can't figure out original frame rate from NTSC laserdisc capture

[clashradio]

I have a US-released laserdisc of a show that I believe was filmed at Shepperton Film Studios in the UK, so it should be 25fps film. I've Bobbed it in VirtualDub and found it is BFF, can not figure out what the original frame rate is. When I apply the usual code for PAL to NTSC material I end up with a frame rate of 28.742 (code below). The goal is upscale to 720p. Sorry about the uncompressed vs. lossless .avi.

LWLibavVideoSource("side 1.avi", format="YUY2")
AssumeBFF()
ConvertToYV12(interlaced=true)
QTGMC().SRestore()
nnedi3_rpow2(2,cshift="Spline36Resize",fwidth=960, fheight=720)

[jagabo]

I get 25 fps with that script.

Field blended frame rate conversions are very easy to detect. Just apply a simple bob and look for frames that look like double exposures:

blended:

[Attachment 47378 - Click to enlarge]

it's a double exposure of the field before:

[Attachment 47379 - Click to enlarge]

and the field after:

[Attachment 47380 - Click to enlarge]

LWLibavVideoSource("side 1.avi", format="YUY2")
AssumeBFF()
Bob()

You'll see the frames alternate between clean and blended. The amount of blending will vary depending on the timing.

[clashradio]

When I apply the code in post #1 to this new Direct Stream Copy .avi, I also get 25fps. But I get 28.742 when rendering the complete 60 minute file. That's not even a valid frame rate? Do you think it has something to do with the beginning of the file? The capture begins before the player is reading the disc. Is VirtualDub looking at those fields and trying to determine a frame rate?

Are field blended frame rate conversions because of the PAL to NTSC conversion? 25 to 29.97?

[jagabo]

When I apply the code in post #1 to this new Direct Stream Copy .avi, I also get 25fps. But I get 28.742 when rendering the complete 60 minute file.

Try changing the SRestore() to SRestore(frate=25). What frame rate to you get?

That's not even a valid frame rate?

Any frame rate is a valid frame rate. But 28.742 doesn't correspond to any professional video standard. It looks to me like SRestore() thinks the video is a 23.976 to 25 fps conversion (23.976 / 25 * 29.97 = 28.742).

Do you think it has something to do with the beginning of the file? The capture begins before the player is reading the disc. Is VirtualDub looking at those fields and trying to determine a frame rate?

My guess is it's not VirtualDub but rather SRestore(). Hence the above suggestion.

Are field blended frame rate conversions because of the PAL to NTSC conversion? 25 to 29.97?

PAL 50 fields per second to NTSC 59.94 fields per second. Other things can cause blended frames too (a blend deinterlace, for example).

[clashradio]

OK, I now have 25fps with "SRestore(frate=25)". Is there a trick to have the audio track along with the conversion? (I tried "ChangeFPS(50)" but still no audio track).

When dealing with field blended frame rate conversion, is that only a symptom of PAL to NTSC? It seems like I've double exposure on standard NTSC interlaced footage?

[jagabo]

LWLibavVideoSource() only loads the video. If you want audio use LWlibavAudioSource() along with it.

v = LWLibavVideoSource("side 1.avi", format="YUY2")
a = LWLibavAudioSource("side 1.avi")
AudioDub(v,a)
AssumeBFF()
QTGMC()
SRestore(frate=25)
nnedi3_rpow2(2,cshift="Spline36Resize",fwidth=960, fheight=720)

[clashradio]

Thank you for the code. I get an error:

AudioDub: need an audio and a video track

Is AudioDub part of LSmash? I do have LSmashSource.dll in my plugins folder.

[jagabo]

Oops, I copied and pasted but forgot to change the audio in put line. It should read:

a = LWLibavAudioSource("side 1.avi", format="YUY2")

I changed the post it people don't get confused in the future.

[clashradio]

Good catch jagabo. New error (see below)

Script error: LWLibavAudioSource does not have a named argument "format"

[jagabo]

Remove the ", format="YUY2".

[clashradio]

New error: there is no function named "nonyuy2clipin"

v = LWLibavVideoSource("Direct Stream.avi", format="YUY2")
a = LWLibavAudioSource("Direct Stream.avi")
AudioDub(v,a)
AssumeBFF()
QTGMC()
SRestore(frate=25)
nnedi3_rpow2(2,cshift="Spline36Resize",fwidth=960, fheight=720)

[jagabo]

That one isn't obvious. Does it give a line number? Please quote the entire error message. Try adding ConvertToYV12(interlaced=true) between AssumeBFF() and QTGMC().

[clashradio]

Adding "ConvertToYV12(interlaced=true)" worked thank you!!!!!!!!