GPU acceleration with LAV Filters sometimes bypassed? (1 Viewer)

kiwijunglist

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    ran one of the test videos using the iPlayer website and while motion wasn't perfect there was no skipping.

    'motion not perfect', suggests maybe your machine was struggling to play the content on the iplayer website as well as within mediaportal.
     
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    BushLin

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    'motion not perfect', suggests maybe your machine was struggling to play the content on the iplayer website as well as within mediaportal.

    I was being hyper critical about the motion since my eyes are scanning for any differences between the playback on that system compared to a far more powerful PC, I'd happily live with such quality as I use iPlayer is for shows I forgot to record.
    If I look at the CPU usage when playing via IE it hovers around 65% but when playing back with MP/OnlineVideos/LAV it swings from 55%-100% and you can guess when the stuttering happens.

    It doesn't look like the flash plugin is using the GPU as much as it could. However, in MP if I choose to download the video first then that eliminates some of the background processes and playback improves... massively; in this state CPU usage sits between 20-35%. If I'm going through menus without downloading first then I can induce the stuttering as the CPU load is critical.

    I'm not in a position to upgrade at the moment and lots of new low power hardware is about to hit the shelves but what I'm starting to wonder whether the content providers are such a moving target that investing in hardware to use a system they consider unsupported method is folly.
    Perhaps I should just put up with waiting for my PS3 to power up and load when wanting to access catch up services or get a sofa friendly keyboard/mouse rather than relying on the likes of the BBC not closing off their platform to OnlineVideos as has happened with 4oD.
    My hardware in this box is far from great but fills the purpose of replacing a Sky+ box with something more silent and flexible but no monthly fee, just steaming from the internet has it stumped at the moment.
    If you do think of anything which could lower the CPU load though, I'd be very interested.
     
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    kiwijunglist

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    There are lower cpu usage non dxva h264 codecs such as coreavc. Other options include increasing MP processor priority and disabling un-needed services and applications through msconfig and services.msc .... Another approach is to format your pc and only install MP + LAV + essential drivers. Ultimately though you may have to accept that your cpu is too slow for some non dxva complaint video in mp. Some other people maybe able to suggest other things... (This is assuming that dxva is working in MP+LAV, however on these particular videos dxva turns off as they are not dxva complaint)
     
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    offbyone

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    Also disable Virus Scanner for the MPUrlSourcefilter cache folder as mentioned in the faq and other threads - this helps a lot on slower PCs.
     

    BushLin

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    I've not tried CoreAVC, that's something for me to investigate but with regards to slimming down the build... I don't even have anti-virus installed; It's just drivers and mediaportal on this box with a fair few windows components disabled, after testing I'll be restoring my backup to before I installed flash player.
     

    BushLin

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    Tried raising the process priority but the problem persists, it's so odd that when running the same stream locally it runs flawlessly... if I were to skip forwards it snappily takes me to my desired point but if I were to try the same thing when playing back the internet streamed version it'd take a good few seconds to stop glitching even though it had already downloaded many minutes further than requested.
     

    BushLin

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    That is when using MediaPortal, just using the 'Downloaded Videos' function of OnlineVideos rather than streaming through the net. I'm not going to ask the author to recode his plugin just for me to avoid the spikes when downloading, just wondering if there's anything that can be done. Sadly, downloading in advance doesn't even come close to saturating a fibre connection, they don't let you grab faster than about 1MB/s :(
     

    BushLin

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    Disabling "Dynamic Refresh Rate Control" made a marginal improvement, as did disabling windows features like "remote differential compression" but in practical terms it just meant there's a slightly lower baseline from where the spike in CPU usage starts.
    Having poked through the logs I can see the content is VC1 and it's documented that a VP2 class Nvidia card can't accelerate that.
    Playing locally shows that a 720p video I'm struggling with is using about 30% or less CPU power and therefore I assume the rest is being munched up by either the process of dynamically downloading and playing a stream (perhaps it works with big chunks of video at a time in separate scripts) OR potentially some DRM mechanism having a nose around to inspect what's going on.
    When running Task Manager or Process Explorer (with admin rights) I couldn't see any process or service suddenly increase in usage when playback stuttered, they were nearly always consuming less than 1%; fairly consistently it was the MediaPortal process suddenly jumping from below 50% usage to max and this would happen fairly randomly and sometimes infrequently but you can tell the system is struggling as skipping back 15secs means the system takes a while to settle back.

    I should point out that I don't want to say "this is fact, you should fix it", I'm not pretending to 100% understand precisely what element(s) of mediaportal or the plugin manifests itself in my use case but am trying to be as scientific as possible in providing feedback. I'm very grateful to everyone who works on Mediaportal and it's many supporting tentacles, I fully intend to donate when I'm in a less restricted financial situation and not even close to complaining at something provided for free especially when I have workarounds to hand.

    Over and out, I'm going to leave this alone for at least the rest of today.
     
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