Resolume Forum

Hi All

thanks to Wes for posting his info on codecs, i have done some basic testing with the PICmjpeg codec.
It seems to perform better than indeo in several ways.

1 - much better visual quality (less compression artefacts)
2 - smoother playback (indeo "stutters" a little)
3 - MUCH faster to encode

minor disadvantage is that it can't be keyframed (defaults to 1 key every 15 frames i think), however, still seems to trigger and scratch fine.

File sizes are about the same as indeo if you use a quality setting of about 18/20 (if you use 20/20 file sizes are about 4x bigger than indeo!)

It is not a free codec - though i don't imagine thats a big problem for most of you...

Supports all windows versions.

I have some gigs coming up soon, so will encode a bunch of files and post again to see how it performs in the mix.

peace

...sorry for the double post - had some web glitch

just bought it now i'm waiting to get my precious codec by mail ....

:o

cheerzZ!

>minor disadvantage is that it can't be keyframed (defaults to 1 key every >15 frames i think), however, still seems to trigger and scratch fine.

(I'm sure) This is because jpeg/mjpeg codecs by their nature 'keyframe' every frame. I think its that windows asks you by default no matter what.

"MJPEG is not the same as MPEG, although the names are confusingly similar. The primary difference is that MPEG [and most other codecs] provides temporal compression, while MJPEG only provides spatial compression."
http://www.siggraph.org/education/mater ... MJPEG.html

I'm not an expert, but as far as I know an mjpeg codec compresses each frame wholly (with a jpeg codec?), as opposed to 'traditional' temporal compression, where only the changes from the previous frame are recorded (thus significantly reducing filesize) with the exeption of the (complete) keyframes of course.

When you scratch or play a temporal codec (say cinepac) backwards your computer has to work backwards from the last keyframe to display each so-called 'delta' frame (Kind of like running up an escalator to ride back down). This takes up processor power and can cause slowdown and choppyness.

Because every frame is rendered whole, it is just as much effort for your machine to scratch or play an mjpeg backwards as it is forwards. I also find much less artefaction (?) from mjpegs and slow playing clips look better.

Mjpeg filesizes are a wee bit bigger and use up more prcessor power than a temporal codec simply playing forwards, but the consistency and quality are well worth it and any recent machine worth its salt these days should have no probs with mjpeg and Resolume 1.5/2

I use midivid jpeg codec which is free and provides me with great results on an rapidly ageing (XP2000+ 512MB Ati9200 2x7200rpmHDD) machine and again, its free - I'm sure the commercial mjpegs are worth it but you can't beat free sometimes...get it here

http://www.midivid.com/codec/jpegcodec.html

Like I said I'm no exert, so experts feel free to put anything wrong right...

Scott