modules/demux/stl.c

   1 /*****************************************************************************
   2  * stl.c: EBU STL demuxer
   3  *****************************************************************************
   4  * Copyright (C) 2010 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30 #include <assert.h>
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_demux.h>
  35
  36 /*****************************************************************************
  37  * Module descriptor
  38  *****************************************************************************/
  39 static int  Open (vlc_object_t *);
  40 static void Close(vlc_object_t *);
  41
  42 vlc_module_begin()
  43     set_description(N_("EBU STL subtitles parser"))
  44     set_category(CAT_INPUT)
  45     set_subcategory(SUBCAT_INPUT_DEMUX)
  46     set_capability("demux", 1)
  47     set_callbacks(Open, Close)
  48     add_shortcut("stl", "subtitle")
  49 vlc_module_end()
  50
  51 /*****************************************************************************
  52  * Local definitions/prototypes
  53  *****************************************************************************/
  54 typedef struct {
  55     mtime_t start;
  56     mtime_t stop;
  57     size_t  blocknumber;
  58     size_t  count;
  59 } stl_entry_t;
  60
  61 struct demux_sys_t {
  62     size_t      count;
  63     stl_entry_t *index;
  64
  65     es_out_id_t *es;
  66
  67     size_t      current;
  68     int64_t     next_date;
  69     bool        b_slave;
  70     bool        b_first_time;
  71 };
  72
  73 static size_t ParseInteger(uint8_t *data, size_t size)
  74 {
  75     char tmp[16];
  76     assert(size < sizeof(tmp));
  77     memcpy(tmp, data, size);
  78     tmp[size] = '\0';
  79
  80     return strtol(tmp, NULL, 10);
  81 }
  82 static int64_t ParseTimeCode(uint8_t *data, double fps)
  83 {
  84     return INT64_C(1000000) * (data[0] * 3600 +
  85                                data[1] *   60 +
  86                                data[2] *    1 +
  87                                data[3] /  fps);
  88 }
  89 static int64_t ParseTextTimeCode(uint8_t *data, double fps)
  90 {
  91     uint8_t tmp[4];
  92     for (int i = 0; i < 4; i++)
  93         tmp[i] = ParseInteger(&data[2 * i], 2);
  94     return ParseTimeCode(tmp, fps);
  95 }
  96
  97 static int Control(demux_t *demux, int query, va_list args)
  98 {
  99     demux_sys_t *sys = demux->p_sys;
 100     switch(query) {
 101     case DEMUX_CAN_SEEK:
 102         return vlc_stream_vaControl(demux->s, query, args);
 103     case DEMUX_GET_LENGTH: {
 104         int64_t *l = va_arg(args, int64_t *);
 105         *l = sys->count > 0 ? sys->index[sys->count-1].stop : 0;
 106         return VLC_SUCCESS;
 107     }
 108     case DEMUX_GET_TIME: {
 109         int64_t *t = va_arg(args, int64_t *);
 110         *t = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 111         if( *t < 0 )
 112             *t = sys->next_date;
 113         return VLC_SUCCESS;
 114     }
 115     case DEMUX_SET_NEXT_DEMUX_TIME: {
 116         sys->b_slave = true;
 117         sys->next_date = va_arg(args, int64_t);
 118         return VLC_SUCCESS;
 119     }
 120     case DEMUX_SET_TIME: {
 121         int64_t t = va_arg(args, int64_t);
 122         for( size_t i = 0; i + 1< sys->count; i++ )
 123         {
 124             if( sys->index[i + 1].start >= t &&
 125                 vlc_stream_Seek(demux->s, 1024 + 128LL * sys->index[i].blocknumber) == VLC_SUCCESS )
 126             {
 127                 sys->current = i;
 128                 sys->next_date = t;
 129                 sys->b_first_time = true;
 130                 return VLC_SUCCESS;
 131             }
 132         }
 133         break;
 134     }
 135     case DEMUX_SET_POSITION:
 136     {
 137         double f = va_arg( args, double );
 138         if(sys->count && sys->index[sys->count-1].stop > 0)
 139         {
 140             int64_t i64 = f * sys->index[sys->count-1].stop;
 141             return demux_Control(demux, DEMUX_SET_TIME, i64);
 142         }
 143         break;
 144     }
 145     case DEMUX_GET_POSITION:
 146     {
 147         double *pf = va_arg(args, double *);
 148         if(sys->current >= sys->count)
 149         {
 150             *pf = 1.0;
 151         }
 152         else if(sys->count > 0 && sys->index[sys->count-1].stop > 0)
 153         {
 154             *pf = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 155             if(*pf < 0)
 156                *pf = sys->next_date;
 157             *pf /= sys->index[sys->count-1].stop;
 158         }
 159         else
 160         {
 161             *pf = 0.0;
 162         }
 163         return VLC_SUCCESS;
 164     }
 165     default:
 166         break;
 167     }
 168     return VLC_EGENERIC;
 169 }
 170
 171 static int Demux(demux_t *demux)
 172 {
 173     demux_sys_t *sys = demux->p_sys;
 174
 175     int64_t i_barrier = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 176     if(i_barrier < 0)
 177         i_barrier = sys->next_date;
 178
 179     while(sys->current < sys->count &&
 180           sys->index[sys->current].start <= i_barrier)
 181     {
 182         stl_entry_t *s = &sys->index[sys->current];
 183
 184         if (!sys->b_slave && sys->b_first_time)
 185         {
 186             es_out_SetPCR(demux->out, VLC_TS_0 + i_barrier);
 187             sys->b_first_time = false;
 188         }
 189
 190         /* Might be a gap in block # */
 191         const uint64_t i_pos = 1024 + 128LL * s->blocknumber;
 192         if(i_pos != vlc_stream_Tell(demux->s) &&
 193            vlc_stream_Seek( demux->s, i_pos ) != VLC_SUCCESS )
 194             return VLC_DEMUXER_EOF;
 195
 196         block_t *b = vlc_stream_Block(demux->s, 128);
 197         if (b && b->i_buffer == 128)
 198         {
 199             b->i_dts =
 200             b->i_pts = VLC_TS_0 + s->start;
 201             if (s->stop > s->start)
 202                 b->i_length = s->stop - s->start;
 203             es_out_Send(demux->out, sys->es, b);
 204         }
 205         else
 206         {
 207             if(b)
 208                 block_Release(b);
 209             return VLC_DEMUXER_EOF;
 210         }
 211         sys->current++;
 212     }
 213
 214     if (!sys->b_slave)
 215     {
 216         es_out_SetPCR(demux->out, VLC_TS_0 + i_barrier);
 217         sys->next_date += CLOCK_FREQ / 8;
 218     }
 219
 220     return sys->current < sys->count ? VLC_DEMUXER_SUCCESS : VLC_DEMUXER_EOF;
 221 }
 222
 223 static int Open(vlc_object_t *object)
 224 {
 225     demux_t *demux = (demux_t*)object;
 226
 227     const uint8_t *peek;
 228     if (vlc_stream_Peek(demux->s, &peek, 11) != 11)
 229         return VLC_EGENERIC;
 230
 231     bool is_stl_25 = !memcmp(&peek[3], "STL25.01", 8);
 232     bool is_stl_30 = !memcmp(&peek[3], "STL30.01", 8);
 233     if (!is_stl_25 && !is_stl_30)
 234         return VLC_EGENERIC;
 235     const double fps = is_stl_25 ? 25 : 30;
 236
 237     uint8_t header[1024];
 238     if (vlc_stream_Read(demux->s, header, sizeof(header)) != sizeof(header)) {
 239         msg_Err(demux, "Incomplete EBU STL header");
 240         return VLC_EGENERIC;
 241     }
 242     const int cct = ParseInteger(&header[12], 2);
 243     const mtime_t program_start = ParseTextTimeCode(&header[256], fps);
 244     const size_t tti_count = ParseInteger(&header[238], 5);
 245     if (!tti_count)
 246         return VLC_EGENERIC;
 247     msg_Dbg(demux, "Detected EBU STL : CCT=%d TTI=%zu start=%8.8s %"PRId64, cct, tti_count, &header[256], program_start);
 248
 249     demux_sys_t *sys = malloc(sizeof(*sys));
 250     if(!sys)
 251         return VLC_EGENERIC;
 252
 253     sys->b_slave   = false;
 254     sys->b_first_time = true;
 255     sys->next_date = 0;
 256     sys->current   = 0;
 257     sys->count     = 0;
 258     sys->index     = calloc(tti_count, sizeof(*sys->index));
 259     if(!sys->index)
 260     {
 261         free(sys);
 262         return VLC_EGENERIC;
 263     }
 264
 265     bool comment = false;
 266     stl_entry_t *s = &sys->index[0];
 267     s->count = 0;
 268
 269     for (size_t i = 0; i < tti_count; i++) {
 270         uint8_t tti[16];
 271         if (vlc_stream_Read(demux->s, tti, 16) != 16 ||
 272             vlc_stream_Read(demux->s, NULL, 112) != 112) {
 273             msg_Warn(demux, "Incomplete EBU STL file");
 274             break;
 275         }
 276         const int ebn = tti[3];
 277         if (ebn >= 0xf0 && ebn <= 0xfd)
 278             continue;
 279         if (ebn == 0xfe)
 280             continue;
 281
 282         if (s->count <= 0) {
 283             comment  = tti[15] != 0;
 284             s->start = ParseTimeCode(&tti[5], fps) - program_start;
 285             s->stop  = ParseTimeCode(&tti[9], fps) - program_start;
 286             s->blocknumber = i;
 287         }
 288         s->count++;
 289         if (ebn == 0xff && !comment)
 290             s = &sys->index[++sys->count];
 291         if (ebn == 0xff && sys->count < tti_count)
 292             s->count = 0;
 293     }
 294
 295     demux->p_sys = sys;
 296     if (sys->count == 0 ||
 297         vlc_stream_Seek(demux->s, 1024 + 128LL * sys->index[0].blocknumber) != VLC_SUCCESS)
 298     {
 299         Close(object);
 300         return VLC_EGENERIC;
 301     }
 302
 303     es_format_t fmt;
 304     es_format_Init(&fmt, SPU_ES, VLC_CODEC_EBU_STL);
 305     fmt.i_extra = sizeof(header);
 306     fmt.p_extra = header;
 307
 308     sys->es = es_out_Add(demux->out, &fmt);
 309     fmt.i_extra = 0;
 310     fmt.p_extra = NULL;
 311     es_format_Clean(&fmt);
 312
 313     if(sys->es == NULL)
 314     {
 315         Close(object);
 316         return VLC_EGENERIC;
 317     }
 318
 319     demux->p_sys      = sys;
 320     demux->pf_demux   = Demux;
 321     demux->pf_control = Control;
 322     return VLC_SUCCESS;
 323 }
 324
 325 static void Close(vlc_object_t *object)
 326 {
 327     demux_t *demux = (demux_t*)object;
 328     demux_sys_t *sys = demux->p_sys;
 329
 330     free(sys->index);
 331     free(sys);
 332 }
 333