I'm looking at getting an HDMI extractor which decodes the following formats to 5.1 - Dolby Digital (AC3)/DTS Would that cover all the surround formats that games use or might use in the future? If games were to use TrueHD or DTS-HD as long as they provided a backup surround track in Dolby Digital (AC3) or DTS it wouldn't really matter to me.
Not really sure what an HDMI extractor is... PC games don't use AC3 or DTS, well certainly not in the way that DVD/BluRay/TV/Consoles do. DDL/DTS-C will be able to sort that, but with the potential for some quality loss.
It extracts the audio from an HDMI signal but there don't seem to be any that can decode to surround anything other than those formats. So what format do games use? Obviously it must be something that most receivers can decode, as that's what most people use. I don't know what DDL/DTS-C is.
PCM is what PC games use, that is why you will only get 2.0 over Coaxial/Optical. Using a GPU is the easiest way to get multi-channel gaming audio, but the receiver has to support multi-channel PCM. DDL/DTS-C is Dolby Digital Live and DTS Connect, essentially software that take the PCM signal and encode it to AC3/DTS in realtime so you can output gaming audio to an older receiver over optical/coaxial, but with a potential audio quality loss.
Ah OK. That's a bugger then as the £40 extractor I'm looking at only decodes DD/DTS and 2.0 LPCM. There's a more expensive one for $118 which decodes 5.1/7.1 LPCM but that price is partly because it has features I don't need, like an HDMI amplifier to boost the signal over long cable runs. Besides, it doesn't decode DD or DTS, so would be useless for playing movies with my RPi or my Xbox360 or STB (both AC3 I believe). I've just checked my Realtek control panel (ALC892) and that does have a DTS Connect tab but it only has two modes, Movie and Music and I guess that would only effect the on-board optical/co-ax outputs, not my HD6950's HDMI audio output. So unless there's some software I can download that will transcode multi-channel PCM to DDL/DTS-C for the HDMI output I guess I'm stuffed. Even if there was, would it automatically detect that the HDMI extractor can only decode 5.1 and downmix the rear back channels (with the Realtek analog outputs I just untick those speakers to force it to downmix them)? This is the £40 unit: http://www.ebay.co.uk/itm/1080P-Dig...SwEetV9ncA&clk_rvr_id=917845504499&rmvSB=true and this is the $118 one: http://www.allaboutadapters.com/hdautorcasts.html
I found this 5.1/7.1 LPCM extractor for £45, so I'll probably get that, as it will work with my PC for gaming and my RPi for movies: http://www.aliexpress.com/item/Hdmi..._73_74_75,searchweb201527_5,searchweb201560_9
I use both audio codecs & I can tell you that Dolby Digital Live you do get audio quality loss since it's doing realtime encoding of PCM to AC3 640kb at 5.1ch 16bit/48hz but with DTS Connect, the realtime encoding of PCM is DTS 1.5mb at 5.1ch 24bit/48hz without any audio quality loss.
Good to know thanks. Using (L)PCM is obviously better then as it avoids these extra encoding steps, although the difference may not be noticeable to some people using lower-end gear.
