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* modules/codec/telx.c: Teletext subtitles decoder, patch courtesy of 

Vincent Penne.
This commit is contained in:
Christophe Massiot 2007-01-17 17:30:53 +00:00
parent 1c2b8a832c
commit 0e867ba1dd
4 changed files with 666 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
AUTHORS
View File

@ -324,6 +324,11 @@ E: heiko.panther@web.de
D: Mac OS X audio device selection framework
S: Germany
N: Vincent Penne
E: ziggy at sashipa dot com
D: teletext decoder
S: France
N: Eric Petit
E: titer@videolan.org
C: titer

2
configure.ac
View File

@ -1126,7 +1126,7 @@ dnl default modules
dnl
VLC_ADD_PLUGINS([dummy logger memcpy])
VLC_ADD_PLUGINS([mpgv mpga m4v m4a h264 ps pva avi asf mp4 rawdv nsv real aiff mjpeg demuxdump flacsys tta])
VLC_ADD_PLUGINS([cvdsub svcdsub spudec subsdec dvbsub mpeg_audio lpcm a52 dts cinepak flac])
VLC_ADD_PLUGINS([cvdsub svcdsub spudec telx subsdec dvbsub mpeg_audio lpcm a52 dts cinepak flac])
VLC_ADD_PLUGINS([deinterlace invert adjust transform wave ripple psychedelic gradient motionblur rv32 rotate noise extract])
VLC_ADD_PLUGINS([converter_fixed mono])
VLC_ADD_PLUGINS([trivial_resampler ugly_resampler])

1
modules/codec/Modules.am
View File

@ -18,6 +18,7 @@ SOURCES_quicktime = quicktime.c
SOURCES_subsdec = subsdec.c
SOURCES_faad = faad.c
SOURCES_dvbsub = dvbsub.c
SOURCES_telx = telx.c
SOURCES_mash = mash.cpp
SOURCES_x264 = x264.c
SOURCES_twolame = twolame.c

659
modules/codec/telx.c Normal file
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@ -0,0 +1,659 @@
/*****************************************************************************
* telx.c : Minimalistic Teletext subtitles decoder
*****************************************************************************
* Copyright (C) 2007 Vincent Penne
* Some code converted from ProjectX java dvb decoder (c) 2001-2005 by dvb.matt
* $Id$
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
/*****************************************************************************
*
* information on teletext format can be found here :
* http://pdc.ro.nu/teletext.html
*
* TODO :
*
*****************************************************************************/
#include <vlc/vlc.h>
#include <assert.h>
#include <stdint.h>
// this is an ugly test so that this source compile for both 0.8.6 and current trunk version
// considere this hack to be temporary, but I need it so that I can maintain my patch
// for both current svn and 0.8.6 in an easy way.
#ifdef VLC_ENOITEM
// svn trunk
#include "vlc_vout.h"
#else
// 0.8.6
#include <vlc/vout.h>
#include <vlc/decoder.h>
#include <vlc/sout.h>
/* #include "vlc_es.h" */
/* #include "vlc_block.h" */
/* #include "vlc_video.h" */
/* #include "vlc_spu.h" */
#endif
#include "vlc_bits.h"
#include "vlc_codec.h"
//#define TELX_DEBUG
#ifdef TELX_DEBUG
# define dbg( a ) msg_Dbg a
#else
# define dbg( a )
#endif
/*****************************************************************************
* Local prototypes
*****************************************************************************/
static int telx_conf_cb ( vlc_object_t *, /* variable's object */
char const *, /* variable name */
vlc_value_t, /* old value */
vlc_value_t, /* new value */
void * ); /* callback data */
/*****************************************************************************
* Module descriptor.
*****************************************************************************/
static int Open ( vlc_object_t * );
static void Close( vlc_object_t * );
static subpicture_t *Decode( decoder_t *, block_t ** );
#define PAGE_TEXT N_("Teletext page")
#define PAGE_LONGTEXT N_("Set displayed teletext page for subtitles, 0 for all pages, 888 should be a standard value. Just leave it to zero if your stream has only one language for subtitles.")
#define IGNORE_SUB_FLAG_TEXT N_("Ignore subtitle flag")
#define IGNORE_SUB_FLAG_LONGTEXT N_("Ignore the subtitle flag, try this if your subtitles don't appear.")
vlc_module_begin();
# define TELX_CFG_PREFIX "telx-"
set_description( _("Teletext subtitles decoder") );
set_capability( "decoder", 50 );
set_category( CAT_INPUT );
set_subcategory( SUBCAT_INPUT_SCODEC );
set_callbacks( Open, Close );
add_integer( "telx-page", 0, telx_conf_cb, PAGE_TEXT, PAGE_LONGTEXT,
VLC_FALSE );
add_bool( "telx-ignore-subtitle-flag", 0, telx_conf_cb, IGNORE_SUB_FLAG_TEXT, IGNORE_SUB_FLAG_LONGTEXT,
VLC_TRUE );
vlc_module_end();
/****************************************************************************
* Local structures
****************************************************************************/
struct decoder_sys_t
{
int i_align;
int is_subtitle[9];
char lines[32][128];
char prev_text[512];
mtime_t prev_pts;
int page;
int erase[9];
uint16_t * active_national_set[9];
};
/****************************************************************************
* Local data
****************************************************************************/
static int i_wanted_page = 0; // default 0 = all pages
static vlc_bool_t b_ignore_sub_flag = 0;
//
// my doc only mentions 13 national characters, but experiments show there
// are more, in france for example I already found two more (0x9 and 0xb)
//
// convertion is in this order :
//
// 0x23 0x24 0x40 0x5b 0x5c 0x5d 0x5e 0x5f 0x60 0x7b 0x7c 0x7d 0x7e (these are the standard ones)
// 0x08 0x09 0x0a 0x0b 0x0c 0x0d (apparently a control character) 0x0e 0x0f
//
static uint16_t national_subsets[][20] = {
{ 0x00a3, 0x0024, 0x0040, 0x00ab, 0x00bd, 0x00bb, 0x005e, 0x0023,
0x002d, 0x00bc, 0x00a6, 0x00be, 0x00f7 }, // english ,000
{ 0x00e9, 0x00ef, 0x00e0, 0x00eb, 0x00ea, 0x00f9, 0x00ee, 0x0023,
0x00e8, 0x00e2, 0x00f4, 0x00fb, 0x00e7, 0, 0x00eb, 0, 0x00ef }, // french ,001
{ 0x0023, 0x00a4, 0x00c9, 0x00c4, 0x00d6, 0x00c5, 0x00dc, 0x005f,
0x00e9, 0x00e4, 0x00f6, 0x00e5, 0x00fc }, // swedish,finnish,hungarian ,010
{ 0x0023, 0x016f, 0x010d, 0x0165, 0x017e, 0x00fd, 0x00ed, 0x0159,
0x00e9, 0x00e1, 0x0115, 0x00fa, 0x0161 }, // czech,slovak ,011
{ 0x0023, 0x0024, 0x00a7, 0x00c4, 0x00d6, 0x00dc, 0x005e, 0x005f,
0x00b0, 0x00e4, 0x00f6, 0x00fc, 0x00df }, // german ,100
{ 0x00e7, 0x0024, 0x00a1, 0x00e1, 0x00e9, 0x00ed, 0x00f3, 0x00fa,
0x00bf, 0x00fc, 0x00f1, 0x00e8, 0x00e0 }, // portuguese,spanish ,101
{ 0x00a3, 0x0024, 0x00e9, 0x00b0, 0x00e7, 0x00bb, 0x005e, 0x0023,
0x00f9, 0x00e0, 0x00f2, 0x00e8, 0x00ec }, // italian ,110
{ 0x0023, 0x00a4, 0x0162, 0x00c2, 0x015e, 0x0102, 0x00ce, 0x0131,
0x0163, 0x00e2, 0x015f, 0x0103, 0x00ee }, // rumanian ,111
{ 0x0023, 0x0024, 0x0160, 0x0117, 0x0119, 0x017d, 0x010d, 0x016b,
0x0161, 0x0105, 0x0173, 0x017e, 0x012f }, // lettish,lithuanian ,1000
{ 0x0023, 0x0144, 0x0105, 0x005a, 0x015a, 0x0141, 0x0107, 0x00f3,
0x0119, 0x017c, 0x015b, 0x0142, 0x017a }, // polish, 1001
{ 0x0023, 0x00cb, 0x010c, 0x0106, 0x017d, 0x0110, 0x0160, 0x00eb,
0x010d, 0x0107, 0x017e, 0x0111, 0x0161 }, // serbian,croatian,slovenian, 1010
{ 0x0023, 0x00f5, 0x0160, 0x00c4, 0x00d6, 0x017e, 0x00dc, 0x00d5,
0x0161, 0x00e4, 0x00f6, 0x017e, 0x00fc }, // estonian ,1011
{ 0x0054, 0x011f, 0x0130, 0x015e, 0x00d6, 0x00c7, 0x00dc, 0x011e,
0x0131, 0x015f, 0x00f6, 0x00e7, 0x00fc }, // turkish ,1100
};
/*****************************************************************************
* Open: probe the decoder and return score
*****************************************************************************
* Tries to launch a decoder and return score so that the interface is able
* to chose.
*****************************************************************************/
static int Open( vlc_object_t *p_this )
{
decoder_t *p_dec = (decoder_t *) p_this;
decoder_sys_t *p_sys = NULL;
vlc_value_t val;
int i;
if( p_dec->fmt_in.i_codec != VLC_FOURCC('t','e','l','x'))
{
return VLC_EGENERIC;
}
p_dec->pf_decode_sub = Decode;
p_sys = p_dec->p_sys = malloc( sizeof(decoder_sys_t) );
if (p_sys == NULL) {
msg_Err( p_dec, "out of memory" );
return VLC_ENOMEM;
}
memset( p_sys, 0, sizeof(decoder_sys_t) );
p_sys->i_align = 0;
for (i=0; i<9; i++)
p_sys->active_national_set[i] = national_subsets[1];
var_Create( p_dec, "telx-page", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
var_Get( p_dec, "telx-page", &val );
i_wanted_page = val.i_int;
var_Create( p_dec, "telx-ignore-subtitle-flag", VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
var_Get( p_dec, "telx-ignore-subtitle-flag", &val );
b_ignore_sub_flag = val.b_bool;
return VLC_SUCCESS;
/* error: */
/* if (p_sys) { */
/* free(p_sys); */
/* p_sys = NULL; */
/* } */
/* return VLC_EGENERIC; */
}
/*****************************************************************************
* Config callback
*****************************************************************************/
static int telx_conf_cb ( vlc_object_t * obj, /* variable's object */
char const * name, /* variable name */
vlc_value_t oldv, /* old value */
vlc_value_t newv, /* new value */
void * data) /* callback data */
{
if (!strcmp(name, "telx-page")) {
i_wanted_page = newv.i_int;
dbg((obj, "display teletext page changed to %d\n", i_wanted_page));
} else if (!strcmp(name, "telx-ignore-subtitle-flag")) {
b_ignore_sub_flag = newv.b_bool;
dbg((obj, "ignore sub flag changed to %d\n", (int) b_ignore_sub_flag));
}
return 0;
}
/*****************************************************************************
* Close:
*****************************************************************************/
static void Close( vlc_object_t *p_this )
{
decoder_t *p_dec = (decoder_t*) p_this;
decoder_sys_t *p_sys = p_dec->p_sys;
free( p_sys );
}
/**************************
* change bits endianness *
**************************/
static uint8_t bytereverse(int n)
{
n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa));
n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc));
n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0));
return n;
}
static int hamming_8_4(int a)
{
switch (a) {
case 0xA8:
return 0;
case 0x0B:
return 1;
case 0x26:
return 2;
case 0x85:
return 3;
case 0x92:
return 4;
case 0x31:
return 5;
case 0x1C:
return 6;
case 0xBF:
return 7;
case 0x40:
return 8;
case 0xE3:
return 9;
case 0xCE:
return 10;
case 0x6D:
return 11;
case 0x7A:
return 12;
case 0xD9:
return 13;
case 0xF4:
return 14;
case 0x57:
return 15;
default:
return -1; // decoding error , not yet corrected
}
}
// utc-2 --> utf-8
// this is not a general function, but it's enough for what we do here
static void to_utf8(char * res, uint16_t ch)
{
if(ch>=0x80){
if(ch>=0x800){
res[0]=(ch>>12)|0xE0;
res[1]=((ch>>6)&0x3F)|0x80;
res[2]=(ch&0x3F)|0x80;
res[3]=0;
} else {
res[0]=(ch>>6)|0xC0;
res[1]=(ch&0x3F)|0x80;
res[2]=0;
}
} else {
res[0]=ch;
res[1]=0;
}
}
static void decode_string(char * res, int res_len,
decoder_sys_t *p_sys, int magazine,
uint8_t * packet, int len)
{
char utf8[7];
char * pt = res;
int i;
for (i=0; i<len; i++) {
int in = bytereverse(packet[i])&0x7f;
uint16_t out = 32;
size_t l;
switch (in) { // special national characters
case 0x23:
out = p_sys->active_national_set[magazine][0];
break;
case 0x24:
out = p_sys->active_national_set[magazine][1];
break;
case 0x40:
out = p_sys->active_national_set[magazine][2];
break;
case 0x5b:
out = p_sys->active_national_set[magazine][3];
break;
case 0x5c:
out = p_sys->active_national_set[magazine][4];
break;
case 0x5d:
out = p_sys->active_national_set[magazine][5];
break;
case 0x5e:
out = p_sys->active_national_set[magazine][6];
break;
case 0x5f:
out = p_sys->active_national_set[magazine][7];
break;
case 0x60:
out = p_sys->active_national_set[magazine][8];
break;
case 0x7b:
out = p_sys->active_national_set[magazine][9];
break;
case 0x7c:
out = p_sys->active_national_set[magazine][10];
break;
case 0x7d:
out = p_sys->active_national_set[magazine][11];
break;
case 0x7e:
out = p_sys->active_national_set[magazine][12];
break;
// some special control characters (empirical)
case 0x0d:
// apparently this starts a sequence that ends with 0xb 0xb
while (i+1<len && (bytereverse(packet[i+1])&0x7f) != 0x0b) i++;
i += 2;
break;
//goto skip;
default:
// non documented national range 0x08 - 0x0f
if (in >= 0x08 && in <= 0x0f) {
out = p_sys->active_national_set[magazine][13 + in - 8];
break;
}
// normal ascii
if (in > 32 && in < 0x7f)
out = in;
}
// handle undefined national characters
if (out == 0) out = 32;
// convert to utf-8
to_utf8(utf8, out);
l = strlen(utf8);
if (pt + l < res + res_len - 1) {
strcpy(pt, utf8);
pt += l;
}
//skip: ;
}
//end:
*pt++ = 0;
}
/*****************************************************************************
* Decode:
*****************************************************************************/
static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
{
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_block;
subpicture_t *p_spu = NULL;
video_format_t fmt;
int error = 1;
//int erase = 0;
int len, offset;
int wanted_magazine = i_wanted_page/100;
int wanted_page = 0x10*((i_wanted_page%100)/10) | (i_wanted_page%10);
int update = 0;
char text[512], * pt = text;
char line[256];
int i, total;
if( pp_block == NULL || *pp_block == NULL ) return NULL;
p_block = *pp_block;
*pp_block = NULL;
len = p_block->i_buffer;
for (offset = 1; offset+46 <= len ; offset += 46) {
uint8_t * packet = (uint8_t *) p_block->p_buffer+offset;
//dbg((p_dec, "header %02x %02x %02x\n", packet[0], packet[1], packet[2]));
/* if (packet[1] != 0x2C) { */
/* printf("wrong header\n"); */
/* //goto error; */
/* continue; */
/* } */
int mpag = (hamming_8_4(packet[4]))<<4 | hamming_8_4(packet[5]);
int row, magazine;
if (mpag < 0) { // decode error
dbg((p_dec, "mpag hamming error\n"));
continue;
}
row = 0xFF & bytereverse(mpag);
magazine = (7 & row) == 0 ? 8 : (7 & row);
row >>= 3;
if (i_wanted_page && magazine != wanted_magazine) continue;
if (row == 0) {
// row 0 : flags and header line
int flag = 0;
int a;
char * t = NULL;
for (a = 0; a < 6; a++)
flag |= (0xF & bytereverse(hamming_8_4(packet[8+a]) )>>4 ) <<(a*4);
dbg((p_dec, "mag %d flags %x page %x character set %d subtitles %d\n%s\n", magazine, flag,
//p_sys->page,
(0xF0 & bytereverse(hamming_8_4(packet[7]) )) |
(0xF & bytereverse(hamming_8_4(packet[6]) )>>4 ),
7 & flag>>21, 1 & flag>>15, t));
/* if (!b_ignore_sub_flag && !(1 & flag>>15)) */
/* continue; */
p_sys->page = (0xF0 & bytereverse(hamming_8_4(packet[7]) )) |
(0xF & bytereverse(hamming_8_4(packet[6]) )>>4 );
decode_string(line, sizeof(line), p_sys, magazine, packet+14, 40-14);
p_sys->active_national_set[magazine] = national_subsets[7 & flag>>21];
p_sys->is_subtitle[magazine] = b_ignore_sub_flag || (1 & flag>>15);
if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
continue;
p_sys->erase[magazine] = (1 & flag>>7);
dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts, (long int)(p_sys->prev_pts+1500000)));
// kludge here :
// we ignore the erase flag if it happens less than 1.5 secondes before last caption
// TODO make this time configurable
if (p_block->i_pts > p_sys->prev_pts + 1500000 &&
p_sys->erase[magazine]) {
int i;
dbg((p_dec, "ERASE !\n"));
p_sys->erase[magazine] = 0;
for (i=1; i<32; i++) {
if (!p_sys->lines[i][0]) continue;
//update = 1;
p_sys->lines[i][0] = 0;
}
}
// replace the row if it's different
if (strcmp(line, p_sys->lines[row])) {
strncpy(p_sys->lines[row], line, sizeof(p_sys->lines[row])-1);
}
update = 1;
} else if (row < 24) {
char * t;
int i;
// row 1-23 : normal lines
if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
continue;
decode_string(line, sizeof(line), p_sys, magazine, packet+6, 40);
t = line;
// remove starting spaces
while (*t == 32) t++;
// remove trailing spaces
for (i=strlen(t)-1; i>=0 && t[i] == 32; i--);
t[i+1] = 0;
// replace the row if it's different
if (strcmp(t, p_sys->lines[row])) {
strncpy(p_sys->lines[row], t, sizeof(p_sys->lines[row])-1);
update = 1;
}
if (t[0])
p_sys->prev_pts = p_block->i_pts;
dbg((p_dec, "%d %d : ", magazine, row));
dbg((p_dec, "%s\n", t));
#ifdef TELX_DEBUG
{
char dbg[256];
dbg[0] = 0;
for (i=0; i<40; i++) {
int in = bytereverse(packet[6+i]) & 0x7f;
sprintf(dbg+strlen(dbg), "%02x ", in);
}
dbg((p_dec, "%s\n", dbg));
dbg[0] = 0;
for (i=0; i<40; i++) {
decode_string(line, sizeof(line), p_sys, magazine, packet+6+i, 1);
sprintf(dbg+strlen(dbg), "%s ", line);
}
dbg((p_dec, "%s\n", dbg));
}
#endif
} else if (row == 25) {
// row 25 : alternate header line
if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
continue;
decode_string(line, sizeof(line), p_sys, magazine, packet+6, 40);
// replace the row if it's different
if (strcmp(line, p_sys->lines[0])) {
strncpy(p_sys->lines[0], line, sizeof(p_sys->lines[0])-1);
//update = 1;
}
}
/* else if (row == 26) { */
/* // row 26 : TV listings */
/* } else */
/* dbg((p_dec, "%d %d : %s\n", magazine, row, decode_string(p_sys, magazine, packet+6, 40))); */
}
if (!update)
goto error;
total = 0;
for (i=1; i<24; i++) {
size_t l = strlen(p_sys->lines[i]);
if (l > sizeof(text)-total-1)
l = sizeof(text)-total-1;
if (l > 0) {
memcpy(pt, p_sys->lines[i], l);
total += l;
pt += l;
if (sizeof(text)-total-1 > 0) {
*pt++ = '\n';
total++;
}
}
}
*pt = 0;
if (!strcmp(text, p_sys->prev_text))
goto error;
dbg((p_dec, "UPDATE TELETEXT PICTURE\n"));
assert(sizeof(p_sys->prev_text)>=sizeof(text));
strcpy(p_sys->prev_text, text);
/* Create the subpicture unit */
p_spu = p_dec->pf_spu_buffer_new( p_dec );
if( !p_spu ) {
msg_Warn( p_dec, "can't get spu buffer" );
goto error;
}
p_spu->b_pausable = VLC_TRUE;
/* Create a new subpicture region */
memset( &fmt, 0, sizeof(video_format_t) );
fmt.i_chroma = VLC_FOURCC('T','E','X','T');
fmt.i_aspect = 0;
fmt.i_width = fmt.i_height = 0;
fmt.i_x_offset = fmt.i_y_offset = 0;
p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
if( !p_spu->p_region ) {
msg_Err( p_dec, "cannot allocate SPU region" );
goto error;
}
/* Normal text subs, easy markup */
p_spu->i_flags = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
p_spu->i_x = p_sys->i_align ? 20 : 0;
p_spu->i_y = 10;
p_spu->p_region->psz_text = strdup(text);
p_spu->i_start = p_block->i_pts;
p_spu->i_stop = p_block->i_pts + p_block->i_length;
p_spu->b_ephemer = (p_block->i_length == 0);
p_spu->b_absolute = VLC_FALSE;
dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts/100000, (long int)p_block->i_length/100000));
error = 0;
error:
if (error && p_spu) {
p_dec->pf_spu_buffer_del( p_dec, p_spu );
p_spu = NULL;
}
block_Release( p_block );
return p_spu;
}