But a few months back Lovefilm switched from Flash to Silverlight for it's streaming video service (yeh, just as everyone else was figuring out SL had no future). And more recently they started offering streaming in HD. And the bad news is it switches streams on the fly so when it's boxed in on the webpage it stays SD, but when you go full-screen is automatically switches to the HD stream.

Problem is, it uses nearly 100% CPU when playing HD video and so the sound breaks up and the video stutters. Again, Flash plays equivalent bitrate video from Vimeo just fine. If I bring up the setting panel for Silverlight it says hardware acceleration is enabled. I'm tempted to think there's some quirk of the videos they are streaming at lovefilm that means it doesn't use hardware to decode them, but then I remember how it uses nearly all the CPU time on Channel 9 too and if Microsoft can't get a Silverlight site right, who can?

The worst part is even if you upgrade to SL5, the video player host needs to enable the option for hw decode. This is why HD Netflix still causes my HTPC CPU to run near 80-90% while streaming. Hopefully Netflix doesn't just abandon their WMC plugin.

Sorry to hear it uses 100% for you, but I can't really see why it would be... could it be that their player is doing a lot more than it should be? Or perhaps their videos are encoded incorrectly and the player has to do a lot more work?

Anyway, and this is more of a question for @rhm, do you see the same high CPU usage when you play videos on C9?

And, if you don't mind, could you go into more detail around "before the 'new design' and move to Azure made Channel 9 pretty much an unuseable mess (a portent of Windows 8) " ... our design and the fact that we are running in Azure has made C9 unusable for you? The design comment is one thing (I don't agree, and I'd love details, but still I'm not surprised that someone may be unhappy with it), but how has the move to Azure made the site more difficult to use?

Consequently, the most likely thing is that your CPU isn't good enough to handle HDTV (actually 1080p decompression will choke a full dual-core Intel processor, which is one of the reasons why Netflix still only supports 720p max).

Flash is probably getting around this problem by not actually showing you HDTV - it's probably adaptively streaming at a lower bitrate and thus avoiding killing your bitrate.

Also iPlayer uses flash which from what you say means it's probably not actually streaming at full quality.

1 day ago, evildictaitor wrote

For the record, Silverlight (and Windows media in general) tends not to use hardware video decompression because hardware isn't very good at doing video decompression.

Consequently, the most likely thing is that your CPU isn't good enough to handle HDTV (actually 1080p decompression will choke a full dual-core Intel processor, which is one of the reasons why Netflix still only supports 720p max).

Flash is probably getting around this problem by not actually showing you HDTV - it's probably adaptively streaming at a lower bitrate and thus avoiding killing your bitrate.

Not very good? The onboard video on my G45 motherboard handles full-screen 1080p video with no issues. CPU stays under 15%.

@Duncan - I haven't seen the issue with C9's player, only Netflix's WMC plugin. It's a common issue if you look around avsforum.com. It's only noticeable on older CPUs as even the Conroe-era Celeron I'm using can handle HD Netflix (although it does spike to 90%). Netflix has pretty crappy encoding on a lot of their streaming, so I could believe that as well.

1 hour ago, spivonious wrote

*snip*

Not very good? The onboard video on my G45 motherboard handles full-screen 1080p video with no issues. CPU stays under 15%.

On my laptop, the nVidia video card handles 1080p h.264 pretty well, with very low CPU usage. And then when you stop watching the video, about 25% of the time it BSODs the system. So yeah, I disabled hardware acceleration for video decoding.

3 hours ago, spivonious wrote

Not very good? The onboard video on my G45 motherboard handles full-screen 1080p video with no issues. CPU stays under 15%.

In that particular codec without DRM and without other videos or graphics intensive action going on at the same time.

You want a panel of videos (it happens more than you think) or to apply a shader to the video (e.g. during adaptive streaming) or use a new codec or use DRM or run it at the same time as Windows Aero Glass, then it'll all be happening in software.

Which is why Microsoft puts their efforts into making software playback good and not concentrating on hardware playback. Because hardware video decompression sucks.

I don't see how multiple streams, adaptive streams, or DRM has anything to do with video decompression. I agree that MS should concentrate on the software side. It's up to the hardware makers to support this software with hardware.

I don't see how multiple streams (1), adaptive streams (2), or DRM (3) has anything to do with video decompression.

(1) Because your graphics card only has one (sometimes two) video decompression cores on it.

(2) Adaptive streams do edge blending so you can't tell when a high quality stream suddenly becomes a lower quality one and vice-versa. This edge blending is done as a shader (to keep frames high). You can't run shaders on the output of a video decompression core without dropping frames, so what you do instead is decompress in software and then get the shader to run in hardware. This means adaptive streaming doesn't like hardware video decompression.

(3) Because DRM requires you to protect the uncompressed video content, so you can't push raw compressed un-DRMed content over a bus to the graphics card.

BluRay disks are a special case for DRM, since the keys are built into BluRay compatible graphics cards, so in your case, you're streaming 1080p compressed DRMed content to the graphics card and it doesn't need to adaptively stream from the disk, doesn't need to send unprotected content over the bus and doesn't need to show more than one video at once.