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mpeg formats and encoding

Last response: in Graphics & Displays
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Anonymous
January 13, 2005 4:00:20 PM

Archived from groups: rec.video.desktop (More info?)

Hello!

For a while now i've wanted to make my own computer video, and has
come to realize that pretty much everyone knows more about the
topic than i do. Also, reading up on various stuff and trying to
decide what to put in such a pvr has left me with a lot of
questions. So i'm hoping someone can help me out with a few
questions. Also, i'll probably make statements which are quite
wrong, feel free to comment on that as well. :) 

Right. So i've learned that stuff in the mpeg4 format is of equal
quality as stuff in the mpeg2 format, with the advantage of taking
up less space than the mpeg2. Is this correct?

I'd like to put my video card in an Epia motherboard, and since it
seems to take a considerable cpu (and the Epia features a
relatively small cpu) to software encode stuff, i'd like to look
into video cards with hardware encoding. I've found several cards
which support mpeg2 hardware encoding, but can someone suggest any
cards with mpeg4 hardware encoding? Also, if it has both mpeg2 and
mpeg4 it'd just be awesome.

I've heard of some programs - MythTV for linux seems to show up in
quite a few postings - that converts from mpeg2 to mpeg4 on the
fly. Does converting stuff like this compromise the quality?

Lastly, the tuners on the video cards - is there a big difference
in quality? In some newgroups i see people claiming that a card
from hauppauge has superior tuners. I've seen a terratec cinercy
something card, and i wasn't too impressed with the quality of the
picture on screen.

Thanks,
Carsten H. Pedersen

More about : mpeg formats encoding

Anonymous
January 13, 2005 4:00:21 PM

Archived from groups: rec.video.desktop (More info?)

Carsten H. Pedersen wrote:

> Right. So i've learned that stuff in the mpeg4 format is of equal
> quality as stuff in the mpeg2 format, with the advantage of taking
> up less space than the mpeg2. Is this correct?

In theory yes, but I wouldn't count on it in practice. MPEG-4 is
clearly better than MPEG-2 for very low bitrate encoding (say... less
than 2 Mbps).

> I'd like to put my video card in an Epia motherboard, and since it
> seems to take a considerable cpu (and the Epia features a
> relatively small cpu) to software encode stuff, i'd like to look
> into video cards with hardware encoding. I've found several cards
> which support mpeg2 hardware encoding, but can someone suggest any
> cards with mpeg4 hardware encoding? Also, if it has both mpeg2 and
> mpeg4 it'd just be awesome.

The Plextor PX-TV402U USB device will do both and includes a tuner.

http://www.plextor.com/english/products/PX-TV402Uadvanc...


> I've heard of some programs - MythTV for linux seems to show up in
> quite a few postings - that converts from mpeg2 to mpeg4 on the
> fly. Does converting stuff like this compromise the quality?

Realtime encoding without a HW encoder generally compromises quality.

> Lastly, the tuners on the video cards - is there a big difference
> in quality? In some newgroups i see people claiming that a card
> from hauppauge has superior tuners.

The Hauppauge TV tuner MPEG encoders have significant noise reduction.
The picture is very clean at the expense of detail. Quality eval can
be very subjective. I can't comment on the differences in tuners
themselves. Lab comparisons on the web are hard to come by.
!