AudioStreamBasicDescription结构说明

/**AudioStreamBasicDescription:mSampleRate;       采样率, eg. 44100mFormatID;         格式, eg. kAudioFormatLinearPCMmFormatFlags;      标签格式, eg. kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPackedmBytesPerPacket;   每个Packet的Bytes数量, eg. 2mFramesPerPacket;  每个Packet的帧数量, eg. 1mBytesPerFrame;    (mBitsPerChannel / 8 * mChannelsPerFrame) 每帧的Byte数, eg. 2mChannelsPerFrame; 1:单声道；2:立体声, eg. 1mBitsPerChannel;   语音每采样点占用位数[8/16/24/32], eg. 16mReserved;         保留 */format.mSampleRate = 44100;format.mFormatID = kAudioFormatLinearPCM;format.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;format.mBytesPerPacket = 2;format.mFramesPerPacket = 1;format.mBytesPerFrame = 2;format.mChannelsPerFrame = 1;format.mBitsPerChannel = 16;