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/*
* Copyright (C) 2003-2013 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 "config.h"
#include "ChainFilterPlugin.hxx"
#include "conf.h"
#include "FilterPlugin.hxx"
#include "FilterInternal.hxx"
#include "FilterRegistry.hxx"
#include "audio_format.h"
#include <glib.h>
#include <list>
#include <assert.h>
struct ChainFilter {
/** the base class */
struct filter base;
std::list<struct filter *> children;
ChainFilter() {
filter_init(&base, &chain_filter_plugin);
}
~ChainFilter() {
for (auto i : children)
filter_free(i);
}
};
static inline GQuark
filter_quark(void)
{
return g_quark_from_static_string("filter");
}
static struct filter *
chain_filter_init(gcc_unused const struct config_param *param,
gcc_unused GError **error_r)
{
ChainFilter *chain = new ChainFilter();
return &chain->base;
}
static void
chain_filter_finish(struct filter *_filter)
{
ChainFilter *chain = (ChainFilter *)_filter;
delete chain;
}
/**
* Close all filters in the chain until #until is reached. #until
* itself is not closed.
*/
static void
chain_close_until(ChainFilter *chain, const struct filter *until)
{
for (auto filter : chain->children) {
if (filter == until)
/* don't close this filter */
return;
/* close this filter */
filter_close(filter);
}
/* this assertion fails if #until does not exist (anymore) */
assert(false);
}
static const struct audio_format *
chain_open_child(struct filter *filter,
const struct audio_format *prev_audio_format,
GError **error_r)
{
struct audio_format conv_audio_format = *prev_audio_format;
const struct audio_format *next_audio_format;
next_audio_format = filter_open(filter, &conv_audio_format, error_r);
if (next_audio_format == NULL)
return NULL;
if (!audio_format_equals(&conv_audio_format, prev_audio_format)) {
struct audio_format_string s;
filter_close(filter);
g_set_error(error_r, filter_quark(), 0,
"Audio format not supported by filter '%s': %s",
filter->plugin->name,
audio_format_to_string(prev_audio_format, &s));
return NULL;
}
return next_audio_format;
}
static const struct audio_format *
chain_filter_open(struct filter *_filter, struct audio_format *in_audio_format,
GError **error_r)
{
ChainFilter *chain = (ChainFilter *)_filter;
const struct audio_format *audio_format = in_audio_format;
for (auto filter : chain->children) {
audio_format = chain_open_child(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_filter_close(struct filter *_filter)
{
ChainFilter *chain = (ChainFilter *)_filter;
for (auto filter : chain->children)
filter_close(filter);
}
static const void *
chain_filter_filter(struct filter *_filter,
const void *src, size_t src_size,
size_t *dest_size_r, GError **error_r)
{
ChainFilter *chain = (ChainFilter *)_filter;
for (auto filter : chain->children) {
/* 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)
return NULL;
}
/* return the output of the last filter */
*dest_size_r = src_size;
return src;
}
const struct filter_plugin chain_filter_plugin = {
"chain",
chain_filter_init,
chain_filter_finish,
chain_filter_open,
chain_filter_close,
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)
{
ChainFilter *chain = (ChainFilter *)_chain;
chain->children.push_back(filter);
}
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