still confused w/ encoding methods

[prey]

searched thru these forums for my answer and i just want to verify with my findings.

i am hoping to backup a dvd onto 2 x 80 min cds and am happy to just watch it on my computer monitor. i am still deciding as to which encoding method (between divx 3.x and mpeg2) to use.

pls correct me if im wrong but it seems that divx might give better results for compression to 1 cd but what about 2 cds? is divx still better for 2 cds?

also, i am aware of the fact that u can fit 800megs on a 80 min svcd. but what about xsvcd (ie non compliant svcd)? i am asking this because a friend i know has problems loading a 790 meg mpeg2 file on 80 min cd. it showed up as 890 meg in nero. also when he tried to convert the 790 meg file into a bin file it turned up as 900megs?

any help will be great
many thanx from a newbie

[vitualis]

If you just want to watch it on your PC, DivX can offer better quality than SVCD. The benefit of X/S/VCD is that you can play it on a stand-alone player and make menus.

Although DivX discs look better on the PC, the "entertainment value" is still not as good as on a good DVD player, TV and sound systems while sitting on a comfy sofa -- which is why VCDs and SVCDs are still often made in preference to DivX.

As for the file size problem, for SVCDs and VCDs, the MPEG files must be correctly muxed and padded/packed. Otherwise, the MPEG file will be padded to correct fit onto the physical sectors on the CDs --> increased file size.

For X/VCDs, I suggest that you multiplex your MPEG with TMPGEnc on the setting of "MPEG-1 Video-CD (non-standard)" first. This will alleviate the filesize/padding issue.

For X/SVCDs, I suggest that you multiplex your MPEG with bbMPEG on the SVCD settings.

Regards.

[prey]

thanks for ur input vitualis!

there is only one point i didnt really understand and that is how to correctly pad the mpeg files correctly? i know that muxing is combining mpv file and mp2 file to a mpeg file. but what is padding?

thanks again

[vitualis]

For VCDs, the "pack size" of the MPEG stream is 2324 bytes. This corresponds to the available user data of each sector on a VCD (in Mode 2).

For standard VCDs, the amount of "user data" only fills 2304 bytes per sector and 20 bytes of "null" data is used as padding to fill it up to 2324 bytes.

For an MPEG stream to be multiplexed correct for use on VCDs, it has to be aware of these settings.

For XVCDs (i.e., non-standard VCD streams), the MPEG encoder will not multiplex the MPEG in such a way that these issues are addressed. If you then present such an MPEG to the authoring proggy (e.g., Nero or VCDImager), it will force it into the 2324 bytes per sector by padding it as needed. This often leads to a significant increase in size.

By multiplexing non-complaint streams beforehand (e.g., TMPGEnc on "MPEG-1 Video-CD (non-standard)" ), there will usually be a slight (negligible) increase in file size and the authoring proggy will accept it without further padding.

Regards.