HDMI audio

Shifty Geezer

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How does audio work with HDMI? For PS3 (and any other HDMI devices not console related) does the single HDMI output socket have to go through a pass-through in the amp? A friend was telling me about amps and current amps with HDMI only support 720p/1080i passthrough, so would that limit the output from PS3? :???:
 
Shifty Geezer said:
How does audio work with HDMI? For PS3 (and any other HDMI devices not console related) does the single HDMI output socket have to go through a pass-through in the amp? A friend was telling me about amps and current amps with HDMI only support 720p/1080i passthrough, so would that limit the output from PS3? :???:

Current HDMI carries a digital bitstream which would need to be decoded at the receiver, similar to SPDIF and optical today but its aggregated in a single cable with video (which can also carry remote control).

HDMI 1.2 adds the ability to carry DVD-Audio or more specifically, High-res PCM digitally to a receiver, which can then decode it and play it out the speakers.

The new audio formats on HD optical are still up in the air as to which HDMI will carry them and what will decode them. The early solution is going to have the player itself decode the audio and output it over 5.1 (or 7.1) analog outputs.

I'm a little confused on the video part of your question tho, can you elaborate?
 
I'm not sure but I think this is how it'll work :

- HDMI cable goes into TV with HDMI slot
-Optical from TV Digital out goes to receiver
-Sound comes out of speakers

I think this way the limit will be bypassed ?
 
rounin said:
I'm not sure but I think this is how it'll work :

- HDMI cable goes into TV with HDMI slot
-Optical from TV Digital out goes to receiver
-Sound comes out of speakers

I dont think you would introduce the TV into the audio chain. IN your scneario you would run an HDMI to the TV for video and an optical straight to the receiver from the player.
 
expletive said:
I'm a little confused on the video part of your question tho, can you elaborate?
You can buy Amps with HDMI ports. I was envisaging a MIDI style HDMI thru. If not, and you just route audio from the HDMI decoding device (TV) via normal audio connections, what's the point of HDMI on the amp?
 
As far as audio is concerned, HDMI was designed to have the bandwidth to carry 8 channels of uncompressed audio (e.g. PCM). This is really the ideal scenario, as that means that the output device would never have to go an extra step of encoding the audio data into Dolby Digital or DTS or something else, and the receiver does not have to decode that stream, just route it to the appropriate speakers. There's less resource utiliziation and fewer codecs all around, and hence everyone wins.

However, that being said, HDMI is backwards compatible to be able to carry encoded digital streams (DD, DTS). Furthermore, I believe only a few receivers support the ability read the uncompressed audio from an HDMI cable (even though it should be fairly trivial). This is unfortunate but seems to be the reality for now.

Of course, while HDMI was suppoposed to simplify everything into one cable, in reality it does add some complexity. For receivers to really support this they will have to be able to add the ability to switch multiple HDMI signals and pass through the video signal while still processing the audio portion of the signal. That's probably where your mention of 720p/1080i passthrough comes into play. Previously, with seperate audio and video cabling you could run your video directly to your display and have your receiver just handle audio without having to switch video. So it's all a tradeoff, although uncompressed audio will still be nice.

More info here.
 
Shifty Geezer said:
You can buy Amps with HDMI ports. I was envisaging a MIDI style HDMI thru. If not, and you just route audio from the HDMI decoding device (TV) via normal audio connections, what's the point of HDMI on the amp?

Well just to clarify a couple of things, when you say AMP you mean a receiver which is a preamp, processor and amplifier in one? My understand of an AMP is JUST the part that amplifies the audio signal.

The other is that HDMI carries a DIGITAL signal so in order to play it through speakers it needs to be converted to analog, then sent to an amplfiier and then to the speakers.

If you mean receivers with HDMI ports, then there may be some bandwidht limitations with older designs in the switching mechanisms but id have to look into it.
 
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expletive said:
I dont think you would introduce the TV into the audio chain. IN your scneario you would run an HDMI to the TV for video and an optical straight to the receiver from the player.

Seems more reasonable than what I wrote. :D I totally forgot that most things have optical out
 
Just a simple guess here, but I think it's a safe bet that PS3 HDMI will carry audio so if you have a HDMI capable reveiver you only need one AV cable. It would also make sense that you can still choose to use an optical out or analog RCA out (maybe even SPDIF as the S in SPDIF is for Sony). In other words, I don't hink you lose anything, which makes sense to me and for most of the market, but if you happen to be completely up-to-date on your equipment chain you get single connector/cable elegance...and wouldn't that be nice for a change? heh ;)
 
wireframe said:
Just a simple guess here, but I think it's a safe bet that PS3 HDMI will carry audio so if you have a HDMI capable reveiver you only need one AV cable. It would also make sense that you can still choose to use an optical out or analog RCA out (maybe even SPDIF as the S in SPDIF is for Sony). In other words, I don't hink you lose anything, which makes sense to me and for most of the market, but if you happen to be completely up-to-date on your equipment chain you get single connector/cable elegance...and wouldn't that be nice for a change? heh ;)

True, but Shifty asked about 1080p, so just having a receiver that has HDMI isn't quite enough, as the receivers that can pass 1080p are just starting to hit the market. Of course, the HDMI on the PS3 will pass audio, that wasn't in question, the scenario we were dealing with was in regards to *assumption* having a 1080p tv with HDMI, but also having a receiver with HDMI, as it stands now there are fewer 1080p receivers than there are 1080p televisions. This is how we got to the scenario of taking the PS3 hdmi output directly to tv (so you could get 1080p) but then taking the optical out to your receiver so that you can get surround sound...thats the way I approached, let me know if I was off base.
 
wireframe said:
Just a simple guess here, but I think it's a safe bet that PS3 HDMI will carry audio so if you have a HDMI capable reveiver you only need one AV cable. It would also make sense that you can still choose to use an optical out or analog RCA out (maybe even SPDIF as the S in SPDIF is for Sony). In other words, I don't hink you lose anything, which makes sense to me and for most of the market, but if you happen to be completely up-to-date on your equipment chain you get single connector/cable elegance...and wouldn't that be nice for a change? heh ;)
Actually, if the device can send uncompressed audio over HDMI than you are losing something, as anything sent over SPDIF would be compressed (and probably lossy).
 
The HDMI connections in PS3 will obviously need to carry audio and video as not everyone owns a mult-channel setup. A lot of people will only use their HDMI equiped TVs for both audio and video and not bother with analog RCAs. The MAIN purpose of HDMI on recievers is a HDMI switch box just like the component inputs on receivers. The main purpose is NOT to get audio to the reciever as most output devices only have one HDMI output connector. Also receivers come with optical and coaxial connections for audio so you wouldn't need HDMI for audio unless it was for copy protected audio like SACD/DVDA. HDMI can be used to replace the analog connections currently used for muli-channel SACD/DVDA.
 
NANOTEC said:
The HDMI connections in PS3 will obviously need to carry audio and video as not everyone owns a mult-channel setup. A lot of people will only use their HDMI equiped TVs for both audio and video and not bother with analog RCAs. The MAIN purpose of HDMI on recievers is a HDMI switch box just like the component inputs on receivers. The main purpose is NOT to get audio to the reciever as most output devices only have one HDMI output connector. Also receivers come with optical and coaxial connections for audio so you wouldn't need HDMI for audio unless it was for copy protected audio like SACD/DVDA. HDMI can be used to replace the analog connections currently used for muli-channel SACD/DVDA.
The HDMI folks would be mighty surprised to hear that their main purpose is not to carry audio, considering it was conceived specifically to carry both uncompressed audio and video. As I've already pointed out (twice) in this thread, HDMI is the only way to get uncompressed multi-channel audio from your box to your receiver (short of having 6-8 RCA plugs), so it certainly has an advantage over optical or coax connections.
 
Sethamin said:
The HDMI folks would be mighty surprised to hear that their main purpose is not to carry audio, considering it was conceived specifically to carry both uncompressed audio and video. As I've already pointed out (twice) in this thread, HDMI is the only way to get uncompressed multi-channel audio from your box to your receiver (short of having 6-8 RCA plugs), so it certainly has an advantage over optical or coax connections.

The main purpose of having HDMI on a receiver is to be able to switch HDMI sources just like component inputs. It's main purpose is not for SACD/DVDA since RCAs work fine for that purpose. Not many SACD/DVDA players can output uncompressed audio through their HDMI connections. Are there any? HDMI is used mostly for HD video and digital audio output to HDTVs in a single cable.
 
External HDMI expansion

HDMI will continue to be the de-facto standard in home video transmission for 2 reasons: 1) uncompressed digital format ensures the best picture quality and 2) HDMI allows content providers to ensure that their intellectual property is protected through HDCP.

It is clear that more equipment such as Cable/Satellite Set Top boxes, DVD players, HD DVD players, Personal video recorders, video game stations, and computer video cards will adopt HDMI/DVI. However, many early-generation HDTV monitors only had 1 or 2 HDMI input leaving the early adopter no way to easily add HDMI enabled sources. Furthermore many Surround Sound Audio Receivers do not include HDMI switching. Octava’s HDMI switching solution was designed to allow end users add HDMI sources and at the same time upgrade their existing Surround Sound Audio Receiver with HDMI switching capabilities. This allows the end user to fully experience the benefits of HDMI.

HDMI switch solution include a http://www.octavainc.com 3x1 and 5x1 HDMI switch. The 3x1 HDMI switch allows the user to connect up to 3 HDMI sources and share it with 1 HD monitor or projector. The 5x1 HDMI switch are for “power usersâ€￾ who intend to add in more sources in the future. .

All products can be connected to DVI-D also simply by using a DVI-D to HDMI cable or adapter.
 
fiddlersu said:
HDMI will continue to be the de-facto standard in home video transmission for 2 reasons: 1) uncompressed digital format ensures the best picture quality and 2) HDMI allows content providers to ensure that their intellectual property is protected through HDCP.

It is clear that more equipment such as Cable/Satellite Set Top boxes, DVD players, HD DVD players, Personal video recorders, video game stations, and computer video cards will adopt HDMI/DVI. However, many early-generation HDTV monitors only had 1 or 2 HDMI input leaving the early adopter no way to easily add HDMI enabled sources. Furthermore many Surround Sound Audio Receivers do not include HDMI switching. Octava’s HDMI switching solution was designed to allow end users add HDMI sources and at the same time upgrade their existing Surround Sound Audio Receiver with HDMI switching capabilities. This allows the end user to fully experience the benefits of HDMI.

HDMI switch solution include a http://www.octavainc.com 3x1 and 5x1 HDMI switch. The 3x1 HDMI switch allows the user to connect up to 3 HDMI sources and share it with 1 HD monitor or projector. The 5x1 HDMI switch are for “power usersâ€￾ who intend to add in more sources in the future. .

All products can be connected to DVI-D also simply by using a DVI-D to HDMI cable or adapter.

I would just like to beat a dead horse and say that many early generation HDTV monitors had neither HDMI nor DVI and IF they had DVI it was generally just DVI and not DVI+HDCP. I would say that even the second generation (what generation would we consider what we are in today?) of early monitors started to implement DVI w/ and w/o HDCP, and far as what we have today I would love to see the number of sets with HDCP, whether DVI or HDMI, vs the number of sets without, and we don't even want to think about adding monitors into the mix, or individual companies implementation of HDCP:rolleyes: . [/dead horse]
 
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