Thread: Any way to squeeze HD playback out of my system?

I recently lost basic cable, making my SD MythTV system worthless for recording. So I bought an HD card, which works well to capture broadcast TV, but my system just doesn't have the power to play back HD without annoyingly jerky video and audio.

I don't have time now to start over with a new motherboard and CPU, but I'd like to make these OTA MPEG transport stream recordings watchable on the system somehow. It sounds like a video card with VDPAU support is not an option as I only have an AGP slot.

I am wondering if I could use ffmpeg to reduce the frame rate (or even reduce the resolution), but playing around with it shows that regular transcoding is super slow and has caused the audio to get out of sync with the video.



Anybody have a great kludge in mind, or is it time to bite the bullet and rebuild my system?

Thanks,
David

Mythbuntu 10.04
1.8 GHz Athalon
GeForce5 FX5200 - AGP
Pinnacle PCTV HD Card - PCI

Originally Posted by dyoung

I recently lost basic cable, making my SD MythTV system worthless for recording. So I bought an HD card, which works well to capture broadcast TV, but my system just doesn't have the power to play back HD without annoyingly jerky video and audio.

I don't have time now to start over with a new motherboard and CPU, but I'd like to make these OTA MPEG transport stream recordings watchable on the system somehow. It sounds like a video card with VDPAU support is not an option as I only have an AGP slot.

I am wondering if I could use ffmpeg to reduce the frame rate (or even reduce the resolution), but playing around with it shows that regular transcoding is super slow and has caused the audio to get out of sync with the video.

Anybody have a great kludge in mind, or is it time to bite the bullet and rebuild my system?

Thanks,
David

Mythbuntu 10.04
1.8 GHz Athalon
GeForce5 FX5200 - AGP
Pinnacle PCTV HD Card - PCI

You'll need a newer er faster video card.

Something like a NV 8800 or newer, unfortuantely, they use a pci-e slot.
With out gpu decoding you are probably maxing out the cpu
you'll also want to take a look at your disk drive speeds.

reduce the >advanced>settings>tv settings>playback profile to slim perhaps and reduce the other setting if its on advanced 2X or 1x to temporal

cheers rileyp

You're talking about VDPAU deinterlace modes on a card that doesn't support deinterlacing, and it's all moot because the question was asked well over a year ago.

Even though this post is over a year old it still provides useful info.
After building a new client I noticed poor playback with both video and audio was studdering.
I installed the 3rd party drivers for my nvidia (a 9800gt) card, but still had issues.

After additional research I made the following adjustments;

added "triple buffering" to the device setting to the xorg.conf and
exable additional audio buffering in the one of the mtv setup windows

Still no real improvement


I later thought lets see what the cpu/memory and network are doing during hd playback

firing up system monitor, I saw real time graphs of resources, network was fine, plenty of memory, no swapping. but apparently video decoding is a single threaded process, one cpu was running at 100 %, pause playback and it drops to about 10 %

Having my Homer Simpson moment, I say "Dough" I need to change the playback profile to vdpau hi quality in one of the mth setup screens.


After the change, cpu utilization hovering around 15% average no playback issues on 1080 material.

Problem solved:


Please note this box is considered a rather old lower end machine, an Hp xw8400 workstation

a single 4 core Intel Xeon proc running at 1.8 ghz, 4 gig memory, a single 180 gb disk and an Nvidia 9800gt.

Hopefully my post will help others who have older low end machines asking similar questions. A decent gpu card that has it's own video decoding capability can make or break the project.