modules/codec/t140.c

   1 /*****************************************************************************
   2  * t140.c : trivial T.140 text encoder
   3  *****************************************************************************
   4  * Copyright © 2007 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #define VLC_MODULE_LICENSE VLC_LICENSE_GPL_2_PLUS
  26 #include <vlc_common.h>
  27 #include <vlc_plugin.h>
  28 #include <vlc_codec.h>
  29 #include <vlc_sout.h>
  30
  31 static int  Open ( vlc_object_t * );
  32
  33 vlc_module_begin ()
  34     set_description( N_("T.140 text encoder") )
  35     set_capability( "encoder", 100 )
  36     set_callback( Open )
  37 vlc_module_end ()
  38
  39
  40 static block_t *Encode ( encoder_t *, subpicture_t * );
  41
  42
  43 static int Open( vlc_object_t *p_this )
  44 {
  45     encoder_t *p_enc = (encoder_t *)p_this;
  46
  47     switch( p_enc->fmt_out.i_codec )
  48     {
  49         case VLC_CODEC_SUBT:
  50             if( ( p_enc->fmt_out.subs.psz_encoding != NULL )
  51              && strcasecmp( p_enc->fmt_out.subs.psz_encoding, "utf8" )
  52              && strcasecmp( p_enc->fmt_out.subs.psz_encoding, "UTF-8" ) )
  53             {
  54                 msg_Err( p_this, "Only UTF-8 encoding supported" );
  55                 return VLC_EGENERIC;
  56             }
  57         case VLC_CODEC_ITU_T140:
  58             break;
  59
  60         default:
  61             if( !p_enc->obj.force )
  62                 return VLC_EGENERIC;
  63
  64             p_enc->fmt_out.i_codec = VLC_CODEC_ITU_T140;
  65     }
  66
  67     p_enc->p_sys = NULL;
  68
  69     p_enc->pf_encode_sub = Encode;
  70     p_enc->fmt_out.i_cat = SPU_ES;
  71     return VLC_SUCCESS;
  72 }
  73
  74
  75 static block_t *Encode( encoder_t *p_enc, subpicture_t *p_spu )
  76 {
  77     VLC_UNUSED( p_enc );
  78
  79     subpicture_region_t *p_region;
  80     block_t *p_block;
  81     size_t len = 0;
  82
  83     if( p_spu == NULL )
  84         return NULL;
  85
  86     p_region = p_spu->p_region;
  87     if( ( p_region == NULL )
  88      || ( p_region->fmt.i_chroma != VLC_CODEC_TEXT )
  89      || ( p_region->p_text == NULL )
  90      || ( p_region->p_text->psz_text == NULL) )
  91         return NULL;
  92
  93     /* This should already be UTF-8 encoded, so not much effort... */
  94     for( const text_segment_t *p_segment = p_region->p_text;
  95                                p_segment; p_segment = p_segment->p_next )
  96     {
  97         if( p_segment->psz_text == NULL )
  98             continue;
  99         len += strlen( p_segment->psz_text );
 100     }
 101
 102     p_block = block_Alloc( len + 1 );
 103     if( !p_block )
 104         return NULL;
 105
 106     p_block->i_buffer = 0;
 107     for( const text_segment_t *p_segment = p_region->p_text;
 108                                p_segment; p_segment = p_segment->p_next )
 109     {
 110         if( p_segment->psz_text == NULL )
 111             continue;
 112         len = strlen( p_segment->psz_text );
 113         memcpy( &p_block->p_buffer[p_block->i_buffer],
 114                 p_segment->psz_text, len );
 115         p_block->i_buffer += len;
 116     }
 117     p_block->p_buffer[p_block->i_buffer] = 0;
 118
 119     p_block->i_pts = p_block->i_dts = p_spu->i_start;
 120     if( !p_spu->b_ephemer && ( p_spu->i_stop > p_spu->i_start ) )
 121         p_block->i_length = p_spu->i_stop - p_spu->i_start;
 122
 123     return p_block;
 124 }