75 lines
2.1 KiB
C++
75 lines
2.1 KiB
C++
/*
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* Copyright (C) 2003-2013 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/** \file
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*
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* Internal stuff for the filter core and filter plugins.
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*/
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#ifndef MPD_FILTER_INTERNAL_HXX
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#define MPD_FILTER_INTERNAL_HXX
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#include <stddef.h>
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struct AudioFormat;
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class Error;
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class Filter {
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public:
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virtual ~Filter() {}
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/**
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* Opens the filter, preparing it for FilterPCM().
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*
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* @param filter the filter object
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* @param audio_format the audio format of incoming data; the
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* plugin may modify the object to enforce another input
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* format
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* @param error location to store the error occurring, or NULL
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* to ignore errors.
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* @return the format of outgoing data or
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* AudioFormat::Undefined() on error
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*/
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virtual AudioFormat Open(AudioFormat &af, Error &error) = 0;
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/**
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* Closes the filter. After that, you may call Open() again.
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*/
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virtual void Close() = 0;
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/**
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* Filters a block of PCM data.
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*
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* @param filter the filter object
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* @param src the input buffer
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* @param src_size the size of #src_buffer in bytes
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* @param dest_size_r the size of the returned buffer
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* @param error location to store the error occurring, or NULL
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* to ignore errors.
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* @return the destination buffer on success (will be
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* invalidated by filter_close() or filter_filter()), NULL on
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* error
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*/
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virtual const void *FilterPCM(const void *src, size_t src_size,
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size_t *dest_size_r,
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Error &error) = 0;
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};
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#endif
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