Graphics cards and DVRs

[Guest]

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

First, my apologies if I've stumbled into the wrong forum, but the
postings I've read so far indicate some decent brainpower in this
newsgroup.

I'm close to buying a new system (probably a Vaio desktop in the 2.8 -
3.2 gig range, at least a gig of memory).

Until recently, I've been set on getting an ATI All-in-Wonder card
(either 9600 or 9800).

However, now I'm hearing all these rave reviews for SnapStream's
BeyondTV3, which supposedly runs best on hardware-encoded cards like
Adaptec Vide-Oh! and most of Hauppage's cards. ATIs are all
non-hardware-encoded.

Here's some context:

1. I'm not a gamer. That said, it looks like the hardware-encoded
cards tend to be markedly inferior (clockspeed-wise) to the ATI AiW.

2. I havn't the faintest notion what "hardware encoding" is.

3. Besides playing around with Adobe Premiere in class a few years
back, I have no background in video editing but would be interested in
learning at some point.

4. I want a decent DVR in my PC.

Suggestions?

Oh, and one last question. I'm uncomfortable with the idea of the DVR
recording to my main hard disk, so I'm adding a second disk (probably
not more than 50 gig) for the exclusive use of the DVR. Wise
precaution, or unnecessary expense?

 

[Guest]

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

Benny Tleilax wrote:

>
> 1. I'm not a gamer. That said, it looks like the hardware-encoded
> cards tend to be markedly inferior (clockspeed-wise) to the ATI AiW.
>

Hardware encoding has nothing to do with the clock speed you're talking
about. That's purely for 3D rendering, mot mpeg-2 encoding.



>
> 2. I havn't the faintest notion what "hardware encoding" is.

Hardware encoding simply means a dedicated chip on the TV tuner card is
doing the mpeg-2 encoding, not the CPU. This lets you get better quality
mpegs with very little CPU or memory resources.

All the system has to do to start recording is to essentially start DMA
transfers from a buffer on the card to the hard drive.

Also, a gig of ram is overkill if you're building a dedicated DVR. I run
XP Pro with 512 MB and have no problems but all the system is used for is
recording. Prior to that I was using my desktop machine for multitasking
and DVR use and that machine also has only 512 MB and Win2K and I never
had problems.

>
>
> 3. Besides playing around with Adobe Premiere in class a few years
> back, I have no background in video editing but would be interested in
> learning at some point.
>

For cutting commercials you don't need a background in video editing.
Womble "Mpeg-VCR" or "VirtualDub-mpeg2" will do the job with very little
effort. The latter is free and a great tool for converting to xvid
(mpeg-4) as well as removing commercials.



>
> 4. I want a decent DVR in my PC.
>
> Suggestions?
>

Yeah - BeyondTV. It will run in the background so you can do all the
things you're used to doing. You would be wise to dedicate a hard drive
just for recording shows if you're multi tasking. That will minimize the
risk of dropping frames.

That said. I have only one hard drive in my dedicated DVR machine and can
easily record two channels at once (two Hauppauge PVR-250 cards) while I
watch a pre-recorded show with no problems.

This is where hardware encoding pays for itself. With software encoding I
frequently was losing frames and audio sync. Since I switched to the
PVR-250 cards, that was no longer an issue.

One more thing - hardware encoding will let you do CBR (constant bit rate)
recording. Software encoding in BeyondTV typically does VBR in my
experience. Editing a show recorded with VBR and maintaining audio sync is
almost impossible, at least in my experience.


>
> Oh, and one last question. I'm uncomfortable with the idea of the DVR
> recording to my main hard disk, so I'm adding a second disk (probably
> not more than 50 gig) for the exclusive use of the DVR. Wise
> precaution, or unnecessary expense?

You're on the right track, but 50 GB is way too small. 250 GB drives are
cheap, if you're doing a lot of recording, I'd go for a 250 GB drive to
dedicate just for DVR use.

At 7000 Kbps CBR mpeg-2, a one hour show works out to 3.3 GB (this gives
you recordings that are crystal clear). Doing the math, you see that a 50
GB will run out of room quickly. I tend to record more in a week than I
can watch (because I can ;->). So for me, a 250 GB drive is a "starter
system". ;->

One more bit of advice - invest in a cheap ATI or Nvidia video card with
composite and S-video out and a remote control so you can watch on a real
TV instead of a tiny PC monitor. You can get decent ones for this purpose
starting around $60. The Firefly remote control is $50, but you're better
off getting it along with BeyondTV if you go that route because you'll
save money.