slight stutter or shake editing mpg files HD

[Doug2006]

Hi, I have an HV 40 and take the video off with Hd Split.

Here is the problem, I put 30 minutes of video in the time line and then want to break it up to 8 -9 minute segments. I tried using the scissors to cut each segment and then delete what I don't want and share - output - mpg optimizer. That gave me five files. The first one is fantastic, what you would expect. The rest all have a jump or stutter at the beginning. Just for one second of play, the rest is great.

So I thought I must be doing something wrong, and then started over with multi-trim. I cut the five segments out using that and the same thing.

I thought I would live with it. So then I converted all the clips to MP4 HD. Just to reduce file size and make easier to upload. Now the thing I was going to live with looks twice as bad. It went from being almost unnoticeable to a major glitch. Rest of video plays great and you can hardly tell any quality difference between it and the original.

So then I started playing around with cutting off the front 1.5 seconds of the clip and that seems to actually work. To get rid of it. But it is more work and I don't think professional.

Then I read something about fade ins so I tried that. I took the original first cut of the second segment and put it into the overlay track and used the little fade in slider in the preview window, to have a slight black fade into the clip. This covers up the jitter but the entire clip is now noticeably degraded. I mean it looks lousy!
I went straight to mp4 this time, instead of making the fade and then using the optimizer to go to the same format and then convert.

So now I am a bit discouraged. I have a fast six core computer am using the latest corel x4 pro and it seems that things are not going to go very well. Simply cutting the video to make edits results in jitter at the start of each cut clip and messing with a fade in just ruins the quality. What to do?

If anyone is interested in seeing what I mean you can see the front 5 seconds of the video here; http://www.youtube.com/watch?v=1JACLwyTgac

I am replacing the earlier not so good videos with newer ones. I feel bad that all that work is marred by what a person must think as shoddy workmanship. Doug

BTW going from the mpg to the mp4 reduces the size by about half which makes up load reasonable, but still an all night affair.

[Ken Berry]

I have a HV20 and also use HDVSplit to capture. I have never had this problem, and have used that camcorder and format for several years now. The only difference that I can see is that you are using Optimiser for output. I always just do my cuts and edits etc, then go to Share > Create Video File > HDV. Since HDV from the Canon always uses exactly the same format, you will thus be producing a new file with exactly the same properties as the original. Have you tried that instead of using Optimiser?

[Doug2006]

Okay, I just tried again and did not use the optimizer and it produces a clean start on the video. One question when I go to the share create video file and hdv there are a bunch of choices. None of which I know. For the test I used 720p 30p for HDV. I have no idea, but know in the camera I shot it at 30 something. Also what is the difference between 1080 which is what my camera outputs and 720? What is the difference between for HDV and PC? As far as I can see the quality of what I just produced seems to be the same as the original. Thanks for the help. Doug

[Ken Berry]

If you look at the Properties of your original video from the camcorder, it will be 1440 x 1080, Upper Field First, 29.97 (or 30) fps. So that essentially is what you want for your output (before you convert it to another format).

Frankly, I am not sure what Corel's reasoning was in providing two different outputs at 1440 x 1080: one for 'HDV" and the other for 'PC' since to all intents and purposes, they are identical, except that those for PC use just 'mpeg-2' while those for HDV use 'mpeg-2 (transport stream)'. I guess the implication is that those for PC use program stream mpeg, as opposed to transport stream. But I always use the latter anyway with excellent results.

The 1280 x 720p version is obviously a smaller frame version, but progressive in the sense that each of its 30 frames per second is a full frame; whereas the 1440 x 1080 versions are interleaved. That is why it shows 60i on those choices since each frame only shows half the lines. Thus it takes two frames to make a full image. So in fact the 60i is often (usually) shown as 30 fps as well, but using Upper Frame First. The 720p is Frame Based, rather than Upper Field First.

The 1280 x 720p format is also a normal television broadcast format for high definition TV.

[Doug2006]

Thanks for the help. I have done some experimenting here at home and found these results.

If I cut up the HD video from the cannon and hdsplit on the time line I have some choices to 'share' it. If I chose same as first clip or mpeg optimizer the beginning of the clip is ruined.

If I choose HDV and HDV 720p-30p for HDV it comes out great and so far I can not tell any difference in size or quality. If I choose HDV 1080i-60i the beginning is ruined.

I can also choose Blue Ray - 1440x1080 and that works with a larger file size. I can go with Blue Ray H264 either 1440x1080p or with out the p and they both work with even a slightly smaller file size then the HDV 720p one.

That probably is enough for one eight hour day. I am glad I found somethings that work. I think it is counter intuitive, I figured staying at the top of Corel's list with either the optimizer or same as first would be the one to use. Apparently not. doug

[Ken Berry]

'Same as first video' only works with certain formats. It was originally developed for standard definition video, and simply doesn't work for many of the high def formats; or else it uses properties which convert the high def to standard def.

As for the Optimizer, I simply avoid it. In my few experiments with it when it first appeared a couple of versions ago, I got some strange results. So now I leave it alone.