Originally Posted by TNO821
I can agree with this...if everything stays in the digital domain (assuming there is error correction involved), I would expect the noise to be a non-issue. But I have never seen great deinterlacing performed on a HTPC, and I blame lousy software for that.
De-interlacing is often carried out by GPUs these days - and whether you consider this a hardware or software process is probably a bit fuzzy.
Depending on the GPU you can get everything from very basic Bob/Weave, Adaptive, Motion Adaptive or Vector Adaptive de-interlacing algorithms used. Vector Adaptive can deliver pretty high quality results.
You do have to do quite a lot of work to ensure that the default driver settings aren't used though (edge enhancement, noise reduction etc. all need to be disabled and they're usually enabled by default)
Again I agree. If your HTPC is just passing through the same bits (say, from a 1080p BD), then, regardless of those bits being audio or video, I would expect the same result Vs. a dedicated video player. This depends on the software doing a proper job, which has not been my experience.
But with DXVA2 and Windows 7 the software doesn't have that huge a part to play - it's the drivers that are key.
Now this I find to be unbelievable. You either must have a rather old Sony TV or you need your eyes checked! TV's built-in deinterlacing is typically very very good (see the results in publications such as Home Theater magazine where they run a battery of deinterlacing tests against TV's, BD players, etc).
Err - I'm a former broadcast R&D engineer, who watches broadcast quality sources on broadcast quality monitors (albeit not in an engineering role any more) - I can certainly see the difference in de-interlacing performance.
My Sony Bravia 40W4000 and 40W2000s are OK - but nothing special - particularly with mixed cadence content (say where you have a mix of 50i native interlaced and 2:2 25p native progressive content on-screen at the same time) Worse still is the 576i to 576p de-interlacing (which can't be inhibited) in my Sky HD box.
The number of times you see combing for a frame or two as the de-interlacer is late deciding whether the source is interlaced or progressive is really annoying. The de-interlacing of the same content in my HTPC with a Vector Adaptive de-interlace is far higher quality.
I am willing to concede that the electrical noise argument matters less and less, as long as everything is both digital and has error-correction.
Given that all broadcasting that matters these days is either H264 or MPEG2, and all sources and displays are largely HDMI digital now, the path from broadcaster to display is pretty much entirely digital. The error correction for the modulation and the transport of the digital video and audio is the same whether a PC or a set-top box/DVR does the demodulation and decoding.
The only real variables are de-interlacing (for 480/576i and 1080i sources) performance and stuff like UIs etc.
So, obviosuly my biggest complaint is that I've been underwhelmed by the software (both the UI, other than with Windows 7 Media Center, and particularly the deinterlacing). So what software (and hardware) would you recommend for a really nice HTPC?
I'm in the UK - but would recommend Win 7 Home Premium with DVB Logics tuner virtualisation (that lets you share a pool of centralised DVB-S/S2 and DVB-T/T2 tuners over a network), and small PCs with decent video cards. They're not as easy to set-up as DVRs, but the flexibility of being able to receive channels from multiple satellites, being able to inject XMLTV listings, coping with teletext, subtitles (DVB and WST) and being able to store recordings on a server allowing you to play recordings on multiple PCs (and share live TV tuners across a network) make the whole system a far better proposition than a reasonably dumb DVR. Also being able to watch my DVD and Blu-ray library over the network on the same box is great.
The very basic cards are fine for Blu-ray 1080p content - but if you watch interlaced sources then you need something that will do a decent VA de-interlace. 3:2 isn't an issue for me - as we have no broadcast 3:2 sources here. Much more if an issue is 2:2 detection (for 25p content carried 50i)
If you don't want any post-processing then the ATI 5450 is pretty good, but the ATI 5570 may be a better choice.
Getting consistent black levels is the biggest challenge IME.