Adding a blu ray player to my PC, Some sound issues

Vindictive

Active Member
Just bought myself a shiny new av amplifier the Yamaha dsp ax863 and some quad lites(thanks to this forum!)

My question is I use my Sammy R86 as my monitor and fancy adding a blu ray drive to the pc, I also have a powercolour ati 4870 1gb graphics card with the dvi-hdmi adapter and all the talk of True HD sound has confused the hell out of me. What will the sound be like through the hdmi output?

Is it worth adding a blu ray player to my pc or buying a stand alone blu ray player with the aim of getting dolby true hd/ DTS hd sound?

I am confused as hell to which path to go down. :lease:
 

Stephen Neal

Distinguished Member
There are, AIUI, three ways of getting the new HD audio codecs (Dolby True HD and DTS HD Master Audio) from a PC into an amplifier without reverting to legacy PCM2.0/Dolby Digital and DTS 5.1 etc.

1. Bitstream output via HDMI. This sends the undecoded True HD or Master Audio over an HDMI1.3 link to your amp, and your amp decodes it. AIUI there is no current solution that delivers this - though the £180 Asus Xonar card - which takes the HDMI video from another graphics card and loops it through adding the audio - is promising it (though this fails with 1080/24p video output currently so is a non-starter for users with 24p displays).

This should deliver guaranteed high quality sound (though you won't get stuff like menu noises etc.) - though it does require a very modern amp with on-board TrueHD and Master Audio decoding (not all HDMI audio amps have this)

It isn't available yet...

2. Decoded Multichannel PCM via HDMI. This requires the PC to decode the audio to PCM 5.1/7.1 and sends it via HDMI. There are a couple of solutions that do this - but none are perfect with all sources. ATI 4xxx series and nVidia 8200s and Intel X45 systems are all capable of doing this - but not all are supported by all bits of software - and some may not be supported currently AT ALL. AIUI Power DVD and Arcsoft Total Media Theater also restrict all audio to 48kHz and 16 bits - which is fine for most sound tracks - but there are 96kHz and 24 bit tracks out there on a few discs which will be downsampled.

The Xonar will also do this (with support for 1. promised) now - but is limited to working with Arcsoft Total Theater - and has the 24p limitation, and is generally regarded as pretty buggy. There is an Auzentech board coming (which promises 1. and 2.) which will be locked to Cyberlink PowerDVD.

This approach also only requires HDMI1.1 or above AIUI - and an amp that can cope with multichannel PCM. (It is also the approach taken by the PS3 Blu-ray player - albeit without the 24bit/96kHz issues)

3. Decoded analogue. I have no experience of this, but believe it to be possible, with on board decoding AND analogue conversion. You would require an amp with multi-channel analogue inputs - and the D/As and audio stages in most sound cards are pretty low quality (and could be quite noisy)


The problem with both 1. and 2. is that Microsoft don't have a nailed down standard for this stuff - and HDMI requires a "Protected Audio Path" for high quality audio to be carried. This means that each card manufacturer is having to team up with a specific software company to ensure compatibility, rather than all software working with all cards.

Bottom line - at the moment there is no perfect solution. I decided to stay with SPDIF quality audio (same as very good DVDs) initially until stuff became clearer, and a 780G based motherboard will deliver this via HDMI with no problems (I'm happily watching Blu-ray and HD-DVD stuff this way at the moment). The ATI 4550 should ship soon, and that may be a £50 solution which may also improve video performance (I hope a cheap passive one appears soon) AND deliver multi-channel PCM via HDMI simply.
 
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Vindictive

Active Member
Wow, that is exactly the info I needed, thanks for taking the time to reply. So it looks like there is no straight forward solutions at the moment. Seems like it is a make do scenario.

I either spend £200 on a standalone player and make the most of the shiny new amp or a buy a £100 Blu-Ray drive and have downsampled sound and wait for a cheaper sound card solution. What i am thinking is will I notice the sound difference? Anyone actually compared?
 

Stephen Neal

Distinguished Member
I think you CAN hear the difference on a reasonably good 5.1 sound system - I can compare my PS3/EP30 running decoded HD audio (or PCM 5.1 tracks) multichannel PCM to my amp, with my PC sending legacy DD/DTS to the amp (i.e. SPDIF quality) and the PS3 is noticably cleaner and more distinct. However the PC is still a very good solution - and if you didn't compare them I suspect you'd still be pretty happy.

So I guess I'm saying - there IS a difference - but the PC running DD/DTS 5.1 is still going to be pretty good - and may cover you until you can get a sound card to do what you want?

(Does you amp have True HD and DTS Master Audio decoding in it? If it doesn't then you aren't going to be able to bitstream over HDMI and will have to decode in the PC. If that is the case then a 4550 or similar video card with multichannel PCM over HDMI support may solve your problem - albeit with the odd 96k/24bit release downsampled to 48k/16bit - but there aren't a huge number of these releases. The 4550 should be out in a short while in the UK AIUI. AIUI you may need a 4550 to do the PIP stuff that appeared in Blu-ray 1.1 - though I don't know which software players support this and Blu-ray 2.0 yet?)

On the other hand - a PS3 or standalone will just sit there and work - and the latest are Blu-ray 2.0 compatible (so will do PIP and the internet stuff with no faffing).

I still chose to watch DVD and Blu-ray physical discs on my PS3. However I am building a jukebox of the discs I own on my HTPC - and the convenience of watching ISO images this way is huge, and I find I'm now watching more of my movies because it is so easy to search my library in My Movies!

You should be able to get the LG HD-DVD/Blu-ray reader (with DVDRW support) for quite a lot less than £100 now - I think I paid about £70 for mine. It is SATA - and I think mine came with a SATA cable and a SATA to MOLEX power adaptor? (My memory may be playing tricks on me)
 
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Vindictive

Active Member
The Yamaha 863 does do True HD and DTS master audio.

I already have a Powercolour 4870 1gb so i am not losing much with the graphic card outputting the audio then just the higher end 96/24 stuff?

I have an Creative SOund blaster Audigy 4, what would the sound be like outputting through that. Will it be just be the standard DTS/ Dolby stuff or the slightly downsampled True HD/ DTS MA?

Why oh why isnt everything straight forward? :suicide:
 

Stephen Neal

Distinguished Member
The Yamaha 863 does do True HD and DTS master audio.

I already have a Powercolour 4870 1gb so i am not losing much with the graphic card outputting the audio then just the higher end 96/24 stuff?
If the 4870 is outputting 5.1 or 7.1 PCM via HDMI then you will only lose quality on the 96kHz or 24bit stuff. My understanding is that there aren't that many releases using this format (apparently there are even a couple using 192kHz /24 bit stereo...).

If your card does do this - and I think the 48xx series do - then I'd go ahead with the Blu-ray drive. If you are happy watching DVDs on your HTPC then the added convenience of a single device that plays Blu-rays and significantly lower cost must surely make it worth a go?

I have an Creative SOund blaster Audigy 4, what would the sound be like outputting through that. Will it be just be the standard DTS/ Dolby stuff or the slightly downsampled True HD/ DTS MA?
It will depend on the disc.

AIUI if you have a multi-channel PCM disc, then this will almost certainly also have a Dolby Digital track. If you chose the Dolby Digital you'll get SPDIF quality 5.1 (as that is what is on the disc), but if you chose to listen to the PCM multichannel track you'll just get 2.0 stereo?

Some discs only come with a Dolby True HD or DTS Master Audio track and don't have a legacy Dolby Digital, DTS or PCM track for a given language. In this case the True HD and Master Audio will have a "core" track - which is a Dolby Digital or DTS SPDIF quality track, with a secondary stream that converts this (adding in the information lost) to make it lossless.

(Or at least that is my understanding)

The PC doesn't usually (ever) decode the Master Audio or True HD track to uncompressed audio and recompress it to DD/DTS 5.1 SPDIF quality - it either replays the core of the track, or replays a separate DD/DTS 5.1 track AIUI.

There WERE a couple of early Blu-rays which only had multi-channel PCM tracks ISTR - these CAN cause problems with PCs with SPDIF output - as you can only get a 2.0 PCM output (and the PC won't recode to DD/DTS 5.1)

The above bit was only in reference to the Audigy being used for coax/SPDIF digital audio output. You MAY find that if you took the ANALOGUE outputs to a 5.1/7.1 analogue input on your amp that you CAN get all of the audio streams in analogue from your PC (still 48/16 limited) - but the quality will then be based on the D/A and Output stages on the Audigy (and how RF-noisy your PC is?). I used to use an off-board USB2 Audigy for HTPC audio - mainly because my original HTPC had no free PCI slots and no SPDIF output on-board. I usually used the SPDIF output - but did play with the multi-channel analogue outputs and was pleasantly surprised at the relatively noise-free results.


Why oh why isnt everything straight forward? :suicide:
Mainly because of DRM these days... That is the main sticking block with bitstream audio output of the new codecs. The resampling issue is similar - though may also be a limitation of Windows.

PC sound handling is still far from perfect...

On the other hand a £500 HTPC can do a LOT more than the equivalent spent on standalone boxes...
 
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Apone

Member
Hi

Remember that if you add a drive, you will also need software to play BD discs.

So a drive will cost approx 50 quid and software such as Cyberlink Power DVD or Arcsoft total media, these will cost approx 50/60 quid.

If i am not mistaken, the 4870 can output 5.1 LPCM via the DVI socket if you have the right adapter- DVI-HDMI. i don't have that card, but i remember reading this in a review.

I have a 2600XT and it plays bd fine and use the motherboard analogue jacks for 5.1 sound to my processor. I also use Cyberlink.

Given you have an amp that can decode the lossless tracks, i would go for a 200/250 quid BD player and not go with the PC option.

I only went for the PC option because i did not want to spend more money on a new amp/processor at the time and this was the best route for me.
 

Stephen Neal

Distinguished Member
Yep - some versions of the LG Blu-ray/HD-DVD ROM drive comes with Cyberlink PowerDVD - but this MAY be limited to 2.0 audio output and not cope with HDMI and SPDIF multi-channel.

So budgeting for an upgrade, or the purchase of the software outright, should be included.

The Sony BDP-S350 can be had for £192 on Amazon last time I checked - and that will decode and/or bitstream output all the HD audio codecs (it will bitstream all of them and on-board decode to Multi-channel PCM all but one flavour ISTR)

You pays your money - you takes your choice!

The standalone will just work straight out of the box - and may be less frustrating than constantly playing with drivers and player software etc. You may find it is a bit slower to load and start playing discs - but it may alro run quieter!
 

Vindictive

Active Member
I think i might take your advive stephen, I might just have a bash at a blu-ray drive and see how it goes. What have a got to lose but £50 and my sanity? Sounds like you dont miss much and wouldnt notice the difference anyway.

Thats the probelm with the internet to much bloody info! (only j/k)
 

Stephen Neal

Distinguished Member
Let us know how you get on. I suspect there will be quite a bit of tinkering required to get it all working compared to a standalone - but the neat integration of an HTPC can be very compelling.
 

MeGa_MiX

Standard Member
What motherboard do you have? I am gonna do exactly the same as yourself with my PC. I think you can use Your SPDIF optical out if you have HD processing on your motherboard.
A few motherboards do HD processing now.
I own the Asus Maximus Extreme and it has 8 channelHD Audio processing on board which apparently does 192KHz/24-Bit.
Should be a month or so till i get the kit together tho...
 

Stephen Neal

Distinguished Member
What motherboard do you have?
I have the MA78GM-S2H Gigabyte board - very popular with loads of people here. Using it with a 4850e CPU.

Use it with two set-ups (long story) - a 40W2000 fed HDMI with separate Toslink audio going to a Marantz amp, and a 40W4000 fed HDMI via an Onkyo 606 amp (fed HDMI audio)

I am gonna do exactly the same as yourself with my PC. I think you can use Your SPDIF optical out if you have HD processing on your motherboard.
I can get SPDIF quality audio via either Toslink optical or HDMI - you switch between them in the Sound section in Control Panels (and there is also an Audio Config change in PowerDVD as well)

You don't get HD quality audio (i.e. Dolby True HD, DTS Master Audio or PCM 5.1 uncompressed tracks) with this solution.

A few motherboards do HD processing now.
I own the Asus Maximus Extreme and it has 8 channelHD Audio processing on board which apparently does 192KHz/24-Bit.
Should be a month or so till i get the kit together tho...
Presumably this is for analogue output though? I have no interest in analogue outputs - in my experience anything going through a 3.5mm jack is usually pretty pants. (And PCs are not a great environment for analogue audio)
 

MeGa_MiX

Standard Member
Will the optical out send the(unprocessed) sound to the Amp for processing then? Will that be possible to achieve 7.1 HD audio if the amp decodes the unprocessed Audio? I thought all the data would be there through the optical SPDIF ready for decoding by the Amp if the PC (HD Decoder) hardware wasn't up to the job.
For THX and DTS and Dolby true HD to work i understand that this is all done on the Amp...
 

MeGa_MiX

Standard Member
I guess the Optical Out(PC) is a Digital Audio Out. The Cyberlink Power DVD ultra software should do the audio decoding for you so you can achieve 7.1 surround sound from your PC even when rigged upto an AV Amp...
 

Stephen Neal

Distinguished Member
Will the optical out send the(unprocessed) sound to the Amp for processing then?
The optical out will send just a PCM 2.0 or DVD-quality Dolby Digital or DTS bitstream.

It will not send a multi-channel PCM, or bitstream Dolby Digital Plus, Dolby True HD, DTS HD High Resolution or DTS HD Master Audio, via optical out - as these formats are not part of the SPDIF standard.

Will that be possible to achieve 7.1 HD audio if the amp decodes the unprocessed Audio?
You will be able to get lossy compressed 5.1 (with Dolby Digital or DTS compression) or lossless 2.0.

Any 7.1 audio is - AIUI - derived from the 5.1 stream (though I have heard of some 6.1 DD or DTS tracks?)

Whilst the audio is "unprocessed" it isn't the full quality stream - it is either a lossy core stream or a separate lossy track.

I thought all the data would be there through the optical SPDIF ready for decoding by the Amp if the PC (HD Decoder) hardware wasn't up to the job.
Optical can only carry a max of 1.5Mbs under the SPDIF standard - the new codecs can require a lot more than this.

For THX and DTS and Dolby true HD to work i understand that this is all done on the Amp...
Nope...

(THX is not really a sound standard - it is a certification scheme)

Dolby True HD and DTS HD HR/MA can only be carried via HDMI - either decoded by the PC to multi-channel PCM or bitstreamed as a True HD or DTS HD stream. Neither of these formats can be carried via SPDIF optical or Toslink.

Whilst SPDIF can carry all flavours of DVD movie audio, it can't carry the new HD codecs and has to drop down to the lossy core streams - or a PCM 2.0 downmix.
 

Stephen Neal

Distinguished Member
I guess the Optical Out(PC) is a Digital Audio Out.
Yep - but it is limited in what audio formats it can carry - basically PCM2.0 or Dolby Digital or DTS. It can't carry multi-channel PCM, Dolby True HD, DTS HD HR or DTS HD MA.

The Cyberlink Power DVD ultra software should do the audio decoding for you so you can achieve 7.1 surround sound from your PC even when rigged upto an AV Amp...
If you take the analogue outputs from a PC, or have an HDMI solution capable of multi-channel PCM then the software should decode the True HD and DTS HD tracks to multichannel PCM, and pass on any older Blu-rays with 5.1 PCM uncompressed tracks.

However the optical outputs from a PC will not be able to carry this multichannel PCM (whether decoded from Dolby True HD or DTS HD, or whether just a straight replay from disc) to an amp - as it only has bandwith for a 1.5Mbs 2.0 stream, not the 4.5Mbs+ required for uncompressed PCM 5.1 or 7.1 streams.

Some of the newer HDMI cards are beginning to allow bitstreaming of True HD and DTS HD streams for amp decoding.
 

Vindictive

Active Member
Right first problem!

Have linked the PC to my Yamaha 863 amp, but the picture is rubbish!

When i directly link the PC to HDMI port 2 on the Samsung R87 I have the it displays at the correct resolution.

However when i connect the PC to the amp then the TV the resolution goes to 1024x768 with no options to change it to the native resoultuion of 1368x768! Its like the pc isnt picking up that its connected to the tv.

Sounds wonderful though!
 

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