Jump to content

Gaps or frozen frames directly after transition


St Bosse
 Share

Recommended Posts

When I have two clips on the time line and joining them with "crossfade" transition, I get either a black gap or a random frame from the second clip frozen for a second at the start of the second clip on the export video of the project. When running the video in VP on the time line, everything is perfect. I have now shuffled and removed and re-placed the clips, tried to overlap them manually, but no success.

The cross fade transition is sure giving me grey hairs!¬†ūü§¶‚Äć‚ôāÔłŹ

Any suggestions?

St B

Link to comment
Share on other sites

Hi

There shouldn't be gaps/ black frames or random images. The export transition should look like the preview transition. (Of course) What format and res are the two clips you are joining and what is the format of the export? I am using VP 10.56 32 bit and with mp4s all seems to be normal. What version are you running? Does this happen with any other transition? Is it a matter of a transition in a split clip or between two different clips?

Another point is...When you click the X at the join  for setting a transition, do you get the choice of Overlapping  the clips or using a still image from each? (This option, I am sure you already know is set under Options/Editing/Video Clip Transitioning

Nat

Link to comment
Share on other sites

If these clips are on track 1, switch to Storyboard mode and confirm that there are no gaps of snippets of other clips between them.

Nat mentions the 'freeze' or 'overlap' choices that may appear if "ask" is the transition option and the clips do not have sufficient content to accommodate the crossfade.

If FREEZE is chosen, the From clip will freeze halfway through the transition until the end...and the To clip be frozen at transition start until motion begins halfway through.

With OVERLAP that won't happen, but video will be slightly shortened, which can throw off sync for UNlinked clips that have separate video and audio.

Share these two clips, and someone will check them out.  Upload the file/s to a free server, such as Google Drive or MS OneDrive, get a shared (public) link, copy the link and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum.  When using Google Drive, if necessary change "restricted" to "anyone with link can view."

Link to comment
Share on other sites

Nat - I am using VP 10.60 64 bit with mp4s. Transitions the last 2 or 3 weeks seems to be a nightmare. First I had the blue selection grab the cursor issue (which is still there) if one accidentally "accepts" by clicking outside the box but I have disciplined myself to rather "enter" to get out. Now on the final fine tuning of my videos, I am getting this. The first two videos' exports both had this problem. (still x12 to go!). I must add that I this morning scanned the video to find the position of the freeze frame and it looks like it is the last frame of the video. That said, I think the "black gap" is actually not a gap but also a freeze frame because in that video the last frame was black because of a fade out.

I am very familiar with transitions, in particular with crossfade because I have used it many many time successfully before. And yes, I know about the overlapping choice which in my opinion has a big shortcoming in design. Surely a software designer should know if he gives someone the choice to overlap that everything after that point should stay in sync and move with? Unless I am missing something, it seems very logical requirement that goes without saying.

The issue happens between two clips on the same track.

-0-0-

borate - I have sent a "Backup" link and an exported video demonstrating the issue. see +/- 25sec in.

 I must add that I this morning scanned the video to find the position of the freeze frame and it looks like it is the last frame of the video. That said, I think the "black gap" is actually not a gap but also a freeze frame because in that video (first case), the last frame was black because of a fade out. (first 2 of 16 projects).
I fixed the first project by manually pushing the clips to overlap even more and some other fiddling around there. I think I accidentally fixed it but it wastes a lot of time and test exports every time.

St B

Link to comment
Share on other sites

7 hours ago, Nationalsolo said:

Hi

. . . What format and res are the two clips you are joining and what is the format of the export? . . . Nat

Original (source) video file format = 1920x1080  
frame rate = 59.94 fps (60)
Bitrate = 50892 kbps

Intermediate export for add back into VP as clips
video file format = 1920x1080  
frame rate = 59.94 fps (60)
Bitrate = 10000 kbps

Final export video file format  =  1920x1080 HD 
frame rate = Constant 29.97 fps (TV NTSC)
Bitrate = 5000 kbps

St B

Link to comment
Share on other sites

Hi

Sorry B don't see that with the posted video..  :mellow:   Here, I see a static pose of the dancers (below) from 20 - 26 seconds as the text scrolls up and the XFade proceeds....

z.jpg

At 27 secs there is a sudden cut to this frame below...

zz.jpg

...This is where the movement starts and  is synched  with the start of the Mazurka.(The actual first chord - not the run up.) There is no movement shown between 26 and 27. Note that the p0ses are quite different so it is a jump-cut..  

Was there a cut at this point) and what was the XFade choice? Static or overlap?

Edit...I've got the clip downloaded now and in VLC the jump cut is still there but not too noticable. I'll load it to VP and look through it. Not noticed any black frames yet.

Coppelia !  Lovely!

Nat

Link to comment
Share on other sites

 Hi Nat,

"Between 26 and 27" is a "copy" of the last frame of the sequence. Not a clue how it gets there.  

"Was there a cut at this point".  - Well it is the "set start" point on the clip preview window. Before that the dancers were standing around and getting their spacing right.

"XFade choice? Static or overlap?".  - Tried both, deleted the cut and replaced it again. No difference. It only happens when I add a X-fade.

"Edit...I've got the clip downloaded now and in VLC the jump cut is still there but not too noticeable". - I also play it in VLC and on different LED TVs. The freeze is about 5 seconds and although you and I may think it is a nice artistic touch, it doesn't go down with the teacher (LOL).

"Not noticed any black frames yet."    I think the "black gap" is actually not a gap but also a freeze frame because in that video (first case), the last frame was black because of a fade out.  My conclusion is that there are no gaps, it is in both cases the last frame that gets dragged into the "freeze zone". So there is only the one issue of the freeze frame,  whatever the image or colour of the last frame.

Thank you guys for your interest and trying to help.

I am currently pressed to deliver this total project but will after delivery try and install VP issues backwards to see at what point this issue started. I never had this before that I can remember.

St B

Link to comment
Share on other sites

Testing in both 10.60 32-and 64-bit, don't see that here. 

The pose just prior to the music likely utilized the FREEZE transition mode, which means that it will be frozen for the first half of the crossfade. 

Then the girls are relatively static until the music starts.

Link to comment
Share on other sites

Thank you borate for the download. Yes that is what I am suppose the get. Check the "frozen" image. It is not there (in the beginning of the clip) if you check the individual clips, that image with arms up high, is the last image of the clip.  

St B

Link to comment
Share on other sites

Humm...don't know what to tell you.  Cannot replicate your result here.

The only irregularity spotted is a very subtle chroma increase on the dancers at the end of the crossfade.

Otherwise, no freeze frames (but for what was noted earlier), no jump cuts.

Link to comment
Share on other sites

Okay, I think I found the solution. It is caused by frame rate! And yes , makes zero sense how, but I experimented by adding a pink blank at the end of the sequence to see if I'll get a blank frozen frame in the said position, but no, it takes the last frame of the clip.

But . . . . then I exported a video at 60fps and not the legacy value of  59.97fps (2x 29.97) , which I notice VP changes to when one specifies 60fps and, what do you know, the issue disappeared! I.e. VP does not like it if one specify exactly on its behalf, it will do its own adjustment (i think).

So if you want to try and replicate the issue, try a video export and specify 59.94fps constant.

St B

Link to comment
Share on other sites

 image.png   Those are the choices.

Results were the same at Constant 60, Variable (SmartMax 60fps) and Variable (Min 30fps, Max 60fps).  29.97 (NTSC)  also looked good.

Link to comment
Share on other sites

Hi

Well, I still see a static pose during the XFade in VP that jumps to my image 2.

There must be a section of clip between my image 1 and my image 2 where the dancers are bringing their right arms down. If you still have the clips of the intro ballerina  and the clip of the dancers in their starting pose that has no cuts then I would try this....

  • Place ballerina on Track 1.
  • Place dancers on Track 2¬†
  • Pull back dancer clip to overlap Track 1 for the required envisaged dissolve. If you don't have enough clip of the pose for this then you can split just before the movement actually starts and slow the pose section down, or copy the pose frame and add it on. (I would prefer the first option) Note that this will affect the ausio so it may need to be unlinked and resynched later.
  • Use the transparency effect with ¬†keyframes (100% - 0% ) to fade Track 2¬†in. This creates your XFade without using the transition which seems to be causing the problem.
  • If necessary resynch the audio
  • Add texts etc to Track 3

The effect should be :  intro Ballerina with scrolling texts and intro music dissolving into dancers in pose and moving into the dance at main chord of the Mazurka. Movement between the pose and the dance should have no jump cut.

I am sure this won't apply but from the point of view of the actual clips.....Did you allow sufficient filming time before your start point to include the pose or was the pose added on later........:unsure:  I've not filmed much on stage but quite a bit with my orchestra and early on I found it was a good idea to start filming well before the "baton" came down so as to have plenty to edit out.

Nat

Link to comment
Share on other sites

Hi Nat,

Thanks for the info and suggestions. I think I solved the hole problem with the framerate discovery. Problem totally disappeared. (see posts earlier).

Yes I do film with lots of lead in and out footage.

St B

 

Link to comment
Share on other sites

After all my projects were finalized and exported (14 of them), I started stringing the exported files together in a new project to form the final production. Then, did the final export using the (technically / politically? correct(lol))  frame rate of  29.97 (NTSC). Mistake! Frozen frames are back! Was surprised at first when somebody contacted me and pointed out the issue. On closer investigation I tried full 30fps and the frozen frames are gone. I can replicate the issue every time when using the 29.97 (NTSC) fps.

So my conclusion is that maybe one should stay away from 29.97 (NTSC) or its double of  59.94fps. 

Is there any technical reason why one should use 29.97 (NTSC) fps?

St B

Link to comment
Share on other sites

hi Borate,

Thanks for the offer. I don't want to waste your time. As you have said, you cannot replicate the situation. I can replicate a specific instance easily by using 29.97 (NTSC) fps. Then again on other clips, 29 will work just fine, but it is unpredictable. So, to be on the safe side, I'll just use 30fps all the time and all is fine.

Thank you for your interest.

St B

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...