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  1. Member
    Join Date
    May 2005
    Location
    Australia
    Search Comp PM
    Hello all,

    I'd like to use a histogram when capturing with AmarecTV. I have Graphstudio running to provide access to my Proc Amp on my GV-USB2 (thanks a million, Jagabo!) and would like to have a histogram.

    I'd be grateful if somebody could advise me how to set this up.

    Thanks!
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  2. With many devices can build a capture graph in GraphStudio then open that graph with AviSynth's AviSource() or DirectShowSource(). Then you can use AviSynth's Histogram() function to get live feedback while you adjust the proc amp. The exact graph varies from device to device. Search through these forums look for examples. I've been playing with a US$6 HDMI capture device that emulates a webcam. Here's an example using that:

    Image
    [Attachment 57964 - Click to enlarge]


    In that image you can see the simple GraphEdit graph (most capture devices will need a more complex graph) that's used both for capturing and for adjusting the proc amp. The AVS script looks like:

    Code:
    DirectShowSource("cap.grf", audio=false, framecount=100000) 
    BilinearResize(width/2, height/2) #  just make it smaller for this test
    TurnRight().Histogram().TurnLeft() # horizontal waveform monitor at the top of the frame
    ConvertToRGB(matrix="rec709") # the device is putting out rec.709
    MPCHC is playing that AVS script. When the proc amp is adjusted you get near realtime feedback in MPCHC (just a small lag which will depend on the device you're using).

    Here's a thread with some more complex graphs:

    https://forum.videohelp.com/threads/399547-Closed-Caption-capture-using-specific-hardware

    Those aren't for AviSynth monitoring but they may give you ideas about kind of filters you need to string together. Leave a video (and audio?) output pin open for AviSynth.
    Last edited by jagabo; 24th Mar 2021 at 06:52.
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  3. Member
    Join Date
    May 2005
    Location
    Australia
    Search Comp PM
    Thanks Jagabo, I'll check that thread out.
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