Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Television Broadcast Gear

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 07-12-2019, 12:32 PM
Chip Chester Chip Chester is offline
VideoKarma Member
 
Join Date: Apr 2012
Posts: 760
While these professional devices will actually remove Macrovision, it's a high-overhead way to do it, in terms of size, complexity and power.

In my years of captioning in the analog domain, I often had to guide editors through the task of modifying video content without disturbing existing captions. That led to the 'wipe from line 22 on down' technique of preserving the VBI information (captions, Nielsen codes, etc.) but replacing visible picture. (For example, this was often used to create 'tagged' spots with individual retail locations from one previously-captioned master.) Doing the opposite had the spin-off effect of disabling Macrovision. So like Jeff, it was not our primary goal.

The challenge in the digital age is verifying which equipment will faithfully throughput (or record/playback) caption data that is in the VANC area of the digital signal. Some extremely popular gear will not. Other popular gear from the same manufacturer will. So I always have to vet the chain of equipment after caption insertion to guard against unpleasant surprises.

Not a Macrovision thing, but my caption equipment can set or reset the record flag in the digital signal. But in a similar vein, my (pro) HD-SDI recorders don't pay attention to that flag, and will record anything.

Last edited by Chip Chester; 07-12-2019 at 12:35 PM.
Reply With Quote
  #2  
Old 07-12-2019, 02:52 PM
ppppenguin's Avatar
ppppenguin ppppenguin is offline
VideoKarma Member
 
Join Date: Oct 2009
Location: London, UK
Posts: 451
Quote:
Originally Posted by Chip Chester View Post
The challenge in the digital age is verifying which equipment will faithfully throughput (or record/playback) caption data that is in the VANC area of the digital signal. Some extremely popular gear will not. Other popular gear from the same manufacturer will. So I always have to vet the chain of equipment after caption insertion to guard against unpleasant surprises.
A bit OT for this thread but having designed SDI audio embedders, both SD and HD, I reckon I've seen most of the incompatibilities that are possible in that area. The original SMPTE272 (SD embedded audio) wasn't very well written (possibly because it was the first for ANC packets) and could be interpreted in various ways. The HD standard was a lot better but I've still found at least 1 truly perverse implementation.
__________________
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:05 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.