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http://we.pcinlife.com/redirect.php?tid=1259597&goto=lastpost2 J2 P4 ^/ W9 z
http://www.anandtech.com/video/showdoc.aspx?i=3643&p=10
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The Race is Over: 8-channel LPCM, TrueHD & DTS-HD MA Bitstreaming; }* A! j8 [: n4 N
- ^& ^- d/ X; A% O6 @2 O9 t, uIt's now been over a year since I first explained the horrible state of Blu-ra4 S/ r4 T8 d" b" R/ _) b* b( E! U
y audio on the PC. I'm not talking about music discs, but rather the audio com7 S- W$ h N& }3 ?. Y
ponent of any Blu-ray movie. It boils down to this: without an expensive sound
1 _- d; B5 ?( w4 G# L0 wcard it's impossible to send compressed Dolby TrueHD or DTS-HD Master Audio s+ B: e( m6 y' [) t5 v: y/ p$ Q
treams from your HTPC to an AV receiver or pre-processor. Thankfully AMD, Inte1 s# x2 I6 ` \8 `9 O, p
l and later NVIDIA gave us a stopgap solution that allowed HTPCs, when equippe; A; \$ K- r& u1 I
d with the right IGP/GPU, to decode those high-definition audio streams and se
6 m* ?0 O+ ^7 knd them uncompressed over HDMI. The feature is commonly known as 8-channel LPC
( A- G4 S% ^) f# S$ y# S2 C2 n4 [9 ]M support and without it all high end HTPC users would be forced into spending, {2 z5 i7 b( P" b
another $150 - $250 on a sound card like the Auzentech HomeTheater HD I just
" K$ f6 R5 F) B' m) Orecently reviewed.
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For a while I'd heard that ATI was dropping 8-channel LPCM support from RV870 ! \6 ~# O$ s& @
because of cost issues. Thankfully, those rumors turned out to be completely u
9 v8 Q# t% M r6 M# ?, x! Xntrue. Not only does the Radeon HD 5870 support 8-channel LPCM output over HDM( t0 h. W# Q- R; u
I like its predecessor, but it can now also bitstream Dolby TrueHD and DTS-HD - r2 U/ E# m& v& ]! W
MA. It is the first and only video card to be able to do this, but I expect ot, E( m1 r0 t2 S7 j5 f4 @5 g, z* A- L+ ~( {
hers to follow over the next year.
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The Radeon HD 5870 is first and foremost a card for gamers, so unless you're b; b8 C' F4 n! M* T/ r' x5 C
uilding a dual-purpose HTPC, this isn't the one you're going to want to use. I
; v& p/ L, N+ N9 pf you can wait, the smaller derivatives of the RV870 core will also have bitst( L* P0 P: a: j# L* \
reaming support for TrueHD/DTS-HD MA. If you can't and have a deep enough HTPC
3 r' K4 a4 O, c3 Y" |( ccase, the 5870 will work.
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In addition to full bitstreaming support, the 5870 also features ATI's UVD2 (U
; {" _6 c( @& |! Hniversal Video Decoder). The engine allows for complete hardware offload of al7 [% s2 F& F" R
l H.264, MPEG-2 and VC1 decoding. There haven't been many changes to the UVD2 , F# j+ w6 {5 v) F* f1 d3 l
engine; you can still run all of the color adjusting post-processing effects a) x7 i5 s5 e1 Y! A4 k
nd accelerate a maximum of two 1080p streams at the same time.# c4 j8 h/ b) O/ @" V# I
3 V6 J- d" l' X, J) m* `7 Z
ATI claims that the GPU now supports Blu-ray playback/acceleration in Aero mod
7 m& u; }& E' i" Z6 N. fe, but I found that in my testing the UI still defaulted to basic mode.
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. g7 R1 s' \. L' L4 MTo take advantage of the 5870's bitstreaming support I had to use a pre-releas8 x F/ g0 e5 F1 M9 J! S
e version of Cyberlink's PowerDVD 9. The public version of the software should+ H! m( m" t2 \7 N6 c$ Z$ g
be out in another week or so. To enable TrueHD/DTS-HD MA bitstreaming you hav
0 Y6 a' k* W- e$ Q2 \8 P; {e to select the "Non-decoded high-definition audio to external device" option
' r+ _* ?6 r/ `0 n; Cin the audio settings panel:
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With that selected the player won't attempt to decode any audio but rather pas, a5 [4 }+ A4 r; M- j' V. R' S
s the encoded stream over HDMI to your receiver. In this case I had an Integra
: O0 ]3 F$ r, ~5 nDTC-9.8 on the other end of the cable and my first test was Bolt, a DTS-HD MA# Z l9 Z0 [ c7 x3 \0 v
title. Much to my amazement, it worked on the first try: S1 ~3 V" F$ r( {" S; J
4 I5 W" z) X6 c
No HDPC errors, no strange player issues, nothing - it just worked.
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W) K. w( w7 U9 l) uNext up was Dolby TrueHD. I tried American History X first but the best I coul9 P3 E- p( q1 Q, P$ j) x. {6 g4 [
d 【请注意文明用词】 of it was Dolby Digital. I swapped in Transformers and found the sam
3 d7 d( l& m. [& re. This ended up being an issue with the early PowerDVD 9 build, similar to is
% i* x: ?- O ]' vsues with the version of the player needed for the Auzentech HomeTheater HD. S9 y. I" \+ A2 E J8 I* B
witching audio output modes a couple of times seemed to fix the problem, I now
7 z; } h+ ~0 l4 N. c) j5 M. Rhad both DTS-HD MA and Dolby TrueHD bitstreaming from the Radeon HD 5870 to m0 t- i/ E. e. k0 F- l
y receiver.( ~+ `% |" Q% O5 j& f; p0 f) _! a7 _
8 @8 H) w; ~) W6 r6 Y6 d3 q
One strange artifact during my testing was the 5870 apparently delivered 1080i0 m" K& j* N* J+ B. p. D6 K
output to my JVC RS2 projector. I'm not exactly sure what went wrong here as
& |, g7 o3 K3 k" k1080p wasn't an issue on any other display I used. I ran out of time before I
4 ?3 j( O& g3 L: T) G# gcould figure out the cause of the problem but I expect it's an early compatibi
% ~7 [0 }8 @+ N; s' [, A5 ulity issue.
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( U4 G/ d7 r5 ^% ^8 o) V* WI can't begin to express how relieving it is to finally have GPUs that impleme
c1 {( o2 I! ^1 {, Y" h8 vnt a protected audio path capable of handling these overly encrypted audio str
4 M; I, x9 d6 j4 G' F! Geams. Within a year everything from high end GPUs to chipsets with integrated
4 P' }( G4 x0 ^graphics will have this functionality. |
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