logo Sign In

drngr

User Group
Members
Join date
15-Jan-2013
Last activity
17-Jun-2021
Posts
317

Post History

Post
#677537
Topic
High-End video capture cards
Time

I've found that the Luma Ramp pattern on DVE interacts with the ATI 750 USB's AGC, but it isn't immediately visible to the naked eye the way that some problematic non-DVD sources apparently are. With the help of a scope filter, this test may be useful as an easily-distributable check. That said, it doesn't trigger a really bad capture device I have that's triggered by a lot of other DVD content, so it certainly isn't foolproof.

Test results with ATI 750 USB:

  • From black, the pattern's contrast gradually drops over 5 seconds.
  • From white, the pattern's contrast gradually drops over 3 seconds.
  • From grey, the pattern's contrast gradually drops over 5 seconds.

TestAGC.iso (RAR, 92KB)

Avisynth script to produce the visualizations: TurnRight().Histogram().TurnLeft()

Post
#677528
Topic
How to capture HDCP-encrypted HDMI sources (Vudu, Netflix, Directv, Virgin Media, etc.)
Time

In the description it says HD72B, which does ignore HDCP.

I don't know about Ireland, but the HD72A + splitter combination is cheaper in the US now that there is a seller offering it for only $55.

If your source device is closer to your TV, it makes more sense to use a splitter since that way you don't need two long cables snaking to and from the computer. Of course if you have everything on one desk, it doesn't matter.

Post
#675756
Topic
Transformers: The Movie (1986 animated version) (a WIP)
Time

Perfectly clear to you; as a reader of your post I saw a factual statement with nothing indicating what you based it on.

It's possible that they're ultimately derived from the same scan, but the two Sony versions and the BD vary wildly at points in terms of color, shadow/highlight detail, and framing. Saying they're the same transfer conjures to mind typical processing/encoding differences and not the deliberate creative changes to this movie.

Post
#675571
Topic
Transformers: The Movie (1986 animated version) (a WIP)
Time

Chewtobacca said:

The UK and Australian BDs use the same transfer as the Ultimate Edition DVD and the 20th Anniversary Special Edition DVD.

Err, what? The color timing between the Sony 20th Anniversary DVD and the UK/AU BD is completely different. No idea about UE DVD.

http://www.avsforum.com/t/1169049/the-transformers-the-movie-1986-4-dvds-vs-blu-ray-uk-comparison-pix

Post
#674329
Topic
Moth3r's guide to LD capture colour correction using AviSynth (emphasis on "correction")
Time

I have a "Digital Processing Systems DPS-470 Digital Component AV Synchronizer" that also functions as a 10-bit test signal generator. In comparison to this, test patterns played from my Philips DVP642 are much too dark.

I've been meaning to see how the Toshiba DVD player I have here compares.

Post
#672141
Topic
Auto IVTC of CAV LDs based on vertical interval data?
Time

In theory it should be possible to perform an inverse telecine with the same accuracy as an LD player's own Pause function using the "white flag" or the frame numbers from the Philips codes.

However, these flags weren't always accurate, leading to jumpy still frames. (Here is a working link to the text file quoted.)

Laserman said:


Now to do this on Laserdisc, they player has to know which two adjacent fields actually make up the frame (othewise you might get one field from one frame of film, and the other field from a diferent frame - not good). So how does an analogue system cope with this? Easy, encode the required information in the VBI (the vertical blank interval). When making the disc, you store the info in the VBI, its often referred to as a 'white flag'. When you hit the pause button on a CAV disc, it reads the flag, and the laser assembly actually does a one track reversal (i.e. 2 fields) and can then redisplay the current frame. It is set in the VBI area outside of picture info, or CC info (its at line 11 or 274 depending on the field). If you get it wrong, the pause feature will have a 'jiggling' frame for 40% of the frames! You can see this on some discs. Sometimes just the 'picture number' is used instead, which is also encoded into the VIL.

"About Laserdiscs"

I have a setup that lets me capture the relevant VBI lines, but it will be quite a while before I have access to my LD player again and I'm not sure whether it's actually worth pursuing. In theory it could help for discs where the pattern breaks often, but those are also probably the releases that are most likely to have the wrong data.