Mpeg Edit

[cuddles]

Anybody know whats available by way of mpeg editors for use in assembling a VCD

[Migou]

Hi,
i remember a program i found that can trim mpeg files...without decompressing-recompressing..

Maybe it'll be useful to you..
http://www.cinax.com/products/ifilmedit.html

Mig.

[elister]

And make sure to use the VCD Mode when editing or you'll hose the bitrate (its like magic, a VCD becomes a mpeg1 file).

[cuddles]

What is meant by hose bitrate??

[DrMordrid]

VCD is a strictly defined format with a fixed bitrate, resolution and other parameters.

What elister is referring to is that most MPEG editors and encoders VCD presets to automatically generate files with the correct settings.

Dr. Mordrid


[This message has been edited by DrMordrid (edited 14 December 1999).]

[ScottV]

I tried iFilmEdit once and I thought it was really good until I realised it was losing frames, i.e. the mark out point I was specifying was not the mark out point I was getting in the 'copy'. It could be up to half a second out sometimes.

Does anybody know if this problem has been fixed. I can't remember what version I tried. I was about 6 months ago.

[elister]

Yeah thats pretty much why i stopped using iFilm edit, you need to give yourself plenty of space between edits (much like letting the camera roll 6-10 seconds before action is yelled) otherwise precise editing cannot be done.

I have yet to see a mpeg editor that really works (iFilmEdit is the best ive seen so far). Instead i just edit raw avi files in adobe and encode it to mpeg latter.

[cuddles]

Thats my end goal, that is to make a video CD.
There any help would be welcome.
I now use ifilmedit to join mpegs so whats my next step.

[cuddles]

I fogot to mention that I ues My220-RRS cards and create mpgs from avi's in MSP5.02 VE. And write to HP100i
What else do I need to get to finish the task.

[SteveR]

Some speculation on what is going on when editing mpegs without decompression-recompression...

Presumably when removing material the editor has to remove a whole Iframe to Iframe section, otherwise some odd-looking artefacts would be generated when playing back through the edit. A typical frame sequence would have Iframes every 15 frames, or roughly half a second for full frame rate video. Could this be where the "up to half second" losses come from?

An alternative approach for an editor would be to decompress, edit then recompress. However this would likely result in a quality loss. The decompressed B & P frames between the Iframes would be of a somewhat lower visual quality than the Iframes. After an abitrary edit point the the new Iframes would most likely come from the lower quality B & P frames (15:1 chance) and the old higher quality Iframes would be turned into B & P frames, leading to an overall degradation of quality. Presumably the mpeg editor chooses higher quality and imprecise edit in preference to a precise edit and loss of quality.

As I said I am just speculating as to what is happening. No doubt someone who actually knows how the mpeg editor work would be able to enlighten us.

[Walrus]

I believe that Video Studio 4.0 can edit MPEGs and only recompress the GOPs that need to be recompressed. Another program I know of that handles this well is the ClipView program that's bundled with the Adaptec Videoh!, a parallel port MPEG encoder. (which is an OEMed version of another product) Actually, I use ClipView a lot because it does a rather good job of arbitrary edits in mpegs (frame accurate) and I can't tell any quality difference at the edit points. The minus side is that it's only available with the videoh! (as far as I know) and it only works under Win9x (no NT support), and it has a very odd UI that takes some time to get used to.

[Mr Happy]

You could try a company called Vitech Mutimedia. They produced a editor called Video clip.... But its not that good and as SteveR says you are still limited to only editing I frames.
All MPEG editors (I know of)are limited to this. Some encoders allow you to change the N and M values (distance between I and P frames) but now we are talking big money.
The best way is to edit as a AVI and then when finished, convert to MPEG.