Split clips don't mesh correctly

keastham

I tried several times to trim (split) unwanted footage from clips. After removing the unwanted footage, the video plays, but at the point where the two clips meet, there is a 3-4 second still image while the audio continues. Finally, the video seems to "catch up," and the audio and video are back in sync.

I tried putting different transitions between the clips. The transition gets halfway done, then freezes in a still image for about 3 seconds, then resumes the video.

Suggestions?

[deleted]

Might be wrong but are you using large format clips ( eg. HD MPEG4 1920 x 1080i clips @ 60fps). Even a simple cut in a clip like this with a bit edited out can take an appreciable time to render into the preview window on some PCs, particularly if they are not particularly fast. (It happens on mine .. and its no slouch.)

You have to remember that VP does not physically create two new clips when you "remove" a bit. It gives that impression possibly but it is simply reading in the data it has saved in the cache regarding the editing you have made of the clip in question and this takes time to do and then it has to display it in reduced format in the preview window. Creating a transition can take even longer as it has to interleave frames from different places in your clip. In the meantime the sound is read relatively quickly and as a result is held up whilst your PC sorts out the join. It then has to reduce and play the frames in the preview window. This is the impression I get.

When you play the unedited clip, is there a lag between the sound and the image?

With the format I mentioned above (the largest my camera can produce) I get a lag of 7 seconds in a 13 second clip! :unsure: This makes editing a bit difficult to say the least. However, if I convert my MPEG4 clips, (I now tend to shoot 1280 x 720 HD MPEG4 @ 30fps) to MPEG2 clips they play and edit with no problems at all. In fact the image looks brighter and the sound clearer.

Try it and see what happens.

Nat

hurmar

I have a similar problem. I have added several clips of hd vid into a movie project. I have cross fade selected for smooth transitions. However I also get the freezing video at the beginning of the next scene. The Audio continues. Sometimes they all catch sometimes they don't. ALSO this problem STAYS with vid even after completion say into a flv file. The problem is not computer related it's videopad.

Nationalsolo wrote:

Hi

Might be wrong but are you using large format clips ( eg. HD MPEG4 1920 x 1080i clips @ 60fps). Even a simple cut in a clip like this with a bit edited out can take an appreciable time to render into the preview window on some PCs, particularly if they are not particularly fast. (It happens on mine .. and its no slouch.)

You have to remember that VP does not physically create two new clips when you "remove" a bit. It gives that impression possibly but it is simply reading in the data it has saved in the cache regarding the editing you have made of the clip in question and this takes time to do and then it has to display it in reduced format in the preview window. Creating a transition can take even longer as it has to interleave frames from different places in your clip. In the meantime the sound is read relatively quickly and as a result is held up whilst your PC sorts out the join. It then has to reduce and play the frames in the preview window. This is the impression I get.

When you play the unedited clip, is there a lag between the sound and the image?

With the format I mentioned above (the largest my camera can produce) I get a lag of 7 seconds in a 13 second clip! This makes editing a bit difficult to say the least. However, if I convert my MPEG4 clips, (I now tend to shoot 1280 x 720 HD MPEG4 @ 30fps) to MPEG2 clips they play and edit with no problems at all. In fact the image looks brighter and the sound clearer.

Try it and see what happens.

Nat

ad101867

Hi, all. I'm new here. . . . I've had a similar problem. In larger projects in which I try to link together multiple .vob files, and when I delete sections and then try to link the resulting pieces together using cross-fade, a snippet of the deleted section appears in the cross-fade, like a ghost! What causes that, and how can it be rectified...?

Thanks a ton,

Andy

[deleted]

It may be the fact that you are using the cross fade effect. (Just a thought :mellow: )

In most video editing packages the cross fade is made by dragging one clip (usually the right hand clip) and visually overlapping it onto the left hand clip to the extent required. When the clip/s play the overlapping section fades in under whilst the second clip fades out.Both continue to play as movies. With this method the combined length of the two clips is shortened by an amount equal to twice the overlap.

In videopad this does not apparently happen. Where the crossfade starts,the first frame of the second clip is held as a still image and is faded in under the left hand clip which continues to play up to its cut off position. At this instant the left hand clip is fully faded in and both clips are visible.

Now the last frame of the left hand clip is held as a still image and faded out whilst the right hand clip plays. In this way the total length of the two clips remains the same (and sound on other tracks remains in sync.)

The downside is that whilst the crossfade is happening there are two static images being faded out and in which, depending on their brightness and the length of time chosen for the dissolve can be jarring as they can be seen as ghost-like still images.

Are you certain that what you are seeing as a ghost is actually moving and not just a faint still image?

It's a possible explanation for the effect you are seeing. If you are rendering or using full frame HD there may be a delay whilst VP sorts out all the rendering required.

You could try making your crossfades shorter (1-2 seconds say) and seeing if the effect is still present.

Nat

ad101867

Nat, thanks for responding. I must not have explained it well enough, because what you're describing isn't what's happening. I don't see static images from the very clips I'm crossfading. Rather, I see stills from the piece I've deleted--and which therefore shouldn't be magically reappearing when I do the crossfade. Any suggestions? . . . I contacted NCH themselves, and the advice I got back was to try using the clip preview pane to set the in-point and out-point, delete what I want and crossfade the remaining pieces. That doesn't work though, because when you set the in-point, the program then automatically cuts from the finished version everything before the in-point, which isn't what I want. I just want to know why "ghost" stills from what I've already deleted magically reappear in the crossfade.

By the way, this occurs with every other transition aside from first "fade" (to black) option. Also, I'm using version 2.41. Does this same problem occur with 3.0?

Thanks again,

Andy

ad101867

Hi again. The only work-around I think I can use is to edit my way to the first point where I want to use a cross-fade, then save that portion of the project as a finalized .avi or whatever--and create multiple segments that way--then link all those segments together in an overall, complete final version. This would likely work, because as I say, these "ghosts" seem to only appear when I'm using raw footage and making deletions and then linking pieces "on the fly."

[deleted]

Hi ad

I have had a play with some MPEG-4 clips to see if I can duplicate the effect you are getting.

I loaded two MPEG-4 1080 clips to the media list and then dragged them down to the timeline so one followed the other. I then switched into time line mode so I could see what was happening. By default (setup in options), a 6 second crossfade was also added between the clips. This was shown (as normal) by a yellow bar across the junction of the two clips. However NOTHING was shown in this respect on the soundtrack line.

At this pont the clips appeared to play correctly with a normal crossfade and the sound played OK across the junction between the clips. The crossfade appearing to be generated as I mentioned above using the first and last frames of each clip. Deleting the crossfade and then reinserting it made no difference to how it appeared on the timeline or how it played.

So, I deleted the default crossfade leaving just the two clips.

I then selected a point in the first clip where a bright red object appeared (I thought this would be better seen in a "ghost" image.)

I then split the clip just before this point. After selecting the section containing the red object I deleted it.....No red object!

The clips played correctly one to another without any "red object" being seen. So this was just as expected.

I now added a 6 second crossfade to the junction by clicking the small blue square on the first clip. A 6 second crossfade gives enough time to see anything untoward. The first thing I noticed was that the yellow effects bar spanned the clips apparently correctly except this time there was also a "crossfade" yellow bar shown on the soundtrack. This was at odds with the crossfade added before the split was made which showed nothing on the soundtrack. Furthermore, tthis was shown to start AT THE JUNCTION of the clips and not in sequence with the film crossfade.....ODD!

On playing the clips this is what was seen..

Clip 1 played up to the start of the crossfade and at this point Clip 2 started to appear.This is what I expected.

However, at the point where the join between the clips is shown, Clip 1 continued to fade out but PLAYED THE DELETED PORTION as evidenced by the "red object" appearing (and fading out over the next 3 seconds).

I mentioned above that a normal crossfade in VP seems to use still frames from each end of the transition in order to keep the overall clip length the same. It would now seem that when a split has been made in the left hand clip and an effect is then added, the original length of the two clips is retained, not by using a still frame from the end of the split clip, but by playing into the split off section for half the duration of the effect.

I think this is what you are getting and appears to be an inherent "fault" with all effects that span points where clips have been split

Your workaround..ie creating avis of the bits you split and then reinserting them will solve the problem but.........

Nat

ad101867

Thanks again, Nat. Yeah, your "but" says it all: the work-around can get the job done, but I shouldn't have to bother with an extra step. Now since I'm fairly new at movie editing, I have a couple maybe-dumb techie questions you might be able to answer. (1) To serve the work-around of multiple finalized segments, what's the best resolution for those segments in order to later have them appear top-quality on a dvd? VP gives all sorts of resolution options for "Save Movie," but what's the best possible setting? (2) Are blank dvds that allow more than 2-hour videos available at your average computer-supply store? Usually the dvd stacks I buy in bulk are disks limited to 2 hours.

Oh yeah--I mentioned I'm using version 2.41, but does the crossfade glitch also happen in 3.0?

[deleted]

HI ad

As I mentioned, unsplit clips dissolve (crossfade) OK using still frames, but once the end of left hand clip is split off and deleted thenVP apparently uses the "deleted" bit to complete the dissolve.

Before going down the road of creating numerous segments try this method for reducing the "ghost".

Put your clips on the time line and split the left one as required and delete the section that you have cut off.

Now add your crossfade effect to the remaining left hand clip.

The yellow effect bar will span the two clips equally, but the overlapping right hand side will fade out using your deleted bit (i.e.making the "ghost")

So, grab the right hand end of the yellow effects bar and drag it closer to the join. This will mean that the crossfade will have less of the left hand clip to fade out, i.e. less of the deleted section will play. If the crossfade is now too short overall, simply drag the left hand end of the yellow bar more to the left. In effect you are making the transition more "off centre"

Adding a dissolve in the normal way it is always centred on the join between the clips, but you have the means to alter the start/finish points of the effect.

See how that works.

Nat