2GB ram isnt enought for SD MPG files project?

Matthew Chaboud · April 27th, 2008, 04:54 PM

To explain this a bit, there is a critical difference between MPEG-2 (or any MPEG) and DV.

DV is an intra-frame format, which means that reading any frame requires only the information for that specific frame. When you ask for frame 10, the DV reader just has to go and fetch the data for frame 10 and decompress it.

MPEG-2 is an inter-frame format, which means that reading any frame may require the decompressed information from a number of other frames. When you ask for frame 10, the MPEG-2 reader may have to read/decompress, for example, frames 1, 4, 7, and 10. Now, that's an awful lot of work, and you typically expect to play back frame 10 after frame 9 (which was after 8, which was after 7). How would you avoid paying the price for reading/decompressing all of those frames over again? You'd cache the data.

That's where the problem lies. There was virtually no performance advantage to holding extra information in memory with older intra-frame codecs, but there is a huge performance advantage with newer inter-frame codecs.

Again, adding more RAM will not keep the app from crashing. If it is crashing (and you have a sufficiently large page-file), it's because you're running out of virtual-address space. This can/will be fixed with further development effort on Vegas.

Mark Stavar · April 27th, 2008, 10:09 PM

Quote:

Originally Posted by Prech Marton

I dont agree. 2gb is enough for every other program that i use.

"we must remember we are editing video, which is resource hungry."

I edit DV video since when i have only Celeron 300 processor and 256MB ram. It worked very well, even with 2 hour project with effect!
So, today i have to add 4GB of ram ONLY because the files is now mpg2 instead of dv avi? This is insane. I know the editing apps are smarter, and faster, but this should not be increase the memory requirement so high, IMHO.

Prech, I have been having the same problems with using MPEG2 files directly off the camera. Vegas crashes once I add around 70 or so, with files ranging in size from 10Mb to 250Mb.

Interestingly, though, with Vegas 7e these same files can be loaded onto the timeline with no difficultly and no crashes. Version 7 appears to be more memory efficient.

I assume that V8 is decoding a lot of stuff into RAM in order to make editing easier, but since I am loading a large number of clips, it is hitting a resource limit and terminating ungracefully.

I eventually loaded everything into V7, rendered out to AVI (DV) and went from there.

Good luck,

regards,

marks

Prech Marton · April 29th, 2008, 03:43 AM

but i like vegas8 because of smart rendering (no recompression)

Today i see an interesting thing:
when i import a previously (smart) rendered single HDV file to vegas8 it import as mainconcept mpeg2 file, and requires 30-50MB of ram. just for importing a single file.
but when i import a file that was captured with vegas and not edited yet, vegas import quickly, it seems that required very little RAM, and properties says: it an mpeg2 transport stream. Ahha!!!
It use different DLL to handle the file, not the mainconcept plugin.
So, is there a utility to convert (smart again) my rendered files, to transport streams? I think the video itself is the same (resolution, fps, 25mbps, gop structure, etc), just the file header is different.
Would be good, to have these files as transport streams. Or only vegas seems so. Maybe Open AS command?

thank all of you.

April 29th, 2008, 03:43 AM	#33
Prech Marton Major Player Join Date: May 2004 Location: hungary Posts: 462	but i like vegas8 because of smart rendering (no recompression) Today i see an interesting thing: when i import a previously (smart) rendered single HDV file to vegas8 it import as mainconcept mpeg2 file, and requires 30-50MB of ram. just for importing a single file. but when i import a file that was captured with vegas and not edited yet, vegas import quickly, it seems that required very little RAM, and properties says: it an mpeg2 transport stream. Ahha!!! It use different DLL to handle the file, not the mainconcept plugin. So, is there a utility to convert (smart again) my rendered files, to transport streams? I think the video itself is the same (resolution, fps, 25mbps, gop structure, etc), just the file header is different. Would be good, to have these files as transport streams. Or only vegas seems so. Maybe Open AS command? thank all of you. __________________ Relaxing clips with waterfalls and music, 3D photos, 3D videos: www.3d-video.hu

April 27th, 2008, 04:54 PM	#31
Matthew Chaboud Regular Crew Join Date: Sep 2006 Location: Chicago, IL, USA Posts: 93	To explain this a bit, there is a critical difference between MPEG-2 (or any MPEG) and DV. DV is an intra-frame format, which means that reading any frame requires only the information for that specific frame. When you ask for frame 10, the DV reader just has to go and fetch the data for frame 10 and decompress it. MPEG-2 is an inter-frame format, which means that reading any frame may require the decompressed information from a number of other frames. When you ask for frame 10, the MPEG-2 reader may have to read/decompress, for example, frames 1, 4, 7, and 10. Now, that's an awful lot of work, and you typically expect to play back frame 10 after frame 9 (which was after 8, which was after 7). How would you avoid paying the price for reading/decompressing all of those frames over again? You'd cache the data. That's where the problem lies. There was virtually no performance advantage to holding extra information in memory with older intra-frame codecs, but there is a huge performance advantage with newer inter-frame codecs. Again, adding more RAM will not keep the app from crashing. If it is crashing (and you have a sufficiently large page-file), it's because you're running out of virtual-address space. This can/will be fixed with further development effort on Vegas.