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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 "FilterPlugin.hxx"
#include "FilterInternal.hxx"
#include "FilterRegistry.hxx"
#include "AudioFormat.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
#include <list>
#include <assert.h>
class ChainFilter final : public Filter {
struct Child {
const char *name;
Filter *filter;
Child(const char *_name, Filter *_filter)
:name(_name), filter(_filter) {}
~Child() {
delete filter;
}
Child(const Child &) = delete;
Child &operator=(const Child &) = delete;
};
std::list<Child> children;
public:
void Append(const char *name, Filter *filter) {
children.emplace_back(name, filter);
}
virtual AudioFormat Open(AudioFormat &af, Error &error) override;
virtual void Close();
virtual const void *FilterPCM(const void *src, size_t src_size,
size_t *dest_size_r, Error &error);
private:
/**
* Close all filters in the chain until #until is reached.
* #until itself is not closed.
*/
void CloseUntil(const Filter *until);
};
static constexpr Domain chain_filter_domain("chain_filter");
static Filter *
chain_filter_init(gcc_unused const config_param ¶m,
gcc_unused Error &error)
{
return new ChainFilter();
}
void
ChainFilter::CloseUntil(const Filter *until)
{
for (auto &child : children) {
if (child.filter == until)
/* don't close this filter */
return;
/* close this filter */
child.filter->Close();
}
/* this assertion fails if #until does not exist (anymore) */
assert(false);
gcc_unreachable();
}
static AudioFormat
chain_open_child(const char *name, Filter *filter,
const AudioFormat &prev_audio_format,
Error &error)
{
AudioFormat conv_audio_format = prev_audio_format;
const AudioFormat next_audio_format =
filter->Open(conv_audio_format, error);
if (!next_audio_format.IsDefined())
return next_audio_format;
if (conv_audio_format != prev_audio_format) {
struct audio_format_string s;
filter->Close();
error.Format(chain_filter_domain,
"Audio format not supported by filter '%s': %s",
name,
audio_format_to_string(prev_audio_format, &s));
return AudioFormat::Undefined();
}
return next_audio_format;
}
AudioFormat
ChainFilter::Open(AudioFormat &in_audio_format, Error &error)
{
AudioFormat audio_format = in_audio_format;
for (auto &child : children) {
audio_format = chain_open_child(child.name, child.filter,
audio_format, error);
if (!audio_format.IsDefined()) {
/* rollback, close all children */
CloseUntil(child.filter);
break;
}
}
/* return the output format of the last filter */
return audio_format;
}
void
ChainFilter::Close()
{
for (auto &child : children)
child.filter->Close();
}
const void *
ChainFilter::FilterPCM(const void *src, size_t src_size,
size_t *dest_size_r, Error &error)
{
for (auto &child : children) {
/* feed the output of the previous filter as input
into the current one */
src = child.filter->FilterPCM(src, src_size, &src_size,
error);
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,
};
Filter *
filter_chain_new(void)
{
return new ChainFilter();
}
void
filter_chain_append(Filter &_chain, const char *name, Filter *filter)
{
ChainFilter &chain = (ChainFilter &)_chain;
chain.Append(name, filter);
}
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