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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"
32 #include "libavutil/xga_font_data.h"
33 #include "avcodec.h"
34 #include "cga_data.h"
35 #include "bintext.h"
36 #include "internal.h"
37 
38 typedef struct XbinContext {
39  AVFrame *frame;
40  int palette[16];
41  int flags;
42  int font_height;
43  const uint8_t *font;
44  int x, y;
45 } XbinContext;
46 
47 static av_cold int decode_init(AVCodecContext *avctx)
48 {
49  XbinContext *s = avctx->priv_data;
50  uint8_t *p;
51  int i;
52 
53  avctx->pix_fmt = AV_PIX_FMT_PAL8;
54  p = avctx->extradata;
55  if (p) {
56  s->font_height = p[0];
57  s->flags = p[1];
58  p += 2;
59  if(avctx->extradata_size < 2 + (!!(s->flags & BINTEXT_PALETTE))*3*16
60  + (!!(s->flags & BINTEXT_FONT))*s->font_height*256) {
61  av_log(avctx, AV_LOG_ERROR, "not enough extradata\n");
62  return AVERROR_INVALIDDATA;
63  }
64  } else {
65  s->font_height = 8;
66  s->flags = 0;
67  }
68 
69  if ((s->flags & BINTEXT_PALETTE)) {
70  for (i = 0; i < 16; i++) {
71  s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
72  p += 3;
73  }
74  } else {
75  for (i = 0; i < 16; i++)
76  s->palette[i] = 0xFF000000 | ff_cga_palette[i];
77  }
78 
79  if ((s->flags & BINTEXT_FONT)) {
80  s->font = p;
81  } else {
82  switch(s->font_height) {
83  default:
84  av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
85  s->font_height = 8;
86  case 8:
87  s->font = avpriv_cga_font;
88  break;
89  case 16:
90  s->font = avpriv_vga16_font;
91  break;
92  }
93  }
94 
95  s->frame = av_frame_alloc();
96  if (!s->frame)
97  return AVERROR(ENOMEM);
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],
112  DEFAULT_BG_COLOR, s->font_height * s->frame->linesize[0]);
113  }
114 }
115 
116 #define FONT_WIDTH 8
117 
118 /**
119  * Draw character to screen
120  */
121 static void draw_char(AVCodecContext *avctx, int c, int a)
122 {
123  XbinContext *s = avctx->priv_data;
124  if (s->y > avctx->height - s->font_height)
125  return;
126  ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
127  s->frame->linesize[0], s->font, s->font_height, c,
128  a & 0x0F, a >> 4);
129  s->x += FONT_WIDTH;
130  if (s->x > avctx->width - FONT_WIDTH) {
131  s->x = 0;
132  s->y += s->font_height;
133  }
134 }
135 
136 static int decode_frame(AVCodecContext *avctx,
137  void *data, int *got_frame,
138  AVPacket *avpkt)
139 {
140  XbinContext *s = avctx->priv_data;
141  const uint8_t *buf = avpkt->data;
142  int buf_size = avpkt->size;
143  const uint8_t *buf_end = buf+buf_size;
144  int ret;
145 
146  s->x = s->y = 0;
147  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
148  return ret;
149  s->frame->pict_type = AV_PICTURE_TYPE_I;
150  s->frame->palette_has_changed = 1;
151  memcpy(s->frame->data[1], s->palette, 16 * 4);
152 
153  if (avctx->codec_id == AV_CODEC_ID_XBIN) {
154  while (buf + 2 < buf_end) {
155  int i,c,a;
156  int type = *buf >> 6;
157  int count = (*buf & 0x3F) + 1;
158  buf++;
159  switch (type) {
160  case 0: //no compression
161  for (i = 0; i < count && buf + 1 < buf_end; i++) {
162  draw_char(avctx, buf[0], buf[1]);
163  buf += 2;
164  }
165  break;
166  case 1: //character compression
167  c = *buf++;
168  for (i = 0; i < count && buf < buf_end; i++)
169  draw_char(avctx, c, *buf++);
170  break;
171  case 2: //attribute compression
172  a = *buf++;
173  for (i = 0; i < count && buf < buf_end; i++)
174  draw_char(avctx, *buf++, a);
175  break;
176  case 3: //character/attribute compression
177  c = *buf++;
178  a = *buf++;
179  for (i = 0; i < count && buf < buf_end; i++)
180  draw_char(avctx, c, a);
181  break;
182  }
183  }
184  } else if (avctx->codec_id == AV_CODEC_ID_IDF) {
185  while (buf + 2 < buf_end) {
186  if (AV_RL16(buf) == 1) {
187  int i;
188  if (buf + 6 > buf_end)
189  break;
190  for (i = 0; i < buf[2]; i++)
191  draw_char(avctx, buf[4], buf[5]);
192  buf += 6;
193  } else {
194  draw_char(avctx, buf[0], buf[1]);
195  buf += 2;
196  }
197  }
198  } else {
199  while (buf + 1 < buf_end) {
200  draw_char(avctx, buf[0], buf[1]);
201  buf += 2;
202  }
203  }
204 
205  if ((ret = av_frame_ref(data, s->frame)) < 0)
206  return ret;
207  *got_frame = 1;
208  return buf_size;
209 }
210 
211 static av_cold int decode_end(AVCodecContext *avctx)
212 {
213  XbinContext *s = avctx->priv_data;
214 
215  av_frame_free(&s->frame);
216 
217  return 0;
218 }
219 
220 #if CONFIG_BINTEXT_DECODER
221 AVCodec ff_bintext_decoder = {
222  .name = "bintext",
223  .type = AVMEDIA_TYPE_VIDEO,
224  .id = AV_CODEC_ID_BINTEXT,
225  .priv_data_size = sizeof(XbinContext),
226  .init = decode_init,
227  .close = decode_end,
228  .decode = decode_frame,
229  .capabilities = CODEC_CAP_DR1,
230  .long_name = NULL_IF_CONFIG_SMALL("Binary text"),
231 };
232 #endif
233 #if CONFIG_XBIN_DECODER
234 AVCodec ff_xbin_decoder = {
235  .name = "xbin",
236  .type = AVMEDIA_TYPE_VIDEO,
237  .id = AV_CODEC_ID_XBIN,
238  .priv_data_size = sizeof(XbinContext),
239  .init = decode_init,
240  .close = decode_end,
241  .decode = decode_frame,
242  .capabilities = CODEC_CAP_DR1,
243  .long_name = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
244 };
245 #endif
246 #if CONFIG_IDF_DECODER
247 AVCodec ff_idf_decoder = {
248  .name = "idf",
249  .type = AVMEDIA_TYPE_VIDEO,
250  .id = AV_CODEC_ID_IDF,
251  .priv_data_size = sizeof(XbinContext),
252  .init = decode_init,
253  .close = decode_end,
254  .decode = decode_frame,
255  .capabilities = CODEC_CAP_DR1,
256  .long_name = NULL_IF_CONFIG_SMALL("iCEDraw text"),
257 };
258 #endif
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