The attachment contains a diff file modifying mplayer.c, cfg-common.h,
libmpdemux/video.c, and adding 2 new files (sub_cc.c and sub_cc.h) in
order to support Closed Captions. I must admit the support is quite
preliminary, but I've found it usable (at least on the only 3 DVDs i
could test it on..).
The modification to cfg-common.h adds a "-subcc" commandline switch to
enable the CC decoder.
This is the first MPlayer patch I submit, and as I said the support is
preliminary. A cleaner solution would definitely be writing a new OSD
renderer for closed captions, in order to support color/background and
so on. For the time being I used the existing subtitle OSD type, thus
decoding only text, and discarding the rest.
Cheers.
Matteo Giani
--- old/mplayer.c 2002-07-19 22:51:34.000000000 +0200
+++ mplayer.c 2002-07-20 21:41:45.000000000 +0200
@@ -26,6 +26,8 @@
#define HELP_MP_DEFINE_STATIC
#include "help_mp.h"
+#include "sub_cc.h"
+
#include "cfgparser.h"
#include "cfg-mplayer-def.h"
--- old/sub_cc.h 1970-01-01 01:00:00.000000000 +0100
+++ sub_cc.h 2002-07-19 17:54:35.000000000 +0200
@@ -0,0 +1,8 @@
+#ifndef SUB_CC_H
+#define SUB_CC_H
+
+extern int subcc_enabled;
+
+extern void subcc_process_data(unsigned char *inputdata,unsigned int len);
+
+#endif /*SUB_CC_H*/
--- old/sub_cc.c 1970-01-01 01:00:00.000000000 +0100
+++ sub_cc.c 2002-07-21 23:43:02.000000000 +0200
@@ -0,0 +1,293 @@
+/*
+ * 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];
+
+int subcc_enabled=0;
+
+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();
+}
+
+
--- old/libmpdemux/video.c 2002-06-27 12:12:31.000000000 +0200
+++ libmpdemux/video.c 2002-07-23 11:03:02.000000000 +0200
@@ -19,6 +19,9 @@
#include "parse_es.h"
#include "mpeg_hdr.h"
+/* sub_cc (closed captions)*/
+#include "../sub_cc.h"
+
/* biCompression constant */
#define BI_RGB 0L
@@ -184,11 +187,19 @@
static void process_userdata(unsigned char* buf,int len){
int i;
+ if(!memcmp(buf,"CC",2)) /* if the user data starts with "CC", assume it is a CC info packet */
+ {
+ if(verbose)printf("video.c: process_userdata() detected Closed Captions!\n");
+ if(subcc_enabled) subcc_process_data(buf+2,len-2);
+ }
+ if(verbose)
+ {
printf( "user_data: len=%3d %02X %02X %02X %02X '",
len, buf[0], buf[1], buf[2], buf[3]);
for(i=0;i<len;i++)
if(buf[i]>=32 && buf[i]<127) putchar(buf[i]);
printf("'\n");
+ }
}
int video_read_frame(sh_video_t* sh_video,float* frame_time_ptr,unsigned char** start,int force_fps){
@@ -234,7 +245,7 @@
switch(i){
case 0x1B3: mp_header_process_sequence_header (&picture, &videobuffer[start]);break;
case 0x1B5: mp_header_process_extension (&picture, &videobuffer[start]);break;
- case 0x1B2: if(verbose) process_userdata (&videobuffer[start], videobuf_len-start);break;
+ case 0x1B2: process_userdata (&videobuffer[start], videobuf_len-start);break;
}
}
--- old/cfg-common.h 2002-07-20 15:53:40.000000000 +0200
+++ cfg-common.h 2002-07-20 21:41:41.000000000 +0200
@@ -2,6 +2,9 @@
// ------------------------- stream options --------------------
+
+
+
#ifdef USE_STREAM_CACHE
{"cache", &stream_cache_size, CONF_TYPE_INT, CONF_RANGE, 4, 65536, NULL},
{"nocache", &stream_cache_size, CONF_TYPE_FLAG, 0, 1, 0, NULL},
@@ -163,6 +166,11 @@
{"subpos", &sub_pos, CONF_TYPE_INT, CONF_RANGE, 0, 100, NULL},
#endif
+#ifdef SUB_CC_H
+ {"subcc", &subcc_enabled, CONF_TYPE_FLAG, 0, 0, 1, NULL},
+#endif
+
+
#else
#include "config.h"
--- old/Makefile 2002-07-10 22:56:50.000000000 +0200
+++ Makefile 2002-07-19 17:56:08.000000000 +0200
@@ -31,7 +31,7 @@
# a BSD compatible 'install' program
INSTALL = install
-SRCS_COMMON = xacodec.c cpudetect.c codec-cfg.c cfgparser.c my_profile.c spudec.c playtree.c playtreeparser.c asxparser.c vobsub.c subreader.c find_sub.c
+SRCS_COMMON = xacodec.c cpudetect.c codec-cfg.c cfgparser.c my_profile.c spudec.c playtree.c playtreeparser.c asxparser.c vobsub.c subreader.c sub_cc.c find_sub.c
SRCS_MENCODER = mencoder.c mp_msg-mencoder.c $(SRCS_COMMON) libao2/afmt.c divx4_vbr.c libvo/aclib.c libvo/osd.c libvo/sub.c libvo/font_load.c me-opt-reg.c
SRCS_MPLAYER = mplayer.c mp_msg.c $(SRCS_COMMON) lirc_mp.c mixer.c mp-opt-reg.c
