ErMac HELP! Huffyuv 3GB output

ErMaC · Post by **ErMaC** » Fri Jul 19, 2002 8:57 pm

Neo-Matrix wrote:but my source material was encoded in dv AVI. i have been told many times that AVI is NOT COMPRESSED!!!

Then whoever you were talking to is an ignorant fool. Read my video guides for an explanation of video compression.

Neo-Matrix · Post by **Neo-Matrix** » Fri Jul 19, 2002 9:24 pm

well what IS UNCOMPRESSED? ill read ur guides and stuff again i guess, see if i missed anything. then encode on my brothers brand new computer.

klinky · Post by **klinky** » Fri Jul 19, 2002 10:00 pm

To understand what uncompressed means you have to go way way back to the very basics.

Uncompressed video is a bunch of uncompressed bitmap images. A bitmap is a uncompressed picture. If you open up MS Paint and draw a picture then save it as a BMP file then you have a bitmap there.

Most bitmaps are 24bit per pixel. So for every pixel of that image it takes 24bits. 8bits = 1byte. So that's 3bytes per pixel.

If you're working with something like DV, that has a resolution of 720x480, then that's 720 * 480 * 24bits = 8294400bits. Divide that by 8 which equals 1036800bytes, divide that by 1024, which equals 1012.5KiloBytes. Now 1024Kilobytes is a megabyte. So that single image there is nearly 1MB!!!!

Now to get fluid motion, you need to have a series of these images going at atleast 24 frames per second. So now you multiply that 1012.5KB * 24 and you have 24300Kilobytes(nearly 24.3MB) per second!!!

You take a three minute long video at 24.3MB per second and you get 4271.4MB! or well over 4GB.

So uncompressed video is huge. Now I believe the FFX videos are encoded in MPEG2, which is quite lossy and removes quite a bit out of the original image. Most of the stuff it removes is stuff you can't see.

DV I believe is a variant of mpeg2. So it's not much different.

AVI is just format that explains how data should be structured in the file, it does not explain what data goes into it, that's the job of the codec.

~klinky

RyanGlazner · Post by **RyanGlazner** » Fri Jul 19, 2002 10:07 pm

*bows in Klinky's direction* You've made it all so clear! 8)

Mechaman · Post by **Mechaman** » Sat Jul 20, 2002 1:21 am

DV is actually related more to MJPEG.
DV is meant as a editing codec, while MPEG2 was always intended as a production codec. As such, while both are lossy, DV is not nearly as lossy between generations as MPEG2, in addition to every frame being a keyframe. So that's why it's encouraged to work in it if your footage is already DV.

There's no real benefit transcoding to HuffYUV. Huff can't restore anything lost in the DV encoding, so all you'll gain is your aforementioned increase in diskspace, for the same quality footage.

RadicalEd0 · Post by **RadicalEd0** » Sat Jul 20, 2002 1:51 am

DV compresseses by about 5:1, huffyuv gets about 2:1 in rgb mode and 4:1 in yuy2 mode. I don't know too much about DV, except that its fixed to either 720x480 @ 29.97 fps or 720x576 @ 25 fps and at a datarate of.. er.. whatever 5:1 of uncompressed is (im too tired to do that much calculating now _ _)
I know it uses an advanced version of the DCT used in jpeg and mpeg 1/2, but my vast knowledge borders on that part of DV ('sides, I don't use it after all)

klinky · Post by **klinky** » Sat Jul 20, 2002 3:55 am

Mechaman wrote:DV is actually related more to MJPEG.
DV is meant as a editing codec, while MPEG2 was always intended as a production codec. As such, while both are lossy, DV is not nearly as lossy between generations as MPEG2, in addition to every frame being a keyframe. So that's why it's encouraged to work in it if your footage is already DV.

There's no real benefit transcoding to HuffYUV. Huff can't restore anything lost in the DV encoding, so all you'll gain is your aforementioned increase in diskspace, for the same quality footage.

I was wrong....

I don't have any use for DV at the moment since I don't have a capture card nor a camera :p So I really don't know much about DV.

Thanx for englightening me

Neo-Matrix · Post by **Neo-Matrix** » Sun Jul 21, 2002 3:35 pm

well screw huffyuv i encoded my 3.7gb uncompressed with tmpgenc and its now 64mb and it looks great full screened. thanks i dont need anymore help now. i should have my video up this week it will be called FFX - Whatever it Takes watch the announcements for my vid if ur interested.

AbsoluteDestiny · Post by **AbsoluteDestiny** » Sun Jul 21, 2002 5:06 pm

Neo-Matrix wrote:well screw huffyuv i encoded my 3.7gb uncompressed with tmpgenc

somehow I dont think you understand what "uncompressed" means. You got to the end but you completely lost the plot along the way.

...try reading the guides and actually understanding what you are doing - it's an edifying experience.

FirestormXIII · Post by **FirestormXIII** » Sun Jul 21, 2002 5:23 pm

Mmmm, edible experiences...