src/input/stream_filter.c

   1 /*****************************************************************************
   2  * stream_filter.c
   3  *****************************************************************************
   4  * Copyright (C) 2008 Laurent Aimar
   5  *
   6  * Author: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <vlc_common.h>
  28 #include <vlc_stream.h>
  29 #include <vlc_modules.h>
  30 #include <libvlc.h>
  31
  32 #include <assert.h>
  33
  34 #include "stream.h"
  35
  36 struct vlc_stream_filter_private
  37 {
  38     module_t *module;
  39 };
  40
  41 static void StreamDelete(stream_t *s)
  42 {
  43     struct vlc_stream_filter_private *priv = vlc_stream_Private(s);
  44
  45     module_unneed(s, priv->module);
  46     vlc_stream_Delete(s->s);
  47     free(s->psz_filepath);
  48 }
  49
  50 stream_t *vlc_stream_FilterNew( stream_t *p_source,
  51                                 const char *psz_stream_filter )
  52 {
  53     assert(p_source != NULL);
  54
  55     /* Stream filters can only filter byte streams. */
  56     if (p_source->pf_read == NULL && p_source->pf_block == NULL)
  57         return NULL;
  58
  59     struct vlc_stream_filter_private *priv;
  60     stream_t *s = vlc_stream_CustomNew(vlc_object_parent(p_source),
  61                                        StreamDelete, sizeof (*priv),
  62                                        "stream filter");
  63     if( s == NULL )
  64         return NULL;
  65
  66     priv = vlc_stream_Private(s);
  67     s->p_input_item = p_source->p_input_item;
  68
  69     if( p_source->psz_url != NULL )
  70     {
  71         s->psz_url = strdup( p_source->psz_url );
  72         if( unlikely(s->psz_url == NULL) )
  73             goto error;
  74
  75         if( p_source->psz_filepath != NULL )
  76             s->psz_filepath = strdup( p_source->psz_filepath );
  77     }
  78     s->s = p_source;
  79
  80     /* */
  81     priv->module = module_need(s, "stream_filter", psz_stream_filter, true);
  82     if (priv->module == NULL)
  83         goto error;
  84
  85     return s;
  86 error:
  87     free(s->psz_filepath);
  88     stream_CommonDelete( s );
  89     return NULL;
  90 }
  91
  92 /* Add automatic stream filter */
  93 stream_t *stream_FilterAutoNew( stream_t *p_source )
  94 {
  95     /* Limit number of entries to avoid infinite recursion. */
  96     for( unsigned i = 0; i < 16; i++ )
  97     {
  98         stream_t *p_filter = vlc_stream_FilterNew( p_source, NULL );
  99         if( p_filter == NULL )
 100             break;
 101
 102         msg_Dbg( p_filter, "stream filter added to %p", (void *)p_source );
 103         p_source = p_filter;
 104     }
 105     return p_source;
 106 }
 107
 108 /* Add specified stream filter(s) */
 109 stream_t *stream_FilterChainNew( stream_t *p_source, const char *psz_chain )
 110 {
 111     /* Add user stream filter */
 112     char *chain = strdup( psz_chain );
 113     if( unlikely(chain == NULL) )
 114         return p_source;
 115
 116     char *buf;
 117     for( const char *name = strtok_r( chain, ":", &buf );
 118          name != NULL;
 119          name = strtok_r( NULL, ":", &buf ) )
 120     {
 121         stream_t *p_filter = vlc_stream_FilterNew( p_source, name );
 122         if( p_filter != NULL )
 123             p_source = p_filter;
 124         else
 125             msg_Warn( p_source, "cannot insert stream filter %s", name );
 126     }
 127     free( chain );
 128
 129     return p_source;
 130 }