Player decoding or Receiver decoding, that is the question

[EWL5]

Originally Posted by axe79

Besides my Ears telling me something else, I have found this info from Eric Stewart who has looked deeply into this.
http://whatsonhdtv.blogspot.com/2008...ray-audio.html

"HDMI 1.3 digital audio output from the PlayStation 3 can be unconverted bitstream output for Dolby Digital 5.1 or DTS 5.1.

HDMI 1.3 digital audio output from the PlayStation 3 can be bitstream output that has been stripped to the equivalent of Dolby Digital 5.1 for Dolby Digital Plus or Dolby TrueHD. It can be bitstream output that has been stripped to the equivalent of DTS 5.1 for DTS-HD High Resolution or DTS-HD Master Audio. In both cases, the "extension" part of the bitstream is discarded and just the "core" bitstream is output.


In the above, I have been careful to state what the PlayStation 3 can do. What it will do, audio-wise, on its HDMI output depends on the device the PS3's HDMI output is connected to. For instance, if the external device is a TV that cannot handle any more than two channels of LPCM input, the PlayStation 3 will downmix everything to LPCM 2.0 before outputting it. This will happen automatically, since HDMI devices coordinate with one another to find a mutually acceptable format.

By the same token, when the PS3 is connected to a device that is not HDMI 1.3-capable, the connection cannot achieve the increased data rates possible with HDMI 1.3. At lower HDMI 1.2 rates, the LPCM output of the PS3 might be internally downsampled so as to reduce its data rate, and thus its audio quality.

Many PS3 aficionados have asked whether Sony might one day issue a System Software upgrade which will allow the PS3 to pass the various compressed audio formats through as bitstreams to be decoded by external gear. In particular, they'd like the lossless codecs, Dolby TrueHD and DTS-HD Master Audio, to be optionally treated as bitstreams for external decoding. Of these two lossless codecs, DTS-HD Master Audio is the one most asked about, since Dolby TrueHD is, after all, able to be decoded internally by the PS3 with no loss of information. (Now, as of April 2008, DTS-HD Master Audio can also be decoded by the PS3, but not passed through as a bitstream.)

To date, Sony has not been terribly responsive to these suggestions. Other than confirming that:

* of the four higher-resolution or lossless audio compression codecs, the only one the PS3 can decode without sacrificing any information is Dolby TrueHD, and

* of the four higher-resolution or lossless audio compression codecs, the PS3 can decode Dolby TrueHD and DTS-HD Master Audio, but not Dolby Digital Plus or DTS-HD High Resolution

* the PS3 cannot pass through any codecs as bitstreams rather than LPCM

* the PS3 can pass through the four advanced audio compression codecs as bitstreams, rather than decoding them to linear PCM, but it can pass them through only in their "core" 5.1-channel, low-bitrate forms"

Now I believe the Onkyo 875 being a HDMI 1.3 receiver is processing the 5:1 Bitstream core through the Burr Brown DAC's (which are a Hi End component)
and enhancing it to a level that the PS3 cannot touch.

What I do know is having built and modified AV system that sounds on Music as good as Meridian, Sugden, etc the soundtrack performance is all that matters to me. Playing Blue ray Bitstream and CD's and albums off a Hard Drive sound as good as each other, they don't on LPCM.

Most AV systems I have listened to sound muddy, dampened, enclosed so I can understand how LPCM injects some artificial sparkle.

Two things:

1) AFAIK, the PS3 does not pass "reduced quality" lossless after decoding all codecs to PCM. The PS3 decodes all and any lossless PCM is transmitted over HDMI and doesn't become lossy. It does not decode any differently than if the receiver had the job of doing the decoding. I am not penalized for owning an HDMI 1.2 receiver because I allow the PS3 to do the decoding and pass the PCM, including any lossless quality, to my receiver for further processing. There is no downsampling done by the PS3 when you ask it to decode to PCM.

2) The core bitstream from TrueHD and DTS-HD MA that you have been talking about is exactly the 640kbps DD and 1.5Mbps DTS I stated in a prior post by me. Let me break it down:

TrueHD track always has a companion 640kbps DD track. The track may be hidden or it may be a discrete choice in the BD audio menu. Similarly, DTS-HD MA and DTS-HD HR have a 1.5Mbps lossy "core" track (sometimes the core can be 768kbps but this is extremely rare). Unlike TrueHD, the MA and HR extension wraps around the lossy "core" to create the lossless track. There's an important difference. With DTS, it's just one discrete soundtrack whereas for TrueHD/DD, it requires physical space on the BD for 2 discrete tracks.

Now that I've adequately confused you, it doesn't surprise me that you prefer bitstreaming from the PS3 as the "core" tracks of TrueHD and DTS-HD MA or DTS-HD HR are quite good when compared head to head to their DVD counterparts that do not get the higher bitrates.