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#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "ttxtsubsfilter.h"
#include "teletext.h"
cTtxtSubsFilter::cTtxtSubsFilter(void)
:
mCount(0),
mPages(0)
{
int i;
for(i = 0; i < 8; i++)
mMagPage[i] = -1;
}
cTtxtSubsFilter::~cTtxtSubsFilter(void)
{
FreePages();
}
void cTtxtSubsFilter::SetPages(size_t count, uint16_t *pages)
{
FreePages();
mPages = (uint16_t *) malloc(count * sizeof(uint16_t));
memcpy((char *) mPages, (char *) pages, count * sizeof(uint16_t));
mCount = count;
if(0) {
fprintf(stderr, "SetPages: %d, ", count);
for(size_t i = 0; i < count; i++)
fprintf(stderr, "%03x ", pages[i]);
fprintf(stderr, "\n");
}
}
// XXX IF MERGING PAGES FROM SEVERAL PIDS (which we currently don't)
// Need to insert a line Y0 if
// - there has been data from other streams inserted and the next line is not a Y0
// there has been data from other magazines and the next line for this mag is not a Y0
// indata and outdata are pointers to a ttxt data row buffers,
// if return value <> 0 outdata countains data to pass on
int cTtxtSubsFilter::Filter(char *indata, char *outdata)
{
int mp;
int mag; // X in ETSI EN 300 706
int packet; // Y
int result = 0;
struct ttxt_data_field *d = (struct ttxt_data_field *) indata;
mp = UNHAM_INV(d->mag_addr_ham[0], d->mag_addr_ham[1]);
mag = mp & 0x7;
packet = (mp >> 3) & 0x1f;
if (0) { // XXX
uint8_t buf[2];
ham8_4byte(mp, buf);
fprintf(stderr, "unham %02x %02x -> %02x, ham: %02x %02x\n",
invtab[d->mag_addr_ham[0]], invtab[d->mag_addr_ham[1]],
mp,
buf[0], buf[1]);
}
// packet 0, change page no in this magazine
if(packet == 0) {
uint8_t no;
int newindex;
no = UNHAM_INV(d->data[0], d->data[1]);
mMagPage[mag] = newindex = Find(mCount, mPages, (mag << 8) | no);
if(newindex != -1) {
//fprintf(stderr, "Filter: %x%02x (%d)\n", mag, no, newindex); // XXX
MakeY0(outdata, indata, mPages[newindex]);
result = 1;
}
} else if(packet >= 1 && packet <= 25) {
if(mMagPage[mag] != -1) {
memcpy(outdata, indata, sizeof(ttxt_data_field));
result = 1;
}
}
return result;
}
void cTtxtSubsFilter::FreePages(void)
{
mCount = 0;
if(mPages) {
free(mPages);
mPages = NULL;
}
}
int cTtxtSubsFilter::Find(int count, uint16_t *pages, uint16_t pageno){
int i;
for(i = 0; i < count; i++) {
if(pages[i] == pageno)
return i;
}
return -1;
}
// make a new Y0 line with the flags in
void cTtxtSubsFilter::MakeY0(char *outdata, char *indata, uint16_t newpageno)
{
struct ttxt_data_field *i = (struct ttxt_data_field *) indata;
struct ttxt_data_field *o = (struct ttxt_data_field *) outdata;
uint8_t hambuf[2];
o->data_unit_id = 3; // EBU Teletxt subtitle data
o->data_unit_length = 44;
o->par_loff = 0xc0; // reserved bits + unknown line
o->framing_code = 0xe4;
// new magazine number (Y = 0)
ham8_4byte((newpageno >> 8) & 0x7, hambuf);
o->mag_addr_ham[0] = invtab[hambuf[0]];
o->mag_addr_ham[1] = invtab[hambuf[1]];
// new page number
ham8_4byte(newpageno & 0xff, hambuf);
o->data[0] = invtab[hambuf[0]];
o->data[1] = invtab[hambuf[1]];
// copy flags
memcpy(o->data + 2, i->data + 2, 6);
// new text
unsigned char txtbuf[32];
size_t txtlen;
size_t n;
txtlen = snprintf((char *) txtbuf, 32, "%03x", newpageno < 0x100 ? newpageno + 0x800 : newpageno);
for(n = 0; n < txtlen; n++) {
if(parity(txtbuf[n]))
o->data[n + 8] = invtab[txtbuf[n] | 0x80]; // XXX wrong parity?
else
o->data[n + 8] = invtab[txtbuf[n]]; // XXX wrong parity?
}
for(; n < 32; n++)
o->data[n + 8] = invtab[(unsigned char) ' ']; // space already has right parity
}
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