Encoding time: What's the limiting factor?

[shaady]

When encoding video to VCD, SVCD, or any other format, what is taking the computer so long? What I mean is...what part of the computer is at it's maximum capacity? Let't treat the software as a constant and leave it out of the equation.

So what is it? CPU speed? RAM? HD speed/fragmentation? Something else?

I'm guessing it's the processor that tends to be the limiting factor.

[vitualis]

Definitely CPU.

Regards.

[gNOMEintheRedHat]

Yup,

Scanning a frame of video then compairing it to the previous frame(s) and the following frame(s) then determining what parts have changed, then determining the most eficiant way to encode the changes and move on to the next frame.

This takes a lot of horsepower....

My hat it of to the TMPGenc folkes, the quality of the finished video from their program is awsome.

gNOME

[xaanin]

Would say CPU, both speed and L1/L2 Cache probably makes a big difference. Also RAM could effect it if you have really low amount of it (heh like 32mb maybe, but then your CPU will be really slow also) =)

[tinycorkscrew]

As others have said, CPU is by far the most important component. TMPGEnc maxes out processor usage.

TMPGEnc doesn't use much RAM, but, as a previous poster said, if you have an extremely low amount, that could cause problems.

[hitechjunkie]

take it from someone needing a CPU/mobo upgrade real bad (currently AMD K6-3 350mhz), it's the CPU!!

[N0SoopForU]

Without a doubt the CPU.

[energy80s]

I was wondering about this myself. Being a "newbie" to the whole VCD scene, I have a very basic machine for video use (an AMD K6-2 500 with 64 meg of RAM). This is fine for audio editing (my normal pastime) but really slow for MPEG encoding of video material. I was thinking of upgrading to 256 meg of RAM as I thought it might increase the speed a bit, but if it isn't going to make much difference then I'll stick with what I've got until I can afford to update the whole motherboard/CPU/case setup.

[iant]

Energy80s,
Having the same basic machine ( AMDk62 500 ) I'd recommend you at least stick a bit more memory in. It will not necessarily speed up the encoding but Windows will page less and it will be more stable. Because it's paging less, you will see a slight improvement in the encode times. (But don't expect miracles. )

Besides, RAMs so darn cheap at the moment, it's still a worthwhile upgrade to throw 256 meg in just to kill the paging.
Have Fun,
Ian

[Vejita-sama]

Besides the CPU the filters you run make a huge difference as does the size of the encoded MPEG. That is encoded a 720x480 MPEG will take longer than encoded a 352x2480 MPEG.

Also resizing slows things down a lot! No filters I can convert a DivX file to MPEG2 w/ CCE on my Tbrid 1.2Ghz at 0.67x the source runtime. But creating the following AVS script file:

----------
loadplugin=mpeg2dec
avisource=xxxxxx.avi
bicubicresize(480,360,0,0.75)
temporalsmoother(2,1)
addborders(0,60,0,60)

slows it down to 1.8x the source runtime!