Playing HD video?
 

Not really a travel related question, but I figure someone here will know the answer...I have some Blu-ray rips of DVDs that I'd like to play on my Ubuntu box. It's an old box with 512 MB RAM and a Pentium 4 2GHz CPU.

When I play these Blu-ray files, the video is all choppy and freezes for extended periods. Would getting a better video card solve my problem, or do I need a new computer/CPU? What video card would you recommend that works well under Ubuntu and ideally can output sound via HDMI?

Thanks!

EDIT: OOPS, if you have an old box, I doubt you'll have PCI Express?

This is my current low cost favorite:

http://www.newegg.com/Product/Produc...82E16814121259

I can play 1080p MKV's on it without a glitch, and it does audio over HDMI when you install the ATI Catalyst package for Linux.

I'd also add more ram, 512 isn't going to help much when you are decoding HD.

Thanks Scott - I'd been looking at that one. But is it the video card that processes the HD video or the CPU? That's really what I was asking, I suppose.

Edit: just looked into it a bit more. I need a card that either uses AGP or the old-school PCI, not PCI Express. Any suggestions?

What type of graphics card do you currently have? You should need the latest and greatest to just play a movie, even if it is at such a high res. Also what size screen are you trying to play it on?

Generally, it's the CPU that does the decoding. As you have found out, the Pentium 4 2GHz is inadequate. It might be able to squeak by when decoding 720p h.264, but 1080p h.264 is definitely out of the question.

When the stars of OS, video card, driver and codec align, it is possible to offload some or all of the decoding task to the video card. AFAIK, right now the development focus is on Windows XP and Vista through the DXVA framework. I don't know if it works on Linux yet.

I think 512MB RAM is adequate, provided that you close other applications during playback. If your software is using CPU to do the decoding, then you will get most benefit from a CPU/motherboard upgrade. In my experience, an AMD 2.5 GHz dual core or Intel 2 GHz dual core is fast enough to decode 1080p h.264 using the free and popular but inefficient ffdshow/ffmpeg codec.

OK, so if I understand things what I really need in order to play high def video is a faster computer. The video card probably doesn't make much of a difference.

I'm trying to play video onto my 50" plasma TV. It doesn't seem capable of playing even 720p video.

Most likely, the weak point is the graphics card, but you're really pushing it with your old box, even under Linux.

To be accurate, the ATI card referenced by ScottC has 'Avivo HD' circuitry capable of offloading most of the decoding, found on ATI Radeon 3xx0 cards and newer; NVidia cards have a comparable Purevideo HD feature.
The hitch is finding software capable of using this circuitry. Some commercially available software is (PowerDVD comes to mind), but most freeware isn't.

I experimented last year with the aforementioned Radeon 3450 in a HTPC powered by a 2x1.9GHz Athlon, which on its own is slightly underpowered for 1080p material (some stuttering); with the Radeon and the Cyberlink codec from PowerDVD, playback was smooth. However, as pointed out by msb0b, it's all too easy to have to play a combination that will not be able to use Avivo HD, and in the end I just upgraded the CPU in that machine to a one capable of handling everything on its own (the 2x2.5GHz mentioned above is a safe baseline for an Athlon X2).

Given the trouble it is to get it working under Windows, I assume you'd be better off upgrading your machine (motherboard+CPU, and thus DDR2 RAM; a motherboard with decent onboard graphics e.g. AMD 690G or above paired with a cheap modern CPU will be enough and less power-hungry than with a dedicated video card), if you are not already familiar with such workarounds and setup under Linux.

BTW there is no use getting a higher-powered video card for movie playback, as the Avivo/Purevideo HD functions are identical throughout the lineup in same-generation ATI/NVidia cards. I find that offloading the decoding to the video card is not that beneficial from a power consumption standpoint, as while the CPU will consume less, the graphics card will consume more; this especially if the CPU can be fine-tuned with an utility such as RMClock, with higher usage thresholds specified before frequency increases (the default AMD and Intel drivers tend to kick the CPU up to full speed at the slightest provocation).

monahos - thanks for the detailed explanation! I'll use this machine as a file server or something and look in to getting a cheap higher-performance to plug in to the TV.

This is why I keep coming back to FlyerTalk. :)