TruHD only extracts 640kbps DD?

[BTBuck1]

So I got Stomp the Yard on Blu-ray. I was looking forward to hearing it in 1.5mbps but then I realized something, This aint HDDVD. On Blu-ray TruHD downsamples to 640kbps on HDDVD it downsamples to like DDplus which has a max of 1.5mbps and the players output at DTS 1.5mbps over optical/digi coax.

I don't know, I just fealt a little cheezed. I can still enjoy the lossless PCM track on my sammy

So for me, at this time...if you're not gonna sample to 1.5mbps, then just toss in DTSHDMA instead. Just my 2 pennies!

[dobyblue]

The HD DVD add-on doesn't downsample to DD+.

It decodes the TrueHD to PCM, then reencodes it to 1.5Mbps DTS.
It does the same for DD+.

TrueHD contains a legacy Dolby Digital track, so when you're watching using your Samsung you're hearing the 640 Kbps DD track without and downsampling, converting or otherwise of the TrueHD track.

This is how NIN works as well. Your Sammy doesn't recognize TrueHD, but it does recognize the Dolby Digital legacy track contained in the TrueHD track.

http://www.dolby.com/assets/pdf/tech...whitepaper.pdf

[Deciazulado]

So it is like this?

DTHD -> PCM -> DTS -> audio waves
 DD         ->        audio waves

Samsung, add on

[BTBuck1]

This all over optical:

The xbox360/HD-A1,2,20,Xa1,2 etc. takes TruHD, takes it down to DolbyDigital (_______mbps anyone know?) and then re-encodes it to DTS 1.5mbps

Then the Blu-ray players take TruHD and extract a 640kbps Dolby Digital core track.

[WriteSimply]

Dolby Digital maxes out at 640kpbs.

TruehHD->DD->DTS. That's a lot of work. Would be better to just go from TrueHD->DTS. Each - denotes transcoding of audio.

BTBuck, I see that you have a PS3. Why not use the PS3 instead and use the HDMI output to get TrueHD?


fuad

[PeterTHX]

DD at 640 is superior to 1.5 DTS anyway (the same way AVC is more efficient than MPEG2 at lower bitrates).

To date, nothing can decode DTS-MA anyway. Dolby TrueHD is supported by the PS3 and Panasonic.

[dobyblue]

Originally Posted by BTBuck1

This all over optical:

The xbox360/HD-A1,2,20,Xa1,2 etc. takes TruHD, takes it down to DolbyDigital (_______mbps anyone know?) and then re-encodes it to DTS 1.5mbps

Then the Blu-ray players take TruHD and extract a 640kbps Dolby Digital core track.

No this bolded part is incorrect.

They do not take it down to Dolby Digital. They convert it to PCM inside the player and then encode it to either Dolby Digital or DTS.

The last part is corecct, the PS3 will extract the DD core from the TrueHD, or if you're using HDMI or analog will convert the THD to PCM and send it out as PCM.

[PeterTHX]

BTW: The core have different bitrate other than 640.

The TrueHD DD core on Legends of Jazz is 448kbps.

[BTBuck1]

Originally Posted by WriteSimply

BTBuck, I see that you have a PS3. Why not use the PS3 instead and use the HDMI output to get TrueHD?


fuad

I don't have a receiver with HDMI audio.

[dialog_gvf]

Originally Posted by dobyblue

The HD DVD add-on doesn't downsample to DD+.

It decodes the TrueHD to PCM, then reencodes it to 1.5Mbps DTS.
It does the same for DD+.

What I wonder is how good that re-encoding can be?

A studio-sourced DD or DTS encoding could take as much time as it needs to get the PCM to the target CBR. HD DVD/Xbox 360 have to do it in real-time.

Are we to believe that this can be accomplished with the same fidelity as a pre-encoded track?

Audio remains a complete mess on HD DVD. And even when HDMI comes along, the XBox 360 can't offer HD audio.

Gary