virtualdub capture 1080p24 questions

[JohnScelso]

I'm capturing video output from an LGBD670 Smart BluRay player using virtualdub. I also capture with AmarecTV. The LG display setting is set at 1080p24. My capture cards supports 1080p24.

The sample content source is labelled "SUPERHD" by the large Internet streaming content provider, and elsewhere its said that SuperHD means 1080p24 by this provider. The quality is noticeably excellent. I'm fairly certain its 1080p24 or better.

Two issues with Virtual dub 1.10.4.xxxx:

1.) When I try to set the frame rate in Capture>Settings it won't allow me to enter 24.000, nor will it let me set the fps to 25 by clicking on the screen icon and choosing. Instead I continue to see the 29.97 value on the icon at the bottom right of the overlay screen.
2.) When I watch the video there is an oscillating hesitation. It happens, probably each second. To make up an explanation, perhaps virtualdub captures the 24 frames sent, and then "waits" four frames, displaying nothing, then captures another 24 frames etc. Each second there is slight pause.

(AmarecTV, uses the same lossless codec, and does not seem to show the pause either during record or playback, when its fps is set to 29.97. AmarecTV drops many, many frames when I choose either p24 or p25 alternatives.)

Questions:

1.) Assuming the source content is 1080p24, the plumbing is 1080p24, as is the capture card, what fps should I choose using virtualdub? Should I being try some kind of realtime 3:2 pulldown or is that something I would use later when encoding the lossless 24fps codec to a lossy 29.97 codec?
2.) Why does virtualdub not accept my fps choice, either when I type it in, or click it in, when the desired fps is lower or other than 29.97


Thanks.

[manono]

1.) Assuming the source content is 1080p24...

That's a very big assumption. You say you're trying to cap streaming content? Then almost certainly it's 29.97fps and if it's not being streamed as that, it's being converted to that along the way.

Should I being try some kind of realtime 3:2 pulldown...

If it's film content and it's hard telecined (interlaced 29.97fps), then cap that and IVTC it later.

...is that something I would use later when encoding the lossless 24fps codec to a lossy 29.97 codec?

That doesn't make any sense to me. If for DVD and if it's film and if you IVTC it, you'll be encoding for progressive 23.976fps (or 24fps) and applying 3:2 pulldown, just like most NTSC DVDs of movies. If for something else you'll keep it at progressive 23.976fps (or 24fps) after the IVTC.

2.) Why does virtualdub not accept my fps choice...

I'm sure others know more about that than I, but if the source is 29.97fps why would you even want to cap at something different?

I'm fairly certain its 1080p24 or better.

Why not open it in MediaInfo and make sure? You should be examining your caps to see what you have. Or post a short sample so someone here can analyze it.

And I've I've been incorrect in anything I've said I apologize and someone will surely come along and correct me.

[DB83]

You are talking is 'mixed metaphors' here. First you mention a blu ray player and then you mention an internet source.

What EXACTLY are you trying to cap. If it is a blu ray then you are going the wrong way to do it. An internet HD source also would unlikely be 24p.

Virtualdub is an analog capture tool. It only understands a VFW capture driver and if your capture card does not have such a driver then it will not work. Period. And as an analog tool it only caps at standard PAL or NTSC fps - think it can also do double rates but never tried.

And if you are dropping frames it is not the card. Your system is not fast enough to handle the data flow. We know nothing about your system either.

[JohnScelso]

Thanks for responding. This is both resolved and not resolved!

To clarify: I am using an LG BD670 BluRay player, whose output is set at 1080p24, to stream internet content, (alleged)1080p24 Neftlix ("NF") SUPERHD, to my 1080p24 hdmi capture card. The Smart BluRayer is Internet-capable, attached to my Ethernet router via wire, and to the capture card via hdmi. NF content is played using the NF app on the LG.

Resolved: The periodic hesitation I saw in the overlay display while capturing with VirtualDub does not show up in the captured content. *That* issue is resolved. The captured content is gorgeous.

Mediainfo shows
Video
Format : YUV
Codec ID : ULY0
Codec ID/Info : Ut Video Lossless Codec
Codec ID/Hint : Ut Video
Duration : 22mn 5s
Bit rate : 206 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Compression mode : Lossless
Bits/(Pixel*Frame) : 3.323
Stream size : 31.9 GiB (99%)

We can speculate about whether or not *that* content was in fact shot as 24fps, but, it doesn't matter. The captures look fine, and they are 1080p.

NF *does* provide short sample films entitled respectively, "23.976" and "29.97" which are shot at those respective frame rates. "23.976" even comes in a version that burns a timer onto the film. The films are quite varied and are very useful as test films. However, for the purpose of making sense of my capture set-up they simply create more unresolved issues that I will try to understand.

Long-story short, nothing makes sense. 23.976fps content sent out a 1080p24MHz setting over HDMI to a 1080p24 capable capture card should work seamlessly, but that seems not to be the case, and I must spend a bit more time trying to correctly document what is actually happening, but it seems as if either the NF client on the LG is changing the framerate, or the LG output is not really 24Mhz, or, the capture/card software is doing who-knows-what.

In any event, Virtualdub so far seems not to accept or display fps values less than 29.97. My other capture software (AmarecTV and Honestech DVR 2.5) does allow frame rates of 24 and 25, though 24 always screws up or drops frames and 25 acts as if it were 29.97.

Thanks again for the responses.

[jagabo]

Resolved: The periodic hesitation I saw in the overlay display while capturing with VirtualDub does not show up in the captured content.

Disable audio playback in VirtualDub. That may help with the preview.

We can speculate about whether or not *that* content was in fact shot as 24fps, but, it doesn't matter. The captures look fine, and they are 1080p.

You don't have to speculate. Just step through the captured video frame by frame. If it was output by the BD player as 24p and captured as 30p there will be a duplicate frame every 5 frames. Those duplicates will be seen as 6 tiny jerks every second at playback.

[DB83]

You should also aquaint yourself with the forum's rules.

Do NOT talk about copying rented material
You are not allowed to rip/copy/record rented video. It includes streaming rented video like netflix, itunes, hulu plus, etc.

[manono]

Frame rate : 29.970 fps

We can speculate about whether or not *that* content was in fact shot as 24fps, but, it doesn't matter.

It does matter. As jagabo suggested, step through it frame-by-frame. If it's sourced from film your next step should be to IVTC it back to film framerate. Or, if it's got dupe frames in every five, remove them.

[JohnScelso]

You don't have to speculate. Just step through the captured video frame by frame. If it was output by the BD player as 24p and captured as 30p there will be a duplicate frame every 5 frames. Those duplicates will be seen as 6 tiny jerks every second at playback.

Thanks for this tip. I'll check it out.

[JohnScelso]

You don't have to speculate. Just step through the captured video frame by frame. If it was output by the BD player as 24p and captured as 30p there will be a duplicate frame every 5 frames. Those duplicates will be seen as 6 tiny jerks every second at playback.

Ok. I mixed up the order of the output devices (LG & 1080i TV) on the splitter. Sometimes, the 29.97fps capture rate shown by mediainfo was correct because the LG negotiated that rate with the TV . I have samples with both no replicated frames, and samples that do contain a duplicate frame every 5 frames.

The important change was to put the LG on port 1 and get the tv out of the negotiation with the splitter. Once that happened, then I did see reliable 24Mhz output from the LG. I used both capture programs, AmarecTV and Virtualdub, they both allowed the lower frame rates, and they both showed more expected outputs. AmarecTV did allow 24fps settings, did show ~24fps output values during capture, and did not drop frames. Virtualdub did show 25fps settings, did show average values ~24fps during output, and did not drop frames.

Virtual dub did not allow me to manually set the capture rate to 23.976. Does anyone know why?

I compared a 10 minute segment of a the reference film, the one with millisecond time values shown on each frame. Both VD25fps and AmarecTV24fps output showed identical frames, but the time tags values associated with each frame number was different. So long as Virtualdub captured each frame with no duplicates or insertions it seems there should be some way to tell it to re-write the output using a frame rate of 23.976 rather than 25.

I did not see a recurring pattern of duplicates, but I did see one frame duplicated on the location on both films. Seemed wierd.

I have not really focused on audio/sync issues. And I have not yet looked more deeply at some of the other samples.

[DB83]

OP

Just that you have no illusions, I have reported this topic for blatant rule violation.

The rule is there so that this site does not fall foul of the copyright holder's rights in repect of rented video.

Expect the topic to be closed quite soon with a message from the Moderator informing you that if you want a back up (record) of these films you should buy the disk.

[Baldrick]

Recording rented video is not okey to discuss in our forum. Just buy it on blu-ray and you wont have such problems.