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-   -   Tool for extracting Hi8 date and time (https://www.digitalfaq.com/forum/video-capture/13829-tool-extracting-hi8.html)

cwig 10-14-2023 11:34 AM

Tool for extracting Hi8 date and time
 
I have some Hi8 tapes that I digitized and I wanted to extract the date and time information from them. I built a tool to extract this information via LANC. You can find the github page with instructions here https://github.com/cwig/hi8_lanc_date_and_time. It requires building a LANC to USB converter using an Arduino board. The tool is not very polished and I probably won't be improving it anymore at this point, however, I thought it would be worth sharing in case anyone else finds it useful. The only other tool I found that could do this was something called "Hi8DateTime" which appears to no longer be available.

latreche34 10-14-2023 06:50 PM

How do you extract date from LANC? Is date stored in the frame raster of an analog Hi8 video? If so what scan lines contain this information?

BW37 10-15-2023 01:06 PM

Interesting reading, mostly over my head…

Sony LANC Protocol

RC Timecode

Sony VCR implementation via LANC

TEAC Implementation of RCTC?

LANC was also used to access service codes on Sony camcorders, etc. by using a special version of the RM-95 wired remote. The “real” ones have the
NORM <—> ADJ switch. Apparently the standard RM-95s can be modded to work as well though I haven’t yet tried on mine.

My 2cents
BW

latreche34 10-15-2023 02:26 PM

I have a Sony Tripod with remote control that uses LANC jack and takes complete control of the camcorder. But for tapes it seems like there isn't enough information about where those bits are stored in the frame raster, We all know that Video8 and Hi8 do not use longitudinal linear tracks compared to other formats to store the time code and other data on tape, So they have to be stored in the blanking area of the frame raster. VHS-decode could actually extract and decode that data if documented, but as always Sony is very secretive about their technology.

Later formats like DVCAM/DV/HDV, Sony used an additional memory chip mounted to the bottom of the cassette and read by a special memory reader in the mechanism using pogo style multi pin contactors, Not sure what type of data but certainly tape content info.

cwig 10-15-2023 02:28 PM

I got most of my information on LANC from these two sources https://github.com/Novgorod/LANC-USB-GUI and https://www.boehmel.de/lanc.htm. Basically the LANC protocol allows you to send commands and read status information from the camera. This includes information on the camcorder state like play, pause, fast-forward, rewind, etc and the date and time information for Hi8. I'm actually not sure how the date/time is stored on the tape itself, but the camcorders that support LANC can send the information directly without rasterizing it in the frame. Interestingly this allows you to capture the date/time information while fast-forwarding without the video showing. The LANC-USB-GUI repo did the hard work of converting the LANC signal into a traditional serial interface and they provide a tool that I think gives the same functionality as the RM-95 remote and shows all the status information from the LANC interface. I think it also includes some of the service remote functionality as well. My tools just uses that's repos work to save out the the date/time for the entire video.

BW37 10-15-2023 03:10 PM

Ahah!

I think I found what we're looking for. I'd seen descriptions of the various 8mm tracks long ago, but finally found this one that seems useful.

This confirms the info from the Wiki link I posted earlier: "The RC timecode can be used in conjunction with the datacode to record the date and the time. The data and RC codes are written between the video and the PCM audio tracks."

So the RCTC is not imbedded within the video information. I assume reading it at high tape speeds must be similar to reading across the video tracks in high speed search modes.

BW

PS: I had some trouble reloading that link (just slow to load?) so here it is in full:

https://photographytraining.tpub.com...System-332.htm

latreche34 10-15-2023 04:26 PM

Oh, So it's laid down within the helical track but away from the frame raster data, Makes all the sense now, thanks for sharing the links, So definitely can be extracted from the RF pickup in VHS-decode without resorting to LANC if the project advances.


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