VITC & Subtitles

VITC - Virtical Interval Time Code

What is Vertical Interval TimeCode (VITC)

https://en.wikipedia.org/wiki/Vertical_interval_timecode

Example of a VITC Readout in HH.MM.SS.FF

 frame:0    pts:7920    pts_time:0.088
 timecode=00:00:06:10
 lavfi.readvitc.tc_str=01:03:02:24
 frame:1    pts:11520   pts_time:0.128
 lavfi.readvitc.found=1
 lavfi.readvitc.tc_str=01:03:03:00

At the top of the visable image there is dots and dashes these respresent bits of data that can embed timecode data for absolute position of media on a tape.

Note: Blackmagic/AJA/Magewell A/D units (ADV-7850) have VITC processing check your refrance captures if using industry standard equipment over SDI you will most likely have SMPTE TC.

How do I create VITC?

There is currently Unai.VITC

VITC and S-VHS & HI8

Formats like Hi8 and SVHS when recorded on a higher end device will normally have VITC it looks like this notice the lines at the top above the video frame:

This is for normal 720x608 archive feeds ware the top VBI data is exposed or full-frame archives

To export VITC to readable file:

ld-chroma-decoder --ffll 2 --lfll 308 --ffrl 2 --lfrl 620 input.tbc

Exports VITC Timcode to a text file:

Simply replace datainput.mkv and vitc.txt names acordingly

ffmpeg.exe -i datainput.mkv -vf "readvitc=scan_max=-1,metadata=print:file=vitc.txt" -f null -

VITS & Teletext/Closed Captioning

NTSC Closed Captioning

Closed Captioning EIA-608

There is CC or Closed Captions in most TV broadcast recordings and some VHS releasess

https://github.com/amiaopensource/sccyou

sccyou is a bash script that allows easy genaration of standard .srt files

PAL Teletext

Thanks to Ali1234 for the R&D into this.

VHS-Teltext Traslator

https://github.com/ali1234/vhs-teletext

Raspberry Pi based CC generator (Uses Composite, can be used on TRRS 3.5mm jack current pi's or older pi's)

https://github.com/ali1234/raspi-teletext