modules/demux/mjpeg.c

   1 /*****************************************************************************
   2  * mjpeg.c : demuxes mjpeg webcam http streams
   3  *****************************************************************************
   4  * Copyright (C) 2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Henry Jen (slowhog) <henryjen@ztune.net>
   8  *          Derk-Jan Hartman (thedj)
   9  *          Sigmund Augdal (Dnumgis)
  10  *          Laurent Aimar <fenrir@via.ecp.fr>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc_common.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_demux.h>
  38
  39 /*****************************************************************************
  40  * Module descriptor
  41  *****************************************************************************/
  42 static int  Open ( vlc_object_t * );
  43 static void Close( vlc_object_t * );
  44
  45 #define FPS_TEXT N_("Frames per Second")
  46 #define FPS_LONGTEXT N_("This is the desired frame rate when " \
  47     "playing MJPEG from a file. Use 0 (this is the default value) for a " \
  48     "live stream (from a camera).")
  49
  50 vlc_module_begin ()
  51     set_shortname( "MJPEG")
  52     set_description( N_("M-JPEG camera demuxer") )
  53     set_capability( "demux", 5 )
  54     set_callbacks( Open, Close )
  55     set_category( CAT_INPUT )
  56     set_subcategory( SUBCAT_INPUT_DEMUX )
  57     add_float( "mjpeg-fps", 0.0, FPS_TEXT, FPS_LONGTEXT, false )
  58 vlc_module_end ()
  59
  60 /*****************************************************************************
  61  * Local prototypes
  62  *****************************************************************************/
  63 static int MimeDemux( demux_t * );
  64 static int MjpgDemux( demux_t * );
  65 static int Control( demux_t *, int i_query, va_list args );
  66
  67 struct demux_sys_t
  68 {
  69     es_format_t     fmt;
  70     es_out_id_t     *p_es;
  71
  72     bool      b_still;
  73     mtime_t         i_still_end;
  74     mtime_t         i_still_length;
  75
  76     mtime_t         i_time;
  77     mtime_t         i_frame_length;
  78     char            *psz_separator;
  79     int             i_frame_size_estimate;
  80     const uint8_t   *p_peek;
  81     int             i_data_peeked;
  82     int             i_level;
  83 };
  84
  85 /*****************************************************************************
  86  * Peek: Helper function to peek data with incremental size.
  87  * \return false if peek no more data, true otherwise.
  88  *****************************************************************************/
  89 static bool Peek( demux_t *p_demux, bool b_first )
  90 {
  91     int i_data;
  92     demux_sys_t *p_sys = p_demux->p_sys;
  93
  94     if( b_first )
  95     {
  96         p_sys->i_data_peeked = 0;
  97     }
  98     else if( p_sys->i_data_peeked == p_sys->i_frame_size_estimate )
  99     {
 100         p_sys->i_frame_size_estimate += 5120;
 101     }
 102     i_data = stream_Peek( p_demux->s, &p_sys->p_peek,
 103                           p_sys->i_frame_size_estimate );
 104     if( i_data == p_sys->i_data_peeked )
 105     {
 106         msg_Warn( p_demux, "no more data" );
 107         return false;
 108     }
 109     p_sys->i_data_peeked = i_data;
 110     if( i_data <= 0 )
 111     {
 112         msg_Warn( p_demux, "cannot peek data" );
 113         return false;
 114     }
 115     return true;
 116 }
 117
 118 /*****************************************************************************
 119  * GetLine: Internal function used to dup a line of string from the buffer
 120  *****************************************************************************/
 121 static char* GetLine( demux_t *p_demux, int *p_pos )
 122 {
 123     demux_sys_t *p_sys = p_demux->p_sys;
 124     const uint8_t *p_buf;
 125     int         i_size;
 126     int         i;
 127     char        *p_line;
 128
 129     while( *p_pos >= p_sys->i_data_peeked )
 130     {
 131         if( ! Peek( p_demux, false ) )
 132         {
 133             return NULL;
 134         }
 135     }
 136     p_buf = p_sys->p_peek + *p_pos;
 137     i_size = p_sys->i_data_peeked - *p_pos;
 138     i = 0;
 139     while( p_buf[i] != '\n' )
 140     {
 141         i++;
 142         if( i == i_size )
 143         {
 144             if( ! Peek( p_demux, false ) )
 145             {
 146                 return NULL;
 147             }
 148             p_buf = p_sys->p_peek + *p_pos;
 149             i_size = p_sys->i_data_peeked - *p_pos;
 150         }
 151     }
 152     *p_pos += ( i + 1 );
 153     if( i > 0 && '\r' == p_buf[i - 1] )
 154     {
 155         i--;
 156     }
 157     p_line = malloc( i + 1 );
 158     if( p_line == NULL )
 159         return NULL;
 160     strncpy ( p_line, (char*)p_buf, i );
 161     p_line[i] = '\0';
 162 //    msg_Dbg( p_demux, "i = %d, pos = %d, %s", i, *p_pos, p_line );
 163     return p_line;
 164 }
 165
 166 /*****************************************************************************
 167  * CheckMimeHeader: Internal function used to verify and skip mime header
 168  * \param p_header_size Return size of MIME header, 0 if no MIME header
 169  * detected, minus value if error
 170  * \return true if content type is image/jpeg, false otherwise
 171  *****************************************************************************/
 172 static bool CheckMimeHeader( demux_t *p_demux, int *p_header_size )
 173 {
 174     bool  b_jpeg = false;
 175     int         i_pos;
 176     char        *psz_line;
 177     char        *p_ch;
 178     demux_sys_t *p_sys = p_demux->p_sys;
 179
 180     if( !Peek( p_demux, true ) )
 181     {
 182         msg_Err( p_demux, "cannot peek" );
 183         *p_header_size = -1;
 184         return false;
 185     }
 186     if( p_sys->i_data_peeked < 5)
 187     {
 188         msg_Err( p_demux, "data shortage" );
 189         *p_header_size = -2;
 190         return false;
 191     }
 192     if( strncmp( (char *)p_sys->p_peek, "--", 2 ) != 0
 193         && strncmp( (char *)p_sys->p_peek, "\r\n--", 4 ) != 0 )
 194     {
 195         *p_header_size = 0;
 196         return false;
 197     }
 198     i_pos = *p_sys->p_peek == '-' ? 2 : 4;
 199     psz_line = GetLine( p_demux, &i_pos );
 200     if( NULL == psz_line )
 201     {
 202         msg_Err( p_demux, "no EOL" );
 203         *p_header_size = -3;
 204         return false;
 205     }
 206
 207     /* Read the separator and remember it if not yet stored */
 208     if( p_sys->psz_separator == NULL )
 209     {
 210         p_sys->psz_separator = psz_line;
 211         msg_Dbg( p_demux, "Multipart MIME detected, using separator: %s",
 212                  p_sys->psz_separator );
 213     }
 214     else
 215     {
 216         if( strcmp( psz_line, p_sys->psz_separator ) )
 217         {
 218             msg_Warn( p_demux, "separator %s does not match %s", psz_line,
 219                       p_sys->psz_separator );
 220         }
 221         free( psz_line );
 222     }
 223
 224     psz_line = GetLine( p_demux, &i_pos );
 225     while( psz_line && *psz_line )
 226     {
 227         if( !strncasecmp( psz_line, "Content-Type:", 13 ) )
 228         {
 229             p_ch = psz_line + 13;
 230             while( *p_ch != '\0' && ( *p_ch == ' ' || *p_ch == '\t' ) ) p_ch++;
 231             if( strncasecmp( p_ch, "image/jpeg", 10 ) )
 232             {
 233                 msg_Warn( p_demux, "%s, image/jpeg is expected", psz_line );
 234                 b_jpeg = false;
 235             }
 236             else
 237             {
 238                 b_jpeg = true;
 239             }
 240         }
 241         else
 242         {
 243             msg_Dbg( p_demux, "discard MIME header: %s", psz_line );
 244         }
 245         free( psz_line );
 246         psz_line = GetLine( p_demux, &i_pos );
 247     }
 248
 249     if( NULL == psz_line )
 250     {
 251         msg_Err( p_demux, "no EOL" );
 252         *p_header_size = -3;
 253         return false;
 254     }
 255
 256     free( psz_line );
 257
 258     *p_header_size = i_pos;
 259     return b_jpeg;
 260 }
 261
 262 static int SendBlock( demux_t *p_demux, int i )
 263 {
 264     demux_sys_t *p_sys = p_demux->p_sys;
 265     block_t     *p_block;
 266
 267     if( ( p_block = stream_Block( p_demux->s, i ) ) == NULL )
 268     {
 269         msg_Warn( p_demux, "cannot read data" );
 270         return 0;
 271     }
 272
 273     if( !p_sys->i_frame_length || !p_sys->i_time )
 274     {
 275         p_sys->i_time = p_block->i_dts = p_block->i_pts = mdate();
 276     }
 277     else
 278     {
 279         p_block->i_dts = p_block->i_pts = VLC_TS_0 + p_sys->i_time;
 280         p_sys->i_time += p_sys->i_frame_length;
 281     }
 282
 283     /* set PCR */
 284     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block->i_pts );
 285     es_out_Send( p_demux->out, p_sys->p_es, p_block );
 286
 287     if( p_sys->b_still )
 288     {
 289         p_sys->i_still_end = mdate() + p_sys->i_still_length;
 290     }
 291
 292     return 1;
 293 }
 294
 295 /*****************************************************************************
 296  * Open: check file and initializes structures
 297  *****************************************************************************/
 298 static int Open( vlc_object_t * p_this )
 299 {
 300     demux_t     *p_demux = (demux_t*)p_this;
 301     demux_sys_t *p_sys;
 302     int         i_size;
 303     bool        b_matched = false;
 304     float       f_fps;
 305
 306     p_demux->pf_control = Control;
 307     p_demux->p_sys      = p_sys = malloc( sizeof( demux_sys_t ) );
 308     p_sys->p_es         = NULL;
 309     p_sys->i_time       = 0;
 310     p_sys->i_level      = 0;
 311
 312     p_sys->psz_separator = NULL;
 313     p_sys->i_frame_size_estimate = 15 * 1024;
 314
 315     b_matched = CheckMimeHeader( p_demux, &i_size);
 316     if( b_matched )
 317     {
 318         p_demux->pf_demux = MimeDemux;
 319         stream_Read( p_demux->s, NULL, i_size );
 320     }
 321     else if( 0 == i_size )
 322     {
 323         /* 0xffd8 identify a JPEG SOI */
 324         if( p_sys->p_peek[0] == 0xFF && p_sys->p_peek[1] == 0xD8 )
 325         {
 326             msg_Dbg( p_demux, "JPEG SOI marker detected" );
 327             p_demux->pf_demux = MjpgDemux;
 328             p_sys->i_level++;
 329         }
 330         else
 331         {
 332             goto error;
 333         }
 334     }
 335     else
 336     {
 337         goto error;
 338     }
 339
 340
 341     f_fps = var_CreateGetFloat( p_demux, "mjpeg-fps" );
 342     p_sys->i_frame_length = 0;
 343
 344     /* Check for jpeg file extension */
 345     p_sys->b_still = false;
 346     p_sys->i_still_end = 0;
 347     if( demux_IsPathExtension( p_demux, ".jpeg" ) ||
 348         demux_IsPathExtension( p_demux, ".jpg" ) )
 349     {
 350         p_sys->b_still = true;
 351         if( f_fps )
 352         {
 353             p_sys->i_still_length = 1000000.0 / f_fps;
 354         }
 355         else
 356         {
 357             /* Defaults to 1fps */
 358             p_sys->i_still_length = 1000000;
 359         }
 360     }
 361     else if ( f_fps )
 362     {
 363         p_sys->i_frame_length = 1000000.0 / f_fps;
 364     }
 365
 366     es_format_Init( &p_sys->fmt, VIDEO_ES, 0 );
 367     p_sys->fmt.i_codec = VLC_CODEC_MJPG;
 368
 369     p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
 370     return VLC_SUCCESS;
 371
 372 error:
 373     free( p_sys );
 374     return VLC_EGENERIC;
 375 }
 376
 377 /*****************************************************************************
 378  * Demux: read packet and send them to decoders
 379  *****************************************************************************
 380  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 381  *****************************************************************************/
 382 static int MjpgDemux( demux_t *p_demux )
 383 {
 384     demux_sys_t *p_sys = p_demux->p_sys;
 385     int i;
 386
 387     if( p_sys->b_still && p_sys->i_still_end )
 388     {
 389         /* Still frame, wait until the pause delay is gone */
 390         mwait( p_sys->i_still_end );
 391         p_sys->i_still_end = 0;
 392         return 1;
 393     }
 394
 395     if( !Peek( p_demux, true ) )
 396     {
 397         msg_Warn( p_demux, "cannot peek data" );
 398         return 0;
 399     }
 400     if( p_sys->i_data_peeked < 4 )
 401     {
 402         msg_Warn( p_demux, "data shortage" );
 403         return 0;
 404     }
 405     i = 3;
 406 FIND_NEXT_EOI:
 407     while( !( 0xFF == p_sys->p_peek[i-1] && 0xD9 == p_sys->p_peek[i] ) )
 408     {
 409         if( 0xFF == p_sys->p_peek[i-1] && 0xD8 == p_sys->p_peek[i] )
 410         {
 411             p_sys->i_level++;
 412             msg_Dbg( p_demux, "we found another JPEG SOI at %d", i );
 413         }
 414         i++;
 415         if( i >= p_sys->i_data_peeked )
 416         {
 417             msg_Dbg( p_demux, "did not find JPEG EOI in %d bytes",
 418                      p_sys->i_data_peeked );
 419             if( !Peek( p_demux, false ) )
 420             {
 421                 msg_Warn( p_demux, "no more data is available at the moment" );
 422                 return 0;
 423             }
 424         }
 425     }
 426     i++;
 427
 428     msg_Dbg( p_demux, "JPEG EOI detected at %d", i );
 429     p_sys->i_level--;
 430
 431     if( p_sys->i_level > 0 )
 432         goto FIND_NEXT_EOI;
 433     return SendBlock( p_demux, i );
 434 }
 435
 436 static int MimeDemux( demux_t *p_demux )
 437 {
 438     demux_sys_t *p_sys = p_demux->p_sys;
 439     int         i_size, i;
 440
 441     bool  b_match = CheckMimeHeader( p_demux, &i_size );
 442
 443     if( i_size > 0 )
 444     {
 445         stream_Read( p_demux->s, NULL, i_size );
 446     }
 447     else if( i_size < 0 )
 448     {
 449         return 0;
 450     }
 451     else
 452     {
 453         // No MIME header, assume OK
 454         b_match = true;
 455     }
 456
 457     if( !Peek( p_demux, true ) )
 458     {
 459         msg_Warn( p_demux, "cannot peek data" );
 460         return 0;
 461     }
 462
 463     i = 0;
 464     i_size = strlen( p_sys->psz_separator ) + 2;
 465     if( p_sys->i_data_peeked < i_size )
 466     {
 467         msg_Warn( p_demux, "data shortage" );
 468         return 0;
 469     }
 470
 471     for( ;; )
 472     {
 473         while( !( p_sys->p_peek[i] == '-' && p_sys->p_peek[i+1] == '-' ) )
 474         {
 475             i++;
 476             i_size++;
 477             if( i_size >= p_sys->i_data_peeked )
 478             {
 479                 msg_Dbg( p_demux, "MIME boundary not found in %d bytes of "
 480                          "data", p_sys->i_data_peeked );
 481
 482                 if( !Peek( p_demux, false ) )
 483                 {
 484                     msg_Warn( p_demux, "no more data is available at the "
 485                               "moment" );
 486                     return 0;
 487                 }
 488             }
 489         }
 490
 491         if( !strncmp( p_sys->psz_separator, (char *)(p_sys->p_peek + i + 2),
 492                       strlen( p_sys->psz_separator ) ) )
 493         {
 494             break;
 495         }
 496
 497         i++;
 498         i_size++;
 499     }
 500
 501     if( !b_match )
 502     {
 503         msg_Err( p_demux, "discard non-JPEG part" );
 504         stream_Read( p_demux->s, NULL, i );
 505         return 0;
 506     }
 507
 508     return SendBlock( p_demux, i );
 509 }
 510
 511 /*****************************************************************************
 512  * Close: frees unused data
 513  *****************************************************************************/
 514 static void Close ( vlc_object_t * p_this )
 515 {
 516     demux_t     *p_demux = (demux_t*)p_this;
 517     demux_sys_t *p_sys  = p_demux->p_sys;
 518
 519     free( p_sys->psz_separator );
 520     free( p_sys );
 521 }
 522
 523 /*****************************************************************************
 524  * Control:
 525  *****************************************************************************/
 526 static int Control( demux_t *p_demux, int i_query, va_list args )
 527 {
 528     return demux_vaControlHelper( p_demux->s, 0, 0, 0, 0, i_query, args );
 529 }