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http://we.pcinlife.com/redirect.php?tid=1259597&goto=lastpost& G9 h; q3 I; {5 Z8 ]( }' |8 I
http://www.anandtech.com/video/showdoc.aspx?i=3643&p=10 0 c) G( U! o0 A+ K7 R& Y3 I( O
( U$ k/ W! {7 e \ U7 A$ LThe Race is Over: 8-channel LPCM, TrueHD & DTS-HD MA Bitstreaming1 [5 J' g7 q( W- A
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It's now been over a year since I first explained the horrible state of Blu-ra1 ~ K5 J/ \( _7 _- z7 U
y audio on the PC. I'm not talking about music discs, but rather the audio com
9 ^# `" S5 Y9 I1 [ponent of any Blu-ray movie. It boils down to this: without an expensive sound
7 @# G* V2 L( A# s" Pcard it's impossible to send compressed Dolby TrueHD or DTS-HD Master Audio s
' q" l% y; \5 d5 n! ltreams from your HTPC to an AV receiver or pre-processor. Thankfully AMD, Inte
' J% o; D. y. O, i) j1 H; Ll and later NVIDIA gave us a stopgap solution that allowed HTPCs, when equippe
% Q6 T3 [2 ^! r' P. i" J; }; Sd with the right IGP/GPU, to decode those high-definition audio streams and se9 h2 m, t8 N% c
nd them uncompressed over HDMI. The feature is commonly known as 8-channel LPC
& E/ Y5 c9 h8 C( I: Y. V+ {1 _' x: F. SM support and without it all high end HTPC users would be forced into spending
, e& N1 y$ [5 g2 @4 f5 [+ ]another $150 - $250 on a sound card like the Auzentech HomeTheater HD I just 1 J! l7 A5 h1 r0 T1 O# c' ^' \7 e
recently reviewed. # M+ z+ ]; B7 V
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For a while I'd heard that ATI was dropping 8-channel LPCM support from RV870 , x# s2 @! C1 A
because of cost issues. Thankfully, those rumors turned out to be completely u
' d% E; m0 M, @4 h7 rntrue. Not only does the Radeon HD 5870 support 8-channel LPCM output over HDM
* U- C% l7 ~7 v- l VI like its predecessor, but it can now also bitstream Dolby TrueHD and DTS-HD
2 q: N( C3 g2 y3 ] _/ Y: D6 W+ xMA. It is the first and only video card to be able to do this, but I expect ot
* N) g# C5 {# Z( shers 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% W6 {& Q0 y# ?1 j, X) U( m
uilding a dual-purpose HTPC, this isn't the one you're going to want to use. I
' V& Z5 J* y- @7 T# q! bf you can wait, the smaller derivatives of the RV870 core will also have bitst
$ H2 k) |9 G$ g+ c t8 Y. |: sreaming support for TrueHD/DTS-HD MA. If you can't and have a deep enough HTPC0 E9 ^$ X- x' K0 B+ P: y
case, the 5870 will work.
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5 E/ H9 H4 x+ e' R( n2 ` kIn addition to full bitstreaming support, the 5870 also features ATI's UVD2 (U$ k# Q$ F! z% a8 Z6 x8 v
niversal Video Decoder). The engine allows for complete hardware offload of al
' j5 W6 ~. B" V" l. s6 j6 s4 Nl H.264, MPEG-2 and VC1 decoding. There haven't been many changes to the UVD2 8 W% F- x9 p9 G# y7 `
engine; you can still run all of the color adjusting post-processing effects a
5 B# J+ q; } cnd accelerate a maximum of two 1080p streams at the same time.4 b6 f& k) _6 G+ c% G$ s" [1 a$ I
9 G* j* ?. C6 q$ A. ?$ bATI claims that the GPU now supports Blu-ray playback/acceleration in Aero mod" B2 r5 L$ p4 M# F" p/ ~, y% d
e, but I found that in my testing the UI still defaulted to basic mode.
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% r' W$ v0 n# ~2 T! C/ K% t5 VTo take advantage of the 5870's bitstreaming support I had to use a pre-releas
+ l- j- Q: D( H7 l; M& N! D; ke version of Cyberlink's PowerDVD 9. The public version of the software should S' o/ e" v: L) x3 k4 I
be out in another week or so. To enable TrueHD/DTS-HD MA bitstreaming you hav0 n/ I) v: |5 Y% Z7 A" i2 f5 D
e to select the "Non-decoded high-definition audio to external device" option
* G! e9 |+ t7 {) D3 `3 u( pin the audio settings panel:! c' t5 M- {$ b( e8 ]
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With that selected the player won't attempt to decode any audio but rather pas1 |: U/ h- ]2 j) e& b0 d
s the encoded stream over HDMI to your receiver. In this case I had an Integra5 Y0 X4 S* ^0 S7 n
DTC-9.8 on the other end of the cable and my first test was Bolt, a DTS-HD MA: j7 I5 s, p* I2 E `
title. Much to my amazement, it worked on the first try:) x$ q+ F; m# j. D+ _* n* t+ ^8 `
C7 n# m0 P- I$ v, vNo HDPC errors, no strange player issues, nothing - it just worked.
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Next up was Dolby TrueHD. I tried American History X first but the best I coul
6 I. H6 H3 O8 _' \0 _6 Kd 【请注意文明用词】 of it was Dolby Digital. I swapped in Transformers and found the sam$ g7 i1 l0 ]5 ]. {7 Z
e. This ended up being an issue with the early PowerDVD 9 build, similar to is
$ q1 Y+ k( ]6 \! vsues with the version of the player needed for the Auzentech HomeTheater HD. S
6 c x* z0 ~; r0 d$ N) I7 C2 _; Ywitching audio output modes a couple of times seemed to fix the problem, I now+ ~. b9 G ^: e' E. B
had both DTS-HD MA and Dolby TrueHD bitstreaming from the Radeon HD 5870 to m( j- l+ F9 @2 ~( [2 C0 v
y receiver.
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5 Z' i" h# k5 J% M' iOne strange artifact during my testing was the 5870 apparently delivered 1080i1 s3 q. @! K! ?
output to my JVC RS2 projector. I'm not exactly sure what went wrong here as # V1 \, R1 Q0 f5 |* L
1080p wasn't an issue on any other display I used. I ran out of time before I 2 q0 H+ {5 r' h' Z5 [( i1 t
could figure out the cause of the problem but I expect it's an early compatibi
* C6 i& \+ b8 e# Y0 N' B" g8 Jlity issue.
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I can't begin to express how relieving it is to finally have GPUs that impleme
( I9 C- _, h3 J( _0 G) pnt a protected audio path capable of handling these overly encrypted audio str
# J& K- S, l1 ~eams. Within a year everything from high end GPUs to chipsets with integrated
) n5 Q% X* ~# h* d3 ngraphics will have this functionality. |
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