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 #include <vlc_codecs.h>
  31
  32 #include "asf.h"
  33 #include "buffer.h"
  34
  35 void  GenerateGuid ( guid_t *p_guid )
  36 {
  37     p_guid->Data1 = 0xbabac001;
  38     vlc_rand_bytes(&p_guid->Data2, sizeof(p_guid->Data2));
  39     vlc_rand_bytes(&p_guid->Data3, sizeof(p_guid->Data3));
  40     vlc_rand_bytes(p_guid->Data4, sizeof(p_guid->Data4));
  41 }
  42
  43 void  asf_HeaderParse ( asf_header_t *hdr,
  44                             uint8_t *p_header, int i_header )
  45 {
  46     var_buffer_t buffer;
  47     guid_t      guid;
  48     uint64_t    i_size;
  49
  50     hdr->i_file_size = 0;
  51     hdr->i_data_packets_count = 0;
  52     hdr->i_min_data_packet_size = 0;
  53     for( unsigned i = 0; i < 128; i++ )
  54     {
  55         hdr->stream[i].i_cat = ASF_STREAM_UNKNOWN;
  56         hdr->stream[i].i_selected = 0;
  57         hdr->stream[i].i_bitrate = -1;
  58     }
  59
  60     var_buffer_initread( &buffer, p_header, i_header );
  61     var_buffer_getguid( &buffer, &guid );
  62
  63     if( !guidcmp( &guid, &asf_object_header_guid ) )
  64     {
  65         /* ERROR: */
  66     }
  67     var_buffer_getmemory( &buffer, NULL, 30 - 16 );
  68
  69     for( ;; )
  70     {
  71         var_buffer_getguid( &buffer, &guid );
  72         i_size = var_buffer_get64( &buffer );
  73
  74         if( guidcmp( &guid, &asf_object_file_properties_guid ) )
  75         {
  76             var_buffer_getmemory( &buffer, NULL, 16 );
  77             hdr->i_file_size            = var_buffer_get64( &buffer );
  78             var_buffer_getmemory( &buffer, NULL, 8 );
  79             hdr->i_data_packets_count   = var_buffer_get64( &buffer );
  80             var_buffer_getmemory( &buffer, NULL, 8+8+8+4);
  81             hdr->i_min_data_packet_size = var_buffer_get32( &buffer );
  82
  83             var_buffer_getmemory( &buffer, NULL, i_size - 24 - 16 - 8 - 8 - 8 - 8-8-8-4 - 4);
  84         }
  85         else if( guidcmp( &guid, &asf_object_header_extension_guid ) )
  86         {
  87             /* Enter it */
  88             var_buffer_getmemory( &buffer, NULL, 46 - 24 );
  89         }
  90         else if( guidcmp( &guid, &asf_object_extended_stream_properties_guid ) )
  91         {
  92             /* Grrrrrr */
  93             int16_t i_count1, i_count2;
  94             int i_subsize;
  95
  96             var_buffer_getmemory( &buffer, NULL, 84 - 24 );
  97
  98             i_count1 = var_buffer_get16( &buffer );
  99             i_count2 = var_buffer_get16( &buffer );
 100
 101             i_subsize = 88;
 102             for( int i = 0; i < i_count1; i++ )
 103             {
 104                 int i_len;
 105
 106                 var_buffer_get16( &buffer );
 107                 i_len = var_buffer_get16( &buffer );
 108                 var_buffer_getmemory( &buffer, NULL, i_len );
 109
 110                 i_subsize += 4 + i_len;
 111             }
 112
 113             for( int i = 0; i < i_count2; i++ )
 114             {
 115                 int i_len;
 116                 var_buffer_getmemory( &buffer, NULL, 16 + 2 );
 117                 i_len = var_buffer_get32( &buffer );
 118                 var_buffer_getmemory( &buffer, NULL, i_len );
 119
 120                 i_subsize += 16 + 6 + i_len;
 121             }
 122
 123             if( i_size - i_subsize <= 24 )
 124             {
 125                 var_buffer_getmemory( &buffer, NULL, i_size - i_subsize );
 126             }
 127             /* It's a hack we just skip the first part of the object until
 128              * the embed stream properties if any (ugly, but whose fault ?) */
 129         }
 130         else if( guidcmp( &guid, &asf_object_stream_properties_guid ) )
 131         {
 132             int     i_stream_id;
 133             guid_t  stream_type;
 134
 135             var_buffer_getguid( &buffer, &stream_type );
 136             var_buffer_getmemory( &buffer, NULL, 32 );
 137
 138             i_stream_id = var_buffer_get8( &buffer ) & 0x7f;
 139             var_buffer_getmemory( &buffer, NULL, i_size - 24 - 32 - 16 - 1);
 140
 141             if( guidcmp( &stream_type, &asf_object_stream_type_video ) )
 142             {
 143                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_VIDEO;
 144             }
 145             else if( guidcmp( &stream_type, &asf_object_stream_type_audio ) )
 146             {
 147                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_AUDIO;
 148             }
 149             else
 150             {
 151                 hdr->stream[i_stream_id].i_cat = ASF_STREAM_UNKNOWN;
 152             }
 153         }
 154         else if ( guidcmp( &guid, &asf_object_stream_bitrate_properties ) )
 155         {
 156             int     i_count;
 157             uint8_t i_stream_id;
 158
 159             i_count = var_buffer_get16( &buffer );
 160             i_size -= 2;
 161             while( i_count > 0 )
 162             {
 163                 i_stream_id = var_buffer_get16( &buffer )&0x7f;
 164                 hdr->stream[i_stream_id].i_bitrate =  var_buffer_get32( &buffer );
 165                 i_count--;
 166                 i_size -= 6;
 167             }
 168             var_buffer_getmemory( &buffer, NULL, i_size - 24 );
 169         }
 170         else
 171         {
 172             // skip unknown guid
 173             var_buffer_getmemory( &buffer, NULL, i_size - 24 );
 174         }
 175
 176         if( var_buffer_readempty( &buffer ) )
 177             return;
 178     }
 179 }
 180
 181 void  asf_StreamSelect  ( asf_header_t *hdr,
 182                               int i_bitrate_max,
 183                               bool b_all, bool b_audio, bool b_video )
 184 {
 185     /* XXX FIXME use mututal eclusion information */
 186     unsigned i;
 187     int i_audio, i_video;
 188     int i_bitrate_total;
 189 #if 0
 190     char *psz_stream;
 191 #endif
 192
 193     i_audio = 0;
 194     i_video = 0;
 195     i_bitrate_total = 0;
 196     if( b_all )
 197     {
 198         /* select all valid stream */
 199         for( i = 1; i < 128; i++ )
 200         {
 201             if( hdr->stream[i].i_cat != ASF_STREAM_UNKNOWN )
 202             {
 203                 hdr->stream[i].i_selected = 1;
 204             }
 205         }
 206         return;
 207     }
 208     else
 209     {
 210         for( i = 0; i < 128; i++ )
 211         {
 212             /* by default, not selected */
 213             hdr->stream[i].i_selected = 0;
 214         }
 215     }
 216
 217     /* big test:
 218      * select a stream if
 219      *    - no audio nor video stream
 220      *    - or:
 221      *         - if i_bitrate_max not set keep the highest bitrate
 222      *         - if i_bitrate_max is set, keep stream that make we used best
 223      *           quality regarding i_bitrate_max
 224      *
 225      * XXX: little buggy:
 226      *        - it doesn't use mutual exclusion info..
 227      *        - when selecting a better stream we could select
 228      *        something that make i_bitrate_total> i_bitrate_max
 229      */
 230     for( i = 1; i < 128; i++ )
 231     {
 232         if( hdr->stream[i].i_cat == ASF_STREAM_UNKNOWN )
 233         {
 234             continue;
 235         }
 236         else if( hdr->stream[i].i_cat == ASF_STREAM_AUDIO && b_audio &&
 237                  ( i_audio <= 0 ||
 238                     ( ( ( hdr->stream[i].i_bitrate > hdr->stream[i_audio].i_bitrate &&
 239                           ( i_bitrate_total + hdr->stream[i].i_bitrate - hdr->stream[i_audio].i_bitrate
 240                                             < i_bitrate_max || !i_bitrate_max) ) ||
 241                         ( hdr->stream[i].i_bitrate < hdr->stream[i_audio].i_bitrate &&
 242                               i_bitrate_max != 0 && i_bitrate_total > i_bitrate_max )
 243                       ) )  ) )
 244         {
 245             /* unselect old stream */
 246             if( i_audio > 0 )
 247             {
 248                 hdr->stream[i_audio].i_selected = 0;
 249                 if( hdr->stream[i_audio].i_bitrate> 0 )
 250                 {
 251                     i_bitrate_total -= hdr->stream[i_audio].i_bitrate;
 252                 }
 253             }
 254
 255             hdr->stream[i].i_selected = 1;
 256             if( hdr->stream[i].i_bitrate> 0 )
 257             {
 258                 i_bitrate_total += hdr->stream[i].i_bitrate;
 259             }
 260             i_audio = i;
 261         }
 262         else if( hdr->stream[i].i_cat == ASF_STREAM_VIDEO && b_video &&
 263                  ( i_video <= 0 ||
 264                     (
 265                         ( ( hdr->stream[i].i_bitrate > hdr->stream[i_video].i_bitrate &&
 266                             ( i_bitrate_total + hdr->stream[i].i_bitrate - hdr->stream[i_video].i_bitrate
 267                                             < i_bitrate_max || !i_bitrate_max) ) ||
 268                           ( hdr->stream[i].i_bitrate < hdr->stream[i_video].i_bitrate &&
 269                             i_bitrate_max != 0 && i_bitrate_total > i_bitrate_max )
 270                         ) ) )  )
 271         {
 272             /* unselect old stream */
 273             if( i_video > 0 )
 274             {
 275                 hdr->stream[i_video].i_selected = 0;
 276                 if( hdr->stream[i_video].i_bitrate> 0 )
 277                 {
 278                     i_bitrate_total -= hdr->stream[i_video].i_bitrate;
 279                 }
 280             }
 281
 282             hdr->stream[i].i_selected = 1;
 283             if( hdr->stream[i].i_bitrate> 0 )
 284             {
 285                 i_bitrate_total += hdr->stream[i].i_bitrate;
 286             }
 287             i_video = i;
 288         }
 289
 290     }
 291 }