src/filter_config.c

   1 /*
   2  * Copyright (C) 2003-2010 The Music Player Daemon Project
   3  * http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include "filter_config.h"
  21 #include "config.h"
  22 #include "conf.h"
  23 #include "filter/chain_filter_plugin.h"
  24 #include "filter_plugin.h"
  25 #include "filter_internal.h"
  26 #include "filter_registry.h"
  27
  28 #include <string.h>
  29
  30
  31 static GQuark
  32 filter_quark(void)
  33 {
  34         return g_quark_from_static_string("filter");
  35 }
  36
  37 /**
  38  * Find the "filter" configuration block for the specified name.
  39  *
  40  * @param filter_template_name the name of the filter template
  41  * @param error_r space to return an error description
  42  * @return the configuration block, or NULL if none was configured
  43  */
  44 static const struct config_param *
  45 filter_plugin_config(const char *filter_template_name, GError **error_r)
  46 {
  47         const struct config_param *param = NULL;
  48
  49         while ((param = config_get_next_param(CONF_AUDIO_FILTER, param)) != NULL) {
  50                 const char *name =
  51                         config_get_block_string(param, "name", NULL);
  52                 if (name == NULL) {
  53                         g_set_error(error_r, filter_quark(), 1,
  54                                     "filter configuration without 'name' name in line %d",
  55                                     param->line);
  56                         return NULL;
  57                 }
  58
  59                 if (strcmp(name, filter_template_name) == 0)
  60                         return param;
  61         }
  62
  63         g_set_error(error_r, filter_quark(), 1,
  64                     "filter template not found: %s",
  65                     filter_template_name);
  66
  67         return NULL;
  68 }
  69
  70 /**
  71  * Builds a filter chain from a configuration string on the form
  72  * "name1, name2, name3, ..." by looking up each name among the
  73  * configured filter sections.
  74  * @param chain the chain to append filters on
  75  * @param spec the filter chain specification
  76  * @param error_r space to return an error description
  77  * @return the number of filters which were successfully added
  78  */
  79 unsigned int
  80 filter_chain_parse(struct filter *chain, const char *spec, GError **error_r)
  81 {
  82
  83         // Split on comma
  84         gchar** tokens = g_strsplit_set(spec, ",", 255);
  85
  86         int added_filters = 0;
  87
  88         // Add each name to the filter chain by instantiating an actual filter
  89         char **template_names = tokens;
  90         while (*template_names != NULL) {
  91                 struct filter *f;
  92                 const struct config_param *cfg;
  93
  94                 // Squeeze whitespace
  95                 g_strstrip(*template_names);
  96
  97                 cfg = filter_plugin_config(*template_names, error_r);
  98                 if (cfg == NULL) {
  99                         // The error has already been set, just stop.
 100                         break;
 101                 }
 102
 103                 // Instantiate one of those filter plugins with the template name as a hint
 104                 f = filter_configured_new(cfg, error_r);
 105                 if (f == NULL) {
 106                         // The error has already been set, just stop.
 107                         break;
 108                 }
 109
 110                 filter_chain_append(chain, f);
 111                 ++added_filters;
 112
 113                 ++template_names;
 114         }
 115
 116         g_strfreev(tokens);
 117
 118         return added_filters;
 119 }