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Oh, those extra frames...

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Thu, 07/26/2012 - 12:11
#1
normcross
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Oh, those extra frames...

Just been doing a little test.

Place an .MTS clip on timeline, Video 2
Select a zone for rendering, missing off say ten to fifteen frames at both ends.
Render, in this case to .avi
Place new render on Video 1, lining up with start of zone.
The new rendered .avi is four frames longer than the selected zone.

Now this is weird:-

The first two frames are a copy of the first frame.
The last four extra frames are a copy of the last frame of the selected section.

Now, with the timeline cursor, cut off the first frame and delete it, any guesses as to what happens next?

No?, well, The next two leading frames are a copy of each other.

Even weirder:-

Drag the start of the clip to shorten it, then drag it back out fully.
Now the start frames move correctly, BUT (and that's a big 'but') Frames three and four are a copy of each other.

OK, I'm managing a workaround for this, but it all is a little strange.

No more hair pulling for me, it's all gone :-)

Latest sunab svn
Ubuntu 12.04 64bit

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Thu, 07/26/2012 - 15:26
#2
normcross
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Re: Oh, those extra frames...

Ah, sorry didn't say, my raw .MTS files straight off my camera's SD card when put into Kdenlive have the two leading frames the same. This never used to happen, but I realise now this has been going on for some time. That's using straight .MTS and proxies.

What's annoying now, is that I can't use a section of a clip that has been put through "SlowmoVideo". I used to replace, lets say, the centre section of a clip with the Slowmo, line up the exact frames and it looked great. Now if I do it, looks great in the Project Monitor but after render, the joins don't match exactly and I get a nasty jump.

Now, in the graph of SlomoVideo, I have to do the whole clip, running the first section as near to normal speed as possible, then slow it down and then speed it up. Takes a long time, but luckily I do that on another computer so it can churn away in it's own time.

Sorry, there's me moaning again. Mustn't grumble. I still always get there in the end.

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Thu, 07/26/2012 - 16:20
#3
OpenThinking
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Re: Oh, those extra frames...

MTS is a very hard format to edit (AVCHD). If you need advanced video editing I'd suggest you transcode the MTS clips to DNxHD. Then you can edit frame by frame in HQ and you don't have to use proxies.

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Sat, 07/28/2012 - 12:53
#4
hvdwolf
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Re: Oh, those extra frames...

Note that there is an issue with h.264 which is handled by mlt, ffmpeg (libavcodec) and others. If you use melt, ffmpeg -i and examine the clip in kdenlive, you sometimes see differences in framelength for clips.
Also: they should start at frame0 and give for example 252 frames (0-251), but melt and ffmpeg are not always correct (or at least: give the same value). This also happens on MacOSX with ffmpeg, melt and even iMovie.
It only happens on 64bit systems.

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Sat, 07/28/2012 - 13:04
#5
normcross
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Re: Oh, those extra frames...

Thanks, that's handy to know there is a problem buried somewhere. This is also happening with my Xvid4 .avi files. I render a lot of files straight to this for stabilising with VirtualDub.

Oh, how I miss my 32 bit :-)

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Mon, 09/24/2012 - 08:31
#6
ORL_AMMD
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Re: Oh, those extra frames...

Hi!

Actually I guess I'm experiencing the same problem.
Firstly I had audio/video sync error, as described here: http://www.kdenlive.org/forum/audio-video-sync-problem-mp4-720p-30-fps-v...

But I now have a slighty more annoying problem, always linked to that: I've to blur several trademarks from my video clip. I try to do it straight on the "master" kdenlive project, as it is lighther, so it's eaiser to use.
The point is that I always have some frames without blur, thought I've explored my kdenlive project frame by frame. Though, one time, something weird occurred: on a precise frame, my blurs weren't well placed. I've changed them, and by reopening the project, I jus found that finally, the blurs were well placed in the origin. Something like the frame at that position is not the same from one time to another.
To go further, I've been importing the master export in the kdenlive project, so that I might be able to check when the blurs are not placed, and so on. Actually, when doing this, I just discovered that I had at several places several frames-time-slip (don't know how to call them), and finally I am totally unable to do it clearly.

I'm a bit in a hury, and I need to get this fixed. I 'm thinking about several solutions:
1. adding the blurs in the initial small project. Problem is I've got to copy all those automated blur movements to the initial small kdenlive project, and I'm not sure it's possible. Another problem is that several videos are accelerated or "nervoused", so I'm not sure my blurs would work on them,
2. using another format to export my initial clips. Actually I use h264 mp4 720p @ 30 FPS, do you think that using another one might help? I'm particularly thinking about exporting in Full HD, as it's said somewhere that those problems occurred only at 720p.
3. any other solutions you might propose and that I might understand!!!

Thanks a lot.
Aurélien

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Mon, 09/24/2012 - 13:06
#7
normcross
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Re: Oh, those extra frames...

I used to have matching frames at the start and end of my clips, but the version of kdenlive I am using now only has them at the end, seven to be precise.

The unwanted frames at the start caused bad audio sync but what I noticed, also proxy problems. What you were watching in the monitor was not exactly the same as the rendered project. Even now, if I toggle off/no the proxy, the clip's thumbnail in the timeline moves backwards and forwards. That tells me that what I see now might not match the render, especially if you still have leading frame problems. Are you using proxies? What kdenlive version?

If I place a raw .MTS clip in the timeline, it has 7 frames all the same at the end. So, I select a zone, avoiding those little nasties, and render to either H.264, MPEG-4 or XVid4 and they all have new 7 matching frames.

Today, I have discovered that MPEG-2 is completely free of this problem, it's all the 'big boys' mentioned above. So, render to MPEG-2, as mentioned above, place that clip in the timeline, add a proxy and when it's toggled off/on the clip thumbnail is rock solid. What you see is what you get :-)

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Tue, 09/25/2012 - 06:10
#8
ORL_AMMD
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Re: Oh, those extra frames...

Thanks a lot for the MPEG-2 advice, I'm going to check.
I do not use any proxy, actually. I've been trying exporting to MPEG-4 instead yesterday, and it seemed better, but I had several weird things in the monitor, still. Actually, I launch the render and eventually went to bed, and this morning, I just discovered I rendered a portion of the project!!! So got to do it once again. I'll tell you if that solves my problem.

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Tue, 09/25/2012 - 07:58
#9
ORL_AMMD
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Re: Oh, those extra frames...

It looks like exporting in MPEG-4 is sufficient for me (which is easier, as the file still have the same name/container), though I've got a "one-frame" problem at a place, but it something else (you know when resizing a clip, sometimes, you have the very first frame replaced by another one, don't know why).

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