[iphone-cocos2d]分享一段Objective-C可調用的游戲中播放音樂(1)

首先需要引入AudioTool 這個framework

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 -?(id)initWithPath:(NSString?*)path
{
????UInt32????????size,?maxPacketSize;
????char????????*cookie;
????int????????????i;
????
????if?(gThereIsAnActiveTrack)
????{
????????NSLog(@"***?WARNING?***?GBMusicTrack?only?plays?one?track?at?a?time!?You?must?close?the?previously?running?track"
??????????????"?before?you?can?play?another.?Requested?track?was:?%@",?[path?lastPathComponent]);
????????return?nil;
????}
????//路徑不存在的話返回空
????if?(path?==?nil)?return?nil; ???// 初始化　　
????if(!(self?=?[super?init]))?return?nil;
????
????//?通過指定的路徑打開音樂 ????if?(noErr?!=?AudioFileOpenURL((CFURLRef)[NSURL?fileURLWithPath:path],?0x01,?0,?&audioFile))
????{
????????NSLog(@"***?Error?***?GBMusicTrack?-?initWithPath:?could?not?open?audio?file.?Path?given?was:?%@",?path);
????????return?nil;
????}
????
????//?得到文件的數據類型
????size?=?sizeof(dataFormat);
????AudioFileGetProperty(audioFile,?kAudioFilePropertyDataFormat,?&size,?&dataFormat);
????
????//?創建一個新的隊列，使用的是指定的特殊數據類型和回調緩存。 ????
????AudioQueueNewOutput(&dataFormat,?BufferCallback,?self,?nil,?nil,?0,?&queue);
????
????//?如果需要的話讀取包的大小并且分配所需要的空間
????if?(dataFormat.mBytesPerPacket?==?0?||?dataFormat.mFramesPerPacket?==?0)
????{
????????//?since?we?didn't?get?sizes?to?work?with,?then?this?must?be?VBR?data?(Variable?BitRate),?so
????????//?we'll?have?to?ask?Core?Audio?to?give?us?a?conservative?estimate?of?the?largest?packet?we?are
????????//?likely?to?read?with?kAudioFilePropertyPacketSizeUpperBound
????????size?=?sizeof(maxPacketSize);
????????AudioFileGetProperty(audioFile,?kAudioFilePropertyPacketSizeUpperBound,?&size,?&maxPacketSize);
????????if?(maxPacketSize?>?gBufferSizeBytes)
????????{
????????????maxPacketSize?=?gBufferSizeBytes;
????????????NSLog(@"***?Warning?***?GBMusicTrack?-?initWithPath:?had?to?limit?packet?size?requested?for?file:?%@",?[path?lastPathComponent]);
????????}
????????numPacketsToRead?=?gBufferSizeBytes?/?maxPacketSize;
????????
????????//給包的描述分配空間
????????packetDescs?=?malloc(sizeof(AudioStreamPacketDescription)?*?numPacketsToRead);
????}
????else
????{
????????//?對于CBR?數據?(Constant?BitRate),?使用合適的數據填充到混村中
????????numPacketsToRead?=?gBufferSizeBytes?/?dataFormat.mBytesPerPacket;
????????
????????//?這種包的描述不需要
????????packetDescs?=?nil;
????}
????
????//?see?if?file?uses?a?magic?cookie?(a?magic?cookie?is?meta?data?which?some?formats?use)
????AudioFileGetPropertyInfo(audioFile,?kAudioFilePropertyMagicCookieData,?&size,?nil);
????if?(size?>?0)
????{
????????//?把緩存數據從文件中copy出來放到音頻隊列中
????????cookie?=?malloc(sizeof(char)?*?size);
????????AudioFileGetProperty(audioFile,?kAudioFilePropertyMagicCookieData,?&size,?cookie);
????????AudioQueueSetProperty(queue,?kAudioQueueProperty_MagicCookie,?cookie,?size);
????????free(cookie);
????}

????AudioQueueAddPropertyListener(queue,?kAudioQueueProperty_IsRunning,?propertyListenerCallback,?self);
????
????//?給特定的緩存分配數據
????packetIndex?=?0;
????for?(i?=?0;?i?<?NUM_QUEUE_BUFFERS;?i++)
????{
????????AudioQueueAllocateBuffer(queue,?gBufferSizeBytes,?&buffers[i]);
????????if?([self?readPacketsIntoBuffer:buffers[i]]?==?0)
????????{
????????????// 檢查讀取到緩存中的包的大小
????????????break;
????????}
????}
????repeat?=?NO;
????trackClosed?=?NO;
????trackEnded?=?NO;
????gThereIsAnActiveTrack?=?YES;
????return?self;
}

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//? Created by Jake Peterson (AnotherJake) on 7/6/08.
//? Copyright 2008 Jake Peterson. All rights reserved.

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防盜加個鏈接：

???作者：Alexliu（alex dotNet Learning）
???出處：http://alexliu.cnblogs.com/

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