modules/access/mms/asf.c

   1 /*****************************************************************************
   2  * asf.c: MMS access plug-in
   3  *****************************************************************************
   4  * Copyright (C) 2001-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <vlc_common.h>
  29 #include <vlc_rand.h>
  30
  31 #include "asf.h"
  32 #include "buffer.h"
  33
  34 static int CmpGuid( const guid_t *p_guid1, const guid_t *p_guid2 )
  35 {
  36     return( ( p_guid1->v1 == p_guid2->v1 &&
  37               p_guid1->v2 == p_guid2->v2 &&
  38               p_guid1->v3 == p_guid2->v3 &&
  39               p_guid1->v4[0] == p_guid2->v4[0] &&
  40               p_guid1->v4[1] == p_guid2->v4[1] &&
  41               p_guid1->v4[2] == p_guid2->v4[2] &&
  42               p_guid1->v4[3] == p_guid2->v4[3] &&
  43               p_guid1->v4[4] == p_guid2->v4[4] &&
  44               p_guid1->v4[5] == p_guid2->v4[5] &&
  45               p_guid1->v4[6] == p_guid2->v4[6] &&
  46               p_guid1->v4[7] == p_guid2->v4[7] ) ? 1 : 0 );
  47 }
  48
  49 void  GenerateGuid ( guid_t *p_guid )
  50 {
  51     p_guid->v1 = 0xbabac001;
  52     vlc_rand_bytes(&p_guid->v2, sizeof(p_guid->v2));
  53     vlc_rand_bytes(&p_guid->v3, sizeof(p_guid->v3));
  54     vlc_rand_bytes(p_guid->v4, sizeof(p_guid->v4));
  55 }
  56
  57 void  asf_HeaderParse ( asf_header_t *hdr,
  58                             uint8_t *p_header, int i_header )
  59 {
  60     var_buffer_t buffer;
  61     guid_t      guid;
  62     uint64_t    i_size;
  63     int         i;
  64
  65     hdr->i_file_size = 0;
  66     hdr->i_data_packets_count = 0;
  67     hdr->i_min_data_packet_size = 0;
  68     for( i = 0; i < 128; i++ )
  69     {
  70         hdr->stream[i].i_cat = ASF_STREAM_UNKNOWN;
  71         hdr->stream[i].i_selected = 0;
  72         hdr->stream[i].i_bitrate = -1;
  73     }
  74
  75     var_buffer_initread( &buffer, p_header, i_header );
  76     var_buffer_getguid( &buffer, &guid );
  77
  78     if( !CmpGuid( &guid, &asf_object_header_guid ) )
  79     {
  80         /* ERROR: */
  81     }
  82     var_buffer_getmemory( &buffer, NULL, 30 - 16 );
  83
  84     for( ;; )
  85     {
  86         var_buffer_getguid( &buffer, &guid );
  87         i_size = var_buffer_get64( &buffer );
  88
  89         if( CmpGuid( &guid, &asf_object_file_properties_guid ) )
  90         {
  91             var_buffer_getmemory( &buffer, NULL, 16 );
  92             hdr->i_file_size            = var_buffer_get64( &buffer );
  93             var_buffer_getmemory( &buffer, NULL, 8 );
  94             hdr->i_data_packets_count   = var_buffer_get64( &buffer );
  95             var_buffer_getmemory( &buffer, NULL, 8+8+8+4);
  96             hdr->i_min_data_packet_size = var_buffer_get32( &buffer );
  97
  98             var_buffer_getmemory( &buffer, NULL, i_size - 24 - 16 - 8 - 8 - 8 - 8-8-8-4 - 4);
  99         }
 100         else if( CmpGuid( &guid, &asf_object_header_extension_guid ) )
 101         {
 102             /* Enter it */
 103             var_buffer_getmemory( &buffer, NULL, 46 - 24 );
 104         }
 105         else if( CmpGuid( &guid, &asf_object_extended_stream_properties_guid ) )
 106         {
 107             /* Grrrrrr */
 108             int16_t i_count1, i_count2;
 109             int i_subsize;
 110             int i;
 111
 112             var_buffer_getmemory( &buffer, NULL, 84 - 24 );
 113
 114             i_count1 = var_buffer_get16( &buffer );
 115             i_count2 = var_buffer_get16( &buffer );
 116
 117             i_subsize = 88;
 118             for( i = 0; i < i_count1; i++ )
 119             {
 120                 int i_len;
 121
 122                 var_buffer_get16( &buffer );
 123                 i_len = var_buffer_get16( &buffer );
 124                 var_buffer_getmemory( &buffer, NULL, i_len );
 125
 126                 i_subsize = 4 + i_len;
 127             }
 128
 129             for( i = 0; i < i_count2; i++ )
 130             {
 131                 int i_len;
 132                 var_buffer_getmemory( &buffer, NULL, 16 + 2 );
 133                 i_len = var_buffer_get32( &buffer );
 134                 var_buffer_getmemory( &buffer, NULL, i_len );
 135
 136                 i_subsize += 16 + 6 + i_len;
 137             }
 138
 139             if( i_size - i_subsize <= 24 )
 140             {
 141                 var_buffer_getmemory( &buffer, NULL, i_size - i_subsize );
 142             }
 143             /* It's a hack we just skip the first part of the object until
 144              * the embed stream properties if any (ugly, but whose fault ?) */
 145         }
 146         else if( CmpGuid( &guid, &asf_object_stream_properties_guid ) )
 147         {
 148             int     i_stream_id;
 149             guid_t  stream_type;
 150
 151             var_buffer_getguid( &buffer, &stream_type );
 152             var_buffer_getmemory( &buffer, NULL, 32 );
 153
 154             i_stream_id = var_buffer_get8( &buffer ) & 0x7f;
 155             var_buffer_getmemory( &buffer, NULL, i_size - 24 - 32 - 16 - 1);
 156
 157             if( CmpGuid( &stream_type, &asf_object_stream_type_video ) )
 158             {
 159                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_VIDEO;
 160             }
 161             else if( CmpGuid( &stream_type, &asf_object_stream_type_audio ) )
 162             {
 163                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_AUDIO;
 164             }
 165             else
 166             {
 167                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_UNKNOWN;
 168             }
 169         }
 170         else if ( CmpGuid( &guid, &asf_object_bitrate_properties_guid ) )
 171         {
 172             int     i_count;
 173             uint8_t i_stream_id;
 174
 175             i_count = var_buffer_get16( &buffer );
 176             i_size -= 2;
 177             while( i_count > 0 )
 178             {
 179                 i_stream_id = var_buffer_get16( &buffer )&0x7f;
 180                 hdr->stream[i_stream_id].i_bitrate =  var_buffer_get32( &buffer );
 181                 i_count--;
 182                 i_size -= 6;
 183             }
 184             var_buffer_getmemory( &buffer, NULL, i_size - 24 );
 185         }
 186         else
 187         {
 188             // skip unknown guid
 189             var_buffer_getmemory( &buffer, NULL, i_size - 24 );
 190         }
 191
 192         if( var_buffer_readempty( &buffer ) )
 193             return;
 194     }
 195 }
 196
 197 void  asf_StreamSelect  ( asf_header_t *hdr,
 198                               int i_bitrate_max,
 199                               bool b_all, bool b_audio, bool b_video )
 200 {
 201     /* XXX FIXME use mututal eclusion information */
 202     int i;
 203     int i_audio, i_video;
 204     int i_bitrate_total;
 205 #if 0
 206     char *psz_stream;
 207 #endif
 208
 209     i_audio = 0;
 210     i_video = 0;
 211     i_bitrate_total = 0;
 212     if( b_all )
 213     {
 214         /* select all valid stream */
 215         for( i = 1; i < 128; i++ )
 216         {
 217             if( hdr->stream[i].i_cat != ASF_STREAM_UNKNOWN )
 218             {
 219                 hdr->stream[i].i_selected = 1;
 220             }
 221         }
 222         return;
 223     }
 224     else
 225     {
 226         for( i = 0; i < 128; i++ )
 227         {
 228             /* by default, not selected */
 229             hdr->stream[i].i_selected = 0;
 230         }
 231     }
 232
 233     /* big test:
 234      * select a stream if
 235      *    - no audio nor video stream
 236      *    - or:
 237      *         - if i_bitrate_max not set keep the highest bitrate
 238      *         - if i_bitrate_max is set, keep stream that make we used best
 239      *           quality regarding i_bitrate_max
 240      *
 241      * XXX: little buggy:
 242      *        - it doesn't use mutual exclusion info..
 243      *        - when selecting a better stream we could select
 244      *        something that make i_bitrate_total> i_bitrate_max
 245      */
 246     for( i = 1; i < 128; i++ )
 247     {
 248         if( hdr->stream[i].i_cat == ASF_STREAM_UNKNOWN )
 249         {
 250             continue;
 251         }
 252         else if( hdr->stream[i].i_cat == ASF_STREAM_AUDIO && b_audio &&
 253                  ( i_audio <= 0 ||
 254                     ( ( ( hdr->stream[i].i_bitrate > hdr->stream[i_audio].i_bitrate &&
 255                           ( i_bitrate_total + hdr->stream[i].i_bitrate - hdr->stream[i_audio].i_bitrate
 256                                             < i_bitrate_max || !i_bitrate_max) ) ||
 257                         ( hdr->stream[i].i_bitrate < hdr->stream[i_audio].i_bitrate &&
 258                               i_bitrate_max != 0 && i_bitrate_total > i_bitrate_max )
 259                       ) )  ) )
 260         {
 261             /* unselect old stream */
 262             if( i_audio > 0 )
 263             {
 264                 hdr->stream[i_audio].i_selected = 0;
 265                 if( hdr->stream[i_audio].i_bitrate> 0 )
 266                 {
 267                     i_bitrate_total -= hdr->stream[i_audio].i_bitrate;
 268                 }
 269             }
 270
 271             hdr->stream[i].i_selected = 1;
 272             if( hdr->stream[i].i_bitrate> 0 )
 273             {
 274                 i_bitrate_total += hdr->stream[i].i_bitrate;
 275             }
 276             i_audio = i;
 277         }
 278         else if( hdr->stream[i].i_cat == ASF_STREAM_VIDEO && b_video &&
 279                  ( i_video <= 0 ||
 280                     (
 281                         ( ( hdr->stream[i].i_bitrate > hdr->stream[i_video].i_bitrate &&
 282                             ( i_bitrate_total + hdr->stream[i].i_bitrate - hdr->stream[i_video].i_bitrate
 283                                             < i_bitrate_max || !i_bitrate_max) ) ||
 284                           ( hdr->stream[i].i_bitrate < hdr->stream[i_video].i_bitrate &&
 285                             i_bitrate_max != 0 && i_bitrate_total > i_bitrate_max )
 286                         ) ) )  )
 287         {
 288             /* unselect old stream */
 289             if( i_video > 0 )
 290             {
 291                 hdr->stream[i_video].i_selected = 0;
 292                 if( hdr->stream[i_video].i_bitrate> 0 )
 293                 {
 294                     i_bitrate_total -= hdr->stream[i_video].i_bitrate;
 295                 }
 296             }
 297
 298             hdr->stream[i].i_selected = 1;
 299             if( hdr->stream[i].i_bitrate> 0 )
 300             {
 301                 i_bitrate_total += hdr->stream[i].i_bitrate;
 302             }
 303             i_video = i;
 304         }
 305
 306     }
 307 }