I think ATI/AMD just disabled this feature in the Windows drivers for 4650 and 4670. You can get acceleration working with the open source drivers in Linux distributions.

Yes, it must be something like that, but I remember reading about some tweaked Xp drivers and so on. Sadly that was a few years ago and now I can only find tweaked drivers for Win 7.

Are you using x264 decoding on You Tube ?

I'm using the HD4350 in XP on an Opteron 2.6 GHz. I'd be interested if you can figure this out.

Best I managed so far: using Catalyst 12.3 AGP hotfix drivers the hardware decoding gets enabled up to 480p. At this resolution the GPU goes to 25-26% while the CPU load drops to 30-40% so the hardware acceleration of the video card is obviously working. Videos run smooth including those at 60fps. HOWEVER if switching to 720p the GPU load drops to zero and the CPU load goes to 100% while the video turns into a slideshow.

All this is in firefox.

agent_x007 wrote:

Are you using x264 decoding on You Tube ?

It is disabled despite having all the correct options in about:config

I sold an AGP HD4650 not long ago with an Athlon 3800+ 939 and 1080p ran butter smooth, 20% cpu utilization. I think I already deleted the test video but I'll look for it anyway.

EDIT1: Found the video, doing a 1080p Bravia Demo it goes down to 13% cpu. Athlon X2 3800+, 3GB of DDR400, 1GB HD4650 AGP, Asus A8V. Sadly no info on the drivers but I was using Windows 7.

Yes, there's no problem with Win 7, the trouble is with the Win Xp drivers for the hd4650 AGP.

I'll have a go with my HD4670 and XP.

Disable VP9 Codec in Firefox

type into adressbar-> about:config
search vp9 and disable.

that way you force h264

I don't believe that it works in XP. I seem to recall that full H264 decoding in hardware might need DXVA 2 and WDDM drivers which limits it to vista or later. XP supports only DXVA 1 and no WDDM drivers. IIRC DXVA 1 does not support full Hardware decoding but only Hardware acceleration for some functions used in video decoding.

I never got hardware video decoding working on XP with a 4670 back in the day.

What happens if you use HTML5 on youtube?

Same thing, no hardware acceleration.

Sounds like the same problem I ran into.

Will those newer APU's run on XP, which have integrated graphics, CPU, etc? Or do the drivers, be it official or unofficial, not exist?

It may have more to do with various flash players being installed over time. So far I tested 3 Xp machines, one has C2duo and hd4670 PCIE, xp 32 bits, does hardware acceleration without issues without anyone tweaking anything. Second one has c2duo and hd6850, xp 64 bits, no hardware acceleration, owner didn't bothered as his e8500 is beefy enough for hd youtube. And finally the P4 3ghz with AGP 4650 and xp 32 bits, no hardware acceleration no matter how much I tried.

It's worth noting that the first computer has very few softwares installed, wasn't used for extensive web browsing and therefore had no flash player installed on the current xp installation.

After doing more research in the history of those 3 pc's mentioned above it appears that the one which has the hardware acceleration enabled is the only one that never had any other ATI/AMD card installed on the current Xp installation.

So I'm starting to suspect that the problem here is that DDU doesn't manage to take all the trash out, so to speak. And some driver bits intended for cards that didn't had hardware acceleration survive and prevent hardware acceleration from working properly.

What other driver cleaners would you recommend to use? (and in what order)

Resurrecting this topic since I got the definitive answer to the question and others may need it too. This browser extension https://addons.mozilla.org/ro/firefox/addon/h264ify/ called h264ify which also exists for Chrome forces youtube to stream h264 video which is easily handled by the HD4650. Not sure how long it will keep working, but for the time being it works just fine.

Did you see any reduction in CPU usage after enabling this extension? If so, did it work in XP and Win7?