[mythtv-users] HD3000 and Myth. Please help me understand

[Steve Adeff]

On Sunday 20 November 2005 13:45, Donavan Stanley wrote:
> On 11/17/05, Steve Adeff <adeffs at gmail.com> wrote:
> > for absolute quality yes, but for basic archival purpose (you know, until
> > HD-DVD's finally come out....), transcoding to mpeg4 is quite good, you
> > can
> > get a 1hr show onto a CDR if you do it right and get maybe a 5%
> > discernable
> > quality loss.
>
> Maybe for you eyes but there's a noticible drop in quality using xvid to
> get even SDTV down to CD size let alone HD.

you must be doing something wrong if you can't get an SD 1hr show into 700mb 
with such a loss in quality. A clean SD source is easy to fit 1hr onto 700mb 
with no discernable quality loss using XviD. I don't know what the space 
savings are though, I haven't played around enough in this area to check.

As for HD:
use IVTC to cut the frame rate to 24000/1001, then scale the resolution to 
960x544. Using the high quality settings and 2-pass for XviD you'll get a 
great encode that can fit onto a 700mb CD with the original AC3 track. 
Noticable issues arise around network logos and for shows with lots of high 
movement scenes you'll lose some background information in slower areas. BUT 
you can burn a 1hr show to a CD.

Another option is to just use IVTC keep the resolution and convert to XviD 
using high quality settings and use constant Q set to 4 or below (2 being the 
best choice). this will cut the size down by roughly 1/2. IVTC is a huge 
space savigs as it basically gets rid of 6fps (30000/10001 -> 24000/1001).

Note with IVTC though, WB uses a weird patterning and normal IVTC methods 
won't work. ABC, NBC, CBS, FOX and UPN all seem to stick with proper IVTC 
patterns and shouldn't be a problem.


-- 
Steve