DVD Closed Captioning support, patch by Matteo Giani <matgiani@ctonet.it>, small changes by me.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@6785 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 292 insertions, 0 deletions

diff --git a/sub_cc.c b/sub_cc.c
new file mode 100644
index 0000000000..2557205722
--- /dev/null
+++ b/sub_cc.c
@@ -0,0 +1,292 @@
+/*
+ * sub_cc.c - Decoder for Closed Captions
+ *
+ * This decoder relies on MPlayer's OSD to display subtitles.
+ * Be warned that the decoding is somewhat preliminary, though it basically works.
+ * 
+ * Most notably, only the text information is decoded as of now, discarding color,
+ * background and position info (see source below).
+ * 
+ * by Matteo Giani
+ *
+ * uses source from the xine closed captions decoder
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "subreader.h"
+
+#include "libvo/video_out.h"
+#include "libvo/sub.h"
+
+
+#define CC_INPUTBUFFER_SIZE 256
+
+#define CC_MAX_LINE_LENGTH 64
+
+static char chartbl[128];
+
+extern int subcc_enabled;
+
+subtitle buf1,buf2;
+subtitle *fb,*bb;
+
+static unsigned int cursor_pos=0;
+
+static int inited=0;
+static unsigned char inputbuffer[CC_INPUTBUFFER_SIZE];
+static unsigned int inputlength;
+
+static void build_char_table(void)
+{
+  int i;
+  /* first the normal ASCII codes */
+  for (i = 0; i < 128; i++)
+    chartbl[i] = (char) i;
+  /* now the special codes */
+  chartbl[0x2a] = 'á';
+  chartbl[0x5c] = 'é';
+  chartbl[0x5e] = 'í';
+  chartbl[0x5f] = 'ó';
+  chartbl[0x60] = 'ú';
+  chartbl[0x7b] = 'ç';
+  chartbl[0x7c] = '÷';
+  chartbl[0x7d] = 'Ñ';
+  chartbl[0x7e] = 'ñ';
+  chartbl[0x7f] = '¤';    /* FIXME: this should be a solid block */
+}
+
+void clear_buffer(subtitle *buf)
+{
+	int i;
+	buf->lines=0;
+	for(i=0;i<SUB_MAX_TEXT;i++) if(buf->text[i]) {free(buf->text[i]);buf->text[i]=NULL;}
+}
+
+
+void subcc_init()
+{
+	int i;
+	//printf("subcc_init(): initing...\n");
+	build_char_table();
+	for(i=0;i<SUB_MAX_TEXT;i++) {buf1.text[i]=buf2.text[i]=NULL;}
+	buf1.lines=buf2.lines=0;
+	fb=&buf1;
+	bb=&buf2;
+	
+	inited=1;
+}
+
+static void append_char(char c)
+{
+	if(!bb->lines) {bb->lines++; cursor_pos=0;}
+	if(bb->text[bb->lines - 1]==NULL) 
+	{
+		bb->text[bb->lines - 1]=malloc(CC_MAX_LINE_LENGTH);
+		memset(bb->text[bb->lines - 1],0,CC_MAX_LINE_LENGTH);
+		cursor_pos=0;
+	}
+	
+	if(c=='\n')
+	{
+		if(cursor_pos>0)
+			bb->lines++;cursor_pos=0;
+	}
+	else 
+	{
+		if(cursor_pos==CC_MAX_LINE_LENGTH-1)
+		{
+			printf("sub_cc.c: append_char() reached CC_MAX_LINE_LENGTH!\n");
+			return;
+		}
+		bb->text[bb->lines - 1][cursor_pos++]=c;
+	}
+}
+
+
+static void swap_buffers()
+{
+	subtitle *foo;
+	foo=fb;
+	fb=bb;
+	bb=foo;
+}
+
+static void display_buffer(subtitle * buf)
+{
+	vo_sub=buf;
+	vo_osd_changed(OSDTYPE_SUBTITLE);
+}
+
+
+static void cc_decode_EIA608(unsigned short int data)
+{
+  
+  static unsigned short int lastcode=0x0000;	
+  unsigned char c1 = data & 0x7f;
+  unsigned char c2 = (data >> 8) & 0x7f;
+
+  if (c1 & 0x60) {		/* normal character, 0x20 <= c1 <= 0x7f */
+	   append_char(chartbl[c1]);
+	   if(c2 & 0x60)	/*c2 might not be a normal char even if c1 is*/
+		   append_char(chartbl[c2]);
+  }
+  else if (c1 & 0x10)		// control code / special char
+  {
+	  int channel= (c1 & 0x08) >> 3;
+	  c1&=~0x08;
+	  if(data!=lastcode)
+	  {
+	  	if(c2 & 0x40) {	/*PAC, Preamble Address Code */
+			append_char('\n'); /*FIXME properly interpret PACs*/
+		}
+		else
+			switch(c1)
+			{
+				case 0x10:	break; // ext attribute
+				case 0x11: 
+					if((c2 & 0x30)==0x30) 
+					{
+						//printf("[debug]:Special char (ignored)\n");
+						/*cc_decode_special_char()*/;
+					}
+					else if (c2 & 0x20) 
+					{
+						//printf("[debug]: midrow_attr (ignored)\n");
+						/*cc_decode_midrow_attr()*/;
+					}
+					break;
+				case 0x14:
+					switch(c2)
+					{
+						case 0x2C: display_buffer(NULL); //EDM
+							   clear_buffer(fb); break;
+						case 0x2d: append_char('\n');	//carriage return
+							   break;
+						case 0x2e: clear_buffer(bb);	//ENM
+							   break;
+						case 0x2f: swap_buffers();	//Swap buffers
+							   display_buffer(fb);
+							   clear_buffer(bb);
+							   break;
+					}
+					break;
+				case 0x17:
+					if( c2>=0x21 && c2<=0x23) //TAB
+					{
+						break;
+					}
+			}
+	  }
+  } 
+  lastcode=data;  
+}
+
+void subcc_decode()
+{
+  /* The first number may denote a channel number. I don't have the
+   * EIA-708 standard, so it is hard to say.
+   * From what I could figure out so far, the general format seems to be:
+   *
+   * repeat
+   *
+   *   0xfe starts 2 byte sequence of unknown purpose. It might denote
+   *        field #2 in line 21 of the VBI. We'll ignore it for the
+   *        time being.
+   *
+   *   0xff starts 2 byte EIA-608 sequence, field #1 in line 21 of the VBI.
+   *        Followed by a 3-code triplet that starts either with 0xff or
+   *        0xfe. In either case, the following triplet needs to be ignored
+   *        for line 21, field 1.
+   *
+   *   0x00 is padding, followed by 2 more 0x00.
+   *
+   *   0x01 always seems to appear at the beginning, always seems to
+   *        be followed by 0xf8, 8-bit number. 
+   *        The lower 7 bits of this 8-bit number seem to denote the
+   *        number of code triplets that follow.
+   *        The most significant bit denotes whether the Line 21 field 1 
+   *        captioning information is at odd or even triplet offsets from this
+   *        beginning triplet. 1 denotes odd offsets, 0 denotes even offsets.
+   *      
+   *        Most captions are encoded with odd offsets, so this is what we
+   *        will assume.
+   *
+   * until end of packet
+   */
+  unsigned char *current = inputbuffer;
+  unsigned int curbytes = 0;
+  unsigned char data1, data2;
+  unsigned char cc_code;
+  int odd_offset = 1;
+
+  while (curbytes < inputlength) {
+    int skip = 2;
+
+    cc_code = *(current);
+
+    if (inputlength - curbytes < 2) {
+#ifdef LOG_DEBUG
+      fprintf(stderr, "Not enough data for 2-byte CC encoding\n");
+#endif
+      break;
+    }
+    
+    data1 = *(current+1);
+    data2 = *(current + 2);
+    current++; curbytes++;
+    
+    switch (cc_code) {
+    case 0xfe:
+      /* expect 2 byte encoding (perhaps CC3, CC4?) */
+      /* ignore for time being */
+      skip = 2;
+      break;
+      
+    case 0xff:
+      /* expect EIA-608 CC1/CC2 encoding */
+      // FIXME check parity!
+      // Parity check omitted assuming we are reading from a DVD and therefore
+      // we should encounter no "transmission errors".
+      cc_decode_EIA608(data1 | (data2 << 8));
+      skip = 5;
+      break;
+      
+    case 0x00:
+      /* This seems to be just padding */
+      skip = 2;
+      break;
+      
+    case 0x01:
+      odd_offset = data2 & 0x80;
+      if (odd_offset)
+	skip = 2;
+      else
+	skip = 5;
+      break;
+      
+    default:
+//#ifdef LOG_DEBUG
+      fprintf(stderr, "Unknown CC encoding: %x\n", cc_code);
+//#endif
+      skip = 2;
+      break;
+    }
+    current += skip;
+    curbytes += skip;
+  }
+}
+
+
+void subcc_process_data(unsigned char *inputdata,unsigned int len)
+{
+	if(!subcc_enabled) return;
+	if(!inited) subcc_init();
+	
+	memcpy(inputbuffer,inputdata,len);
+	inputlength=len;
+	subcc_decode();
+}
+