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View Full Version : Re: Can SMPTE Be Embedded In S/PDIF?


Graham Hinton
June 30th 03, 11:59 PM
In article >,
(Len Moskowitz) wrote:

>Might anyone know if SMPTE time code can be embedded in an S/PDIF
>digital audio data stream? If so, might you point me to a data format
>description?

Not in S/PDIF if you mean the Consumer Format, but AES/EBU Professional
Format has a TOD field in the Channel Status bits. The distinction is
blurred and the two formats are superceded by IEC-958.

Pro Format has been sent on S/PDIF hardware for many years, but very few
readers extract the TOD information. Most devices just ignore it and
transmit zeros. This would be an ideal method of getting accurate timecode
into any workstation instead of LTC or MTC and it has simply been ignored.

The TOD code is a 32 bit field embedded over 192 sub-frames. I've never
seen a definition of the field itself though.

Crystal Semiconductor AN21 has the digital audio format information.

Otis_thick
July 2nd 03, 07:12 AM
IEC958-the "new" pro/sumer spdif format can carry SMPTE timcode
embedded. I am using a Dolby DP-569 DD encoder that will embed SMPTE
TC on the (IEC958) coax SPDIF stream into sound card coax input using
"Dolby Recorder" software utility.

(Graham Hinton) wrote in message >...
> In article >,
> (Len Moskowitz) wrote:
>
> >Might anyone know if SMPTE time code can be embedded in an S/PDIF
> >digital audio data stream? If so, might you point me to a data format
> >description?