Re: HD vs. SD, MPEG2-to-AVI

khobar wrote:
"RS" <mail@xxxxxxxx> wrote in message news:43f4e940$1_3@xxxxxxxxxxxxxxxxxxxx

khobar wrote:





MPEG2 editing is a bit problematic due to
compression/recompression/re-encoding issues but, obviously, is an

option

especially since I've now come across a reference to uncompressed HD

content

taking about 9.4GB/minute as opposed to DV's 840MB/minute. That's a lot

more

space than I anticipated, which is why I'm trying to get a handle on the
numbers.

Once its compressed, its compressed. The loss in quality comes with the
compression. Turning it back into an AVI file isn't going to put you
anywhere that your original Mpg file didn't already have you at.


From my understanding, if you cut an mpeg file, all frames between key
frames have to be reconstructed. Then when you make a change, all affected
frames have to be recompressed. Then if you make another change, the process
is repeated. This is why a) mpeg is more "difficult" to work with and b) why
even modest editing can create degradation of the video. Converting to
uncompressed AVI essentially decompresses the entire video, thus there is a
"real" frame for each frame of video which are independent of all other
frames. So cutting an AVI is straighforward and doesn't involve
recompression during the edit.


For simple cuts editing there are a couple programs such as videoredo
and Womble Mpeg Wizard that can do up your cuts and recompile your new
file without undue transcoding. Quick like a bunny it is.


I've not looked into mpeg editors in quite some time - I've at least heard
of Womble (due to recent searching for info on HD - go figure). I've heard
mention of quickness with regards to working with HD, so that's a positive
sign. One problem I have in editing is that my cuts are rarely straight
forward. I usually end up trimming or adding a few frames here and there
depending on the timing - I employ a lot of experimentation to get what I
want. That's a concern regarding mpeg.

I does sound as if I have more reading to do. I'll check into Womble and
Videoredo because converting HD to AVI doesn't sound practical except maybe
for very short projects.

There's a third alternative I've used in Studio, and it works sometimes:
preview capture where a low-res "representation" of the actual video is
captured and edited. Once it is complete one is supposed to simply click on
"Make Video/Movie/Disc/etc" whereby Studio will then do all the actual
capturing/editing/rendering/etc. and produce a finished product. I suppose I
could hope and pray that Studio 10's Liquid-based engine is more capable
than previous versions.

Anyway, thanks for the ideas.


There was a really long rant thread about Studio 10 a while back. Seems that more than one person was not a satisfied customer.

I'm pretty ignorant about HD video all in all. But I do know that I've used that Womble thingy once or twice and I was able to recompile my mpg without transcoding. Hour long video and that little progress bar just flew by and I had my new file in just a minute or so.

I believe Sony Vegas and probably Premiere Pro will work with the Mpg HD files as well.
.

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