objective-c - core audio callback, inTimeStamp at the beginning or end of recording

Question

In core audio, when the recordingCallback is called:

static OSStatus recordingCallback(void *inRefCon, 
                              AudioUnitRenderActionFlags *ioActionFlags, 
                              const AudioTimeStamp *inTimeStamp, 
                              UInt32 inBusNumber, 
                              UInt32 inNumberFrames, 
                              AudioBufferList *ioData) {

does inTimeStamp reference the time when the audio began to be received or the time when the audio was finished being received.

was it

X if X is equal to the time when recording began

or

X + the buffer length

thank you,

nonono

Answer 1

时间戳是捕获缓冲区的时间，特别是系统的总线时间（有关详细信息，请参阅CoreAudio 邮件列表上的此线程）。所以它指的是缓冲区第一个样本中的时间，而不是最后一个样本。