freezing

Technically-oriented discussion of classic films on everything from 35mm to Blu-Ray
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drednm
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freezing

Unread post by drednm » Fri Jun 03, 2016 12:08 pm

WHY do I get freeze frames around trim points? Seems to happen whether I use WONDERSHARE or AVS for trimming out "reel change" and other unwanted blips and slugs.... any ideas?
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Marr&Colton
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Re: freezing

Unread post by Marr&Colton » Fri Jun 17, 2016 5:16 pm

As a former theatre operator and projectionist, WHY, for the sake of realism, wouldn't you want cue marks at reel changes?
In the case of transfers of old TV prints, which sometimes have cue marks every few minutes, I wouldn't want them either.

When seeing the first "motor" cue mark, then the second "changeover" cue mark, I remember how enjoyable it was to
do seamless changeovers many years ago.

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MoviecollectorOH
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Re: freezing

Unread post by MoviecollectorOH » Thu Jan 19, 2017 8:41 am

If you are talking about trim points on digital media, that is because the frames are encoded into groups where the frames are really supposed to be adjacent to each other (GOPs, or Groups of Pictures). That has to do with way a video codec works (MPEG2, MP4, etc). If you have trim points made with a program that is unaware of these delineations, then you end up with glitches as the video decompresser visibly crashes and recovers.

One way around this is to use VideoRedo to do your trimming. The programmers have designed it in such a way that trim points are intelligently recoded, so that you end up with two well formed GOPs at each trim point instead of malformed GOPs. Recoding is a slow process, but in this case it is only invoked at the trim points themselves (unless of course if you are recoding the entire thing - for instance compressing it or going from one codec to another where every frame gets recreated). VideoRedo TV Suite is their midrange consumer-level product, and that takes care of this for HD. For UHD either this will work, or else their professional-range product will.

Oops sorry, old thread.

P.S. Just wanted to add that with VideoRedo you can also open or import a video previously edited in another program and cut a frame or two from each side of a previous trim point, just to let it know it is there, then save to a new file. VideoRedo will then make two well formed GOPs at the trim point.

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