xdcam ex codec v.s. ProHd HDV codec

[Amos Kim]

I've had no experience or knowledge of xdcam ex codec but have experience with jvc hdv codec... can someone explain the advantages of the new codec over the old hdv? Let's say we compare the xdcam ex 19mbs to hdv 19mbs... what improvements would I see? Less compression? both 4:2:0?

thanks

[Tim Dashwood]

Originally Posted by Amos Kim

Let's say we compare the xdcam ex 19mbs to hdv 19mbs... what improvements would I see? Less compression? both 4:2:0?

These would be EXACTLY the same (assuming the JVC mpeg-2 encoder hasn't been tweaked.) They are both Mpeg2 long-GOP 4:2:0 at the same bit rate.
I assume the same GOP rules (6 frames for 24P, 12 frames for 60P) still apply.

The advantage of the new HM series is the ability to use the higher 35mbps bit rate.

[Amos Kim]

pardon my ignorance, but what difference would I see comparing 19mbs and 35mbs?

[Tim Dashwood]

Originally Posted by Amos Kim

pardon my ignorance, but what difference would I see comparing 19mbs and 35mbs?

Less compression at 35mbps so less undesirable artifacts and blocking.

I'll shoot some comparisons soon and post them.

[Sean Adair]

Originally Posted by Tim Dashwood

Less compression at 35mbps so less undesirable artifacts and blocking.
I'll shoot some comparisons soon and post them.

looking forward to some stressful examples!
720p 24 can be made to hiccup, but I expect a big difference at 720p 60 over 200 series.
Of course 35mbs is what opens up 1080p, which wouldn't be attempted at 19 or 25 mbs mpg2. I'd like to see how the 1080p 30 holds up to "stress" as well. Hope it's as clear as 720p 24 is at 19mbs!

[Justin Ferar]

The 720p60 at 35Mb is really the magic question here for me.

[Sean Adair]

Originally Posted by Justin Ferar

The 720p60 at 35Mb is really the magic question here for me.

Agreed! I also believe that the key to better performance than the HD200 series here isn't entirely a compression issue. The new chip and processing stage will hopefully be clean from noise in dark areas. Video noise is a challenge for compression algorithms, where ugliness gets magnified.