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ali1234 / vhs-teletext

Software to recover teletext data from VHS recordings.
GNU General Public License v3.0
179 stars 21 forks source link

t42 format description #53

Closed turlututututu closed 4 years ago

turlututututu commented 4 years ago

Hi first of all amazing work :)

I am interested in having a dump of Teletext page so that I could see what packets build it and them interpret it by "hand" for debug purposes.

My main goal would be to extract those pages from a ts and then examine it.

The file format .t42 seems to fit my needs but I don't know how it is to be read ? Is there any description of the format?

Thanks in advance!

ali1234 commented 4 years ago

T42 is just concatenated packets. Each one is 42 bytes, hence the name. The clock run in and framing code are not included as they never change. The packet format is as described in the spec.

turlututututu commented 4 years ago

Thank you for your quick response! Could you point me torward the spec? I didn't find it on the repo unless you are talking about ETS and such?

ali1234 commented 4 years ago

https://www.etsi.org/deliver/etsi_i_ets/300700_300799/300706/01_60/ets_300706e01p.pdf

turlututututu commented 4 years ago

Thanks a million!