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  1. I am a bit confused about how Filtering and Converting Format (with filter) works with VirtualDub.

    Now, the source is RGB, and i want to add a filter that is a timestamp overlay, namely "addframenumber.vdf".

    This seem to work in RGB32.

    Now i later want to convert this to YV12 with Rec.601, which i am guessing is the one that says "Convert to YV12", as the other ones namely say Rec.709.

    For this to work, i must also check the "Skip 24-bit conversion", else it will stay in RGB32.

    So, basically, how does it all work, it's a pretty good mess compared to simple Avisynth, which i can, but don't want to use in this particular scenario, as it's just a wasted extra step.

    Thanks
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  2. Member PuzZLeR's Avatar
    Join Date: Oct 2006
    Location: Toronto Canada
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    But why don't you just use AviSynth? It's so much easier showing the channels separately, converting each, filtering each, then merging them (info around the 'Net if you search).

    Now, I love VirtualDub, but I too am confused about its inner workings here, and yes it is a real mess regarding RGB32/RGBA/RGB24/etc and never have any clue as to what version does this or that, so I don't bother with it. For example, Your overlay works with RGB32 because of the alpha channel, but have no clue what's going on under the hood of VirtualDub with RGB32 or RGBA or any conversions or whatnot.

    Unless someone has a solution to this, I believe you're better off using AviSynth.
    I hate VHS. I always did.
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  3. The thing is that this is a Realtime conversion, the overlay is a Timestamp added to a recording, so this can't be done at Avisynth afterwards (at least not as easy).

    And then i simply save this, but saving it as RGB takes up twice the space to YV12, and i usually stockpile these, and then batch encode them.
    And having RGB will just makes me have to batch encode twice as often (Yes i am lazy;P).

    So i simply want to make that conversion automatic.

    So no fancy stuff just, Source RGB - > Add Time Stamp (RGB32) -> Convert to YV12 -> Write to .Avi

    And i am happy
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  4. VirtualDub uses rec.601 by default.
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  5. Okay, then that's out of the way.

    Now, the problem is Upsampling and probably Dowsample, and the "Skip 24-bit conversion" which i have no idea what it means.

    I guess if the Source is RGB, and the first filter (at top) is the Timestamp, it will upsample to RGB32, which doesn't really alter anything as RGB32/24 are identical except the alpha channel, and then just put Convert To YV12 under that, it will simply to a RGB24 -> RGB32 -> YV12 conversion at Rec.601.

    But the Skip 24-bit conversion is what's bothering me, i know that if i check it, i will get YV12 if i choose that format last in the filtering list.
    If i don't check it, it will be RGB32, which doesn't make much sense to me.
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  6. Member PuzZLeR's Avatar
    Join Date: Oct 2006
    Location: Toronto Canada
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    I see what you mean, and can't help you with any shortcut. Like I said, VirtualDub is a mess when it comes to this. Even Avery Lee himself is all over the place with it in different versions.

    Personally, with huge HDD space today, and i7 processors, the "long way" (such as with multiple conversions instead of less) is not "so long" anymore. Actually, contrary to you, I consider this the "lazy" way since I couldn't bother figuring it out.

    Hopefully someone else has an answer to your liking.
    I hate VHS. I always did.
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  7. RGB 32 from RGB 24 is not really an "upsample". It's simply adding an 8 bit alpha channel. The original RGB values are intact.

    By the way, VirtualDub can show you the colorspace each filter is working in. Enable the Show Image Formats option on the Filters dialog.
    Last edited by jagabo; 2nd Jun 2014 at 10:48.
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