VideoHelp Forum
+ Reply to Thread
Results 1 to 11 of 11
Thread
  1. Member
    Join Date
    Dec 2010
    Location
    quebec
    Search Comp PM
    i read a thread here where during the capture process one can tweak the brigthness and color

    i searched for that specific thread but i can seam to find it

    i notice that when i play my vcr *hr-s5800u* throught my pc (ati aiw ve) via s-video

    the colors look a little pale

    should i tweak it a little during capture or leave them
    and tweak later on (avisynth maybe or the mpeg encoder)

    i have lordsmurf's virtualdub version where i notice that in the proc amp settings (i think it's in the WDM driver) everything is at defaults (128) except the sharpness (201) should i keep it that way ?

    i find virtualdub's proc amp ajustment so much easier that avisynth
    that would be so much easier for me .. is there some things i should watch out for while teaking ?

    i plan to capture huffy (yuy2) and encode for dvd (avstodvd)

    jvc hr-s5800u > tbc-1000 > all in wonder ve all with s-video

    thank you for your time
    Last edited by smartel; 17th May 2011 at 14:01.
    Quote Quote  
  2. Member
    Join Date
    Dec 2010
    Location
    quebec
    Search Comp PM
    will these proc amp tweaks have an influence on the capture ?
    Quote Quote  
  3. If you have tapes with color bars it's best to experiment with that
    Try with the values below but it might not be optimum, cards have different minimum/maximum values in general
    brightness: + 11 units (or 18 max)
    contrast: no change
    sat: -1 unit
    hue : +3 units (or 7 max)

    For ntsc vhs tapes only
    *** DIGITIZING VHS / ANALOG VIDEOS SINCE 2001**** GEAR: JVC HR-S7700MS, TOSHIBA V733EF AND MORE
    Quote Quote  
  4. Originally Posted by smartel View Post
    i have lordsmurf's virtualdub version where i notice that in the proc amp settings (i think it's in the WDM driver) everything is at defaults (128) except the sharpness (201) should i keep it that way ?
    Not if your video needs to be adjusted.
    Quote Quote  
  5. Member
    Join Date
    Dec 2010
    Location
    quebec
    Search Comp PM
    they don't have color bars on them
    so i guess i'll go with the best skin tones or natural items (sky , grass etc ) for reference
    i'll capture the tapes by content not whole tapes
    but i guess that the tape recorded with the same machine should have the same balance all over
    with each particular tape
    Quote Quote  
  6. It's possible to fix after the capture process (unlike i see writen often) , take a look capture ; reference ; result (tweaked with avisynth)
    If you pay close attention to the histogram they match almost perfectly after my little tweaks.

    In my (little) experience tweaks on the fly will not give satisfactory results especially for the phase (hue) there always will be one or two colors not correcly phased, not by a mile but still...And indeed each tape is different to complicate the things further (i have verified this myself as i have tapes with color bars 3 at least , each is different, for the phase mainly slight changes but they're here)
    *** DIGITIZING VHS / ANALOG VIDEOS SINCE 2001**** GEAR: JVC HR-S7700MS, TOSHIBA V733EF AND MORE
    Quote Quote  
  7. Member
    Join Date
    Dec 2010
    Location
    quebec
    Search Comp PM
    well ,, seams that tweaking on the fly would give me just another sets of problems

    so i guess that i'll have to tweak anyway , so tweaking just one time after the capture should be more than enough

    is their an avisynth script that i could just import into avspmod that would give me those kind of sliders ?
    (i just bassically use existing script cause i'm very dumb and lazy with avisynth)

    and since my tbc-1000 is also a kind of distribution amplifier wouldn't it give me a better signal with less fainted colors ?

    and a friend of mine has an handycam DCR-HC20 , it doesn't have a tbc i think,
    but would this help me if i worked into dv format instead of avi ?
    Last edited by smartel; 18th May 2011 at 20:55.
    Quote Quote  
  8. Here is my script:
    LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\VideoScope\VScope.dll")
    ################################################## ################################################## ################################################## ############
    function int2mode(int index) { return Select(index, "classic", "levels", "color") } #for HISTOGRAM
    Avisource("C:\MyVideo.avi", fourCC="LAGS", pixel_type="YUY2").trim(20,26) # fourc= HFYU for huffyuv / pixel_type: YV12,YUY2,RGB32/24 / trim for image range
    AssumeTFF # for interlaced content, top field first
    Tweak(3.0,0.9,-7,1.0,coring=false) # For hue, sat, brightness, contrast modifications
    ConverttoRGB32(matrix="rec601",interlaced=true)
    separatefields() # to separate the fields (interlaced content)
    LoadVirtualdubplugin("C:\Program Files\VirtualDubMod\plugins\Hue.vdf", "hsi",1)
    hsi(-1, 1, 3, 0, 1) # Red (primary color)
    hsi(1, 1, 0, 0, 4) # Blue (primary color)
    hsi(0, 1, 5, 0, 2) # Green (primary color)
    hsi(0, 1, 7, 0, 32) # Magenta (secondary color)
    hsi(0, 1, -4, 0, 8) # Yellow (secondary color)
    hsi(1, 1, 1, 0, 16) # Cyan (secondary color)
    LoadVirtualdubplugin("C:\Program Files\VirtualDubMod\plugins\colormill.vdf", "colormill",1)
    # Colormill for highlight (Levels)
    colormill(25700, 25700, 25700, 25700, 23396, 28513, 25700, 25700, 25700, 25700, 25700, 25700, 25700, 1124, 5) # Gives good results with my tapes even for I Q components
    weave() # for reinterlacing the fields
    ConverttoYV12(matrix="rec601",interlaced=true)
    #Levels(7, 1.000, 255, 0, 255, coring=true) # can tweak the levels if needed
    ColorYUV(analyze=true)
    Histogram(int2mode([<"HistogramMode", 0, 2, 2>])) # Histogram with Slider / You can pick the mode (0,1 or 2)
    ConverttoYUY2(interlaced=true) # for VIDEOSCOPE
    VideoScope("both", true, "Y") # Videoscope
    You have to download the filters colormill and HSi (hue, saturation, intensity) for virtualdub and also the videoscope filter for avisynth Here

    If you wanna tweak the hsi and colormill values i suggest you do that in virtualdub, save the .vdf and open the .vdf with the notepad then copy/paste the values in the avs script. If you do that you might wanna ignore (put a #) all lines after the converttorgb32 line.

    Good luck
    Last edited by themaster1; 18th May 2011 at 22:11.
    *** DIGITIZING VHS / ANALOG VIDEOS SINCE 2001**** GEAR: JVC HR-S7700MS, TOSHIBA V733EF AND MORE
    Quote Quote  
  9. Originally Posted by smartel View Post
    they don't have color bars on them
    so i guess i'll go with the best skin tones or natural items (sky , grass etc ) for reference
    Most important is to get the black and white levels close to right -- and definitely not crushed at either end. You can always darken the dark parts or lighten the light parts later. But if the darks or lights are crushed you can't restore any detail there.
    Quote Quote  
  10. Member
    Join Date
    Dec 2010
    Location
    quebec
    Search Comp PM
    ohh yeah !! i'll try to digest all of that , maybe tomorrow if i find time

    i just captured a 1989 vhs tape and the colors seamed fine ,
    i guess it depends on the quality of the source original tape (polaroïd)

    i'll cut it into segments , was taped in 6 h mode ..

    the first fourth of the tape was kinda crappy , with tracking errors

    i may search for multiple capture averaging if it helps ..
    i also have a couple of players that i could bring back to life

    and yes , vhs capturing is lots of work , lots of trial and error

    and thanks for your help
    Quote Quote  
  11. Regarding the levels (all simulated images):

    Say you record this levels chart with a VHS deck:
    Click image for larger version

Name:	orig.jpg
Views:	525
Size:	12.7 KB
ID:	6843

    If you capture with too much contrast, the darks are too dark, the brights are too bright:
    Click image for larger version

Name:	crushed.jpg
Views:	447
Size:	31.6 KB
ID:	6844
    All the darker bars are completely black and all the lighter bars are completely white.

    You can't restore any detail in those bars by filtering later on:
    Click image for larger version

Name:	crushed_fixed.jpg
Views:	584
Size:	25.6 KB
ID:	6845
    Note how the bars around 50 and 55, and 200 and 205, are now restored to nearly their original brightness. But the bars from 0 to 30, and 225 to 255 are gone. There is no way of getting them back.

    On the other hand, if you record with too little contrast:
    Click image for larger version

Name:	low_cont.jpg
Views:	452
Size:	44.8 KB
ID:	6846
    Note how the blacks aren't very black and the whites aren't very bright.

    You can stretch the contrast back out by filtering later on:
    Click image for larger version

Name:	low_cont_fixed.jpg
Views:	479
Size:	35.0 KB
ID:	6847
    The levels aren't exactly right, and noise is accentuated, but you can see the darker and lighter bars.
    Last edited by jagabo; 19th May 2011 at 08:46.
    Quote Quote  



Similar Threads

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