/* * $Id$ * * Copyright (C) 2006 Stephen F. Booth * * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "CoreAudioUtils.h" #include // CoreAudio utility function static NSArray *sAudioExtensions = nil; // Return an array of valid audio file extensions recognized by Core Audio NSArray * getCoreAudioExtensions() { OSStatus err; UInt32 size; @synchronized(sAudioExtensions) { if(nil == sAudioExtensions) { size = sizeof(sAudioExtensions); err = AudioFileGetGlobalInfo(kAudioFileGlobalInfo_AllExtensions, 0, NULL, &size, &sAudioExtensions); if(noErr != err) { return nil; } [sAudioExtensions retain]; } } return sAudioExtensions; } BOOL hostIsBigEndian() { #ifdef __BIG_ENDIAN__ return YES; #else return NO; #endif } AudioStreamBasicDescription propertiesToASBD(NSDictionary *properties) { AudioStreamBasicDescription asbd; asbd.mFormatID = kAudioFormatLinearPCM; asbd.mFormatFlags = 0; asbd.mSampleRate = [[properties objectForKey:@"sampleRate"] doubleValue]; asbd.mBitsPerChannel = [[properties objectForKey:@"bitsPerSample"] intValue]; asbd.mChannelsPerFrame = [[properties objectForKey:@"channels"] intValue];; asbd.mBytesPerFrame = (asbd.mBitsPerChannel/8)*asbd.mChannelsPerFrame; asbd.mFramesPerPacket = 1; asbd.mBytesPerPacket = asbd.mBytesPerFrame; asbd.mReserved = 0; if ([[properties objectForKey:@"endian"] isEqualToString:@"big"] || ([[properties objectForKey:@"endian"] isEqualToString:@"host"] && hostIsBigEndian() )) { asbd.mFormatFlags |= kLinearPCMFormatFlagIsBigEndian; asbd.mFormatFlags |= kLinearPCMFormatFlagIsAlignedHigh; } if ([[properties objectForKey:@"unsigned"] boolValue] == NO) { asbd.mFormatFlags |= kLinearPCMFormatFlagIsSignedInteger; } return asbd; }