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     vlc_tick_t start;
  56     vlc_tick_t stop;
  57     size_t  blocknumber;
  58     size_t  count;
  59 } stl_entry_t;
  60
  61 typedef struct
  62 {
  63     size_t      count;
  64     stl_entry_t *index;
  65
  66     es_out_id_t *es;
  67
  68     size_t      current;
  69     vlc_tick_t  next_date;
  70     bool        b_slave;
  71     bool        b_first_time;
  72 } demux_sys_t;
  73
  74 static size_t ParseInteger(uint8_t *data, size_t size)
  75 {
  76     char tmp[16];
  77     assert(size < sizeof(tmp));
  78     memcpy(tmp, data, size);
  79     tmp[size] = '\0';
  80
  81     return strtol(tmp, NULL, 10);
  82 }
  83 static vlc_tick_t ParseTimeCode(uint8_t *data, double fps)
  84 {
  85     return CLOCK_FREQ * (data[0] * 3600 +
  86                          data[1] *   60 +
  87                          data[2] *    1 +
  88                          data[3] /  fps);
  89 }
  90 static vlc_tick_t ParseTextTimeCode(uint8_t *data, double fps)
  91 {
  92     uint8_t tmp[4];
  93     for (int i = 0; i < 4; i++)
  94         tmp[i] = ParseInteger(&data[2 * i], 2);
  95     return ParseTimeCode(tmp, fps);
  96 }
  97
  98 static int Control(demux_t *demux, int query, va_list args)
  99 {
 100     demux_sys_t *sys = demux->p_sys;
 101     switch(query) {
 102     case DEMUX_CAN_SEEK:
 103         return vlc_stream_vaControl(demux->s, query, args);
 104     case DEMUX_GET_LENGTH: {
 105         *va_arg(args, vlc_tick_t *) =
 106             sys->count > 0 ? sys->index[sys->count-1].stop : 0;
 107         return VLC_SUCCESS;
 108     }
 109     case DEMUX_GET_TIME: {
 110         vlc_tick_t *t = va_arg(args, vlc_tick_t *);
 111         *t = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 112         if( *t < 0 )
 113             *t = sys->next_date;
 114         return VLC_SUCCESS;
 115     }
 116     case DEMUX_SET_NEXT_DEMUX_TIME: {
 117         sys->b_slave = true;
 118         sys->next_date = va_arg(args, vlc_tick_t);
 119         return VLC_SUCCESS;
 120     }
 121     case DEMUX_SET_TIME: {
 122         vlc_tick_t t = va_arg(args, vlc_tick_t);
 123         for( size_t i = 0; i + 1< sys->count; i++ )
 124         {
 125             if( sys->index[i + 1].start >= t &&
 126                 vlc_stream_Seek(demux->s, 1024 + 128LL * sys->index[i].blocknumber) == VLC_SUCCESS )
 127             {
 128                 sys->current = i;
 129                 sys->next_date = t;
 130                 sys->b_first_time = true;
 131                 return VLC_SUCCESS;
 132             }
 133         }
 134         break;
 135     }
 136     case DEMUX_SET_POSITION:
 137     {
 138         double f = va_arg( args, double );
 139         if(sys->count && sys->index[sys->count-1].stop > 0)
 140         {
 141             vlc_tick_t i64 = f * sys->index[sys->count-1].stop;
 142             return demux_Control(demux, DEMUX_SET_TIME, i64);
 143         }
 144         break;
 145     }
 146     case DEMUX_GET_POSITION:
 147     {
 148         double *pf = va_arg(args, double *);
 149         if(sys->current >= sys->count)
 150         {
 151             *pf = 1.0;
 152         }
 153         else if(sys->count > 0 && sys->index[sys->count-1].stop > 0)
 154         {
 155             *pf = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 156             if(*pf < 0)
 157                *pf = sys->next_date;
 158             *pf /= sys->index[sys->count-1].stop;
 159         }
 160         else
 161         {
 162             *pf = 0.0;
 163         }
 164         return VLC_SUCCESS;
 165     }
 166     case DEMUX_CAN_PAUSE:
 167     case DEMUX_SET_PAUSE_STATE:
 168     case DEMUX_CAN_CONTROL_PACE:
 169     case DEMUX_GET_PTS_DELAY: {
 170         return demux_vaControlHelper( demux->s, 0, -1, 0, 1, query, args );
 171     }
 172     default:
 173         break;
 174     }
 175     return VLC_EGENERIC;
 176 }
 177
 178 static int Demux(demux_t *demux)
 179 {
 180     demux_sys_t *sys = demux->p_sys;
 181
 182     vlc_tick_t i_barrier = sys->next_date - var_GetInteger(demux->obj.parent, "spu-delay");
 183     if(i_barrier < 0)
 184         i_barrier = sys->next_date;
 185
 186     while(sys->current < sys->count &&
 187           sys->index[sys->current].start <= i_barrier)
 188     {
 189         stl_entry_t *s = &sys->index[sys->current];
 190
 191         if (!sys->b_slave && sys->b_first_time)
 192         {
 193             es_out_SetPCR(demux->out, VLC_TICK_0 + i_barrier);
 194             sys->b_first_time = false;
 195         }
 196
 197         /* Might be a gap in block # */
 198         const uint64_t i_pos = 1024 + 128LL * s->blocknumber;
 199         if(i_pos != vlc_stream_Tell(demux->s) &&
 200            vlc_stream_Seek( demux->s, i_pos ) != VLC_SUCCESS )
 201             return VLC_DEMUXER_EOF;
 202
 203         block_t *b = vlc_stream_Block(demux->s, 128);
 204         if (b && b->i_buffer == 128)
 205         {
 206             b->i_dts =
 207             b->i_pts = VLC_TICK_0 + s->start;
 208             if (s->stop > s->start)
 209                 b->i_length = s->stop - s->start;
 210             es_out_Send(demux->out, sys->es, b);
 211         }
 212         else
 213         {
 214             if(b)
 215                 block_Release(b);
 216             return VLC_DEMUXER_EOF;
 217         }
 218         sys->current++;
 219     }
 220
 221     if (!sys->b_slave)
 222     {
 223         es_out_SetPCR(demux->out, VLC_TICK_0 + i_barrier);
 224         sys->next_date += VLC_TICK_FROM_MS(125);
 225     }
 226
 227     return sys->current < sys->count ? VLC_DEMUXER_SUCCESS : VLC_DEMUXER_EOF;
 228 }
 229
 230 static int Open(vlc_object_t *object)
 231 {
 232     demux_t *demux = (demux_t*)object;
 233
 234     const uint8_t *peek;
 235     if (vlc_stream_Peek(demux->s, &peek, 11) != 11)
 236         return VLC_EGENERIC;
 237
 238     bool is_stl_25 = !memcmp(&peek[3], "STL25.01", 8);
 239     bool is_stl_30 = !memcmp(&peek[3], "STL30.01", 8);
 240     if (!is_stl_25 && !is_stl_30)
 241         return VLC_EGENERIC;
 242     const double fps = is_stl_25 ? 25 : 30;
 243
 244     uint8_t header[1024];
 245     if (vlc_stream_Read(demux->s, header, sizeof(header)) != sizeof(header)) {
 246         msg_Err(demux, "Incomplete EBU STL header");
 247         return VLC_EGENERIC;
 248     }
 249     const int cct = ParseInteger(&header[12], 2);
 250     const vlc_tick_t program_start = ParseTextTimeCode(&header[256], fps);
 251     const size_t tti_count = ParseInteger(&header[238], 5);
 252     if (!tti_count)
 253         return VLC_EGENERIC;
 254     msg_Dbg(demux, "Detected EBU STL : CCT=%d TTI=%zu start=%8.8s %"PRId64, cct, tti_count, &header[256], program_start);
 255
 256     demux_sys_t *sys = malloc(sizeof(*sys));
 257     if(!sys)
 258         return VLC_EGENERIC;
 259
 260     sys->b_slave   = false;
 261     sys->b_first_time = true;
 262     sys->next_date = 0;
 263     sys->current   = 0;
 264     sys->count     = 0;
 265     sys->index     = calloc(tti_count, sizeof(*sys->index));
 266     if(!sys->index)
 267     {
 268         free(sys);
 269         return VLC_EGENERIC;
 270     }
 271
 272     bool comment = false;
 273     stl_entry_t *s = &sys->index[0];
 274     s->count = 0;
 275
 276     for (size_t i = 0; i < tti_count; i++) {
 277         uint8_t tti[16];
 278         if (vlc_stream_Read(demux->s, tti, 16) != 16 ||
 279             vlc_stream_Read(demux->s, NULL, 112) != 112) {
 280             msg_Warn(demux, "Incomplete EBU STL file");
 281             break;
 282         }
 283         const int ebn = tti[3];
 284         if (ebn >= 0xf0 && ebn <= 0xfd)
 285             continue;
 286         if (ebn == 0xfe)
 287             continue;
 288
 289         if (s->count <= 0) {
 290             comment  = tti[15] != 0;
 291             s->start = ParseTimeCode(&tti[5], fps) - program_start;
 292             s->stop  = ParseTimeCode(&tti[9], fps) - program_start;
 293             s->blocknumber = i;
 294         }
 295         s->count++;
 296         if (ebn == 0xff && !comment)
 297             s = &sys->index[++sys->count];
 298         if (ebn == 0xff && sys->count < tti_count)
 299             s->count = 0;
 300     }
 301
 302     demux->p_sys = sys;
 303     if (sys->count == 0 ||
 304         vlc_stream_Seek(demux->s, 1024 + 128LL * sys->index[0].blocknumber) != VLC_SUCCESS)
 305     {
 306         Close(object);
 307         return VLC_EGENERIC;
 308     }
 309
 310     es_format_t fmt;
 311     es_format_Init(&fmt, SPU_ES, VLC_CODEC_EBU_STL);
 312     fmt.i_extra = sizeof(header);
 313     fmt.p_extra = header;
 314
 315     sys->es = es_out_Add(demux->out, &fmt);
 316     fmt.i_extra = 0;
 317     fmt.p_extra = NULL;
 318     es_format_Clean(&fmt);
 319
 320     if(sys->es == NULL)
 321     {
 322         Close(object);
 323         return VLC_EGENERIC;
 324     }
 325
 326     demux->p_sys      = sys;
 327     demux->pf_demux   = Demux;
 328     demux->pf_control = Control;
 329     return VLC_SUCCESS;
 330 }
 331
 332 static void Close(vlc_object_t *object)
 333 {
 334     demux_t *demux = (demux_t*)object;
 335     demux_sys_t *sys = demux->p_sys;
 336
 337     free(sys->index);
 338     free(sys);
 339 }
 340