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Diffstat (limited to '')
-rw-r--r-- | src/filter/FilterInternal.hxx | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/src/filter/FilterInternal.hxx b/src/filter/FilterInternal.hxx new file mode 100644 index 000000000..d2e619540 --- /dev/null +++ b/src/filter/FilterInternal.hxx @@ -0,0 +1,71 @@ +/* + * Copyright (C) 2003-2014 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 filter the filter object + * @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, or nullptr + * to ignore errors. + * @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 filter the filter object + * @param src the input buffer + * @param error location to store the error occurring, or nullptr + * to ignore errors. + * @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 |