Cutting Clip causes lost and repeated frames

[parisredwine]

I am using Video Studio 11 to cut up an 11GB HD file that I captured from my Canon HV20. The aim is to cut the file up into bits that can be stored on 4.7GB DVDs and then re-assembled later exactly as it was.

If cut the clip up using the Cut Clip at Jog Slider method, I find that the first couple of frames of the new clip (about 4.5 GB) are ok, but then frame 3 repeats about 2 or three times during frame 3,4 and 5, then I see frame 6> Because Frame 3 repeats three times and the real frames 4 and 5 have been lost, there is a glitch in the clip.

What is happening and how can I stop it from happening.

[Ken Berry]

Welcome to the forums!

I am afraid I have no real idea of what is causing your specific problem. I have a HV-20 and VS11.5+ and have never come across this one before. Offhand, it could be because you are cutting into a 'Group of Pictures' (GOP) at the wrong spot. MPEGs (which is of course what your HDV is) are made up of a series of GOPs, and each GOP is a specific number of frames (in your case, usually 15) that contain all the relevant information pertaining to that piece of the video. It starts with an I-frame which contains all the data, and is followed by other frames which contains only parts, and different parts, of the data. So if you cut it in the wrong place, the first few frames of the new clip (and the last few frames of the clip from which it was cut) will not have all the information needed to display that GOP properly. Hence the repeats or apparent repeats and other glitches.

I assume in making your cuts, you have expanded the timeline out fully so that it is literally frame by frame so that you can see that you are cutting at the last frame of a particular scene?

In terms of your overall workflow, I have given up capturing extremely long clips such as you have done (11 GB or of course higher). When capturing, I now use a small freeware program called HDVSplit which does exactly as its names suggests and captures and splits HDV format video directly from the camera by scene. You might want to try it if you haven't already. That way, you can archive a series of smaller, consecutively number clips onto a number of DVDs and (probably) not face the problem you currently have as HDVSplit automatically detects where to cut the video without disturbing the GOPs...

[parisredwine]

Many thanks for the welcome.

Interesting idea about GOP. However I did a quick test using data from another tape and randomly cutting the clip seemed to be fine.

The only difference seems to be that the source of the problem clip was a standard quality DV tape, whilst the one that did work was recorded on a proper high quality HDV tape.

Could it be that the DV tape is not handling the HDV recording and corrupting crucial info that is needed to do the clip making.

[Trevor Andrew]

Hi

Just a thought

If you are capturing to a file greater than 4.7 Gb and you need to cut the clip.
You would now have to render the clip to a new video file in order to fit to disc.

If you were to capture to smaller clips under 4.7 Gb you would only have to burn the disc.

No editing. No re-coding.

I tend to use 4.3 Gb, to be sure.

[Ken Berry]

parisredwine -- nice thought re the mini DV tape, but I have a Canon HV20 and use only standard DV tapes with it. In fact, I did not know there were even 'proper' HDV tapes. In fact that was one of the attractions of the camera -- that is uses standard DV tapes! And I have never had any trouble with it. But I am prepared to concede that anything is possible. How you correct it on the existing tape, though, is another matter.

The only thing I can think of is, if the glitch only occurs at the beginning of each new cut video, then to make sure that you build in redundancy. In other words, make the cut on the original twice around the same spot. First you cut it where you need to so that the first part of the tape is saved exactly the way you want. Then you highlight that part of the tape and select Save Trimmed Video. A *new* file of that first part is created, but the original video remains uncut. So then start a new project and reinsert the original video, and make your cut well before where you really want the video to start. That way the glitches will occur in a part of the tape which you still have in the first cut bit, and the usable part of the second clip now contains everything you want, with the glitches in bits you don't need because you already have them on the other clip. A bit klutzy but it should work.

Trevor -- the problem is that the OP is trying to burn a data disc to store the video for later use, and not a video DVD. However your thought about files smaller than 4.7 GB is reflected also in my suggestion of using HDVSplit which, unless you were filming something in one long continuous shoot, will produce a series of small clips with every scene change.