1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Jerky playback of DTV with Nebula card, any ideas?

Discussion in 'Desktop & Laptop Computers Forum' started by Jackass, Oct 1, 2003.

  1. Jackass

    Jackass
    Well-known Member

    Joined:
    Jan 9, 2003
    Messages:
    3,045
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +593
    I bought this card off these very forums but i'm getting jerky playback with v3.03 software, a P4 1.8A Ghz c/w 256 MB memory, XP Pro on a gigabyte 8IRXP motherboard.

    I've got TT autokiller, DVDregion killer, Girder and VNC running in the taskbar.

    I emailed Nebula but they said that in v3.03 playback was improved even with the ACPI driver installed.
    After watching TV on a Nokia 221T STB the picture is unwatchable.

    I enabled the 'frame smoothing' option in the advanced tab but it made no difference. :(

    Any ideas, is my processor in need of an upgrade?

    Any help appreciated.

    Steve.
     
  2. Mark Ward

    Mark Ward
    Member

    Joined:
    Sep 12, 2001
    Messages:
    1,796
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    41
    Location:
    Kent
    Ratings:
    +18
  3. Jackass

    Jackass
    Well-known Member

    Joined:
    Jan 9, 2003
    Messages:
    3,045
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +593
    Links not working Mark,

    I'll do a search.

    Cheers.
     
  4. Mr.D

    Mr.D
    Well-known Member

    Joined:
    Jul 14, 2000
    Messages:
    11,049
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    133
    Ratings:
    +1,126
    I do notice some jerkiness on video material.
    The deinterlace setting in the advanced settings is best left off if you are watching film based material ( otherwise it will blur the picture)

    I only switch it on if its a video based program.
    I leave the frame smoothing on all the time.

    The manual switching is a bit of a pain : not like good old Dscaler!.

    I've also noticed something a little weirder. If I record something the recording plays back well from HD with no jerkiness whereas if I watch it live I will see the odd jerk ( then I close my curtains and he goes away!) this might be frame dropping rather than a deinterlace/refresh issue though but it seems odd that it always plays fine from HD.
     
  5. BBD

    BBD
    Active Member

    Joined:
    Mar 13, 2001
    Messages:
    430
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Lutterworth
    Ratings:
    +3
    I have commented on this problem in the past. I found it a real problem in the past but later software releases have improved it a lot although not completely. I also upgraded my PC from XP2000+ 256mb to XP 2200+ 512mb this also seemed to help although I know people are using it successfully on much lower spec machines.
     
  6. Mark Ward

    Mark Ward
    Member

    Joined:
    Sep 12, 2001
    Messages:
    1,796
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    41
    Location:
    Kent
    Ratings:
    +18
    Edited my previous post to make link work.

    It would appear that there's something wrong with the "Add Link" button in the text editor.

    See if it's helpful,

    Mark.
     
  7. Markatlarks

    Markatlarks
    Standard Member

    Joined:
    Jan 8, 2003
    Messages:
    123
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Truro, Cornwall
    Ratings:
    +2
    Here is a conversation I have had recently - It may assist:

    To: 'andrew@nebula-electronics.com' To: 'andrew@nebula-electronics.com'

    Sent: Wednesday, August 20, 2003 11:24 AM

    Subject: RE: Nebula and Sky



    Andrew - Hi



    It's me again - Following up from your last email.



    I have done as you said and I now have Sky!

    Very good - Thank you.



    However - there is always a However!



    In both the digital and analogue modes I seem to get judder or 'missing frames' - Can I get over this a normal dvd playing is fine?



    I am not sure if this makes sense but - especially in sport viewing the picture is not smooth?



    In case you can advise let me tell you that I am using a Pentium4 2.4mhz with 1gb of memory and a Radeon 9000 graphics card.



    I am taking the feed out of the DVI port into a Sony HS10 video projector and it is projecting about a 7 foot image.



    I have not as yet been able to get Dscaler to work - more about that later.



    If you can advise It would be much appreciated.



    About Dscaler - You mention that the chip is a BT8788 - Yet there is no mention of this 'exact' chip. Also the Tuner aspect of Dscaler does not have any entries it Dscalers drop down box. This could be the Beta software - however Could you let me have the name/details of the Tuner so I can insert this next time



    Many thanks for your help on this - I hope it is not above and beyond the call of duty!


    ----------------------------------------------------------------------------
    REPLY
    ----------------------------------------------------------------------------
    -----Original Message-----
    From: Andrew Saunders @ Nebula Electronics Ltd. [mailto:andrew@nebula-electronics.com]
    Sent: 20 August 2003 13:59
    To: Roberts, Mark
    Subject: Re: Nebula and Sky



    Hi Mark,



    Thanks for your e-mail!



    It is good to hear that you have now managed to get Sky and thus I will see if I can now answer your new questions. Regarding the frame judder, can you please press the 'i' key while watching live video and then let me know if you see any frame drops occuring. If you do then there are a few possible reasons for this and they are as follows:



    1) Your CPU is not quite capable of realtime video playback using our software. However as you have a 2.4GHz P4 this certainly isn't the case.

    2) Your machine could be using an ACPI driver which is causing frame presentation timings to occur at the wrong times thus it produces either dropped frames or juddering. The ACPI driver normally causing this issue is the ACPI Uniprocessor Driver and it is certainly much worse if you use the frame smoothing option in our software. As such you can either choose to leave frame smoothing off and accept that there won't be dropped frames, or try to improve overall frame presentation by switching to the "Advanced Configuration and Power Interface (ACPI) PC" driver. If you do the later change and then enable frame smoothing you should find that the image presentation is the best our software can currently provide, thus hopefully it will solve your issues. However, please note that changing this driver can have some severe consequences and as such you make this change at your own risk. We have never had a problem going from Uniprocessor down to the Advanced... one, but if you try to do the opposite on a machine that has never had the Uniprocessor driver installed, you will find that it just isn't compatible in most cases. Thus please only consider doing this change if you have the Uniprocessor driver installed.

    3) The refresh rate of your monitor isn't set to a multiple of 25 and thus this has caused further timing issues. Please change to a resolution and refresh rate, such as 75Hz so that your playback is as smooth as possible.



    Regarding your DScaler issues, please can you look for a Connexant part with the code 8788 some where in it. When asked to choose a tuner don't specify one and hopefully the software will happily identify the card and start using it (after of course you select from the File drop down menu). Hopefully this will help you get up and running as I have tried these settings myself and they seemed to give me the most success. One other thing to note is that the colour format may be incorrect at startup so please ensure that you switch to PAL-I in the option lists as this should ensure your colours, etc are correctly displayed.



    Thanks again for your e-mail and if you have any other questions or comments please feel free to e-mail us again as we are always happy to help!



    Kind Regards,



    Andrew Saunders

    Nebula Electronics Ltd


    ________________________________________

    I hope this helps. By the way I had bg 'artifact' noise problems. Thought it was the Nebula box - turned out that I had severe signal loss due to a coulpe of joint connections. When I replaced the coax - all went back to normal.
     
  8. BBD

    BBD
    Active Member

    Joined:
    Mar 13, 2001
    Messages:
    430
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Lutterworth
    Ratings:
    +3
    Blimey!! tech support from Nebula on DScaler + capture card.
     
  9. Jackass

    Jackass
    Well-known Member

    Joined:
    Jan 9, 2003
    Messages:
    3,045
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +593
    Thanks guys for the tips, its now working reasonably okay although it can only get better with more software updates and PC processor upgrade :)
     
  10. Mr.D

    Mr.D
    Well-known Member

    Joined:
    Jul 14, 2000
    Messages:
    11,049
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    133
    Ratings:
    +1,126
    I really like the DigiTV and think its a great piece of kit but I wish they'd get together with the Dscaler guys and share some techniques to their mutual benefit.

    Dscaler ( utterly wonderful) slightly soft picture but terrific silky smooth deinterlacing and judder terminator).

    DigiTV (very good piece of kit) Sharp as a tack totally clean but how I wish it would playback as nicely as Dscaler ( film deinterlace is easy of course but some judder terminator type gizmo would really sing)

    I'd love to be able to use Dscaler to playback from a DigiTV.
     

Share This Page

Loading...