Discrete HTPC GPU Shootout
by Ganesh T S on June 12, 2011 10:30 PM EST
We will now devote a couple of sections to open source / freeware software for HTPCs running Windows 7.
One of the main issues with the integrated GPUs in the Clarkdale/Arrandale and Sandy Bridge CPUs is the fact that the Intel HD Graphics engine doesn't play nice with open source software. Commercial Blu-ray playback software have woeful support for MKVs and HD audio bitstreaming from non-Blu-ray sources. Users of the Intel IGP are often left to implement a series of hacks (such as using the Arcsoft and Cyberlink decoders in other DirectShow players) to get the expected HTPC experience.
Windows 7 uses the DirectShow / Media Foundation framework for media processing. A detailed description of the framework is beyond the scope of this piece. However, what we need to specifically be aware of is the architecture of the DirectShow framework, as described here.
The two important components of the filter chain in the above link are the splitter and the decoder. MPC-HC is undoubtedly the most common DirectShow based media player used to playback HD material. The player aims to make the task of the filter construction transparent to the user by packaging a variety of source filters for various containers. These include the Gabest MPEG Splitter, internal Matroska Splitter (I remember preferring the Haali Matroska Splitter from the CCCP codec pack in late 2009), MP4 Splitter, OGG Splitter etc. A look at the standalone filters reveals the large number of standalone source filters / splitters which are in the self-contained executable.
It is preferable to have a single actively developed multi-format splitter capable of handling a wide variety of containers with a multitude of audio and video codecs / subtitle formats. This is where the LAV Splitter project comes in. Basic supported for decrypted Blu-rays (playback of MPLS / index.bdmv files) is the icing on the cake.
With HD audio capable AV receivers becoming the rule rather than the exception, one increasingly finds users interested in HD audio bitstreaming. MediaSmartServer's Damian has a great guide dealing with the usage of ffdshow for HD audio bitstreaming. Advanced users often consider ffdshow Audio as bloatware for those who just want HD audio bitstreaming. LAV Splitter comes with the optional LAV Audio Decoder which achieves the same purpose. For users who want HD audio to be decoded in a bit-perfect manner, the LAV Splitter can also connect to the Arcsoft Audio Decoder as explained here. In this section, we will deal only with HD audio bitstreaming.
The gallery below shows the sequence of steps to install LAV Splitter and Audio Decoder on a Windows 7 machine for usage with MPC-HC. You can also use any other DirectShow based player. The LAV Audio Decoder is then configured to bitstream all the HD audio formats.
Ensure that all the file formats chosen in screenshot 5 are unselected in screenshot 8 (MPC-HC options -> Internal Filters -> Source Filter). Also, the Transform Filters for AC3 and DTS must be unselected to ensure that the LAV Audio Decoder is used. Screenshots 9 through 12 show the setting up of the LAV Audio Decoder for bitstreaming in the External Filters section using the 'Add Filter' button. Screenshots 13 through 16 show the setting up of the LAV Splitter in a similar manner. Fortunately, the default settings in the splitter configuration are good to go unless you have some specific requirements with respect to the language code or don't want the LAV Splitter to activate for some specific extensions. Make sure that both the LAV Splitter and the LAV Audio Decoder are set to 'Prefer' in the External Filters section.
Playing back interlaced VC-1 clips with the default codecs in MPC-HC usually results in a blank screen. To resolve this, the Arcsoft Video Decoder needs to be registered and used. (The WMV Decoder DMO codec is able to play back such clips, but it does software decode). After installing Arcsoft TMT (TMT 5 was used to test this out), the Arcsoft Video Decoder (ASVid.ax) was manually registered using the regsvr32 command in Administrator mode. This exposes the decoder for inclusion in the External Filters section in MPC-HC, as in the first picture of the gallery below. However, setting the decoder to Preferred doesn't enable its usage unless the checkactivate.dll from this doom9 post gets placed in the same folder as ASVid.ax. After this process, an interlaced VC-1 clip can be loaded into MPC-HC. In the default configuration, you will still end up with a blank screen. The VC-1 output compatibility of the LAV Splitter needs to be configured to reflect the presence of the Arcsoft VC-1 decoder, as in the rest of the screenshots in the gallery below. Note that this configuration is necessary only for AMD (and Intel) GPUs. NVIDIA GPUs have a open source decoder capable of playing back interlaced VC-1 clips in any DirectShow based player. We will cover that in the next section.
Once configured, you should be able to see the filters in action during the playback of any media file in the appropriate container.
Playing The DaVinci Code's BR Folder Structure - index.bdmv
(Click to Enlarge)
We have never seen the ffdshow Audio decoder successfully bitstream E-AC3 (Dolby Digital Plus). With the LAV Audio Decoder, there were no such issues.
Dolby Digital + Lights Up on the Onkyo 606
The ease of use of the LAV Audio Decoder, its tight integration with LAV Splitter and the ability to use the Arcsoft HD audio decoder for DTS-HD / DTS-ES streams (for which no open source decoders exist) make it a very attractive option for HTPC users.
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casteve - Monday, June 13, 2011 - link
I hope to see a review of the HD 6670, now that (at least) Sapphire has released a passive version.Drae - Monday, June 13, 2011 - link
... it'd be nice to see more use of Linux please. I realise there are a lack of "testing" and "evaluation" tools under Linux but that shouldn't prevent the testing of basic media needs. What's this about no bit streaming support under Linux? Boxee would disagree - as would:http://phoronix.com/forums/showthread.php?27348-Tr...
along with XBMC's audioengine (involving work by the guy in the above link). Maybe Windows 8 will sort out the mess that is WMC and all the messing (or bypassing with MPC-HC) that is required to get it working solidly. But right now if you want something that approaches a plug and play media experience XBMC (and its off-spring Openelec) under Linux is a lot closer than Windows. Equally the more coverage such solutions get the more likely greater time will be spent fixing the remaining issues under the Linux OS - hello there Intel and AMD.
Finally there is a great move now - go look at AVS' fora for examples - away from large media center pc's to small, quiet (silent) systems. These don't require 300W or 500W power supplies and huge cases with twelve fans and fifty million led's. They are ITX based systems sitting in small ITX sized boxes running 65/80/90/120W PicoPSU's with much greater efficiency and thus lower power use/running costs/silence. Placing these discrete cards in such systems would be a nice test of these picopsu units - given the apparently low power draw shown in the articles (something I'm very interested in seeing right now given the poor support of Linux by Intel on Sandybridge - the GT430 would be a good interim solution for me).
TLDR: Please don't limit yourselves to Windows testing and ATX/mATX sized systems when writing HTPC articles
ganeshts - Monday, June 13, 2011 - link
Drae, Thanks for the info and the link.The issue with Linux HTPCs is the fact that there is a semblance of support from only NVIDIA.
Don't get me wrong! I am a huge Linux fan, and always prefer free / open-source software. But, from a video perspective, is there a multi-GPU platform similar to DXVA ? Every vendor has their own flavour (NVIDIA - VDPAU / Intel - VA-API / AMD - XvBA). From the audio side, it looks like the link you mention is the only avenue available for bitstreaming, and that too for NVIDIA GPUs only. I will keep close tabs on what is happening in this area, and when the time is right, I will definitely post a piece on Linux HTPCs, considering one card from each of the vendors.
cjs150 - Tuesday, June 14, 2011 - link
As always it depends on what you want from an HTPC. For me I want to play Blu rays, stream HD movies from file server, watch and record TV and do some web browsing but in total silence (or as close to as possible).For me ITX systems are the way to go using a 150W PICO-pSU but critical is that they have to work with appropriate IR remote (Logitech DiNovo looks interesting)
I am happy to use Linux or Windows but it just has to work
alfredska - Monday, June 13, 2011 - link
This kind of quality review is what made AnandTech a name to remember early on. I'm glad to see such thoroughness and well thought out presentation of information. Looking forward to more reviews by Ganesh.UrQuan3 - Wednesday, June 15, 2011 - link
Agreed, this is an excelent article. I tried cross referencing to the "Zotec Zbox" article from the 9th (I own an E-350) and the earlier benchmarking was useless. I already know the E-350 won't do full processing, but I wanted to know where it sits compared to these platforms that pull 3-10 times the power.Think a 'software mode' might have been useful? An i5 could have done a fair amount of this processing without a hardware assist, saving the 70watts the cards were pulling and avoiding some of the integrated's compatability issues.
Shadowmaster625 - Monday, June 13, 2011 - link
I dont get the video card focus in the realm of HTPC. It seems that software is a far more important piece of the picture than a video card. Windows media center and XBMC both work like crap, and/or are unacceptably slow and clunky when it comes to browsing media. I do NOT tolerate that kind of lag, especially on a 3 ghz quadcore with an ssd/hdd drive setup. I dont expect miracles when trying to browse through a gigabyte of media, but still it should be faster. And then there's audio sync problems that like to appear out of nowhere. But you'd never know any of these problems exist from reading these articles. Shrug.I have found that VLC media player and windows explorer are the most reliable combination. But using windows explorer on an htpc is ugly and painful.
JasonInofuentes - Tuesday, June 14, 2011 - link
I think part of the problem is the degree to which there's news. A thorough review of Media Center might be warranted, the next time it changes, but was pretty thoroughly covered here (http://www.anandtech.com/show/2864/) and here (http://www.anandtech.com/show/2760). XBMC has a more frequent update cycle than Windows, and there's obviously interest so this might be an idea to explore further.As far as the difficulties with each of these platforms, a Z68 platform and SRT might be the solution here. So the size of the files is not really the problem, it's that when you browse to a folder the user wants to be able to scroll around the list or grid and have all of the information pertinent to those files readily available. You don't want to scroll over to a file in your West Wing Season 5 folder and wait for the Title to load so you know whether it's the episode you were looking for, you want that information to be up the instant you scroll to it, or even better for it to be glanceable before you even start scrolling. In order to achieve this the OS's load all of the information for all of the files in the folder. So if you have a few dozen files in a folder that's the metadata for each files, the thumbnail preview and then the usual file system queries the OS would do anytime it accesses the drive. That can add up to a lot of small reads, and that leads to that big stall as you scoot around your media.
Now, the throw money at it solution is move to ALL SSD storage. But I've got 4TB of media and don't have that kind of money to throw at the problem. SRT should help though. If I recall, the metadata and thumbnail files are stored locally in the folder with the files, but since SRT caches the frequently accessed files, then for a system used exclusively for media the only thing that should populate the SSD cache is going to be these small reads that otherwise slow down your system.
I am suddenly overwhelmed with an urge to get my hands on a Z68 to try this out! And you are quite right that VLC and Windows Explorer are the most reliable programs for browsing and playing back media, but the price you pay for pretty is often performance.
vailr - Monday, June 13, 2011 - link
As an exercise in "possibility thinking", I'd be interested in a sub-category of a complete "solar powered" desktop-format PC review. Designed (theoretically) for someone living in a remote area, off the electrical grid, yet still having internet via satellite, cell phone signal, or otherwise connected. Designed for ultra low power consumption, mostly dependent on solar and/or wind power produced on site. Yet maximal possible performance (under such power restrictions) for either: generic gaming desktop PC, and also for a HTPC. Using SSD's and/or laptop HD's for storage, and with an energy sipping CPU (dual-core Atom vs. Intel i330, for example), combined with either: on-CPU chip video or a "PCIe bus only" powered video card, and yet somewhat viable as a gaming PC or as a HTPC.Maybe even qualify for an article in Home Power magazine? http://homepower.com
Penti - Monday, June 13, 2011 - link
Why? Running a 100 W PC of batteries is pretty pointless.Just install FTTH and a powerline if you like to game or do other intensive tasks needing GPU-power, fast cpus or ridiculous amounts of memory (workstation type stuff). It would be the most efficient solution any way. You don't even need any power for any modems. You certainly can run a PC of battery power off grid, but why destroy your work with that. It would be hard to store much electrical power.
Otherwise you would pretty much had to get by with a low-powered laptop. No monitor.
Do the unabomber type guys need any gaming? If so they need to install a good damn power line or at least a diesel-generator. They don't have the money and skills to build energy storage and buy panels thats enough to power a modern home any way.