Blackmagic Intensity MJPEG vs. HDV - which uses more computer power to edit?
 

Say a person buys a blackmagic Intensity card ...

Which allows You to capture Motion-JPEG which is a much less intensive codec than uncompressed and is almost "visually lossless" - and looks better than HDV.

Preface; HDV- as we know is a lot of info to decode and thats why some of us use ASPECT HD which converts the HDV to Cineform codec to edit, allowing you to edit more streams of HD.

However, assume you don't have Aspect HD... but you do have an INtensity card In which case my question is;

Which will be more CPU computer intensive - editing HDV, or editing MJPEG codec ?? Which codec will allow you to edit more streams of HD?

PS: ofcourse the computer bing used is a factor, but what if its a new system with a Quad core Intel processor or Quad AMD processor and 4gbs of RAM.

The objective of the Black Magic Intensity card is to allow " Non-Compressed" video streams to be offloaded from your camera via the HDMI port...

A true non-compressed video stream without any compression at all would be too large for your computer to handle... so Black Magic instead uses one of the next best codec's... MJPG... a slightly compressed format

The other next best codec is cineform AVI intermediate, Cineform does the same thing but they use a wavelet form of file compression that also slightly compresses the stream so your computer can handle it...

both claim to be visually lossless, but Cineform's wavelet technology seems to edge MJPG out...

the bigest issue with editing HDV is due to long GOP schemes.... this is where the camera sorta bursts out the footage in spurts of footage...

its a hog on CPU performance....

Cineform seems to be the least CPU intensive...

Most to Least list
 

Please list these in order of CPU intensiveness:
FROM MOST INTENSIVE to LEAST:

1-Uncompressed HD
2-HDV native
3-Motion JPEG
4-Cineform HD
5-DV/DVcam SD




Can anyone confirm Is this list correct?

I think you have them in the correct order... the first one, non compressed
is more strengent on the hard drives and gives the impression that it alone is what is causing the CPU issues...

If you only want to know the impact on the CPU, Uncompressed HD is probably about even with SD DV/DVCAM but that won't give you any idea on the impact on the whole system. Uncompressed is easy on the CPU as there is no compression/re-compression when doing an operation, but it will choke your I/O subsystem.

HDV is probably the hardest on the CPU but it is easy on the I/O. The intermediate codecs bring the I/O down to a manageable level but I have read that with some software that HDV editing has been streamlined in the code enough that it is as fast as the intermediates.