diff options
| -rw-r--r-- | Makefile.am | 2 | ||||
| -rw-r--r-- | src/filter/chain_filter_plugin.c | 177 | ||||
| -rw-r--r-- | src/filter/chain_filter_plugin.h | 48 | ||||
| -rw-r--r-- | src/filter_registry.c | 1 | ||||
| -rw-r--r-- | src/filter_registry.h | 1 |
5 files changed, 229 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am index 3d16ca77..156c1c2d 100644 --- a/Makefile.am +++ b/Makefile.am @@ -45,6 +45,7 @@ mpd_headers = \ src/filter_internal.h \ src/filter_plugin.h \ src/filter_registry.h \ + src/filter/chain_filter_plugin.h \ src/filter/volume_filter_plugin.h \ src/buffer2array.h \ src/command.h \ @@ -583,6 +584,7 @@ endif FILTER_SRC = \ src/filter/null_filter_plugin.c \ + src/filter/chain_filter_plugin.c \ src/filter/volume_filter_plugin.c diff --git a/src/filter/chain_filter_plugin.c b/src/filter/chain_filter_plugin.c new file mode 100644 index 00000000..ec8bef5c --- /dev/null +++ b/src/filter/chain_filter_plugin.c @@ -0,0 +1,177 @@ +/* + * Copyright (C) 2003-2009 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "filter/chain_filter_plugin.h" +#include "filter_plugin.h" +#include "filter_internal.h" +#include "filter_registry.h" + +#include <assert.h> + +struct filter_chain { + /** the base class */ + struct filter base; + + GSList *children; +}; + +static struct filter * +chain_filter_init(G_GNUC_UNUSED const struct config_param *param, + G_GNUC_UNUSED GError **error_r) +{ + struct filter_chain *chain = g_new(struct filter_chain, 1); + + filter_init(&chain->base, &chain_filter_plugin); + chain->children = NULL; + + return &chain->base; +} + +static void +chain_free_child(gpointer data, G_GNUC_UNUSED gpointer user_data) +{ + struct filter *filter = data; + + filter_free(filter); +} + +static void +chain_filter_finish(struct filter *_filter) +{ + struct filter_chain *chain = (struct filter_chain *)_filter; + + g_slist_foreach(chain->children, chain_free_child, NULL); + g_slist_free(chain->children); + + g_free(chain); +} + +/** + * Close all filters in the chain until #until is reached. #until + * itself is not closed. + */ +static void +chain_close_until(struct filter_chain *chain, const struct filter *until) +{ + GSList *i = chain->children; + struct filter *filter; + + while (true) { + /* this assertion fails if #until does not exist + (anymore) */ + assert(i != NULL); + + if (i->data == until) + /* don't close this filter */ + break; + + /* close this filter */ + filter = i->data; + filter_close(filter); + + i = g_slist_next(i); + } +} + +static const struct audio_format * +chain_filter_open(struct filter *_filter, + const struct audio_format *audio_format, + GError **error_r) +{ + struct filter_chain *chain = (struct filter_chain *)_filter; + + for (GSList *i = chain->children; i != NULL; i = g_slist_next(i)) { + struct filter *filter = i->data; + + audio_format = filter_open(filter, audio_format, error_r); + if (audio_format == NULL) { + /* rollback, close all children */ + chain_close_until(chain, filter); + return NULL; + } + } + + /* return the output format of the last filter */ + return audio_format; +} + +static void +chain_close_child(gpointer data, G_GNUC_UNUSED gpointer user_data) +{ + struct filter *filter = data; + + filter_close(filter); +} + +static void +chain_filter_close(struct filter *_filter) +{ + struct filter_chain *chain = (struct filter_chain *)_filter; + + g_slist_foreach(chain->children, chain_close_child, NULL); +} + +static const void * +chain_filter_filter(struct filter *_filter, + const void *src, size_t src_size, + size_t *dest_size_r, GError **error_r) +{ + struct filter_chain *chain = (struct filter_chain *)_filter; + + for (GSList *i = chain->children; i != NULL; i = g_slist_next(i)) { + struct filter *filter = i->data; + + /* feed the output of the previous filter as input + into the current one */ + src = filter_filter(filter, src, src_size, &src_size, error_r); + if (src == NULL) + chain_close_until(chain, filter); + } + + /* return the output of the last filter */ + *dest_size_r = src_size; + return src; +} + +const struct filter_plugin chain_filter_plugin = { + .name = "chain", + .init = chain_filter_init, + .finish = chain_filter_finish, + .open = chain_filter_open, + .close = chain_filter_close, + .filter = chain_filter_filter, +}; + +struct filter * +filter_chain_new(void) +{ + struct filter *filter = filter_new(&chain_filter_plugin, NULL, NULL); + /* chain_filter_init() never fails */ + assert(filter != NULL); + + return filter; +} + +void +filter_chain_append(struct filter *_chain, struct filter *filter) +{ + struct filter_chain *chain = (struct filter_chain *)_chain; + + chain->children = g_slist_append(chain->children, filter); +} diff --git a/src/filter/chain_filter_plugin.h b/src/filter/chain_filter_plugin.h new file mode 100644 index 00000000..f8462b22 --- /dev/null +++ b/src/filter/chain_filter_plugin.h @@ -0,0 +1,48 @@ +/* + * Copyright (C) 2003-2009 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/** \file + * + * A filter chain is a container for several filters. They are + * chained together, i.e. called in a row, one filter passing its + * output to the next one. + */ + +#ifndef MPD_FILTER_CHAIN_H +#define MPD_FILTER_CHAIN_H + +struct filter; + +/** + * Creates a new filter chain. + */ +struct filter * +filter_chain_new(void); + +/** + * Appends a new filter at the end of the filter chain. You must call + * this function before the first filter_open() call. + * + * @param chain the filter chain created with filter_chain_new() + * @param filter the filter to be appended to #chain + */ +void +filter_chain_append(struct filter *chain, struct filter *filter); + +#endif diff --git a/src/filter_registry.c b/src/filter_registry.c index db47ab7d..c8887aab 100644 --- a/src/filter_registry.c +++ b/src/filter_registry.c @@ -25,6 +25,7 @@ const struct filter_plugin *const filter_plugins[] = { &null_filter_plugin, + &chain_filter_plugin, &volume_filter_plugin, NULL, }; diff --git a/src/filter_registry.h b/src/filter_registry.h index af873316..0eb4b8f0 100644 --- a/src/filter_registry.h +++ b/src/filter_registry.h @@ -27,6 +27,7 @@ #define MPD_FILTER_REGISTRY_H extern const struct filter_plugin null_filter_plugin; +extern const struct filter_plugin chain_filter_plugin; extern const struct filter_plugin volume_filter_plugin; const struct filter_plugin * |