PCM and Bitstream (TrueHD)

[xego]

Hdmi s&*^ks!


Seriously does it have to be this difficult? Reading this post I see all these kind people trying to bash their heads against the HDMI wall so that this guy can get a better audio experience. It is like arguing over what the book of Revelations really means. Maybe the engineers that came up with the HDMI spec were playing RPGames at the same time..."You have to have the golden sword or you will get lossy audio" ...I am glad you guys are here because I am sure I will be reduced to tears when I buy a receiver this month...please stand by...x

 

[avliner]

First off, welcome to the forum

Matter of fact, you don't need a golden sword at all (maybe a silver one...)

To be in the safe side, just get an AVR of your choice which internally decodes the new HD lossless formats; there is, DolbyTrue HD and DTS-HD MA and you'll be just fine with that for quite a while...

 

[TLS Guy]

First off, welcome to the forum

Matter of fact, you don't need a golden sword at all (maybe a silver one...)

To be in the safe side, just get an AVR of your choice which internally decodes the new HD lossless formats; there is, DolbyTrue HD and DTS-HD MA and you'll be just fine with that for quite a while...

That is good advice.

 

[jostenmeat]

I owned the RX-V1600 and it was able to apply PLIIx to a 5.1 PCM source, but the RX-V1600 was not capable of accepting 7.1 PCM, this is per my own experiments, and per Yamaha. I'm not sure if the RX-V1700 can accept 7.1 PCM over HDMI, but it should definitely be able to apply PLIIx to a 5.1 source for a 7.1 experience which is very good. I use PLIIx for everything that isn't natively 7.1.

Hey that's interesting. From what I can remember from my AV meanderings is that the opposite is usually the case. Specifically, older receivers can handle 7.1 PCM, but might lack the processing power or software/FW to matrix. Just my impressions.

I know the RX-V1700 has 8 ch. analog inputs, so those could also be used for 7.1 PCM if it can't be done over HDMI, but I'm pretty sure his blu ray player doesn't have analog outputs.

His BDP does 7.1 mch analog no problem. For good measure, it can bitstream and decode all of the relevant formats, and can also downmix these to 2ch PCM.

Seriously does it have to be this difficult? Reading this post I see all these kind people trying to bash their heads against the HDMI wall so that this guy can get a better audio experience. It is like arguing over what the book of Revelations really means. Maybe the engineers that came up with the HDMI spec were playing RPGames at the same time..."You have to have the golden sword or you will get lossy audio" ...I am glad you guys are here because I am sure I will be reduced to tears when I buy a receiver this month...please stand by...x

Actually, with all of the complaints about HDMI, at least it worked from the get-go with version 1.0. A lot of people mistakenly thought they HAD TO HAVE 1.3, etc, and simply didn't know that 1.0 is good enough to handle lossless audio, simply assuming the player can decode the formats. Again, even though there are probably a lot of things one can complain about, I hope all other future formats work properly from the get-go.

For instance, while 1.0 worked fine for audio at the beginning, a lot of HDMI TVs could not accept 1080p, even if touted as a 1080p TV. Now that's baloney. I have no idea what kind of clusterhump 3D may or may not present us with.

 

[yepimonfire]

if im not mistaken PCM takes less computing power to process PCM because with lossy formats, the codec must be decompressed first then it is processed as PCM, all digital audio ends up as PCM by the time it is over because DAC's can't convert dolby digital or dts directly to analog sound, they must first be decompressed. the only issue i think you would have is not having enough bandwidth to send PCM, 48KHZ PCM is about 900kbps per channel, at 6 channels, thats 5.4 MBPS of data

 

[GlocksRock]

Hey that's interesting. From what I can remember from my AV meanderings is that the opposite is usually the case. Specifically, older receivers can handle 7.1 PCM, but might lack the processing power or software/FW to matrix. Just my impressions.

Maybe some older receivers can do it just fine, but I know for a fact that the RX-V1600 can only do 5.1 PCM over HDMI, 7.1 PCM over HDMI is a no go, but you can still apply PLIIx to the 5.1 PCM stream, so it still sounds good with a matrixed 7.1. Not sure if they fixed the RX-V1700 to handle 7.1 PCM over HDMI, but since he has analog outputs on his player he can go that route if it can't.

 

[xego]

Maybe some older receivers can do it just fine, but I know for a fact that the RX-V1600 can only do 5.1 PCM over HDMI, 7.1 PCM over HDMI is a no go, but you can still apply PLIIx to the 5.1 PCM stream, so it still sounds good with a matrixed 7.1. Not sure if they fixed the RX-V1700 to handle 7.1 PCM over HDMI, but since he has analog outputs on his player he can go that route if it can't.

Thats interesting about the Pro-logic IIx ...all that I know about it is that it is some kind of height channel? I am going to be getting a 7.1 receiver but wont have the additional speakers until I can upgrade to some good floorstanders. I wont have the room to properly place surrounds but a PLIIx could work. Is PLIIx a lossless HD audio variation? or is it Lossy like Pro-logic?

 

[s162216]

Thats interesting about the Pro-logic IIx ...all that I know about it is that it is some kind of height channel? I am going to be getting a 7.1 receiver but wont have the additional speakers until I can upgrade to some good floorstanders. I wont have the room to properly place surrounds but a PLIIx could work. Is PLIIx a lossless HD audio variation? or is it Lossy like Pro-logic?

You mean PLIIz, that adds two height channels at the front and also does what PLIIx does which is convert to 7.1 by matrixing, so effectively your getting 9.1. Its not lossless, but in my experience I can't really tell the difference that much from 2 channel to 3 channel for instance. You most likely won't be able to tell any difference with a high bitrate lossless track or with LPCM. Blu ray allows uo to 14.1 audio so in the future it might be built into the sound tracks as discrete audio.

if im not mistaken PCM takes less computing power to process PCM because with lossy formats, the codec must be decompressed first then it is processed as PCM, all digital audio ends up as PCM by the time it is over because DAC's can't convert dolby digital or dts directly to analog sound, they must first be decompressed. the only issue i think you would have is not having enough bandwidth to send PCM, 48KHZ PCM is about 900kbps per channel, at 6 channels, thats 5.4 MBPS of data

Its a common misconception that its the cable (i.e optical or coax) that limits what can be sent over SPDIF. Actually TOSLINK optical can be used to send many tens of megabytes of data over it but recievers limit what they will accept and output. For instance, my Sony STR-DE495 will accept 48Khz PCM in 6 channel but if sent the same in 96KHz 6 channel, it disables the surrounds and centre and only allows stereo. Some computer sound cards for instance will output 192Khz 6 channel over optical but unless your using pro audio stuff then all of it is downconverted and downsampled to 2 channel 96Khz by the receiver. However DTS do a technology called DTS 96/24 where you can (with a compatible receiver) get 96Khz 6 channel as it is just a core DTS stream plus an extension that contains the extra bits which the receiver adds onto the main audio.

 

[miggs29]

Thank you all for all the responses. However, I am a bit confused. If I go PCM out of the BD player to the AVR. Do I go RCA out from the BD player to the AVR into multichannel input. If so, do I leave the HDMI from the BD player going to the AVR and then one HDMI out from the AVR to the TV for video? Do I need to tell the AVR that the audio coming in from the BD is analog? If so, how? Or do I tell the BD player to send PCM out to the AVR by HDMI and only deal with HDMI? Sorry for the confusion.

Also, If I go PCM out from the BD player via multichannel to the AVR, do I need to set the speaker level and delays on the BD player? If so, then what happens when I am watching Directv? Are my speaker levels lost? also the sub crossover? Will they be independent???? BD and Cab/Sat?

 

[jostenmeat]

Thank you all for all the responses. However, I am a bit confused. If I go PCM out of the BD player to the AVR. Do I go RCA out from the BD player to the AVR into multichannel input. If so, do I leave the HDMI from the BD player going to the AVR and then one HDMI out from the AVR to the TV for video? Do I need to tell the AVR that the audio coming in from the BD is analog? If so, how? Or do I tell the BD player to send PCM out to the AVR by HDMI and only deal with HDMI? Sorry for the confusion.

I'm short on time, but I don't think you have to use mch analogs. It's all pretty much in the very simple BDP menu. Go to audio, or whatever, and change MA+TRUEHD to PCM. Voila.

It's really that simple.

If you still can't figure it out, I will take a look at the manual for you in the near future. However, this is so simple, you don't even need a manual.

Also, If I go PCM out from the BD player via multichannel to the AVR, do I need to set the speaker level and delays on the BD player? If so, then what happens when I am watching Directv? Are my speaker levels lost? also the sub crossover? Will they be independent???? BD and Cab/Sat?

If you did use mch analogs, yes the BDP provides all bass mgmt, and you will never get 7.1 unless the disc itself is 7.1 natively.

All of your other sources will be fine. You assign your sources with their own settings/inputs. Super duper simple. This of course is in the receiver.

 

[goodman]

If the blu ray player is doing the decoding internally, all formats that are sent out to the AVR will be sent as PCM, this includes all flavors of dolby digital as well as DTS. If your player is capable of outputting bitstream over HDMI and your receiver can decode the latest HD audio formats, then you will see your receiver display the TrueHD or DTS HD Master Audio logo(s). Just because you see MPCM on your receiver doesn't mean you aren't hearing dolby true hd or dts hd master audio, it just means that it has already been decoded by the player.

If you send the decoded signal over analog cables, are you still hearing True HD or MA, or is it something else?

 

[GlocksRock]

If you send the decoded signal over analog cables, are you still hearing True HD or MA, or is it something else?

You would be hearing the TrueHD or dts-hd ma after it has been decoded to PCM.

 

[goodman]

Does decoding to PCM degrade the sound in any way?

 

[avliner]

Does decoding to PCM degrade the sound in any way?

Not at all; it's just about the same though

 

[yepimonfire]

Does decoding to PCM degrade the sound in any way?

as i stated before all audio must be converted to PCM eventually, whether its in the blu ray player or receiver.

 

[TLS Guy]

as i stated before all audio must be converted to PCM eventually, whether its in the blu ray player or receiver.

We had audio, and good audio long before PCM!

 

[yepimonfire]

with analog sources yes. with digital sources all things must be converted to PCM because that is what a DAC converts to analog.

 

[TLS Guy]

with analog sources yes. with digital sources all things must be converted to PCM because that is what a DAC converts to analog.

DSD decoders also convert to analog and they are not PCM based. There does not have to be a PCM conversion. I do not convert it.

 

[Svea_Knight]

You Yammie doesnt decode HD audio such as Dolby True HD or DTS-HD.
You just have to set your BD Player to Linear PCM in order to enjoy HD sound as long as you have your BD player connected through HDMI.
Some say that it doesnt degrade the sound doing so if you have a really good BD player. Personally if you have a really good receiver that can handle it, I would put it to Bitstream. I myself notice a better, detailed and clear sound when I did the change, but only if your receiver can handle it.

 

[moves]

If the blu ray player is doing the decoding internally, all formats that are sent out to the AVR will be sent as PCM, this includes all flavors of dolby digital as well as DTS. If your player is capable of outputting bitstream over HDMI and your receiver can decode the latest HD audio formats, then you will see your receiver display the TrueHD or DTS HD Master Audio logo(s). Just because you see MPCM on your receiver doesn't mean you aren't hearing dolby true hd or dts hd master audio, it just means that it has already been decoded by the player.

great answer... i wonder what I have my PS3 set to............ I thought I had it sent to send NOT bistream... this might be the problem that I have.