68 lines
1.9 KiB
C++
68 lines
1.9 KiB
C++
/*
|
|
* Copyright (C) 2003-2015 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
|
|
*
|
|
* Internal stuff for the filter core and filter plugins.
|
|
*/
|
|
|
|
#ifndef MPD_FILTER_INTERNAL_HXX
|
|
#define MPD_FILTER_INTERNAL_HXX
|
|
|
|
#include <stddef.h>
|
|
|
|
struct AudioFormat;
|
|
class Error;
|
|
template<typename T> struct ConstBuffer;
|
|
|
|
class Filter {
|
|
public:
|
|
virtual ~Filter() {}
|
|
|
|
/**
|
|
* Opens the filter, preparing it for FilterPCM().
|
|
*
|
|
* @param af the audio format of incoming data; the
|
|
* plugin may modify the object to enforce another input
|
|
* format
|
|
* @param error location to store the error occurring
|
|
* @return the format of outgoing data or
|
|
* AudioFormat::Undefined() on error
|
|
*/
|
|
virtual AudioFormat Open(AudioFormat &af, Error &error) = 0;
|
|
|
|
/**
|
|
* Closes the filter. After that, you may call Open() again.
|
|
*/
|
|
virtual void Close() = 0;
|
|
|
|
/**
|
|
* Filters a block of PCM data.
|
|
*
|
|
* @param src the input buffer
|
|
* @param error location to store the error occurring
|
|
* @return the destination buffer on success (will be
|
|
* invalidated by Close() or FilterPCM()), nullptr on
|
|
* error
|
|
*/
|
|
virtual ConstBuffer<void> FilterPCM(ConstBuffer<void> src, Error &error) = 0;
|
|
};
|
|
|
|
#endif
|