VideoHelp Forum

Our website is made possible by displaying online advertisements to our visitors. Consider supporting us by disable your adblocker or Try ConvertXtoDVD and convert all your movies to DVD. Free trial ! :)
+ Reply to Thread
Results 1 to 12 of 12
Thread
  1. Hi
    I see the word "lambda" used but I never understand what it means. (Apart from it being the 11th letter in the Greek Alphabet.) What's its history in terms of video-anything? Is it a type of codec, does it reference some kind of algorithm, is it specific to video editing...? What does it mean, what does it do, why that word instead of some other word...?
    Thanks
    Quote Quote  
  2. Banned
    Join Date
    Oct 2014
    Location
    Northern California
    Search PM
    Could be anything but in computing it is related to functional programming where the boundaries between data and functions on this data are watered down.

    Quote Quote  
  3. Where have you seen it?

    In video and image processing it typically used in rate distortion optimization (RDO) models for compression. It's not necessarily specific to video world ("lambda" is use in many fields)
    Quote Quote  
  4. Originally Posted by poisondeathray View Post
    Where have you seen it?
    Most recently over at http://avisynth.org.ru/mvtools/mvtools2.html .

    Is it just something people toss in as a space-holder, like 'foo' and 'bar'? X = this, lambda = that?

    It feels like one of those things everyone else is talking about familiarly, 'knowledgeably' in class, and I'm wracking my brains trying to remember if the teacher's ever actually just introduced it and given it a clear, crisp, fundamental explanation.
    Quote Quote  
  5. "lambda" doesn't necessarily have a specific meaning unless there is a specific context . It can be a variable that means something different in a different scenario

    In the mvtools context, it tells you what it means in the documentation. This isn't something taught in school. It could have just as easily been called "mike" or "david"

    You can visualize the effects of using different lambda values by using mshow() to see the motion vectors
    Quote Quote  
  6. Thanks, that's what I'd been wondering. That school reference was just an analogy for the feeling of confusion: Where'd "lambda" come from, how did it come to be a word used in so many ways when it doesn't seem to have any meaningful origin of its own that would explain its presence in these contexts.
    Cheers
    Quote Quote  
  7. I don't know the origins, besides "Greek"

    But it sure sounds "scientific-y"

    You can see it's used in many diverse areas, that have absolutely no relationship to one another. So if there is some historical relevance, many fields don't use that in their choice of using "lambda"

    http://en.wikipedia.org/wiki/Lambda
    Quote Quote  
  8. Yup. Another perfectly cromulent word!

    I like how Python uses it. "May as well call it lambda, I'm just going to throw it away anyway..."

    Thanks, all.
    Quote Quote  
  9. maybe "lambda" sounds better than "lamb-baaa"
    Click image for larger version

Name:	lambda.jpg
Views:	317
Size:	43.3 KB
ID:	28902
    Quote Quote  
  10. Oh great, so it's used in connection with RAM as well...
    Quote Quote  
  11. Member
    Join Date
    Dec 2005
    Location
    Canada
    Search Comp PM
    Ewe said it!
    Quote Quote  
  12. Member netmask56's Avatar
    Join Date
    Sep 2005
    Location
    Sydney, Australia
    Search Comp PM
    Way back when homosexuality was banned, a small medallion of the Greek letter lambda hanging on a golden chain around the neck was used to indicate one's orientation to others. So lambda has a very varied use......
    BeyonWiz T3 PVR ~ Popcorn A-500 ~ Samsung ES8000 65" LED TV ~ Windows 7 64bit ~ Yamaha RX-A1070 ~ QnapTS851-4G
    Quote Quote