pcm/PcmConvert: move code to new class PcmChannelsConverter

1 files changed, 83 insertions, 0 deletions

diff --git a/src/pcm/ChannelsConverter.hxx b/src/pcm/ChannelsConverter.hxx
new file mode 100644
index 000000000..4311b9671
--- /dev/null
+++ b/src/pcm/ChannelsConverter.hxx
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2003-2013 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_CHANNELS_CONVERTER_HXX
+#define MPD_PCM_CHANNELS_CONVERTER_HXX
+
+#include "check.h"
+#include "AudioFormat.hxx"
+#include "PcmBuffer.hxx"
+
+#ifndef NDEBUG
+#include <assert.h>
+#endif
+
+class Error;
+template<typename T> struct ConstBuffer;
+
+/**
+ * A class that converts samples from one format to another.
+ */
+class PcmChannelsConverter {
+	SampleFormat format;
+	unsigned src_channels, dest_channels;
+
+	PcmBuffer buffer;
+
+public:
+#ifndef NDEBUG
+	PcmChannelsConverter()
+		:format(SampleFormat::UNDEFINED) {}
+
+	~PcmChannelsConverter() {
+		assert(format == SampleFormat::UNDEFINED);
+	}
+#endif
+
+	/**
+	 * Opens the object, prepare for Convert().
+	 *
+	 * @param format the sample format
+	 * @param src_channels the number of source channels
+	 * @param dest_channels the number of destination channels
+	 * @param error location to store the error
+	 * @return true on success
+	 */
+	bool Open(SampleFormat format,
+		  unsigned src_channels, unsigned dest_channels,
+		  Error &error);
+
+	/**
+	 * Closes the object.  After that, you may call Open() again.
+	 */
+	void Close();
+
+	/**
+	 * Convert a block of PCM data.
+	 *
+	 * @param src the input buffer
+	 * @param error location to store the error
+	 * @return the destination buffer on success,
+	 * ConstBuffer::Null() on error
+	 */
+	gcc_pure
+	ConstBuffer<void> Convert(ConstBuffer<void> src, Error &error);
+};
+
+#endif