On 22/03/2023 15:08, Mark Undrill wrote:
On 22/03/2023 13:50, NY wrote:
Snip>
Sadly VideoRedo is no longer supported or maintained, following the
unexpected death of the company's owner who did not leave the company
in a
way that the senior developer could take it over so it's folded. I only
found that out when I reported the error.
That's sad to hear.Thanks for the heads-up.
There is a *potential* problem that even people who have bought licences
(as I have) may one day find that the programme stops working because it
is programmed to "phone home" every year, and if the money to run the
licensing server stops being paid (and his widow may choose not to keep
paying) the software may (or may not) die - the effect is unknown
because apparently that bit of code was designed to be deliberately
obscure to stop hackers...
The chief developer, who now works for another company, has said that he
will try his best to set up a replacement licensing server if the real
one dies.
VRD is a damn good program. I use it all the time to edit out the crap
(sorry, "continuity announcements, trailers and adverts") from
recordings I want to keep. I've not come across any other programme that
is as easy to use or does such a good job.
The problem with editing MPEG and H264 is that the inter-frame
compression means that some "key" frames are presented in their entirety (subject to still-frame JPEG-type compression) but then there is a
sequence of "difference frames" which only describe differences between
the current frame and the most recent full (key) frame. If you just chop
the video in the middle of a run of difference frames and then restart
in the middle of another run of difference frames, all those second
difference frames will be calculated with respect to a key frame that is
not there, so you get a few frames of ghost image and picture break up.
That's what a lot of video cut-and-shut programs to. VRD creates a brand
new key frame at the start of the new sequence (after your cut) by
adding its key frame (which you have chosen to cut out) to the first
difference frame, and then calculating new difference frames from that synthesised one up to the next key frame in the original video. That is
how you get clean edits with no glitching. You see it reported as
"Processing frame 1/15" etc on the progress dialogue box, especially
when working on HD programmes: H264 compression is a lot more "tangled"
and interdependent than MPEG so needs longer (slower) work to smooth
over the cuts.
I suppose the nearest equivalent in a film-editing analogy is the
difference between joining bits of film with adhesive tape over the
bottom of one frame and the top of the next one (*), and doing it
properly with A/B rolls of film which are printed in succession onto the
same positive to hide the splices.
(*) If you watch some of the Southern TV children's programmes from the
1970s (eg Freewheelers) on Talking Pictures TV you can see a glitch at
each edit-point in the film inserts because they did it the cheaper way
- hey, it's "only television".
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