VideoHelp Forum
+ Reply to Thread
Results 1 to 17 of 17
Thread
  1. Member
    Join Date
    Jul 2018
    Location
    Sweden
    Search Comp PM
    I used an Avisynth script and encoded an anime DVD with MeGUI.

    Here is the script I used:
    deint = TDeint(mode=2, mtnmode=3, blim=100)
    TFM(cthresh=4, slow=2, clip2=deint)
    vInverse()
    TDecimate(mode=1)
    Crop(4, 0, -4, -0)
    LanczosResize(844, 480)

    In the IVTC'ed video where the ending theme is played, it looks jerky. Do I need to deinterlace to make it look smooth or can I use another IVTC script? I have attached a part of the IVTC'ed video and the DVD. Thank you for your help.
    Image Attached Files
    Quote Quote  
  2. The first part of that video is true 30i, 60 different fields per second. Later it switches to 30p encoded as 30i. So none of it can be IVTC'd to 23.976 fps smoothly. If you really want to get rid of the interlacing and encode progressive use QTGMC to make 60p. Or QTGMC().SelectEven(), or TFM() to create 30p.
    Image Attached Files
    Last edited by jagabo; 12th Oct 2018 at 12:42.
    Quote Quote  
  3. Member
    Join Date
    May 2014
    Location
    Memphis TN, US
    Search PM
    Jagabo got here first, heh.

    [edit] Or QTGMC(FPSDivisor=2) to get 30p.
    Last edited by LMotlow; 12th Oct 2018 at 12:47.
    - My sister Ann's brother
    Quote Quote  
  4. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    And what about better compression to add 2px black bar on top and on bottom? resulting in 848x480? Seems to me be better output, but probably some serious reason to have 844x480, don't know.


    Bernix
    Quote Quote  
  5. Member
    Join Date
    May 2014
    Location
    Memphis TN, US
    Search PM
    Originally Posted by Bernix View Post
    And what about better compression to add 2px black bar on top and on bottom? resulting in 848x480? Seems to me be better output, but probably some serious reason to have 844x480, don't know.
    Where do you see 844x480? Every video in this thread is 720x480 and plays at 16:9 DAR.
    - My sister Ann's brother
    Quote Quote  
  6. The other option would be to make VFR output, but it's more complicated
    Quote Quote  
  7. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    @LMotlow
    O.k. sorry watched video and didn't inscpect it. Just last line in avisynth script confused me then.

    Sorry.


    Bernix
    Quote Quote  
  8. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    This deserve new answer post. So iam not as stupid as i though Now seems to be post above bit sarcastic


    Bernix
    Quote Quote  
  9. Member
    Join Date
    May 2014
    Location
    Memphis TN, US
    Search PM
    Originally Posted by Bernix View Post
    This deserve new answer post. So iam not as stupid as i though Now seems to be post above bit sarcastic
    Nope, you're, right, I'm wrong. The "ivtc.mkv" encoded sample is most certainly an oddball 844x480 with a forced 16:9 DAR (the frame itself is not 1:777778:1, it's a slightly fatter 1.804:1 ratio and will play unencoded on a 16:9 TV with slight pillarboxing. I imagine the owner has a reason for 844x480, but by golly I've found that trying to figure out the reasons for eccentric off-the-wall processing around here is just a waste of time. I'd expect some problems with it, though, because the 866 width is neither mod16, nor mod8, nor mod4. it's just a skinny mod-2, which a lot of filters, encoders and players will just screw up, resulting in another forum post for help.
    Last edited by LMotlow; 13th Oct 2018 at 02:12.
    - My sister Ann's brother
    Quote Quote  
  10. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    Glad you take it as sportsman. You could bite a bit, but you didn't. I appreciate your great behave.


    Bernix
    Quote Quote  
  11. I'd be willing to defend the aspect ratio.

    If you assume the original DVD has a display aspect ratio of exactly 16:9, which they often do.... and there's nothing to prove it's a generic, ITU or an MPEG4 aspect ratio.... so if you assume the 720x480 DVD is exactly 16:9 and crop 4 pixels from each side, after resizing to 844x480 the aspect error is 0.01756%, or virtually zero.

    If you put a 16:9 DVD in a Bluray player connected to a TV via HDMI and tell it to output 720x480, I'm pretty sure the majority of TVs would resize it to exactly 16:9, not 1.8 something. In fact if you connected a Bluray player to a TV at 1080p, I'm pretty sure most Bluray players would upscale it to exactly 16:9 too.

    That's not to say the aspect ratio can't be 20/11 (mpeg4 aspect ratio) or ITU, but it mightn't be either.

    It wasn't uncommon for devices with both analogue and HDMI input/outputs to resize the video differently according to the connection type, but these days everything's HDMI and exact 16:9 resizing would be very common.
    https://lurkertech.com/lg/video-systems/#pixelaspect_hdmi

    If you added two pixels of black each side and encoded at 848x480 with x264 at the same CRF value as you used for encoding at 844x480, I'd be astounded if the final file size changed much.
    Last edited by hello_hello; 13th Oct 2018 at 13:15.
    Quote Quote  
  12. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    Hi @hello_hello,
    and what is wrong then with 848 that is dividible by 16. Better for compression suppose. If everything ends 16/9 this is closer, or add black bars, but i understand then those 4px will be part of video so bit deformed. Actually do not think that anybody can notice it. In fact who can recognize by looking not measuring 16/9 and 16/10 video and it is in terms of math big difference. Simply i think that 848 is better for old and even new codecs. It of course has nothing to do with smoothnes. But bigger resolution, that in paradox can result in smaller bitrate at same quality.


    Probably I'm missing something. There is also (for some PC player only and mkv file and only for some video renderers EVR CP, DX11,9 and many others) do virtual crop to 844 later. I know this feature is very limited. Not supported by MadVR and probably some old eighter.


    Bernix
    Quote Quote  
  13. I'm not saying there's anything wrong with it, but for x264 I doubt it'd make much difference to compression, and for older codecs, wasn't one of the reasons for cropping black borders to prevent them from messing with motion estimation?

    1080p isn't mod16, but for some reason it always gets a free pass.

    Anyway, from the small amount of testing I did a while back, the mod didn't make enough difference to compression for me to worry about it.
    https://forum.videohelp.com/threads/353220-Why-do-most-people-crop-out-the-black-bars-...VD#post2219933.
    Quote Quote  
  14. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    At least is 1080 mod8 and 844 is just mod4 and yes, modern codecs are mod2 but in this case are you sure mod4, all mechanism of x264 can be realy be used? And in fact, black bars takes very few bits. And if generated black bars, i doubt there is any interferation, When capture, black bars probably are not always just black bars and can caused problem.

    Thats all.


    Bernix
    Quote Quote  
  15. Originally Posted by Bernix View Post
    But in this case are you sure mod4, all mechanism of x264 can be realy be used?
    Have you seen any evidence suggesting otherwise?

    Originally Posted by Bernix View Post
    And in fact, black bars takes very few bits. And if generated black bars, i doubt there is any interferation, When capture, black bars probably are not always just black bars and can caused problem.
    The same 5001 frames of video each time. Original resolution 720x480 and x264's default settings. Try it yourself to see if mod16 improves compression for you, because if anything it appears to decrease it. That surprised me a little.

    Original de-interlaced.
    Yadif()
    Trim(5000,10000)

    Mod16 file size 14.3 MB

    After cropping.
    Yadif()
    Crop(2,0,-2,0)
    Trim(5000,10000)

    Mod4 file size 14.0 MB

    After cropping and adding black borders.
    Yadif()
    Crop(2,0,-2,0)
    AddBorders(2,0,2,0)
    Trim(5000,10000)

    Mod16 file size 14.3 MB

    Again, this time cropping all the black first.

    Yadif()
    Crop(18,0,-18,0)
    Trim(5000,10000)

    Mod4 file size 13.7 MB

    Yadif()
    Crop(18,0,-18,0)
    AddBorders(2,0,2,0)
    Trim(5000,10000)

    Mod16 file size 14.1 MB
    Last edited by hello_hello; 13th Oct 2018 at 15:02.
    Quote Quote  
  16. Member Bernix's Avatar
    Join Date
    Apr 2016
    Location
    Europe
    Search Comp PM
    Hi,
    just curious x264 settings. Have you all sort of partition enabled? Just curious and of course most probably am wrong.


    Berni
    Quote Quote  
  17. Originally Posted by hello_hello View Post
    The same 5001 frames of video each time. Original resolution 720x480 and x264's default settings.
    --
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!