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Diffstat (limited to 'src/pcm/Resampler.hxx')
-rw-r--r-- | src/pcm/Resampler.hxx | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/pcm/Resampler.hxx b/src/pcm/Resampler.hxx new file mode 100644 index 000000000..9b6ccbbc7 --- /dev/null +++ b/src/pcm/Resampler.hxx @@ -0,0 +1,74 @@ +/* + * 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. + */ + +#ifndef MPD_PCM_RESAMPLER_HXX +#define MPD_PCM_RESAMPLER_HXX + +#include "util/ConstBuffer.hxx" +#include "Compiler.h" + +struct AudioFormat; +class Error; + +/** + * This is an interface for plugins that convert PCM data to a + * specific sample rate. + */ +class PcmResampler { +public: + virtual ~PcmResampler() {} + + /** + * Opens the resampler, preparing it for Resample(). + * + * @param af the audio format of incoming data; the plugin may + * modify the object to enforce another input format (however, + * it may not request a different input sample rate) + * @param new_sample_rate the requested output sample rate + * @param error location to store the error + * @return the format of outgoing data or + * AudioFormat::Undefined() on error + */ + virtual AudioFormat Open(AudioFormat &af, unsigned new_sample_rate, + Error &error) = 0; + + /** + * Closes the resampler. After that, you may call Open() + * again. + */ + virtual void Close() = 0; + + /** + * Resamples a block of PCM data. + * + * @param src the input buffer + * @param src_size the size of #src_buffer in bytes + * @param dest_size_r the size of the returned buffer + * @param error location to store the error occurring, or nullptr + * to ignore errors. + * @return the destination buffer on success (will be + * invalidated by filter_close() or filter_filter()), nullptr on + * error + */ + gcc_pure + virtual ConstBuffer<void> Resample(ConstBuffer<void> src, + Error &error) = 0; +}; + +#endif |