Down-Sample HD? Possible? (1 Viewer)

apoptygma

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The hardware on my HTPC is pretty sub-par, it's a 2.4ghz P4 with 1gb of DDR1,
Plays divx perfect, interface navigation is smooth and Digital Tv Tuning Via my crappy Dvico Lite is smooth too -
Thing is it doesn't play HD properly, it's rather jerky which is to be expected. I'm wondering if there's any way I can get it to render HD Digital TV in standard Digital Resolution so that I can still watch the TV shows that show only on HD channels, currently the only alternative I have is to fire up the "Dvico Fusion" software package and watch them there as that seems a little more optimized for the particular card

I should clarify that I'm using MP 1.0.0.0 RC3 - the full MediaPortal not just the TVclient, and posted here as I think it's the most relevant sub-forum though I could be mistaken
 

Taipan

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    Thing is it doesn't play HD properly, it's rather jerky which is to be expected.
    No, I don't think that "is to be expected" ... ;)

    What decoder are you using for HD?
    Is the HD MPEG2 or MPEG4?
    What video card are you using?
     

    apoptygma

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    I'm using the default MPEG2 decoder that ships with MP, I've tried flipping it over to the nvidia decoder and didn't notice a change in performance. Not sure what you mean by "Is the HD MPEG2 or MPEG4?" this is live TV - streaming from the Dvico tuner, I believe that means it's just MPEG2
    Video card is only a Geforce MX-4000
     

    Taipan

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    I'm using the default MPEG2 decoder that ships with MP
    This decoder does not support hardware acceleration (DxVA).

    Not sure what you mean by "Is the HD MPEG2 or MPEG4?"
    I assume that you are in Australia? In which case the HD channels are MPEG-2. In most other countries HD TV is MPEG-4 (H264)

    Video card is only a Geforce MX-4000
    I don't know that particular card, but it may not include hardware acceleration of MPEG2 video (DxVA)?

    You will get "jerk-free" HD video if you use a decoder which has hardware acceleration (like the CyberLink decoder, or the Dvico DxVA decoder) with a video card that includes hardware acceleration (like an AT 9550, etc). This combination will take the MPEG-2 decoding load off your CPU and give you perfect HD video ... :)
     

    apoptygma

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    You will get "jerk-free" HD video if you use a decoder which has hardware acceleration (like the CyberLink decoder, or the Dvico DxVA decoder) with a video card that includes hardware acceleration (like an AT 9550, etc). This combination will take the MPEG-2 decoding load off your CPU and give you perfect HD video ... :)

    Yea I'm 99% sure this card has no Hardware acceleration inbuilt hence why my original comment was to see if it would be possible to decode a lower-bitrate version of the HD signal and take some load off the card. Although having said that it's highly likely that the actual down-sampling if at all possible would just add overhead anyway.

    I'll have a go with some other codecs, but is there anyway to actually configure the individual codecs to modify output? I wasn't able to find any kind of control panel/settings for the nvidia decoder where I could "turn down" any post-processing and sacrifice some picture quality for framerate which is what I'm after.

    I might run some diagnostics and see what the CPU usage is during HD playback, Anyone know of a tool that will monitor GPU usage? It would be good to figure out where the bottleneck is and how cheeply I can get the needed increase in performance as Hardware-accelerated TV-Tuners are very expensive, If a faster Graphics card or CPU will help It would save a lot of money for me.

    Here's a Link to the tuner DViCO FusionHDTV Tuner PCI, USB: Home > Products > DVB-T Lite

    It states :

    Dvico's proprietary HDTV SW decoder
    Dvico's own dual HDTV software decoders for both non-DxVA
    and DxVA VGAs Provides the best VGA compatibility with non
    DxVA full software decoder
    Provides low CPU consumption with DxVA SW decoder
    Dvico's own AC3, AAC Audio decoder

    Which I'm reading as "there's nothing on this card that will make your TV run nicer, It's all SW rendering" ya?

    Third post in a row here and I'm starting to get the vibe that "hardware acceleration" means something other than what I initially suspected, I thought it mean the card has some ability to do processing tasks but from the descriptions it seems like it's more a case of it offloading CPU rendering to the GPU?

    Ok here's another option - what's the codec for sound that's going to have the least overhead? I'm currently only running a 2-speaker setup so It doesn't matter if the sound is god-aweful or fantastically rendered - It's going to sound the same. I think I've left this as the default sound codec as well, maybe I could get a few extra frames per second changing to something more sensible
     

    Taipan

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    I'll have a go with some other codecs, but is there anyway to actually configure the individual codecs to modify output?
    If you mean, to reduce the pixels, or the frame-rate, then the answer is no.


    Which I'm reading as "there's nothing on this card that will make your TV run nicer, It's all SW rendering" ya?
    Yes, correct.

    Third post in a row here and I'm starting to get the vibe that "hardware acceleration" means something other than what I initially suspected, I thought it mean the card has some ability to do processing tasks but from the descriptions it seems like it's more a case of it offloading CPU rendering to the GPU?
    Yes, correct again ... ;)

    Ok here's another option - what's the codec for sound that's going to have the least overhead? I'm currently only running a 2-speaker setup so It doesn't matter if the sound is god-aweful or fantastically rendered - It's going to sound the same. I think I've left this as the default sound codec as well, maybe I could get a few extra frames per second changing to something more sensible
    Sound decoding uses very little CPU.

    Again, I will assume that you are from Australia (since you seem to want to keep that a secret .. ;)) and that your motherboard has an AGP slot for the video card - in which case you can get an ATI Radeon 9550 for about $60 that should do the trick. An even better option is the ATI HD3650 AGP, for about $110. Use either of those with the Dvico DxVa decoder and you will be laughing ... :D
     

    apoptygma

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    Again, I will assume that you are from Australia (since you seem to want to keep that a secret .. ;)) and that your motherboard has an AGP slot for the video card - in which case you can get an ATI Radeon 9550 for about $60 that should do the trick. An even better option is the ATI HD3650 AGP, for about $110. Use either of those with the Dvico DxVa decoder and you will be laughing ... :D

    Yea I'm in Aus, that's no secret :p I'll give the DxVa a go tomorrow night and if it doesn't cut it i'll invest in a faster card - thanks for all your help Taipan, I'll report back soon incase anyone else ends up googling this thread up from being in the same boat (I've found during the process of setting up my media centre, googled forum posts are the #1 source of answers)
     

    Spragleknas

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    The GeForce MX4000 is a GeForce 4 card, and does not even fulfil the requirement for using MP, as it is not even DX9 capable.
     

    apoptygma

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    Yea I did notice that, looking at the requirements the other day. But it works fine so *shrug*
    I chose it because it's about the fastest passive-cooled card I could fit into my case, cost me all of 20 bucks on ebay and does the job!
     

    moesfeld

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    I think downsampling would even eat more performance than decoding HD content directly.

    I chose it because it's about the fastest passive-cooled card I could fit into my case,
    Well as you said "fit into my case" i assume it can only take low profile cards.
    For HD content (H264 i think for Australia as Taipan said) you would at least need
    a ATI HD2400 for fully GPU decode. (The Sapphire Radeon HD 2400 Pro Passiv low profile AGP) i.e. paired with a DVXA supporting codec.
    But look around in the Forum before you spend money because imho some people had problems with the hd2400
     

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