GOP Size, DC Precision

[Skunk]

I did a few searches and I'm sorry, but I can't find answers to this question. What exactly (in laymans terms) do "GOP Size" and "DC Precision" do, and when should I use them?

Also, I just learned about "dynamicaly assign bitrates". It sounds like I should be using it, but I dont see it anywhere in RC5. Is it the default now, or am I just missing it?

EDIT - Typos

[jdobbs]

It is no longer an option -- it is always used. There never really was a time that is shouldn't have been used, but when first I coded it I wanted there to be a way to back out in case something was wrong with it.

[Trahald]

GOP = group of pictures.. a gop contains a reference picture ( basically a single lossly compressed picture that can be decompressed without reference to any other frames akin to a .png or .jpg) the other pictures(frames) are based upon the first picture which allows them to be smaller but they cannot be decompressed without the frames leading up to it. a group of pictures is about 12-18 frames. in dvd the length limit of a gop is about .6 seconds worth of frames. (omitting some detail to make it semi easy to read)

dc precision i'll leave to someone else .. i dont fully understand it enough to put it into laymans terms. generally higher dc precision (10 bits is max for dvd) will make an image more like the original but requires more bitrate. 8 (min for dvd) is used for lower bitrates found more in svcd use.

[Skunk]

ummmm. ok. lol. sounds like the answer to "when should I use them" is never. I dont think that based on what you told me my video quality will really be affected by messing with these options. :D