--- /dev/null
+/*****************************************************************************
+ * 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;
+}
+
projects / vlc / commitdiff