Suggestions for a HTPC

[lurker2100]

I'm looking into building a home theater PC based on SnapStream. So far I've got a Shuttle XPC with an AthlonXP 2400+, 512MB PC2700 RAM (overkill I know, but cheaper than PC2100!) and a 120GB hard drive. My questions involve the video card and tv tuner.

Originally for the video card I was looking at an ATI 7000 AGP 32mb card with TV out. After reading through some of the posts, it seems like the GeForce 5200 is a popular card. What benefits does the GeForce offer over the ATI? Keep in mind I won't be using this machine for anything other than home theater stuff, i.e. no gaming.

Secondly, I had been thinking of the Hauppauge PVR 250 for my tuner but I understand that it's not good for streaming live video. If that's true, then I'll have to look elsewhere. I was thinking of an ASUS 7133. Does anyone have any comments on this? It's cheaper than the Hauppauge PCI TV tuner card that SnapStream sells which is why I was considering it.

I'm also looking at using the AVCast product at www.crossbarmedia.com to distribute the video signal to the 3 TVs in my home.

Thanks in advance for any help you can offer.

[V_D_O]

I believe the FX cards have better TV outputs than ATIs, although the Matrox cards are the best for this kind of thing.
No, the PVR cannot stream live. More or less any PCI card using WDM drovers should work in theory, bud do make sure it can record at least 640x480, and should preferably be stereo.

[Sef]

I borrowed a GeForce FX 5200 from work to compare with the Radeon 9200. Here's a summary of my findings:


The drivers for the FX have a nice 'zoom' slider that lets you resize the image on the TV to remove the borders. The Radeon drivers needed tweaking with Rage3D Tweak to enable the overscan option, and even then you can only turn it on or off, no zoom ability. When I entered FullScreen mode in PVS, the zoom reverted to full black borders, you probably have to set it up for every screen mode.

Although both pictures were great, the S-Video TV-out quality seemed a little hazy on the FX compared to the Radeon, although I can't put my finger on exactly why. I'd have to see the two running side by side to compare properly.

Both cards are fanless (the 9200 Pro has a fan, the non-Pro doesn't), but the heatsink on the FX is enormous. On removing the FX the heatsink was incredibly hot to the touch, whereas the Radeon's was just warm. I'd worry about putting the FX into a HTPC because of the heat it generates.


In conclusion, I think I'll stick with my 9200. The zoom feature is a nice option that I wish the Radeon had, but the perceived (or imagined) quality difference and the heat issue put me off the FX.

Hope that helps.

[Rich A]

I have pretty much the setup that you describe except that I am using the on-board NVidia Video.

Some things to ponder. First the Haupauge 250 doesn't have TV out. The 350 does. But the 350 TV out is not yet supported by Snapstream and it only works with the Mpeg for source and then only with the Hauppauge PVR software. I only upgraded to the 350 myself (from a 250) to get the use of it's FM radio.

The TV card you are looking at may be cheaper but it also may only have encoding done in SOFTWARE. Not a hardware based encoder like the PVR-250/350. And that's key to getting everything running correctly.

Many of the current TV tuner cards do not have on card hardware encoding. If you go the route of one of those your CPU will be running at very high use rates. Plus all kinds of things come into play. Like dropped frames, video/audio sync and so on. Plus you'll not likely be able to do other things with your HTPC while it's encoding.

The reason you are going with another type of card, as I see it, is to get other types of streaming video. The PVR-250/350 only do Mpeg because they are using their on-card Mpeg-2 hardware to encode. DE-coding is done with software however.

Putting both a video card and a TV tuner card into one of those Shuttle boxes will make for a VERY tight squeeze. But more important might be the added heat produced by having another card in there, plus the less air flow having that 2nd card installed can create.

The Shuttle box with the NVidia chip set has a built in dual head (two monitor vga ports) plus an S-Video / Composite TV out. It works well with both the Snapstream software and Hauppauge PVR cards.

The biggest thing you want to consider is the hardware mpeg encoding. I don't know about the "streaming video" thing. My own unit is used to directly play back any of the captured mpeg to any TV in the house via an injected signal produced by a modulator that is feeding the HTPC's TV out to the whole house A/V distribution. I'm curious what you would need "streaming" video for with an HTPC?

With the 250/350 (I own both) during the highest DVD quality encoding (720x480 @ 12 Mb/s) my CPU use is under 4 percent. That makes for a nice cool system. Plus I can do anything even while it's encoding. like playback pre-recorded mpegs or even edit them or author and burn a DVD.

I see a lot of guys who are unhappy with results when using a software based encoder.

[lurker2100]

Here's a reason why I was wondering about the streaming: my brother, who is a big Chicago Cubs fan, is away at school right now. He can't watch the games where he is but if he could stream live TV off of my cable feed, he'd be able to watch them. Of course it wouldn't be the best quality in the world, but he'd at least get the audio. Can you stream at all with the 250? Is it just that it will eat up a lot of CPU if you do? I can definately understand the benefits of having the hardware encoding, which is why I was first considering the 250.

I've never built a small form factor machine before so I don't really know how much heat to expect. Rich, you make a good point about having both a video card and a tuner card in there. I thought I read in another post something about there being a benefit to having a video card that supports DirectX9. It wasn't a reference to gaming, IIRC, but something to do with video. Can anyone clear this up for me?

Rich, why do you have both the 250 and the 350?

Thanks again, everyone, for all your comments and suggestions.

[V_D_O]

Streaming can be used for other things - for example, I like to lie in bed and watch TV, when I'm not in the TV room. This is easily acvhieved streaming TV off the HTPC and onto a laptop via the wireless network.

No, streaming live off the PVR is not supported at all in PVS. It would take a lot of CPU to decompress the MPEG video to raw data and then recompress it into WMV data, all in realtime.

[lurker2100]

That's what I figured, but I had hope still!

[Rich A]

Originally posted by V_D_O
Streaming can be used for other things - for example, I like to lie in bed and watch TV, when I'm not in the TV room. This is easily acvhieved streaming TV off the HTPC and onto a laptop via the wireless network.

No, streaming live off the PVR is not supported at all in PVS. It would take a lot of CPU to decompress the MPEG video to raw data and then recompress it into WMV data, all in realtime.

With all the computers and electronics I have around the house, if I brought a laptop to bed with me, my wife would have me watching the laptop and sleeping in the dog house. <grin>

[lurker2100]

Rich,

At what resolution do you run the TV-out?

[WillP]

You can stream wmv if you record with the PVR-250. You just can't do it live. You can record in mpeg2 and transcode to wmv. Then the wmv's can be streamed. Although if you need live streaming, the PVR-250 is out.

If you're worried about heat, then not using a hardware encoding card (like the PVR250) should be your biggest concern. This is because your cpu is likely to be generating a lot of heat when using software encoding. Although I think those shuttle boxes can handle the heat alright.

Also, if you're going to be running other software on this machine, expect some stuttering problems using software encoding. Don't get me wrong, its ok to use sw encoding, but I urge you to search the forums / knowledge base and make yourself aware of the possible pitfalls.

Will

[Rich A]

Originally posted by lurker2100
Rich,

At what resolution do you run the TV-out?

I believe it's running at 800x600. With the NVidia video on the Shuttle main board you can choose to "clone" the VGA to the TV out. On the PVR box I'm running everything 800x600. The other two computers in the media room run 1280 x 1024.

I can switch the VGA monitor and keyboard and mouse to any of the three PCs or a ReplayTV from one central position so I can do everything from one spot .. Ham Radio, day to day computer work, multimedia editing and authoring and view program the ReplayTV or HTPC. When I want to just enjoy "watching" I have it set up so I can remotely access the HTPC or either of two ReplayTVs (one just died today BTW) from the living room large TV set.

A comment about the "streaming". What I'm doing is more geared toward the distribution of audio/video throughout the house. So I have no need to "stream". Rather I have the cable distribution matrix going to any room where I might be viewing something.

If I needed to watch TV in bed, or playback something from any of the media devices I would rather pick up the remote on the night stand and turn on the bedroom TV than putz with a laptop. <grin> Different strokes for diifferent folks. heh heh.

But I know there are instances where streaming may be needed for some. It's not that I'm saying my way is better, but rather I just can't comment on it as I "try" to only speak about those things where I've had "on-hand" working experience.

Off topic note .. I've been running the SnapStream PVR now for about 2 months and it has performed wonderfully. The quality of the captured mpeg is outstanding and the DVDs I've authored with it are the best I've had yet (quality wise). However since firing up this HTPC my two remaining ReplayTVs have been giving me nothing but trouble. Lost a tuner in one and a hard drive in the other and now am having trouble with no video signals. Granted these are a couple years old. I wonder if those ReplayTV boxes are jealous of the HTPC?

[V_D_O]

Well, AFAIK, SW encoding on a 2400+ should be no problem. I use a 2.4B and have never had any CPU usage problems - for reference, it takes ~35-45% CPU to encode to MPEG2 DVD-high quality. Adding live streaming on top of that *used* to take me to ~70%, but SS broke something recently, and now any kind of streaming takes 100%. And watching live in the FSUI while recording while streaming live took me to ~95-100% CPU, resulting in only a couple of dropped frames, but perfectly watchable video. Streaming live on its own took ~30-35% CPU.

I'd suggest buying and trying a normal (non-PVR) card to see how you get along. If it doesn't work, you should be able to return it, if not, its only about $30.

Do bear in mind two things, a) that the 2400+ is not true 2400MHz, and b) that Intel chips tend to perform better than AMDs in video encoding and the like.

[EDIT] Rich, however much I'd love to have TVs and coax in every room, I'm only limited to 2, none in my bedroom, so PVS is my only choice - this is what attracted me to it way back in v2.0 [/EDIT]

[lurker2100]

I think I will take your suggestion and try the SW encoding first. It'll help keep the cost down and, as you said, I can always return it if I'm not satisfied.

Cost is really the main reason I'm planning on going with the AMD. The 2400+ is $80 vs a P4 2.2 at about $150. The benchmarks at www.anandtech.com show the 2400+ trailing the 2.2 in the DivX encoding and leading the 2.2 by a bit in Windows Media 9 encoding. With those margins I figure that I'm better off saving the money and going with the AMD. (Those figures are from the article about the 3000+ Barton.) Of course that's just framerate, no mention of actual CPU utilization.

Thanks for the info, V_D_O.

[Rich A]

Originally posted by lurker2100
I think I will take your suggestion and try the SW encoding first. It'll help keep the cost down and, as you said, I can always return it if I'm not satisfied.

Cost is really the main reason I'm planning on going with the AMD. The 2400+ is $80 vs a P4 2.2 at about $150. The benchmarks at www.anandtech.com show the 2400+ trailing the 2.2 in the DivX encoding and leading the 2.2 by a bit in Windows Media 9 encoding. With those margins I figure that I'm better off saving the money and going with the AMD. (Those figures are from the article about the 3000+ Barton.) Of course that's just framerate, no mention of actual CPU utilization.

Thanks for the info, V_D_O.

Keep in mind that not all software "real time" encoding is the same. Some get help from the video cards with "pre-encoding" filters and such. The ATI All In Wonder cards for example will give you various cpu use depending on the card itself and which ATI Multimedia center you use. The older ATI MMCs' encoding used the Ligos software engine. The newest MMC (8.5) works the best, but only with the Radeon versions of ATI All in Wonder cards.

Using a hardware based encoder is also going to reduce the heat build up in the box that is caused by a CPU doing it's thing.

But as V_D_O says, it surely can't hurt to try the software encoder with a tuner card first. FWIW I used to do real time software based SVCD encoding with a lowly K6-450 years ago. But anything over 3 Mb/s caused problems. Like the man said, a 2400 Athlon should handle it. Just make sure you test it out and give it a good "shake down" cruise.

[lurker2100]

Well after reading through all the excellent tips and advice I've come to a decision. In the end I decided to go with a setup similar to Rich's. I purchased a Shuttle SN41G2 XPC, AthlonXP 1900+, 256mb PC2700 RAM, 80gb 8mb cache HD, and the SnapStream deal with the 250-PVR.

I decided that with my current internet connection (DSL 768/256 riiiiiight) my upload speeds are not stable and usually not very good so streaming media, live or otherwise, really isn't a viable option. Maybe someday I'll have better upload speeds and hopefully by then SnapStream will support multiple tuners so I'll be able to just pop in one of those cheap tuners to stream with.

I was going to ask why my AIW 9700 does streaming even though it has hardware assisted MPEG encoding, but Rich beat me to it. Thanks.

Thank you everyone for your help. Once I get all the parts and pieces (coming from 4 different vendors!) I'll post back with how things run. I'm really looking forward to setting this machine up.