TV Tuner CPU usage

[Slick5150]

I have a Haupagge WinTV PVR II PCI tuner, and no matter what program I've tried (DScaler, Showshifter, etc..), the CPU usage when watching TV is quite high. I thought the tuner card did all the work, so why is it unloading so much on the CPU? It ranged anywhere from like 35-40, and I've seen it spike at times up to like 99% for some reason.

What is normal CPU usage for a tuner card like mine?

My system:
Epox 8RDA+ nforce2 board
Athlon XP 2800+ CPU
Geforce 6600GT
1gb RAM
160GB Seagate drive

Thanks for any help

 

[Slick5150]

Anybody?

 

[Trevante]

Does your card do hardware encoding or software encoding? Sounds like it uses software encoding. If it does, then your CPU has to do all the encoding, which puts more stress on the CPU. If you get a TV tuner that does hardware encoding, your CPU usage should decrease. It might also be the program you're using that's eating your CPU, try a different program (Media Portal is a good one).

 

[Slick5150]

My card is supposed to do hardware encoding, which is why I was surprised to see the CPU usage so high.

 

[0roo0roo]

hm probably doing some filtering to make it look better. dscaler certain does. some of its options really eat up cpu, but it doesn't amtter as its all very low prioirty

 

[Slick5150]

Well what can I use that would use less CPU? I certainly can notice a difference at times if I'm watching TV or not

 

[Matthias99]

Which board do you have, exactly? There's no "Hauppauge WinTV PVR II" that I know of.

The PVR-150/250/350/500 are all hardware encoders. Just about everything else they make is software encoding. If you have a software encoding card, nothing will really lower your CPU usage that much. If you don't know exactly what you have, try recording (without watching what you're recording) and see if the CPU usage is still high. You can also try just playing back a recorded video (without recording going on) to see how much CPU is being used for playback. Your CPU still gets used -- possibly quite a bit, depending on the type of video and the video card you have -- when playing video files.

 

[CrimsonCutie]

if you are running DScaler, your CPU is will be very high... its even in their faq (or it use to be). Its useing your CPU to do the de-interlaceing and all the tweaks its doing to the video stream; its "taxing".

 

[rbV5]

Hardware TV "encoders" reduce CPU useage during "encoding", not "viewing" live TV (exception below)

For video playback (unless you are using the TV out of PVR 350, which does feature hardware "decoding" of MPEG2 output) Your graphics card itself handles the displaying of live TV, which will only benefit from the capabilities of the graphics card, the power of your CPU, and the features of the playback software itself, not the harware encoder chip on the TV tuner.

You should see quite a difference in CPU utilization during playback using different filtering and perhaps video rendering modes as well as the resolution/bitrate of the video file itself.

Bottom line, unless you are background recording TV, your CPU is going to get a workout viewing live TV, or your recorded video. How much depends on the capabilities of your graphics card, your underlying PC platform and the video file itself.

 

[Slick5150]

Originally posted by: Matthias99
Which board do you have, exactly? There's no "Hauppauge WinTV PVR II" that I know of.

The PVR-150/250/350/500 are all hardware encoders. Just about everything else they make is software encoding. If you have a software encoding card, nothing will really lower your CPU usage that much. If you don't know exactly what you have, try recording (without watching what you're recording) and see if the CPU usage is still high. You can also try just playing back a recorded video (without recording going on) to see how much CPU is being used for playback. Your CPU still gets used -- possibly quite a bit, depending on the type of video and the video card you have -- when playing video files.

Sorry, it's the PVR-250.

 

[mmesker]

You need to use the Hauppauge software to get the hardware encoding. DScaler doesn't support it and is defaulting to software mode, which will jack up your CPU usage considerably.

 

[Jeff7]

The PVR-250 uses hardware encoding, however, the way it works, for whatever reason, is that when you watch TV you are actually watching an MPEG2 stream from the card.
It takes the TV stream, encodes it to MPEG2 in hardware, but then it uses software to decode this stream, which you watch in WinTV2K. That's why there's a delay between the input and what you see.
I'm not sure why Hauppauge decided to do this. Their PVR-PCI card, the 250's predecessor and their first venture into the PVR realm, displayed a live TV feed. The MPEG2 stuff only came into play when you'd click Pause or Record. But that card had constant driver issues, and they eventually just abandoned it.

The PVR-350 has a hardware DEcoder built in as well, but again, Hauppauge chose an odd use for this - the hardware decoder only functions when the TV-out of the PVR-350 is used. For the computer monitor it just uses software.

I wish they didn't have such weird methods of implementing features. It is nice having a hardware MPEG2 encoder, because encoding high quality MPEG2 at full resolution in realtime with no dropped frames can take a powerful processor.


Maybe there's third party software that can get around this, I don't know. This forum has a Third Party section for the PVR-250/350 cards.

 

[Matthias99]

Originally posted by: mmesker
You need to use the Hauppauge software to get the hardware encoding. DScaler doesn't support it and is defaulting to software mode, which will jack up your CPU usage considerably.

There is no "software" mode on the PVR-150/250/350/500. The feed always goes through the encoder chip, AFAIK.

And it works just fine with 3rd-party recording software. It all goes to the same driver. DScaler, however, generally uses a *lot* of CPU time for MPEG2 playback, since it uses much better scaling algorithms than something like Windows Media Player.

 

[dew042]

On my hardware based dual tuner I can record two shows at once at about 20% cpu usage since it encodes in hardware. But if I view a TV stream it maxes the cpu since its decoding an mpeg stream in software....


dew.

 

[Slick5150]

Huh. Weird. So is there a better card out there for just watching live TV without using much CPU power? (Recording is not a big deal to me as I will rarely/never be doing this)