how 2 do fast playback / preview

[odysseus]

I'd like to be able to play back at 5 or 10 times normal speed to find sections I want to keep or cut.

And it needs to be in Virtualdub so I can do the cutting instead of taking notes on a player & typing the values into vdub later.

on my machine Virtualdub by itself doesn't want to play back very fast. And when I choose 'drop frames when behind' it starts dropping 10, then 30, then 100 & pretty soon I get no updates for 10 seconds ....

using AviSynth I tried using

ChangeFPS
AssumeFPS
ConvertFPS

and also multiple Decimate(2) in a row.

And the playback just seems to be the same speed but displaying every 10th frame
Sync to audio is turned off & no audio stream specified.

[rfmmars]

VD is not for playback, but there are codecs that you can use which will let it playback at normal speed plus drag the pointer as fast as you want acroos the clip.

MPEG2

Leadtools (MJPEG)

There may be others but I have not found them. Maybe other board members will have some tips.

richard
www.photorecall.net

[odysseus]

Thanks for the response.

The problem with using the pointer is that it's jerky. In some areas you may skip 300 frames & in other areas you may skip 10 at a time.

You may miss what you're looking for in one section and waste time moving the mouse slowly in another section.

Originally posted by rfmmars
plus drag the pointer as fast as you want acroos the clip.

[rfmmars]

That's just my point..........You won't have that jerkiness with that codec. No I did not miss your point at all. If you want to preview at 5 times the speed and do quick edits without dealing with key frames, then use what I use in final editing, Magix's MEP2004.

You will still need that codec or mpeg2. How I have it setup is I have Avisynth frame serving to Virtualdubmpeg2, and it frame serving to MEP2004 all at the same time.

The speed is superfast as long as you don't have any heavy filters in the chain in the first two frame server. Do your timeline editing first and then add the filters.

The program isn't free, its $79.00 to $99.00 US, but what a combination. For the demo codec download the (MJPEG) at www.leadtools.com $9.95 to buy, and if you want to see what MEP2004 is all about go to www.magix.com If you are in Europe the program is called Video Deluxe 2004-2005 Plus.

richard

[Didée]

odysseus:

What kind of source are you actually dealing with?

Anyway ... just for quickly browsing the source & finding cut points, I won't suggest to spend any money and then re-encode your source file, just for viewing & cutting.

VirtualDubMod offers the option "Enable DirectDraw Acceleration" / "Allow Video Overlays", which will speed up the playback considerably. I'm not sure about 'normal' VirtualDub, though.

In AviSynth, simply put something like

XyzSource( whatever )
KillAudio()
ReduceBy2()
AssumeFPS(150)

If you happen to have an AVI as source file, then drop the "KillAudio()" and replace the source line with "AviSource(whatever, audio=false)"

This, together with activated overlay in Vdub, will allow you very fast playback, and should be sufficient for cutting.


Then:

For finding cut points, manual browsing is much faster then simple playback:

- Load your avs script in Vdub.
+ Hold the [ALT] key.
+ Browse forward with the arrow key.

= ZzzzzooooooooommmmmmmmmmmmM .... super-fast browsing.

Before you had the time to work long enough to get those $79 - $99, you've already successfully browsed & cut dozens and dozens of hours of video ;)


- Didée

[t_2]

It is my impression that if you hold down the arrow key on your keyboard AviSynth opened in VirtualDub will playback as fast as your machine is capable which may be 2 or 3 times faster than the actual framerate even for full PAL and NTSC resolutions. Maybe a Pentium Extreem could do 5X!!. Or what about editing offline. VirtualDub's job control can batch encode the files to one quarter resolution at night, while you are asleep, and then you could skim through them in the above manner at 10x.

[esby]

zarxrax made some times ago a post of a script that enabled to preview a video.
The goal was to skip regulary some frames in order to map the video.
(in an anime music video creation context)


check this thread
http://forum.doom9.org/showthread.php?s=&threadid=72949

esby

[odysseus]

source is DVD2AVI, lots of Bollywood stuff.

directdraw & overlays are in the base virtualdub as well.

The fast function in the other thread is great (but it changes the frame numbering so you can't edit & save the timeline & open it in the regular (non-fast) clip later).

That AVS function also shows that there's something in vdub slowing down the fast-preview.

That AVS fast preview function, when I set it to show 1 frame out of 50 (the same as what vdub does with the alt-key) plays MUCH MUCH smoother and seemingly 3 times faster than the vdub alt-right-arrow..

Originally posted by Didée
odysseus:
What kind of source are you actually dealing with?
+ Hold the [ALT] key.
+ Browse forward with the arrow key.
= ZzzzzooooooooommmmmmmmmmmmM .... super-fast browsing.

- Didée

[esby]

The fast function in the other thread is great (but it changes the frame numbering so you can't edit & save the timeline & open it in the regular (non-fast) clip later).


... bool "frame" ...

Put it to true,
and you'll have the frame number displayed on the image,
so if you open your original video in the same time,
with another vdub instance, you'll be able to work with it.

You can also note each frame number you need on notepad and work with vdub after.

esby

[odysseus]

Yes, this looks to be the best solution so far.

Originally posted by esby
... bool "frame" ...
esby

[odysseus]

If I have 2 vdubs open, doing editing in one & viewing in the other one, the frame numbers of both will diverge as I do more edits.

within a few minutes of deleting 10 frames here, 100 frames there, the version of the film being viewed in the preview vdub will have zero frames cut out of it, and is reporting a "clean" number of frames.

while the film that's being edited will not be clean at all .... the frame counts in the 2 vdubs will only match up to that very first edit.

back to the drawing board ... uhhhh ... I don't have a drawing board, so back to the Autocad : )

Originally posted by esby
... bool "frame" ...

Put it to true,
and you'll have the frame number displayed on the image,
so if you open your original video in the same time,
with another vdub instance, you'll be able to work with it.

You can also note each frame number you need on notepad and work with vdub after.

esby

[stickboy]

Originally posted by odysseus
If I have 2 vdubs open, doing editing in one & viewing in the other one, the frame numbers of both will diverge as I do more edits.Use ShowFrameNumber() in both instances. That way you know exactly which frames correspond to which frame numbers from the original clip, and you can handle the shifting frame numbers.

Or make your edits backwards, from end to start. :)

The way I do edits, divergence is usually not an issue. I do edits in the AviSynth script itself, not in VirtualDub (it's easier keeping everything in one place, I think). Consequently, rather than having two VirtualDub windows open, I use VirtualDub and a text editor.

I usually pick out which sections I want to keep rather than deleting sections I don't want, which makes things much more straightforward:src = AVISource("somefile.avi")

src.Trim(0, 4852)
\ ++ src.Trim(5981, 6590)
\ ++ src.Trim(9218, 18920)
# et cetera

[Didée]

Somehow, I don't really get your issue, odysseus.

Usually I set up a "quick preview" script like I posted above. In parallel, an editor window with the script is open. In there, I add/edit trim ranges just the way stickboy does.

Together with ALT+Arrow (and eventually mouse dragging, if I know the next break is manymany minutes ahead), even a 4-hours-capture can be cutted down in something like 10 minutes - depending on practice ;)

For me, that's a quite acceptable effort.

- Didée


ugly typo edited

[odysseus]

Didée, Please don't take my posts as complaining. Far from it. I was hoping that someone out there had found a better method/habit/workflow/technique of working with these tools than I had.

Right now I work exactly as you do, alt-right/left to fast forward, mouse if I know there's nothing to cut for the next 1000 or more frames.

Originally posted by Didée
Somehow, I don't really get your issue, odysseus.


I like this, I'll start experimenting with it.

Stickboy - Use ShowFrameNumber() in both instances. That way you know exactly which frames correspond to which frame numbers from the original clip, and you can handle the shifting frame numbers.