[linux-audio-dev] SMTPE/MTC Again

Martijn Sipkema msipkema at sipkema-digital.com
Tue Apr 15 05:25:01 UTC 2003

>  >       * a protocol that encodes time information in an audio stream
>  >       * a format for specifying time (HH:MM:SS:FF)
> Except for video editors, the HH:MM:SS:FF format is completely
> irrelevant. Just think seconds. What the time code does is to 
> define a relation between a transport position in seconds and a
> particular sample. Once you have this mapping, the format of
> the timecode does not matter at all.
>  > wrong scenario. suppose i want to store the point in time where (say)
>  > a zero crossing happens. SMPTE will not allow me to do that. i have to
>  > store it as a sample position.
> Again, why use the HH:MM:SS:FF format ? If you divide the 'sample
> position' by the sample rate, you get a time in seconds. Conversely,
> given a time in seconds, you can find the sample. This has nothing to
> do with SMPTE or any other particular time code format.

For JACK I'd rather work with samples. And, as you say, this can
easily be converted to seconds dividing by the nominal sample rate.

If for a SMPTE synced JACK we would have the SMPTE frames mapped to
samples in the transport info I think everybody would be happy.


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