[linux-audio-dev] Timestamping?

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Subject: [linux-audio-dev] Timestamping?
From: Simon Per Soren Kagedal (simon_AT_cs.uoregon.edu)
Date: Fri Jun 08 2001 - 03:02:18 EEST

Hi,

The current (Paul's) LAAGA proposal does not timestamp buffers. Is
this a design problem or something that could be extended..? I'm
looking through the OSX documentation. It's "process" callback for
AudioUnits looks like this, page 48 in the PDF:

typedef CALLBACK_API_C( ComponentResult, AudioUnitRenderSliceProc )
                       (void *inComponentStorage,
                        AudioUnitRenderActionFlags inActionFlags,
                        const AudioTimeStamp *inTimeStamp,
                        UInt32 inOutputBusNumber,
                        AudioBuffer *ioData);
                
And the timestamp looks like (page 109 in PDF):

struct AudioTimeStamp
{
        Float64 mSampleTime; // the absolute sample time
        UInt64 mHostTime; // the host's root timebase's
                                        // time
        Float64 mRateScalar; // the system rate scalar
        UInt64 mWordClockTime; // the word clock time
        SMPTETime mSMPTETime; // the SMPTE time
        UInt32 mFlags; // the flags indicate which
                                        // fields are valid
};

                
I don't personally understand what all those different times are and
why they are needed, but shouldn't we have something like this?

Simon.

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