modules/codec/scte18.c

   1 /*****************************************************************************
   2  * scte18.c : SCTE-18 EAS decoder
   3  *****************************************************************************
   4  * Copyright (C) 2016 - VideoLAN Authors
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 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 Lesser 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, see <http://www.gnu.org/licenses/>.
  18  *****************************************************************************/
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 #include <vlc_common.h>
  25 #include <vlc_plugin.h>
  26 #include <vlc_codec.h>
  27
  28 #include "atsc_a65.h"
  29 #include "scte18.h"
  30 #include "substext.h"
  31
  32 #include <time.h>
  33
  34 /*****************************************************************************
  35  * Module descriptor.
  36  *****************************************************************************/
  37 static int  Open (vlc_object_t *);
  38 static void Close(vlc_object_t *);
  39
  40 vlc_module_begin ()
  41     set_description(N_("SCTE-18 decoder"))
  42     set_shortname(N_("SCTE-18"))
  43     set_capability( "spu decoder", 51)
  44     set_category(CAT_INPUT)
  45     set_subcategory(SUBCAT_INPUT_SCODEC)
  46     set_callbacks(Open, Close)
  47 vlc_module_end ()
  48
  49 struct decoder_sys_t
  50 {
  51     atsc_a65_handle_t *p_handle;
  52 };
  53
  54 //#define GPS_UTC_EPOCH_OFFSET 315964800
  55 //#define GPS_CUR_UTC_LEAP_OFFSET  16 /* 1 Jul 2015 */
  56
  57 typedef struct scte18_cea_t
  58 {
  59     uint16_t i_eas_event_id;
  60     char     rgc_eas_originator_code[3];
  61     char *   psz_eas_event_code;
  62     char *   psz_nature_of_activation;
  63     uint8_t  alert_message_time_remaining;
  64     uint32_t event_start_time;
  65     uint16_t event_duration;
  66     uint8_t  alert_priority;
  67
  68     char *   psz_alert_text;
  69
  70 } scte18_cea_t;
  71
  72 /****************************************************************************
  73  * Local prototypes
  74  ****************************************************************************/
  75 #define BUF_ADVANCE(n) p_buffer += n; i_buffer -= n;
  76
  77 static inline scte18_cea_t * scte18_cea_New()
  78 {
  79     return calloc( 1, sizeof(scte18_cea_t) );
  80 }
  81
  82 static void scte18_cea_Free( scte18_cea_t *p_cea )
  83 {
  84     free( p_cea->psz_alert_text );
  85     free( p_cea->psz_nature_of_activation );
  86     free( p_cea->psz_eas_event_code );
  87     free( p_cea );
  88 }
  89
  90 static scte18_cea_t * scte18_cea_Decode( atsc_a65_handle_t *p_handle, const block_t *p_block )
  91 {
  92     size_t len;
  93     scte18_cea_t *p_cea = scte18_cea_New();
  94     if( !p_cea )
  95         return NULL;
  96
  97     const uint8_t *p_buffer = p_block->p_buffer;
  98     size_t i_buffer = p_block->i_buffer;
  99
 100     if( i_buffer < 34 || p_buffer[0] != 0 )
 101         goto error;
 102
 103     BUF_ADVANCE(1);
 104
 105     p_cea->i_eas_event_id = GetWBE( p_buffer );
 106     BUF_ADVANCE(2);
 107
 108     memcpy( p_cea->rgc_eas_originator_code, p_buffer, 3 );
 109     BUF_ADVANCE(3);
 110
 111     len = p_buffer[0];
 112     if( i_buffer < 23 + len )
 113         goto error;
 114     p_cea->psz_eas_event_code = malloc( len + 1 );
 115     memcpy( p_cea->psz_eas_event_code, &p_buffer[1], len );
 116     p_cea->psz_eas_event_code[len] = 0;
 117     BUF_ADVANCE( len + 1 );
 118
 119     len = p_buffer[0];
 120     if( i_buffer < len + 22 )
 121         goto error;
 122     p_cea->psz_nature_of_activation = atsc_a65_Decode_multiple_string( p_handle, &p_buffer[1], len );
 123     BUF_ADVANCE(1 + len);
 124
 125     if( i_buffer < 21 )
 126         goto error;
 127     p_cea->alert_message_time_remaining = p_buffer[0];
 128     BUF_ADVANCE(1);
 129
 130     p_cea->event_start_time = GetDWBE( p_buffer );
 131     BUF_ADVANCE(4);
 132
 133     p_cea->event_duration = GetWBE( p_buffer );
 134     if( p_cea->event_duration != 0 && ( p_cea->event_duration < 15 || p_cea->event_duration > 6000 ) )
 135         goto error;
 136     BUF_ADVANCE(2);
 137
 138     p_cea->alert_priority = p_buffer[1] & 0x0f;
 139     switch( p_cea->alert_priority )
 140     {
 141         case EAS_PRIORITY_TEST:
 142         case EAS_PRIORITY_LOW:
 143         case EAS_PRIORITY_MEDIUM:
 144         case EAS_PRIORITY_HIGH:
 145         case EAS_PRIORITY_MAX:
 146             break;
 147         default:
 148             goto error;
 149     }
 150
 151     BUF_ADVANCE(2);
 152
 153     BUF_ADVANCE(2); //OOB_ID
 154
 155     BUF_ADVANCE(2); //
 156     BUF_ADVANCE(2); //
 157
 158     BUF_ADVANCE(2); //audio_OOB_ID
 159
 160     len = GetWBE( p_buffer );
 161     if( i_buffer < len + 2 )
 162         goto error;
 163     p_cea->psz_alert_text = atsc_a65_Decode_multiple_string( p_handle, &p_buffer[2], len );
 164
 165     return p_cea;
 166
 167 error:
 168     scte18_cea_Free( p_cea );
 169     return NULL;
 170 }
 171
 172 static int Decode( decoder_t *p_dec, block_t *p_block )
 173 {
 174     if ( p_block == NULL ) /* No Drain */
 175         return VLCDEC_SUCCESS;
 176     subpicture_t *p_spu = NULL;
 177
 178     if (p_block->i_flags & (BLOCK_FLAG_CORRUPTED))
 179         goto exit;
 180
 181     scte18_cea_t *p_cea = scte18_cea_Decode( p_dec->p_sys->p_handle, p_block );
 182     if( p_cea )
 183     {
 184         p_spu = decoder_NewSubpictureText( p_dec );
 185         if( p_spu )
 186         {
 187             subpicture_updater_sys_t *p_spu_sys = p_spu->updater.p_sys;
 188
 189             p_spu->i_start = p_block->i_pts;
 190             if( p_cea->alert_message_time_remaining )
 191                 p_spu->i_stop = p_spu->i_start + CLOCK_FREQ * p_cea->alert_message_time_remaining;
 192             else
 193                 p_spu->i_stop = VLC_TS_INVALID;
 194
 195             p_spu->b_ephemer  = true;
 196             p_spu->b_absolute = false;
 197
 198             p_spu_sys->region.inner_align = SUBPICTURE_ALIGN_TOP;
 199             p_spu_sys->p_default_style->i_style_flags = STYLE_BOLD | STYLE_BACKGROUND;
 200             p_spu_sys->p_default_style->i_features |= STYLE_HAS_FLAGS;
 201             p_spu_sys->p_default_style->i_background_color = 0x000000;
 202             p_spu_sys->p_default_style->i_background_alpha = STYLE_ALPHA_OPAQUE;
 203             p_spu_sys->p_default_style->i_features |= STYLE_HAS_BACKGROUND_COLOR | STYLE_HAS_BACKGROUND_ALPHA;
 204             p_spu_sys->p_default_style->i_font_color = 0xFF0000;
 205             p_spu_sys->p_default_style->i_features |= STYLE_HAS_FONT_COLOR;
 206
 207             p_spu_sys->region.p_segments = text_segment_New( p_cea->psz_alert_text );
 208             decoder_QueueSub( p_dec, p_spu );
 209         }
 210         msg_Info( p_dec, "Received %s", p_cea->psz_alert_text );
 211         scte18_cea_Free( p_cea );
 212     }
 213
 214 exit:
 215     block_Release( p_block );
 216     return VLCDEC_SUCCESS;
 217 }
 218
 219 static int Open( vlc_object_t *object )
 220 {
 221     decoder_t *dec = (decoder_t *)object;
 222
 223     if ( dec->fmt_in.i_codec != VLC_CODEC_SCTE_18 )
 224         return VLC_EGENERIC;
 225
 226     decoder_sys_t *p_sys = malloc( sizeof(decoder_sys_t) );
 227     if( unlikely(!p_sys) )
 228         return VLC_ENOMEM;
 229
 230     p_sys->p_handle = atsc_a65_handle_New( NULL );
 231     if( !p_sys->p_handle )
 232     {
 233         free( p_sys );
 234         return VLC_EGENERIC;
 235     }
 236
 237     dec->p_sys = p_sys;
 238     dec->pf_decode = Decode;
 239     dec->fmt_out.i_codec = 0;
 240
 241     return VLC_SUCCESS;
 242 }
 243
 244 static void Close( vlc_object_t *p_object )
 245 {
 246     decoder_t *p_dec = (decoder_t *)p_object;
 247     decoder_sys_t *p_sys = (decoder_sys_t *) p_dec->p_sys;
 248     atsc_a65_handle_Release( p_sys->p_handle );
 249     free( p_sys );
 250 }
 251