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Added Cyrillic support for Teletext #319

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Merged
merged 6 commits into from
Mar 13, 2016
Merged

Added Cyrillic support for Teletext #319

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2a58388
Partial fix for Cyrilic support
bigharshrag Mar 12, 2016
03b8f93
Partial fix for Cyrilic support
bigharshrag Mar 12, 2016
f3c386f
Clearer code
bigharshrag Mar 13, 2016
e8ae287
Testing first buffer error
bigharshrag Mar 13, 2016
5661e4f
Added Cyrilic support
bigharshrag Mar 13, 2016
d249b1c
Added Cyrillic support (+ removed debugging statements)
bigharshrag Mar 13, 2016
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76 changes: 58 additions & 18 deletions src/lib_ccx/telxcc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -196,8 +196,9 @@ typedef enum
GREEK,
ARABIC,
HEBREW
} g0_charsets_t;
} g0_charsets_type;

g0_charsets_type default_g0_charset;

// Note: All characters are encoded in UCS-2

Expand Down Expand Up @@ -503,6 +504,26 @@ uint32_t unham_24_18(uint32_t a)
return (a & 0x000004) >> 2 | (a & 0x000070) >> 3 | (a & 0x007f00) >> 4 | (a & 0x7f0000) >> 5;
}

//Default G0 Character Set
void set_g0_charset(uint32_t triplet)
{
// ETS 300 706, Table 32
if((triplet & 0x3c00) == 0x1000)
{
if((triplet & 0x0380) == 0x0000)
default_g0_charset = CYRILLIC1;
else if((triplet & 0x0380) == 0x0200)
default_g0_charset = CYRILLIC2;
else if((triplet & 0x0380) == 0x0280)
default_g0_charset = CYRILLIC3;
else
default_g0_charset = LATIN;
}
else
default_g0_charset = LATIN;
}

// Latin National Subset Selection
void remap_g0_charset(uint8_t c)
{
if (c != primary_charset.current)
Expand All @@ -523,7 +544,6 @@ void remap_g0_charset(uint8_t c)
}



// wide char (16 bits) to utf-8 conversion
void ucs2_to_utf8(char *r, uint16_t ch)
{
Expand Down Expand Up @@ -559,7 +579,7 @@ uint16_t telx_to_ucs2(uint8_t c)

uint16_t r = c & 0x7f;
if (r >= 0x20)
r = G0[LATIN][r - 0x20];
r = G0[default_g0_charset][r - 0x20];
return r;
}

Expand Down Expand Up @@ -896,6 +916,7 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele

if (y == 0)
{

// CC map
uint8_t i = (unham_8_4(packet->data[1]) << 4) | unham_8_4(packet->data[0]);
uint8_t flag_subtitle = (unham_8_4(packet->data[5]) & 0x08) >> 3;
Expand Down Expand Up @@ -953,29 +974,39 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele
if (page_number != tlt_config.page)
return;


// Now we have the begining of page transmission; if there is page_buffer pending, process it
if (ctx->page_buffer.tainted == YES)
{
// Convert telx to UCS-2 before processing
for(uint8_t yt = 1; yt <= 23; ++yt)
{
for(uint8_t it = 0; it < 40; it++)
{
if (ctx->page_buffer.text[yt][it] != 0x00)
ctx->page_buffer.text[yt][it] = telx_to_ucs2(ctx->page_buffer.text[yt][it]);
}
}
// it would be nice, if subtitle hides on previous video frame, so we contract 40 ms (1 frame @25 fps)
ctx->page_buffer.hide_timestamp = timestamp - 40;
if (ctx->page_buffer.hide_timestamp > timestamp)
{
ctx->page_buffer.hide_timestamp = 0;
}
process_page(ctx, &ctx->page_buffer, sub);

}

ctx->page_buffer.show_timestamp = timestamp;
ctx->page_buffer.hide_timestamp = 0;
memset(ctx->page_buffer.text, 0x00, sizeof(ctx->page_buffer.text));
ctx->page_buffer.tainted = NO;
ctx->receiving_data = YES;
primary_charset.g0_x28 = UNDEF;

c = (primary_charset.g0_m29 != UNDEF) ? primary_charset.g0_m29 : charset;
remap_g0_charset(c);

if(default_g0_charset == LATIN) // G0 Character National Option Sub-sets selection required only for Latin Character Sets
{
primary_charset.g0_x28 = UNDEF;
c = (primary_charset.g0_m29 != UNDEF) ? primary_charset.g0_m29 : charset;
remap_g0_charset(c);
}
/*
// I know -- not needed; in subtitles we will never need disturbing teletext page status bar
// displaying tv station name, current time etc.
Expand All @@ -995,7 +1026,7 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele
for (uint8_t i = 0; i < 40; i++)
{
if (ctx->page_buffer.text[y][i] == 0x00)
ctx->page_buffer.text[y][i] = telx_to_ucs2(packet->data[i]);
ctx->page_buffer.text[y][i] = packet->data[i];
}
ctx->page_buffer.tainted = YES;
}
Expand Down Expand Up @@ -1081,9 +1112,14 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele
{
// ETS 300 706, chapter 9.4.2: Packet X/28/0 Format 1 only
if ((triplet0 & 0x0f) == 0x00)
{
primary_charset.g0_x28 = (triplet0 & 0x3f80) >> 7;
remap_g0_charset(primary_charset.g0_x28);
{
// ETS 300 706, Table 32
set_g0_charset(triplet0); // Deciding G0 Character Set
if(default_g0_charset == LATIN)
{
primary_charset.g0_x28 = (triplet0 & 0x3f80) >> 7;
remap_g0_charset(primary_charset.g0_x28);
}
}
}
}
Expand All @@ -1098,7 +1134,7 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele
// ETS 300 706, chapter 9.5.1: Packet M/29/0
// ETS 300 706, chapter 9.5.3: Packet M/29/4
uint32_t triplet0 = unham_24_18((packet->data[3] << 16) | (packet->data[2] << 8) | packet->data[1]);

if (triplet0 == 0xffffffff)
{
// invalid data (HAM24/18 uncorrectable error detected), skip group
Expand All @@ -1110,11 +1146,15 @@ void process_telx_packet(struct TeletextCtx *ctx, data_unit_t data_unit_id, tele
// ETS 300 706, table 13: Coding of Packet M/29/4
if ((triplet0 & 0xff) == 0x00)
{
primary_charset.g0_m29 = (triplet0 & 0x3f80) >> 7;
// X/28 takes precedence over M/29
if (primary_charset.g0_x28 == UNDEF)
set_g0_charset(triplet0);
if(default_g0_charset == LATIN)
{
remap_g0_charset(primary_charset.g0_m29);
primary_charset.g0_m29 = (triplet0 & 0x3f80) >> 7;
// X/28 takes precedence over M/29
if (primary_charset.g0_x28 == UNDEF)
{
remap_g0_charset(primary_charset.g0_m29);
}
}
}
}
Expand Down