Home » HTPC » ffdshow DXVA with subtitles? I think so.

ffdshow DXVA with subtitles? I think so.

I was messing around with my codecs this morning and decided to update my ffdshow installation to clsid’s revision3291 (32-bit).  I don’t remember the last revision I had, but I know it did not have the new DXVA decoder available for h.264 and VC-1 sources.  What really piqued my interest, was that it included settings for subtitles.  DXVA+subtitles+ffdshow?  I had a hard time accepting it, but I was interested enough to give it a test run.

This is not really a guide because I’m not going to cover everything necessary to get all of this working.  I stopped using Shark007‘s codecs a little while back because I had issues in getting settings to stick for me.  I decided to go back to using Win7DSFilterTweaker which allowed me to install and configure only what I wanted, the way I wanted.

The only codecs I have installed (x86) are clsid’s ffdshow revision 3291, Haali Media Splitter and AC3Filter 1.63b.  That’s all I need and it’s all I use (I use Microsoft’s default TV/DVD codecs).  I used the Win7DSFilterTweaker to allow ffdshow as my preferred codec for just about everything aside from TV/DVD sources.  I may do a separate guide on that later, but I’m pretty sure you can find one if you spend a minute or two on Google.

The first thing you want to do, is to make certain h.264/AVC is not enabled in the standard ffdshow decoder…it must be set to disabled.

Next, open the ffdshow DXVA decoder properties and go to the Hardware acceleration section of the menu.  Check to enable H264 and, if you want, check to enable VC1.  The next part is concerning subtitles, so if you don’t use them, you can actually skip this part and be done.  Go down to the Post processing drop down menu and select Surface overlay.  Subtitles will not work if you do not enable that setting.

Next, go to Subtitles in the menu and make sure there is a check mark present in the box to enable it.  You can pretty much accept defaults here, but I also make certain Accept embedded subtitles is checked for compatibility with some of my files.  The rest of the settings you can play with to taste, but that’s all that’s needed to get them working.

You’re done.  If Win7DSFilterTweaker has been used correctly to setup your codecs, Media Center is ready for your HD MKV files with hardware accelerated decoding…including subtitles.

Now, the bad news…for me anyway.  I was never able to see any signs of hardware acceleration using this.  The DXVA decoder was definitely being used and I downloaded properly encoded h.264 and VC-1 files to make sure it was not just my own files, but I never saw a decrease in CPU usage nor elevated use of my ATi HD 2600 Pro GPU.  I’m hoping it was just my hardware or driver (using latest Catalyst), but I just could not get it to give me any kind of reassuring results.  I tried in Media Center, Media Player and Media Player Classic Home Cinema with identical results.

I would like to know what any of you get if you decide to try this, however.  I’m perfectly happy without hardware acceleration as what I use plays my 720p encoded files perfectly fine.  This is some good ground-breaking for ffdshow though!


  1. Sinjen says:

    When I was testing a similar setup for my nvidia based machine I could right click the vobsub icon when videos with subs were playing and get properties on the various codecs being used to play the file. I thought it odd that I could get the properties that way, but it was possible nonetheless. In this instance, I was able to see the properties for “MPCVideoDec.ax”. Doing so allowed me to see that for half, or more, of my files hardware acceleration was not being used :)


  2. Sinjen says:

    I’m not sure what’s so different about CoreAVC, other than it’s explicit support of CUDA, but using it along with a CUDA enabled GPU has enabled hardware acceleration for all my titles, except VC-1, which I easily converted in REAL TIME to h.264 AVC with MediaCoder. I only had 4 of these so converting wasn’t a big deal. Subtitles also work great and do not break HW acceleration.


    • Jon says:

      I have one nVidia card that supports CUDA, but it’s not installed in anything…it’s an 8400 GS. I’d like to use it, but the only system I’d put it on takes S-Video and it doesn’t work when that’s its primary interface (video goes blank when driver initializes).

      I tried CoreAVC some time back and liked it, but the version I used didn’t obey display aspect ratio, so some files played back incorrectly (4:3 instead of 16:9).

  3. bitzorro says:

    i have been reading over at the ffdshow tryouts project: Discussion & Development forum,and it looks like it only works for .sup (bluray subtitles)
    and using external player(Mpc-Hc).
    windows media center/media player is never mentiond!

    i for shore hope i´m wrong?

    mvh bitzorro

  4. Jamie says:

    I’m seriously considering bypassing the onboard ATI video on my motherboard and getting a nvidia GT210 for the CUDA support. Seems this is going to be the only way to reliably get subtitles support with hardware decoding still enabled. DXVA support just doesnt seem to be coming along fast enough.

    Shame CoreAVC have indicated they have no plans to support DXVA not ATIStream/SimHD and instead will be focusing on CUDA.

    • Jon says:

      I’m just glad I don’t need DXVA. It’s been more trouble than it’s worth long before it was placed on the pedestal it sits now.

    • Jon says:

      Cool…I just wonder where that registry entry comes into play. It seems as though the length I went to in order to get it going made it look as though it was enabled, but it was not. I’ll have to try this out later and see what happens. Good news!

  5. bitzorro says:

    shark007 claims hees software has been able to do this for weeks!!!
    i guess all the htpc communitys have missed something big time!


    mvh bitzorro

    • Jon says:

      It may have been supported in his pack, but I stopped using it. I was having too many issues with settings not sticking and “Run As Administrator” simply not working. I prefer a more compact solution anyway. I still have his pack on a couple of HTPCs my kids use since they don’t require much configuration. I’m happy with it there.

  6. tm says:

    [HowTo] Enable DXVA H264 Decoding for MKV + Subtitles for Windows Media Player/Center on Windows 7


  7. Raman says:

    You should at least have a Radeon HD 3000 series or a nvidia 8000 series graphics card in order for DXVA to work (I think)

  8. Wally says:

    There is no “hardware accelleration” tab in my FFDshow settings >:(

  9. Semisonic says:

    Thanks man! You’re really my savior. Would never guess about the Post processing option myself.

    Of course, if you use the player like MPC-HC, you usually don’t have to mess around so much, since it has an internal support for both DXVA and subtitles. But in my case the subtitle properties in MPC-HC weren’t enough, so i’m very happy i bumped into your post =).

  10. jason wong says:

    Well here it is, 2012 and this still doesn’t work in FFDshow even with the newest version. I’ve tried shark too and it doesn’t work. H.264 DXVA acceleration works but VC-1 acceleration does not. I know my machine supports it with my ati 6870 and cpu usage is really low with windows media player or MPC-HC using their DXVA vc-1 filters.

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