: 5.1 Toslink Output


TaylorTech
2009-11-11, 12:06 AM
Hey everyone! I did a quick forum search and found nothing on the subject.

I want to buy this: http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0770HDS0010121939&catid=
But my computer only does 2channel toslink output. I need this as I want to use this system as my speakers. Also, 5.1, 7.1 sound cards usually only do 2ch toslink so I don't know how to find any helpful info.

I also need something cheap, so any suggestions are greatly appreciated!


Thanks!
Tay;pr

blueroomelectro
2009-11-11, 12:45 AM
You could try AC3filter to send raw PCM through the TOSLINK output.

CHrisCHu
2009-11-11, 03:44 AM
I've never heard of 2-channel-only toslink. Toslink is Toslink. It's digital and it's up to the software to throw in however many channels of data. What your computer spec suggests is most likely that the sound card hardware encodes only up to 2 channels into Dolby 2.0. However, on all sound cards that support digital output there's a bypass mode that sends whatever Dolby 5.1 signals from the source (e.g. DVD) to the digital output unmodified.

Furthermore, ffdshow audio decoder is a very powerful tool that can convert any source into Dolby 5.1 compatible streams live (e.g. it can take 2-channel mp3 music or even 2-channel live analog input on your sound card and uses the decoder's cross-channel matrix/reverb/DSP and feeds out a Dolby 5.1 stream onto Toslink/Coax).

However, most HTIB with DVD player includes NO digital input. The only 5.1 source of these HTIB's are from the internal DVD player, or perhaps at most 1 digital input. The spec of the Samsung HTIB your link points to doesn't seem to suggest any digital input. I highly recommend going for a 5.1 sound system WITHOUT a DVD player.

EDIT: The Samsung in question does input 1 digital input. These days everything has digital audio output and you can easily run out of digital audio inputs for your sound system. I have a Sony 5.1 sound system (without DVD player) and it has 1 Toslink and 1 Coax digital audio input and it's way too few. I end up getting a Joytech 7-component-input (5-Toslink) switch to cope with my rig (I don't use the component video switch). I have 1 HDTV, 1 Shaw HDDVR, 1 DVD recorder, 2 computers. That's 5 digital audio inputs already. And I haven't counted game consoles yet.

klskls
2009-11-11, 07:49 AM
I agree with what Chris said re: the integrated dvd player.
If budget allows, put as much of your money towards the actual AVR and speakers (assuming you already have a dvd player?). DVD players are cheap now, and getting an AVR with as many digital connections as you can afford will make you a happy man in the future.
If you're stuck with only one input, monoprice sells a cheap manual optical audio switcher that can carry 3 connections to 1 input with a dial to choose between sources. But it means you have to get up off your couch if you're going from watching a dvd to live tv.

Good luck, and keep us updated on your selections!

kls.

TaylorTech
2009-11-11, 12:41 PM
I don't need any extra inputs as it's just hooking up to my computer. I do however need those potential software solutions you speak of. Does anyone already do this? Converting every file is not an option. It's just, in my sound properties, it says that I only have 2ch 192khz PCM/Windows Media/DTS audio. I need five more of these channels, even if they are software processed.

I will check out AC3 filter when I get home.


Thanks!
Taylor

CHrisCHu
2009-11-11, 05:11 PM
Converting every file is not an option.
With AC3Filter or ffdshow audio decoder, you don't convert file for the 5.1 feature. Anything you play through those decoders they convert real-time to 5.1 (if you choose). The players don't even need to know about these decoders. It's all transparent. With ffdshow, you can optionally set it up to add a tray icon whenever it's in use. You can then easily enable/disable any or all volume/reverb/DSP matrix components for the real-time conversion. You can also set up separate profiles with different matrix components base on different source/number-of-channels/filename/player, etc. It's a really powerful tool. It's free and included in the K-lite codec package which includes ffdshow video decoder, another power tool.

Regarding upconvert DVD player in a HTIB or standalone, your PC does the same job and more (like optional frame-interpolation processing, the kind of processing a 120Hz TV does). There's no need to get an upconvert DVD player (standalone or HTIB) for the upconvert feature.

Also, from my experience, HTIB usually have inferior sound components than sound system without DVD player. I'm not talking standalone AVR and high-end speakers. The Sony D5.1 sound system I bought in US (I used to work in the US) was on sale for just CDN$140 and comes with the amplifer and speakers (HT-DDW790) and it sounds better than all other D5.1 sound systems I've heard with or without DVD player.

TaylorTech
2009-11-11, 07:25 PM
Ok. I will look into all of this. I'm testing out AC3 filter, and will do a tad more research on those speakers.

ScaryBob
2009-11-11, 07:45 PM
Do searches for Dolby Digital software decoding for your software and pass through for your audio card/motherboard audio. Both the software and sound card need to be set correctly. Some software (like promo versions of DVD players) do not support DD5.1 and require an upgrade. There is lots of free software that does support DD5.1 though. Software that uses external codecs also needs the right codec (like AC3Filter), which needs to be configured correctly as well.

Just so you know what should be happening, here is the process. The software decodes the video file's DD5.1 internally (or with an external codec) and passes it to the sound card. The sound card then passes it, unchanged, to the digital audio port. The receiver then sees the DD5.1 and decodes it to analog.

I've never heard of 2-channel-only toslink.
Correct. Toslink is the physical link and has no such limitations. However, most PC sound cards are only capable of processing 2 channel PCM. In order to output DD5.1, they must be put in pass through mode.

CHrisCHu
2009-11-11, 08:57 PM
Agree with what ScaryBob says and I just want to add that:

However, most PC sound cards are only capable of processing 2 channel PCM. In order to output DD5.1, they must be put in pass through mode.

"processing 2 channel PCM" means the sound card hardware can handle no more than 2 source channels from its mixer and pack them into a stream for the digital output. This is all about the sound card's hardware capability. Like ScaryBob says, only pass through mode can output DD5.1 on most soundcards. However, that doesn't mean the software cannot convert 2-channel source into DD5.1 stream and "passthru" to the sound card hardware. In other words, the sound card hardware doesn't know whether the stream comes directly from the internal DVD player or from ffdshow audio decoder.

PPL4GOLF
2009-11-14, 02:59 PM
There are fancy features on some sound devices (even onboard) that does convert to DTS5.1 (DTS Interactive) or DD5.1 in some others. The sound quality is degraded though still passable.

Passthrough mode is still the best and should be use whenever possible. Even for HD audio like DTS-MA or DTS-HD, the receiver does a better job with the DTS core than using DTS-MA to analog 5.1 to DTS5.1 again through TOSLINK.

TrueHD is different.

mlord
2009-11-14, 04:50 PM
I just tell MythTV to use passthrough mode, and my sound system gets 5.1 from the toslink connection no problemo.

Cheers

CHrisCHu
2009-11-14, 11:31 PM
There are fancy features on some sound devices (even onboard) that does convert to DTS5.1 (DTS Interactive) or DD5.1 in some others. The sound quality is degraded though still passable.
That's because soundcard with hardware conversion capability (i.e. DTS Connect and DD Live) takes the 2-to-6-channel analog signals and convert them to digital and pack to a DTS/DD compatible stream. If you already have a DTS/DD compatible stream, the best is to do passthru' for sure.

With ffdshow audio decoder, digital source (like 2-channel mp3 music) are converted and packed into DD 5.1 stream in all-digital processing. Any possible sound degradation will come from optional user-selected DSP and DD5.1 spec limitation (if source is of higher-spec).

I configure my ffdshow audio decoder to pass through DTS/DD5.1 signals and convert anything else to DD5.1 if possible. Theoretically, I can also set to convert mp3s only if bitrate is lower than a certain number. Even then, I still have the option to easily disable the conversion from the systray. And I hook up only the Toslink to my amp. I don't use the analog channels except for headphones for late nite.