74 lines
1.9 KiB
C++
74 lines
1.9 KiB
C++
/*
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* Copyright 2003-2019 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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#ifndef MPD_FILTER_HXX
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#define MPD_FILTER_HXX
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#include "AudioFormat.hxx"
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#include <assert.h>
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template<typename T> struct ConstBuffer;
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class Filter {
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protected:
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AudioFormat out_audio_format;
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explicit Filter(AudioFormat _out_audio_format) noexcept
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:out_audio_format(_out_audio_format) {
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assert(out_audio_format.IsValid());
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}
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public:
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virtual ~Filter() noexcept {}
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/**
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* Returns the #AudioFormat produced by FilterPCM().
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*/
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const AudioFormat &GetOutAudioFormat() const noexcept {
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return out_audio_format;
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}
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/**
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* Reset the filter's state, e.g. drop/flush buffers.
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*/
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virtual void Reset() noexcept {
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}
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/**
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* Filters a block of PCM data.
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*
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* Throws std::runtime_error on error.
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*
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* @param src the input buffer
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* @return the destination buffer on success (will be
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* invalidated by deleting this object or the next FilterPCM()
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* or Reset() call)
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*/
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virtual ConstBuffer<void> FilterPCM(ConstBuffer<void> src) = 0;
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/**
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* Flush pending data and return it. This should be called
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* repeatedly until it returns nullptr.
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*/
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virtual ConstBuffer<void> Flush();
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};
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#endif
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