ChannelLayoutsAreEqual.cpp

/*
 *  Copyright (C) 2010, 2011, 2012 Stephen F. Booth <me@sbooth.org>
 *  All Rights Reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *    - Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    - Neither the name of Stephen F. Booth nor the names of its 
 *      contributors may be used to endorse or promote products derived
 *      from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "ChannelLayoutsAreEqual.h"

bool
ChannelLayoutsAreEqual(const AudioChannelLayout *lhs, const AudioChannelLayout *rhs)
{
	if(lhs == rhs)
		return true;

	if(nullptr == lhs || nullptr == rhs)
		return false;

	// First check if the tags are equal
	if(lhs->mChannelLayoutTag != rhs->mChannelLayoutTag)
		return false;
	
	// If the tags are equal, check for special values
	if(kAudioChannelLayoutTag_UseChannelBitmap == lhs->mChannelLayoutTag)
		return (lhs->mChannelBitmap == rhs->mChannelBitmap);
	
	if(kAudioChannelLayoutTag_UseChannelDescriptions == lhs->mChannelLayoutTag) {
		if(lhs->mNumberChannelDescriptions != rhs->mNumberChannelDescriptions)
			return false;
		
		size_t bytesToCompare = lhs->mNumberChannelDescriptions * sizeof(AudioChannelDescription);
		return (0 == memcmp(&lhs->mChannelDescriptions, &rhs->mChannelDescriptions, bytesToCompare));
	}
	
	return true;
}