Faster MPEG Encoding

[Otter]

I am assuming that h/w encoder is the way to go to speed up MPEG encoding. I have't read extensively, but I got the sense that most of it was done as part of the capture. I am concerned that editing an MPEG-2 stream will be less precise than editing in AVI and then encoding. Is this correct?

Whats board / config for PC and Premiere? And no, I am not prepared to ante up for a G5....yet.

TIA

Otter

 

[pdoege]

This almost entirely depends upon what you are doing.

The video bitrate and physical size and the quality that you have selected make a huge difference.

The type of MPEG that you are using also makes a big difference.

In general, using MPEG2 4:2:0, a modern machine is faster than the last generation of hardware accelerators.

MPEG is very lossy. I would keep it in the original format, or in something like DV or lossless MJPEG and then dump it to MPEG when you are done.

Of course, if you have the ability to use I frame only 4:4:4 then you can stay MPEG2 all the way through.

Like I said, it depends.

Peter

PS. About the accuracy. A decent editing package can compensate for the MPEG GOPs.
PSS. about the hardware. The editing software that I wrote runs fine on p3 1Ghz boxes. A modern fast P4 makes it scream. That being said, I've never used Premiere.

 

[Otter]

pdoege once bubbled...
<snip>

In general, using MPEG2 4:2:0, a modern machine is faster than the last generation of hardware accelerators.
<snip>

Hmm..MaybeI should know this. What does the 4:2:0 notation mean?

 

[pdoege]

Hey Otter -

There is a lot of stuff to know about MPEG

Lots of info on the net.

Anyway, MPEG works by throwing away samples that people don't notice. A typical mpeg stream throws away half of all of the color info.

So, for every 4 brightness samples, MPEG typically only keeps 2 color samples. Hence 4:2:0 (The zero is transparency data....)

A very high quality MPEG stream keeps the samples around, so there are 4 color samples for every 4 brightness samples. This is written as 4:4:4

Peter

 

[Otter]

Thanks for the info. I don't ever remember seeing anywhere on TMPGenc or Premiere where I can set those parameters. I am usually burning < 1hr DVDs so I go with the highest bitrate possible -- usually VBR and 8MB. Perhaps the codec infers the proper b:s:t based upon that.

Otter

 

[pdoege]

I could be wrong. I cannot think of many packages that allow 4:4:4. It is sort of a rare option.

Peter