How to preciesly define start and end?

[Kent Wang]

Is there some more precise way to define the start and end of a project? I know it has to start on an I-frame, but how about some sort of display in the GUI telling me which frame number I'm on, like the VirtualDub status bar does?

[Kedirekin]

You could determine it empirically. After all, there are typically only 2 I frames per second of video.


create a d2v of the entire video
make an avs script for that
open the avs in VDub
find the frame you want - note the timecode
advance slider in DVD2AVI to that time code
go back and forth in VDub to find the matching frame

[Kedirekin]

I just looked. Does the playback # in the stats window tell you what frame you're on?

[hakko504]

Originally posted by Kedirekin
I just looked. Does the playback # in the stats window tell you what frame you're on? Almost. If you run a playback from the beginning it will not differ very much, only one or two discarded at the start (before first I-frame)It is quite unreliable though, because if you use the [ button to mark a new start then that I-frame will become playback #0. If playback # and coded # differs then your computer isn't quite fast enough to playback video in full speed.

[Nic]

"if playback # and coded # differs then your computer isn't quite fast enough to playback video in full speed."

Im not sure that's quite correct. playback refers to the number of frames that should be played back, coded refers to the number of frames that have been parsed. These numbers differ when the repeat-first-field flag is used and therefore you end up with more frames than actually coded in the MPEG-2 file. Forced Film mode ignores the rff flag and coded # and playback # should equal each other.

When previewing in DVD2AVI, it will never drop frames, it will display every frame as quick as it can.

Cheers,
-Nic

[hakko504]

I stand corrected :)

[Die*wrek*show]

As far as interlacing goes, I've noticed the beginning and ending of movies contain more ntsc, in addition to being unneccessary. The more ntsc, the more problems with force film. Here is my question. When you save the project with those ntsc parts cut out(beginning and end), does it help as far as force film goes? The reason I ask is because the last movie I did has flirting with 4%ntsc with the beginning and end cut out using dvd2avi. Using the whole vob stream as-is would probably have made the ntsc even higher than 4%.

[hakko504]

@Die*wrek*show

No, because it still does exactly the same things in both the NTSC and FILM parts of the remaining parts of the movie. But you gain in bitrate because there is less movie to compress later.

I mixed things up

[Die*wrek*show]

ok thanks hakko and nice to meet you. From now on, if I encounter a movie with a little too much ntsc in the beginning and end, I'll edit out those parts from the vobs directly or choose field operation "none". :p

[Kent Wang]

What exactly is wrong with leaving those NTSC bits in? I assume you're only referring to the corporate logo animations.

[jorel]

Originally posted by Kent Wang
Is there some more precise way to define the start and end of a project? I know it has to start on an I-frame, but how about some sort of display in the GUI telling me which frame number I'm on, like the VirtualDub status bar does?

maybe neuron2 can build a "frame selection" for us(like in d2s)
in his amazing DVD2AVI/MPEG2DEC!

is my "dream" of long time ago,it's posted somewhere here!

neuron2,can you here me(us)?
one more "miracle" isn't impossible for you!
(and thanks for that job,i can't stop to read the news every day)

;)
:p

[hakko504]

Originally posted by Kent Wang
What exactly is wrong with leaving those NTSC bits in? I assume you're only referring to the corporate logo animations. Well, Nothing wrong, except that DVD2AVI does not handle NTSC very well when you FORCE_FILM a clip, it just removes every 5th field. See also my last reply in this thread (http://forum.doom9.org/showthread.php?s=&goto=newpost&threadid=44150) and the explanation I gave in this thread (http://forum.doom9.org/showthread.php?s=&threadid=39461).

[Kent Wang]

But you're just maiming corporate logos right? Wouldn't it be at least better than no logos? I guess that's a matter of opinion though.

Though improved precision would allow you to cut out those logos better.

[Die*wrek*show]

I've been using a modified version of kidirekin's suggestion for a while now as a means of doing two things at once. Namely, precise selection and overcoming the frame drop issue(i still use 1.76 for now). Here's what I've been doing, any suggestions would be welcome. Oh, and this method assumes the entire movie will be done on one disk(you can imagine the changes that would be needed for splitting).
First, open the first vob in virtualdub. After it parses, decide which I-frame you want the movie to actually begin on. Memorize that frame. Then go backwards a couple of I-frames. Memorize that one too, it's your dvd2avi start frame. Then open dvd2avi without closing virtual dub and load only the first vob. Then move the slider to the dvd2avi start frame you memorized above. Select the beginning. Keep dvd2avi open. Then close virtual dub, and then re-open using the last vob of the movie(if it's a short movie it might be just one vob), and let it parse. Then decide on which I-frame you want the movie to actually end on. Memorize that frame. Then go forward a couple of I-frames. This is your dvd2avi end frame, memorize it. Then open dvd2avi without closing virtualdub and go to the dvd2avi end frame you memorized above. Select the end. Close virtualdub and save the project. Now when you use the dvd2avi you will have to use an encoder that lets you do source selection within the encoder program so you can select the actual beginning I-frame and the actual ending I-frame.
2 things-One, this won't work well at all on sections of a movie that are completely black
Two, If your memory is great you can close virtualdub after you memorize your frames:p