Settings for slower comptuer

[tismon]

I'm sure that this has been discussed somewhere, but my searches haven't produced anything so please feel free to just refer.

I am trying to use a PCTV HD Mini (80e) on an atom based netbook, which is certainly under-powered for this sort of thing.
With ffdshow, the MPEG2 stream works pretty well on a few lower resolution channels, but on anything higher, the audio stutters and then stops, and the video slows to a crawl.

I can't change the hardware, but I can change what I throw at it. I'd like to force all channels to a lower resolution and change any settings that I can to reduce the load.

I would greatly appreciate any help and/or suggestions. Thank you.

[mvallevand]

You can't reduce the quality of the streams, NextPVR records what it captures (I'm assuming you are watching OTA ATSC since most clear QAM is SD) and while you might be able to run ParallelProcessing to transcode recordings on the fly your netbook could be underpowered for watching and transcoding at the same time.

The only solution I am aware of that might help is to get a Broadcom Crystal HD chip but that typically means that you have to take out the integrated WiFi card and use USB for Wifi. The Crystal HD is not perfect it only helps with video that it accelerate, so you likely would still problems with Silverlight, some Flash HD especially if you are streaming via Wifi.

Martin

[tismon]

Wow, thanks for the quick reply. That's always a welcoming sign to new users.

I was afraid that we wouldn't be able to force SD, but I was hopeful since some true TVs seem to be able. Though they may be doing just as you said.
As for the Crystal chip, I'm actually planning on adding the BCM970015 as long as the tiny usb hub I've got is able to power everything else. Though I didn't realize that it helped with MPEG2 as well (thought only h.264), but it looks like you're right. Is there any chance that NextPVR can utilize it?

Thanks

[johnsonx42]

NextPVR neither knows nor cares about any hardware decoding help, whether it's the video card or a dedicated decoder chip doing it. It's up to your chosen video decoder to utilize the available hardware decode assets.

[mvallevand]

I am pretty sure the Broadcom Crystal HD has it's own DirectShow 32 bit decoder. I am not sure if this enough for it to show up in NextPVR's drop down.

Martin

[tismon]

From what I've read recently, I think that's right for the BCM970015. The BCM970012 was a bit more limited from what I understand.

The end goal for this is to uncase the tv tuner (along with a few other things) and modify it into the netbook and hopefully use a custom nested, fractal antenna that I'd like to mount behind the lcd. I realize that this is all a lot to hope for (the usb hub will hold up, reception, IR accessibility, etc), but this is an older netbook and I want the challenge.

Next step is to look for a way to bring the IR signal to the tuner while it is installed underneath the netbook. Best options so far are either to unsolder and extend the built-in IR receiver or attempt a custom fiber-optic type line. I'd rather do the fiber, but I'm not sure where to start.

Though all that's unrelated to this thread. Thanks for the help.

[smajor]

On some lower powered hardware I use for clients, I had some luck with CoreAVC (http://corecodec.com/products/coreavc) for H.264 produced by my HDPVR that allowed it to be played. I don't know if it'd work for your streams.

I'd never use CoreAVC for playback on something with beefy enough hardware. CoreAVC gets you by, but better hardware and better codecs get better quality. I know that's not always in the cards, however.

[jcjefferies]

Most graphics chips have some video acceleration built in. Run DXVAchecker and it will tell you what DXVA functions it runs. However ignore all the info and go straight to the DSF/MFT tab and select "DSF/MFT viewer" and under DirectShow make sure "Show in groups" is ticked. In the "Video" group there will be lots of decoder most of which are not used by NextPVR. Click on the decoders in turn that NextPVR uses and see if "GPU Acceleration" tab turns black which means that decoder supports DXVA on that hardware.

I use a recent Asus motherboard in a client and as I only play SD video I use the built in AMD graphics which uses 128MB of the main RAM and has modest DXVA functions. Using the twin core 3GHZ Athlon processors it runs at between 10-15% when playing SD video so video acceleration is not needed. However I noticed that the Cyberlink filters were the only ones I had which supported video acceleration on this setup and in use they ran at 6-10% which is a reasonable reduction in processor use. If you try a number of decoders you may find one which provides some acceleration. Another thing you can try is a different video renderer instead of the default as I seem to remember from tests I did that "Overlay" used about half the processor power.

[Reddwarf]

Most graphics chips have some video acceleration built in. Run DXVAchecker and it will tell you what DXVA functions it runs. However ignore all the info and go straight to the DSF/MFT tab and select "DSF/MFT viewer" and under DirectShow make sure "Show in groups" is ticked. In the "Video" group there will be lots of decoder most of which are not used by NextPVR. Click on the decoders in turn that NextPVR uses and see if "GPU Acceleration" tab turns black which means that decoder supports DXVA on that hardware.

I use a recent Asus motherboard in a client and as I only play SD video I use the built in AMD graphics which uses 128MB of the main RAM and has modest DXVA functions. Using the twin core 3GHZ Athlon processors it runs at between 10-15% when playing SD video so video acceleration is not needed. However I noticed that the Cyberlink filters were the only ones I had which supported video acceleration on this setup and in use they ran at 6-10% which is a reasonable reduction in processor use. If you try a number of decoders you may find one which provides some acceleration. Another thing you can try is a different video renderer instead of the default as I seem to remember from tests I did that "Overlay" used about half the processor power.

Apologies for hijacking the thread, I have a slow client and I was trying to run DXVAChecker on it, under W7Ux86, but it won't run. It displays the startup message about donation etc, but then nothing. Any hints?

[jcjefferies]

I am using version 2.7.0 whch is dated Feb 2012. The Donate message only appears the first time you run it when it creates a config file in the same directory. The earlier version 2.6.2 dated Dec 2011 which may have come with SAF6 does not have the decoder functions. I have used it on several XP and Vista computers without a problem. After the "Donate" message and "Version Check" it takes 5-10 seconds to display the appear. All I can suggest is run it from a USB memory stick on another computer first then try it on your other computer.