[User 82703]

Hi all,

I built a HTPC a month or so with AMD Athlon II 3.0Ghz and ATI 5450 with 512MB DDR2. OS is Win7 Home Premium 64-bit. My understanding was hardware acceleration should be fully supported in XBMC for this setup. However, on some high-bitrate files (particularly VC-1 1080) I still see buffering and some stuttering. I thought the 5450 with DXVA enabled would play everything perfectly smoothly, but maybe not?

So how do I make sure if the hardware acceleration is working properly? I do have DXVA2 checked in the video settings.

Even for a regular SD ISO, when I pull up the video stats (keyboard command O) I often see CPU averages in the 20-30% range, sometimes spiking even higher. Is that normal?

Thanks in advance.

[Sranshaft]

DXVA2, from what I'm aware of, is only available during playback of h264 video files. So files like .mp4 or .mkv(?) only. .iso, .avi and whatnot will only use FFmpeg.

[jhsrennie]

If you press o ("oh" not "zero") when playign a video I think the diagnostic info indicates whether DXVA is being used, thoguh i forget the details.

JR

[User 82703]

DXVA2, from what I'm aware of, is only available during playback of h264 video files. So files like .mp4 or .mkv(?) only. .iso, .avi and whatnot will only use FFmpeg.

If that's the case, that would definitely explain it. The high bitrate files I have seen some issues with were m2ts, I believe.

So if I wanted perfect playback, my other option would be to use some kind of external player through XBMC?

And @jhsrennie, when I pull up the OSD, I do see DXVA2 in the info displayed, but again - I am not sure if it is actually being used or if that just means it is enabled.

Thanks!

[>>X<<]

It has nothing to do with the container its the codec that's important in this case VC-1

Why don't you turn off DXVA and see if there is a difference in how much CPU load there is

[jhsrennie]

And @jhsrennie, when I pull up the OSD, I do see DXVA2 in the info displayed, but again - I am not sure if it is actually being used or if that just means it is enabled.

I've just tested on my PC and it's the second line that shows whether DXVA is being used. If you see "dxva" in this line then dxva is actually being used.

JR

[ashlar]

VC-1 content is hardware decoded. The only real problem can happen if it's 1080i content (interlaced).

[User 82703]

VC-1 content is hardware decoded. The only real problem can happen if it's 1080i content (interlaced).

Sorry for my ignorance - when you say HW decoded, do you mean CPU or GPU? And if GPU, that means that my CPU usage for a VC-1 file should be quite low, correct? What would a typical CPU % be?

I guess I am just surprised to see any stuttering/buffering issues at all with my setup. I know it's not top of the line, but I would have thought it should be more than adequate.

[foghat]

yes, gpu decoded. For me, with dxva turned off, my cpu is about 60-70% with dxva on cpu is less than 15% usually less than 10%