Change Frame rate

[steveski]

Hi,

I've been hepling out a friend with issues he ran into after recording some footage from a digital tv transmission.

Firstly, it was a widescreen transmission but the actual footage was 4:3 so there's black padding left and right, but the card has recorded a total width of 720 x 576, obviously intended for dvd.
So, we can crop the signal running an d2v and avs script, then either resize within avs or CCE.
The problem is that the new reencode was coming out too slow, even though I left the frame rate in CCE set to 25 fps.
Upon further investigation, it appears the video has been recorded as progressive frame, and rather than saving as 25fps, it's actually 50fps, which explains the slow down when reencoding.

Now, I would have thought that the encoder would use the timecode as a reference and actually drop every second frame and maintain the full speed of the video, but that's obviously not the case.
I can't select 50fps within CCE, so I was wondering if anyone could suggest a way of getting this to be interpreted as a 25 fps stream without slowing the thing down without doing an interim recode to lossless avi or similar?

Another option he's tried is to load the file into Premiere, but the first GOP isn't closed and Premiere won't load it.
I tried Cutterman and set an in point as the second I Frame and the out point as the end of the film. The problem here is that the new stream doesn't render correctly, it's all green and you just see a strip at the top of the screen. DGIndex is able to render it correctly, so it obviously has more built in smarts than about mpg2 than other software does.

Anyway, if anyone has any ideas, please let me know.
TIA

Steveski

[Guest]

Add SelectEven() to your script.

[Mug Funky]

as neuron said, try avisynth (load the original mpeg with DGindex, save out a .d2v, import that into an avisynth script - it's easier than it sounds).

additionally, you can re-interlace the video with:

assumetff().separatefields().selectevery(4,0,3).weave() in an avisynth script, then encode it with CCE as interlaced, offset line = 0 (ie top field first).

i'm guessing you're in australia, recording either ABC, SBS or Seven digital... so much for HDTV - they just deinterlace SD stuff and call it HD unfortunately.

[steveski]

Cool, thanks for the info, I'll give it a burl.
And yes I'm in Australia. I guess HD hardware is just too expensive for our lowly broadcasters to bother with.
Took years for frickin' broadband to get here too.
Thanks again.


Steve

[steveski]

Excellent!!!
I just ran some tests.

Use SelectEven() if you want to maintain progressive frame.

If you want to reinterlace with assumetff().separatefields().selectevery(4,0,3).weave() then don't use SelectEven() as otherwise end up with a video runnign double speed.

Thanks again for your help folks.


Steve

[CooperS]

What is the point of capturing the HD stuff rather than the SD from those particular chanels then?

[um3k]

What is the point of capturing the HD stuff rather than the SD from those particular chanels then?

Since it's transmitted digitally, it's almost certainly still higher quality than an analog broadcast.

[halsboss]

Yes, however capturing the SD TS, you can demux and then DIRECTLY use the mpv and ac3/mp2 in the DVD authoring program (edit prior if you like) - no conversion necessary and all digital too. It's a proven method :) so I hear.