File Sizing

[Stace]

Guys,

When encoding to Xvid using AGK I tend to make files sizes around about 15mb per minute........90 minute film 1.3gb + 400mb for AC3 sound = 1.7gb file. I am more than happy with the results but wondered if it was time to tweak???

Can I make the file size smaller without noticable loss in picture quality (42" Plasma)?? or should I be making it larger??

On some older movies (mostly 80's) I tend to stick to the 2 Channel audio track and convert to CBR MP3 256 or 320, what sort of file size allocation should I allow for that?

Thanks in Advance
Stace :D

[zacoz]

"Tweak" is probably your key word Stace. You can no doubt make small reductions without noticeable loss in quality. It's just a matter of how much you reduce it until you hit the level that is unacceptable for you - it's very subjective. I would also suggest checking in your log what the compressibility percentage and resolution you're getting at the moment is, so you can consider how much these change during your tweaking. As posted by others in various threads, the individual source itself (not just the type of source) has an impact on the compressibility also.

As to using 2 channel CBR 256 or 320, this would seem to me to be severe overkill. With the sources you're using these on can you actually tell the difference between this and say VBR 128/160 ?

Utlimately it's your choice of where the sweet spot for you is between quality and compressibility.

[laserfan]

zacoz is right this depends on the movie (and your TV!). As a rule of thumb I use 10Mb/min and sometimes even less.

And if you're going to convert from the AC3 track at all, because maybe it's older and 2-channel only anyway, why bother w/anything but 128? I only use CBR 128kbps but I found that my standalone players don't like VBR MP3...

[Stace]

Thanks!

[CWR03]

If you really want to tweak things, I'd recommend the full Gordian Knot. For example, some older movies will be grainy which increases the needed bitrate, so in order to lower the bitrate that would need to be cleaned up.