vo_mga: minor code cleanup
[mplayer.git] / sub_cc.c
blob51959e029a7dbdfd9425c2c424a07827eaafae00
1 /*
2 * decoder for Closed Captions
4 * This decoder relies on MPlayer's OSD to display subtitles.
5 * Be warned that decoding is somewhat preliminary, though it basically works.
7 * Most notably, only the text information is decoded as of now, discarding
8 * color, background and position info (see source below).
10 * uses source from the xine closed captions decoder
12 * Copyright (C) 2002 Matteo Giani
14 * This file is part of MPlayer.
16 * MPlayer is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * MPlayer is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License along
27 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
28 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
35 #include "config.h"
36 #include "sub_cc.h"
38 #include "subreader.h"
40 #include "libvo/video_out.h"
41 #include "libvo/sub.h"
44 #define CC_MAX_LINE_LENGTH 64
46 static char chartbl[128];
48 static subtitle buf1,buf2;
49 static subtitle *fb,*bb;
51 static unsigned int cursor_pos=0;
53 static int initialized=0;
55 #define CC_ROLLON 1
56 #define CC_ROLLUP 2
58 static int cc_mode=CC_ROLLON;
59 static int cc_lines=4; ///< number of visible rows in CC roll-up mode, not used in CC roll-on mode
61 static void build_char_table(void)
63 int i;
64 /* first the normal ASCII codes */
65 for (i = 0; i < 128; i++)
66 chartbl[i] = (char) i;
67 /* now the special codes */
68 chartbl[0x2a] = 'á';
69 chartbl[0x5c] = 'é';
70 chartbl[0x5e] = 'í';
71 chartbl[0x5f] = 'ó';
72 chartbl[0x60] = 'ú';
73 chartbl[0x7b] = 'ç';
74 chartbl[0x7c] = '÷';
75 chartbl[0x7d] = 'Ñ';
76 chartbl[0x7e] = 'ñ';
77 chartbl[0x7f] = '¤'; /* FIXME: this should be a solid block */
80 static void clear_buffer(subtitle *buf)
82 int i;
83 buf->lines=0;
84 for(i=0;i<SUB_MAX_TEXT;i++) if(buf->text[i]) {free(buf->text[i]);buf->text[i]=NULL;}
88 /**
89 \brief scroll buffer one line up
90 \param buf buffer to scroll
92 static void scroll_buffer(subtitle* buf)
94 int i;
96 while(buf->lines > cc_lines)
98 if(buf->text[0]) free(buf->text[0]);
100 for(i = 0; i < (buf->lines - 1); i++) buf->text[i] = buf->text[i+1];
102 buf->text[buf->lines-1] = NULL;
103 buf->lines--;
108 void subcc_init(void)
110 int i;
111 //printf("subcc_init(): initing...\n");
112 build_char_table();
113 for(i=0;i<SUB_MAX_TEXT;i++) {buf1.text[i]=buf2.text[i]=NULL;}
114 buf1.lines=buf2.lines=0;
115 fb=&buf1;
116 bb=&buf2;
118 initialized=1;
122 static void display_buffer(subtitle *buf)
124 vo_sub = buf;
125 vo_osd_changed(OSDTYPE_SUBTITLE);
129 static void append_char(char c)
131 if(!bb->lines) {bb->lines++; cursor_pos=0;}
132 if(bb->text[bb->lines - 1]==NULL)
134 bb->text[bb->lines - 1]=malloc(CC_MAX_LINE_LENGTH);
135 memset(bb->text[bb->lines - 1],0,CC_MAX_LINE_LENGTH);
136 cursor_pos=0;
139 if(c=='\n')
141 if(cursor_pos>0 && bb->lines < SUB_MAX_TEXT)
143 bb->lines++;cursor_pos=0;
144 if(cc_mode==CC_ROLLUP){ //Carriage return - scroll buffer one line up
145 bb->text[bb->lines - 1]=calloc(1, CC_MAX_LINE_LENGTH);
146 scroll_buffer(bb);
150 else
152 if(cursor_pos==CC_MAX_LINE_LENGTH-1)
154 fprintf(stderr,"CC: append_char() reached CC_MAX_LINE_LENGTH!\n");
155 return;
157 bb->text[bb->lines - 1][cursor_pos++]=c;
159 //In CC roll-up mode data should be shown immediately
160 if(cc_mode==CC_ROLLUP) display_buffer(bb);
164 static void swap_buffers(void)
166 subtitle *foo;
167 foo=fb;
168 fb=bb;
169 bb=foo;
173 static void cc_decode_EIA608(unsigned short int data)
176 static unsigned short int lastcode=0x0000;
177 unsigned char c1 = data & 0x7f;
178 unsigned char c2 = (data >> 8) & 0x7f;
180 if (c1 & 0x60) { /* normal character, 0x20 <= c1 <= 0x7f */
181 append_char(chartbl[c1]);
182 if(c2 & 0x60) /*c2 might not be a normal char even if c1 is*/
183 append_char(chartbl[c2]);
185 else if (c1 & 0x10) // control code / special char
187 // int channel= (c1 & 0x08) >> 3;
188 c1&=~0x08;
189 if(data!=lastcode)
191 if(c2 & 0x40) { /*PAC, Preamble Address Code */
192 append_char('\n'); /*FIXME properly interpret PACs*/
194 else
195 switch(c1)
197 case 0x10: break; // ext attribute
198 case 0x11:
199 if((c2 & 0x30)==0x30)
201 //printf("[debug]:Special char (ignored)\n");
202 /*cc_decode_special_char()*/;
204 else if (c2 & 0x20)
206 //printf("[debug]: midrow_attr (ignored)\n");
207 /*cc_decode_midrow_attr()*/;
209 break;
210 case 0x14:
211 switch(c2)
213 case 0x00: //CC roll-on mode
214 cc_mode=CC_ROLLON;
215 break;
216 case 0x25: //CC roll-up, 2 rows
217 case 0x26: //CC roll-up, 3 rows
218 case 0x27: //CC roll-up, 4 rows
219 cc_lines=c2-0x23;
220 cc_mode=CC_ROLLUP;
221 break;
222 case 0x2C: display_buffer(NULL); //EDM
223 clear_buffer(fb); break;
224 case 0x2d: append_char('\n'); //carriage return
225 break;
226 case 0x2e: clear_buffer(bb); //ENM
227 break;
228 case 0x2f: swap_buffers(); //Swap buffers
229 display_buffer(fb);
230 clear_buffer(bb);
231 break;
233 break;
234 case 0x17:
235 if( c2>=0x21 && c2<=0x23) //TAB
237 break;
242 lastcode=data;
245 static void subcc_decode(unsigned char *inputbuffer, unsigned int inputlength)
247 /* The first number may denote a channel number. I don't have the
248 * EIA-708 standard, so it is hard to say.
249 * From what I could figure out so far, the general format seems to be:
251 * repeat
253 * 0xfe starts 2 byte sequence of unknown purpose. It might denote
254 * field #2 in line 21 of the VBI. We'll ignore it for the
255 * time being.
257 * 0xff starts 2 byte EIA-608 sequence, field #1 in line 21 of the VBI.
258 * Followed by a 3-code triplet that starts either with 0xff or
259 * 0xfe. In either case, the following triplet needs to be ignored
260 * for line 21, field 1.
262 * 0x00 is padding, followed by 2 more 0x00.
264 * 0x01 always seems to appear at the beginning, always seems to
265 * be followed by 0xf8, 8-bit number.
266 * The lower 7 bits of this 8-bit number seem to denote the
267 * number of code triplets that follow.
268 * The most significant bit denotes whether the Line 21 field 1
269 * captioning information is at odd or even triplet offsets from this
270 * beginning triplet. 1 denotes odd offsets, 0 denotes even offsets.
272 * Most captions are encoded with odd offsets, so this is what we
273 * will assume.
275 * until end of packet
277 unsigned char *current = inputbuffer;
278 unsigned int curbytes = 0;
279 unsigned char data1, data2;
280 unsigned char cc_code;
281 int odd_offset = 1;
283 while (curbytes < inputlength) {
284 int skip = 2;
286 cc_code = *(current);
288 if (inputlength - curbytes < 2) {
289 #ifdef LOG_DEBUG
290 fprintf(stderr, "Not enough data for 2-byte CC encoding\n");
291 #endif
292 break;
295 data1 = *(current+1);
296 data2 = *(current + 2);
297 current++; curbytes++;
299 switch (cc_code) {
300 case 0xfe:
301 /* expect 2 byte encoding (perhaps CC3, CC4?) */
302 /* ignore for time being */
303 break;
305 case 0xff:
306 /* expect EIA-608 CC1/CC2 encoding */
307 // FIXME check parity!
308 // Parity check omitted assuming we are reading from a DVD and therefore
309 // we should encounter no "transmission errors".
310 cc_decode_EIA608(data1 | (data2 << 8));
311 skip = 5;
312 break;
314 case 0x00:
315 /* This seems to be just padding */
316 break;
318 case 0x01:
319 odd_offset = data2 & 0x80;
320 if (!odd_offset)
321 skip = 5;
322 break;
324 default:
325 //#ifdef LOG_DEBUG
326 fprintf(stderr, "Unknown CC encoding: %x\n", cc_code);
327 //#endif
328 break;
330 current += skip;
331 curbytes += skip;
336 void subcc_process_data(unsigned char *inputdata,unsigned int len)
338 if(!subcc_enabled) return;
339 if(!initialized) subcc_init();
341 subcc_decode(inputdata, len);