAME("Binary text"),
224  .p.type = AVMEDIA_TYPE_VIDEO,
225  .p.id = AV_CODEC_ID_BINTEXT,
226  .priv_data_size = sizeof(XbinContext),
227  .init = decode_init,
228  FF_CODEC_DECODE_CB(decode_frame),
229  .p.capabilities = AV_CODEC_CAP_DR1,
230 };
231 #endif
232 #if CONFIG_XBIN_DECODER
233 const FFCodec ff_xbin_decoder = {
234  .p.name = "xbin",
235  CODEC_LONG_NAME("eXtended BINary text"),
236  .p.type = AVMEDIA_TYPE_VIDEO,
237  .p.id = AV_CODEC_ID_XBIN,
238  .priv_data_size = sizeof(XbinContext),
239  .init = decode_init,
240  FF_CODEC_DECODE_CB(decode_frame),
241  .p.capabilities = AV_CODEC_CAP_DR1,
242 };
243 #endif
244 #if CONFIG_IDF_DECODER
245 const FFCodec ff_idf_decoder = {
246  .p.name = "idf",
247  CODEC_LONG_NAME("iCEDraw text"),
248  .p.type = AVMEDIA_TYPE_VIDEO,
249  .p.id = AV_CODEC_ID_IDF,
250  .priv_data_size = sizeof(XbinContext),
251  .init = decode_init,
252  FF_CODEC_DECODE_CB(decode_frame),
253  .p.capabilities = AV_CODEC_CAP_DR1,
254 };
255 #endif
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:216
ff_cga_palette
const uint32_t ff_cga_palette[16]
Definition: cga_data.c:30
XbinContext::palette
int palette[16]
Definition: bintext.c:46
hscroll
static av_unused void hscroll(AVCodecContext *avctx)
Definition: bintext.c:114
av_unused
#define av_unused
Definition: attributes.h:164
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:435
AVPacket::data
uint8_t * data
Definition: packet.h:595
FFCodec
Definition: codec_internal.h:127
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: bintext.c:53
avpriv_vga16_font_get
const uint8_t * avpriv_vga16_font_get(void)
Definition: xga_font_data.c:430
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
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
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:523
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:347
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
DEFAULT_BG_COLOR
#define DEFAULT_BG_COLOR
Definition: bintext.c:113
XbinContext::y
int y
Definition: bintext.c:50
decode.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
av_fallthrough
#define av_fallthrough
Definition: attributes.h:67
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:332
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:449
XbinContext::flags
int flags
Definition: bintext.c:47
XbinContext::x
int x
Definition: bintext.c:50
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: bintext.c:145
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:278
draw_char
static void draw_char(AVCodecContext *avctx, int c, int a)
Draw character to screen.
Definition: bintext.c:130
BINTEXT_PALETTE
#define BINTEXT_PALETTE
Definition: bintext.h:34
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
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
AV_CODEC_ID_IDF
@ AV_CODEC_ID_IDF
Definition: codec_id.h:608
codec_internal.h
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
AV_CODEC_ID_BINTEXT
@ AV_CODEC_ID_BINTEXT
Definition: codec_id.h:606
cga_data.h
FONT_WIDTH
#define FONT_WIDTH
Definition: bintext.c:42
a
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:41
attributes.h
xga_font_data.h
ff_xbin_decoder
const FFCodec ff_xbin_decoder
ff_bintext_decoder
const FFCodec ff_bintext_decoder
XbinContext
Definition: bintext.c:44
AVCodecContext::extradata
uint8_t * extradata
Out-of-band global headers that may be used by some codecs.
Definition: avcodec.h:522
bintext.h
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:179
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
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:84
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:265
XbinContext::font
const uint8_t * font
Definition: bintext.c:49
AVCodecContext
main external API structure.
Definition: avcodec.h:439
BINTEXT_FONT
#define BINTEXT_FONT
Definition: bintext.h:35
Windows::Graphics::DirectX::Direct3D11::p
IDirect3DDxgiInterfaceAccess _COM_Outptr_ void ** p
Definition: vsrc_gfxcapture_winrt.hpp:53
AV_CODEC_ID_XBIN
@ AV_CODEC_ID_XBIN
Definition: codec_id.h:607
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
XbinContext::font_height
int font_height
Definition: bintext.c:48
XbinContext::frame
AVFrame * frame
Definition: bintext.c:45
AVPacket
This structure stores compressed data.
Definition: packet.h:572
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:466
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:600
ff_idf_decoder
const FFCodec ff_idf_decoder
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB24
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:97
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