i have seen a ton of seperate avi filters to run your project through, that can offer anything from enhancing the images, to adding special effects to the film, etc. Is thier any filters out there for mpegs?? More specifically ones in the vcd format?? I looked around but my searches didnt come up with anything

-- Doug (mazinz@aol.com), January 01, 2000

Answers

MPEG has been envisioned from day one as basically a distribution format, among others, and one main objective of that is to keep filesizes and bitrates as low as possible with the highest possible quality that can be squeezed from them; this I'm told. The one method that has realised this in MPEG is the use of group-of-pictures (GOP) scheme where one full frame, the I frame is stored for every GOP, the rest in that GOP being either B frames or P frames. B and P frames are not full frames; rather they only contain data relating to how a particular frame at that point should look like as interpolated from the last I frame, in simplest terms. If any manipulation is to be done to a segment in an MPEG stream that segment has to be re-encoded back such that all frames are I frames, the filters applied, then re- encoded back to MPEG. Basically AVI do not have GOP, and all frames are I frames, which is why they require humongous amounts of disk space, but which is also why they are much more amenable to filtering and special effects, etc.: no h/w and s/w resources and time are wasted encoding and decoding all B and P to I and back on the fly or not. So professionals do all their editing and so on in AVI and only the final output files are encoded to MPEG; it's simply much more efficient and faster this way. Recognizing this, all sorts of audio/video editing s/w were written to manipulate AVI. For example Adobe Premiere will allow you to do what you need to your AVIs and then you may put a plug-in such as Panasonic encoder to do the final rendering to an MPEG file. MPEG files being that hard to manipulate maybe that's why the only two s/w I know of for MPEG-1 that at least allows simple cut, paste, join, etc are M-editor from Darim and VCDCutter.

-- EMartinez (epmartinez@hotmail.com), January 02, 2000.

thanks for the info. If their was a program out there(which i believe thier is)to disable the 4gig file size then i would be using the avi file system. But until then i will just have to deal without using the cool filters offred for avi.

-- Doug (mazinz@aol.com), January 03, 2000.

Hello.

The new Video Studio (ver 4) by Ulead can edit MPEG files, and supposedly, treat them as if they were AVI files. Check it out on their site.

-- Josh (jhome@net.com), January 05, 2000.

Doug can you explain why you have a problem with the 4G limit, that can be about 70 minutes of VCD avi or if you encode direct to VCD Mpeg-1 about 300 minutes which is way beyond the vcd limit.

Be aware however that some encoders have a 2G input limit (LSX stand alone has)and I do not know if that applies to the Panasonic. So the Gates 2G limit could control what you do and not 4G. Rollon Windows 2000 as I think that has no limit.

The LSX 2G limit is one of the reasons I tried to resize in Mpeg2 as that can be accepted as an input to the Panasonic encoder. The 74 minutes of VCV would then easily be achieved within a 2G file size.

I have several months ago asked LSX to make it possible to batch encode more than a total of 2G into one mpeg-1 output file as that will solve everything. They promise that with the next major update. The time line versions will also be limited by what the edit program can output. For example Premiere cannot render a file beyond 2G as an output size.

Video Studio 4 will accept mpeg files as well as avi's type 1 or 2 and also includes native mpeg2 editing. All that means is you can go direct to a vcd file from the timeline. The Mpeg encoder in VS4 is a timeline LSX but I do not know what the output quality is like, VCD's done in VS 3 where of a lot lower standard and I did not want to stop small amounts of camera panning or zooming to make it OK.

-- Ross McL (rmclennan@esc.net.au), January 06, 2000.