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Extract teletext subtitles and convert into UTF-8 text.

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Ticket #147
This commit is contained in:
Andreas Öman 2010-10-26 17:53:36 +00:00
parent 2f8724de87
commit f96428ca8a
4 changed files with 177 additions and 5 deletions
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6
src/parsers.c
View file

@ -1182,6 +1182,12 @@ parse_subtitles(th_transport_t *t, th_stream_t *st, const uint8_t *data,
static void
parser_deliver(th_transport_t *t, th_stream_t *st, th_pkt_t *pkt)
{
if(SCT_ISAUDIO(st->st_type) && pkt->pkt_pts != PTS_UNSET &&
(t->tht_current_pts == PTS_UNSET ||
pkt->pkt_pts > t->tht_current_pts ||
pkt->pkt_pts < t->tht_current_pts - 180000))
t->tht_current_pts = pkt->pkt_pts;
#if 0
printf("PARSE: %-12s %d %10"PRId64" %10"PRId64" %10d %10d\n",
streaming_component_type2txt(st->st_type),

164
src/teletext.c
View file

@ -31,12 +31,16 @@
#include "tvhead.h"
#include "teletext.h"
#include "transports.h"
#include "packet.h"
#include "streaming.h"
/**
*
*/
typedef struct tt_mag {
int ttm_curpage;
uint8_t ttm_lang;
uint8_t ttm_page[23*40 + 1];
} tt_mag_t;
@ -95,6 +99,79 @@ static const uint8_t hamtable[] = {
0xff, 0x0e, 0x0f, 0xff, 0x0e, 0x8e, 0xff, 0x0e,
};
static const uint8_t laG0_nat_opts_lookup[16][8] = {
{1, 4, 11, 5, 3, 8, 0, 1},
{7, 4, 11, 5, 3, 1, 0, 1},
{1, 4, 11, 5, 3, 8, 12, 1},
{1, 1, 1, 1, 1, 10, 1, 9},
{1, 4, 2, 6, 1, 1, 0, 1},
{1, 1, 1, 1, 1, 1, 1, 1}, // 5 - reserved
{1, 1, 1, 1, 1, 1, 12, 1},
{1, 1, 1, 1, 1, 1, 1, 1}, // 7 - reserved
{1, 1, 1, 1, 3, 1, 1, 1},
{1, 1, 1, 1, 1, 1, 1, 1}, // 9 - reserved
{1, 1, 1, 1, 1, 1, 1, 1},
{1, 1, 1, 1, 1, 1, 1, 1}, // 11 - reserved
{1, 1, 1, 1, 1, 1, 1, 1}, // 12 - reserved
{1, 1, 1, 1, 1, 1, 1, 1}, // 13 - reserved
{1, 1, 1, 1, 1, 1, 1, 1}, // 14 - reserved
{1, 1, 1, 1, 1, 1, 1, 1} // 15 - reserved
};
static const uint8_t laG0_nat_replace_map[128] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 5, 6, 7, 8,
9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 11, 12, 13, 0
};
/*
* Latin National Option Sub-Sets
* ETSI EN 300 706 Table 36
*/
static const uint16_t laG0_nat_opts16[13][14] = {
{0, '#', 'u', 'c', 't', 'z', 0xc3bd, 0xc3ad, 'r', 0xc3a9, 0xc3a1, 'e', 0xc3ba, 's' }, // 0 - Czech/Slovak
{0, 0xc2a3, '$', '@', '-', 0xc2bd, '-', '|', '#', '-', 0xc2bc, '#', 0xc2be, 0xc3b7}, // 1 - English
{0, '#', 0xc3b5, 'S', 0xc384, 0xc396, 'Z', 0xc39c, 0xc395, 's', 0xc3a4, 0xc3b6, 'z', 0xc3bc}, // 2 - Estonian
{0, 0xc3a9, 0xc3af, 0xc3a0, 0xc3ab, 0xc3aa, 0xc3b9, 0xc3ae, '#', 0xc3a8, 0xc3a2, 0xc3b4, 0xc3bb, 0xc3a7}, // 3 - French
{0, '#', '$', 0xc2a7, 0xc384, 0xc396, 0xc39c, '^', '_', 0xc2ba, 0xc3a4, 0xc3b6, 0xc3bc, 0xc39f}, // 4 - German
{0, 0xc2a3, '$', 0xc3a9, 0xc2ba, 0xc3a7, '-', '|', '#', 0xc3b9, 0xc3a0, 0xc3b2, 0xc3a8, 0xc3ac}, // 5 - Italian
{0, '#', '$', 'S', 'e', 'e', 'Z', 'c', 'u', 's', 'a', 'u', 'z', 'i' }, // 6 - Lettish/Lithuanian
{0, '#', 'n', 'a', 'Z', 'S', 'L', 'c', 0xc3b3, 'e', 'z', 's', 'l', 'z' }, // 7 - Polish
{0, 0xc3a7, '$', 'i', 0xc3a1, 0xc3a9, 0xc3ad, 0xc3b3, 0xc3ba, 0xc2bf, 0xc3bc, 0xc3b1, 0xc3a8, 0xc3a0}, // 8 - Portuguese/Spanish
{0, '#', 0xc2a4, 'T', 0xc382, 'S', 'A', 0xc38e, 'i', 't', 0xc3a2, 's', 'a', 0xc3ae}, // 9 - Rumanian
{0, '#', 0xc38b, 'C', 'C', 'Z', 'D', 'S', 0xc3ab, 'c', 'c', 'z', 'd', 's' }, // 10 - Serbian/Croation/Slovenian
{0, '#', 0xc2a4, 0xc389, 0xc384, 0xc396, 0xc385, 0xc39c, '_', 0xc3a9, 0xc3a4, 0xc3b6, 0xc3a5, 0xc3bc}, // 11 - Swedish/Finnish/Hungarian
{0, 'T', 'g', 'I', 'S', 0xc396, 0xc387, 0xc39c, 'G', 'i', 's', 0xc3b6, 0xc3a7, 0xc3bc} // 12 - Turkish
};
/*
* Map Latin G0 teletext characters into a ISO-8859-1 approximation.
* Trying to use similar looking or similar meaning characters.
* Gtriplet - 4 bits = triplet-1 bits 14-11 (14-8) of a X/28 or M/29 packet, if unknown - use 0
* natopts - 3 bits = national_options field of a Y/0 packet (or triplet-1 bits 10-8 as above?)
* inchar - 7 bits = characted to remap
* Also strips parity
*/
static uint16_t
tt_convert_char(int Gtriplet, int natopts, uint8_t inchar)
{
int no = laG0_nat_opts_lookup[Gtriplet & 0xf][natopts & 0x7];
uint8_t c = inchar & 0x7f;
if(!laG0_nat_replace_map[c])
return c;
else
return laG0_nat_opts16[no][laG0_nat_replace_map[c]];
}
static uint8_t
ham_decode(uint8_t a, uint8_t b)
{
@ -180,6 +257,69 @@ update_tt_clock(th_transport_t *t, const uint8_t *buf)
}
static void
extract_subtitle(th_transport_t *t, th_stream_t *st,
tt_mag_t *ttm, int64_t pts)
{
int i, j, off = 0;
uint8_t sub[2000];
int is_box = 0;
for (i = 0; i < 23; i++) {
int anything = 0;
for (j = 0; j < 40; j++) {
char ch = ttm->ttm_page[40 * i + j];
switch(ch) {
case 0 ... 7:
break;
case 0x0a:
is_box = 0;
break;
case 0x0b:
is_box = 1;
break;
default:
if (ch >= 0x20 && is_box) {
uint16_t code = tt_convert_char(0, ttm->ttm_lang, ch);
if(code & 0xff00)
sub[off++] = (code & 0xff00) >> 8;
sub[off++] = code;
anything |= ch != 0x20;
}
}
}
if(anything)
sub[off++] = '\n';
}
if(off == 0 && st->st_blank)
return; // Avoid multiple blank subtitles
st->st_blank = !off;
if(st->st_curpts == pts)
pts++; // Avoid non-monotonic PTS
st->st_curpts = pts;
sub[off++] = 0;
th_pkt_t *pkt = pkt_alloc(sub, off, pts, pts);
pkt->pkt_componentindex = st->st_index;
streaming_message_t *sm = streaming_msg_create_pkt(pkt);
streaming_pad_deliver(&t->tht_streaming_pad, sm);
streaming_msg_free(sm);
/* Decrease our own reference to the packet */
pkt_ref_dec(pkt);
}
/**
*
@ -211,6 +351,23 @@ dump_page(tt_mag_t *ttm)
}
#endif
static void
tt_subtitle_deliver(th_transport_t *t, th_stream_t *parent, tt_mag_t *ttm)
{
th_stream_t *st;
if(t->tht_current_pts == PTS_UNSET)
return;
TAILQ_FOREACH(st, &t->tht_components, st_link) {
if(parent->st_pid == st->st_parent_pid &&
ttm->ttm_curpage == st->st_pid - PID_TELETEXT_BASE) {
extract_subtitle(t, st, ttm, t->tht_current_pts);
}
}
}
/**
*
*/
@ -242,6 +399,7 @@ tt_decode_line(th_transport_t *t, th_stream_t *st, uint8_t *buf)
switch(line) {
case 0:
if(ttm->ttm_curpage != 0) {
tt_subtitle_deliver(t, st, ttm);
if(ttm->ttm_curpage == 192) {
// dump_page(ttm);
@ -264,7 +422,7 @@ tt_decode_line(th_transport_t *t, th_stream_t *st, uint8_t *buf)
s34 = ham_decode(buf[6], buf[7]);
c = ham_decode(buf[8], buf[9]);
// ttd->magazine_serial = c & 0x10 ? 1 : 0;
ttm->ttm_lang = c >> 5;
if(s12 & 0x80) {
/* Erase page */
@ -290,8 +448,6 @@ tt_decode_line(th_transport_t *t, th_stream_t *st, uint8_t *buf)
case 1 ... 23:
for(i = 0; i < 40; i++) {
c = buf[i + 2] & 0x7f;
if(c < 32)
c += 0x80;
ttm->ttm_page[i + 40 * (line - 1)] = c;
}
break;
@ -314,7 +470,7 @@ teletext_input(th_transport_t *t, th_stream_t *st, const uint8_t *tsb)
x = tsb + 4;
for(i = 0; i < 4; i++) {
if(*x == 2) {
if(*x == 2 || *x == 3) {
for(j = 0; j < 42; j++)
buf[j] = bitreverse(x[4 + j]);
tt_decode_line(t, st, buf);

5
src/transports.c
View file

@ -66,11 +66,13 @@ stream_init(th_stream_t *st)
st->st_curdts = PTS_UNSET;
st->st_curpts = PTS_UNSET;
st->st_prevdts = PTS_UNSET;
st->st_pcr_real_last = PTS_UNSET;
st->st_pcr_last = PTS_UNSET;
st->st_pcr_drift = 0;
st->st_pcr_recovery_fails = 0;
st->st_blank = 0;
}
@ -206,6 +208,7 @@ transport_start(th_transport_t *t, unsigned int weight, int force_start)
pthread_mutex_lock(&t->tht_stream_mutex);
t->tht_status = TRANSPORT_RUNNING;
t->tht_current_pts = PTS_UNSET;
/**
* Initialize stream

7
src/tvhead.h
View file

@ -463,6 +463,10 @@ typedef struct th_stream {
char *st_nicename;
/* Teletext subtitle */
char st_blank; // Last subtitle was blank
} th_stream_t;
@ -772,6 +776,9 @@ typedef struct th_transport {
loglimiter_t tht_loglimit_tei;
int64_t tht_current_pts;
} th_transport_t;
const char *streaming_component_type2txt(streaming_component_type_t s);