modules/stream_filter/accesstweaks.c

   1 /*****************************************************************************
   2  * accesstweaks.c Access controls tweaking stream filter
   3  *****************************************************************************
   4  * Copyright (C) 2015 VideoLAN Authors
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 /*****************************************************************************
  22  * Preamble
  23  *****************************************************************************/
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <vlc_common.h>
  29 #include <vlc_plugin.h>
  30 #include <vlc_stream.h>
  31 #include <assert.h>
  32
  33 static int  Open(vlc_object_t *);
  34 static void Close(vlc_object_t *);
  35
  36 vlc_module_begin ()
  37     set_shortname("accesstweaks")
  38     set_category (CAT_INPUT)
  39     set_subcategory (SUBCAT_INPUT_STREAM_FILTER)
  40     set_capability ("stream_filter", 0)
  41     /* Developers only module, no translation please */
  42     set_description ("Access controls tweaking")
  43     set_callbacks (Open, Close)
  44
  45     add_bool ("seek", true, "forces result of the CAN_SEEK control", NULL, false)
  46         change_volatile ()
  47     add_bool ("fastseek", true, "forces result of the CAN_FASTSEEK control", NULL, false)
  48         change_volatile ()
  49     add_shortcut("tweaks")
  50 vlc_module_end ()
  51
  52 struct stream_sys_t
  53 {
  54     bool b_seek;
  55     bool b_fastseek;
  56 };
  57
  58 /**
  59  *
  60  */
  61 static int Control( stream_t *p_stream, int i_query, va_list args )
  62 {
  63     stream_sys_t *p_sys = p_stream->p_sys;
  64
  65     switch( i_query )
  66     {
  67     case STREAM_CAN_FASTSEEK:
  68         if( !p_sys->b_fastseek || !p_sys->b_seek )
  69         {
  70             *va_arg( args, bool* ) = false;
  71             return VLC_SUCCESS;
  72         }
  73         break;
  74     case STREAM_CAN_SEEK:
  75         if( !p_sys->b_seek )
  76         {
  77             *va_arg( args, bool* ) = false;
  78             return VLC_SUCCESS;
  79         }
  80         break;
  81
  82     default:
  83         break;
  84     }
  85
  86     return vlc_stream_vaControl( p_stream->p_source, i_query, args );
  87 }
  88
  89 static ssize_t Read( stream_t *s, void *buffer, size_t i_read )
  90 {
  91     return vlc_stream_Read( s->p_source, buffer, i_read );
  92 }
  93
  94 static int Seek( stream_t *s, uint64_t offset )
  95 {
  96     stream_sys_t *p_sys = s->p_sys;
  97
  98     assert( p_sys->b_seek );
  99     return vlc_stream_Seek( s->p_source, offset );
 100 }
 101
 102 static int Open( vlc_object_t *p_object )
 103 {
 104     stream_t *p_stream = (stream_t *) p_object;
 105
 106     stream_sys_t *p_sys = p_stream->p_sys = malloc( sizeof(*p_sys) );
 107     if (unlikely(p_sys == NULL))
 108         return VLC_ENOMEM;
 109
 110     p_sys->b_seek = var_InheritBool( p_stream, "seek" );
 111     p_sys->b_fastseek = var_InheritBool( p_stream, "fastseek" );
 112
 113     p_stream->pf_read = Read;
 114     p_stream->pf_seek = p_sys->b_seek ? Seek : NULL;
 115     p_stream->pf_control = Control;
 116
 117     return VLC_SUCCESS;
 118 }
 119
 120 static void Close ( vlc_object_t *p_object )
 121 {
 122     stream_t *p_stream = (stream_t *)p_object;
 123     free( p_stream->p_sys );
 124 }