XDCAM EX codec, any artifacts?

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DanHD

Well-known member
I've only had one day of experience with this camera, but I'm going to be using my buddy's EX1 to shoot a promo for his school's football team. I'm filming during a night game, so I needed the lowlight performance, and I really need the resolution for this one.

I know HDV goes crazy with a ton of random motion on screen. I've seen a bunch of artifacts and horror stories and all that.

Now I know XDCAM EX uses a similar LongGOP compression, and it probably has the same motion prediction algorythyms as HDV, but still

how well does it stand up against motion? Pans? ect.

I'll be doing many pans, tracking on fast moving players, ect

I've that once the information coming in overloads the codec and exceeds the bit rate, the EX1 starts sacrificing resolution and all that. and you get "low res pans"

As EX1 owners and operators, you guys know your camera, so have you had ANY issues with the codec itself?

Or should I include the rental of an HPX500 in the budget and spend a little more for intraframe
 
If you're worried about fast motion pans causing CMOS artifacts or the XDCAM codec giving up a bit for motion, rent the HPX500.

Having said that, if you've ever shot HDV the XDCAM HQ 35mbps codec is better than HDV. You can shoot HDV (25mbps codec) on the EX by selecting SP mode.

I've never shot anything less than 35mbps on the EX1. I'll bet the EX1 works fine for your night game. About a year ago, I posted night soccer game footage that looked fine.

With this type of shooting, it's better in a multicamera shoot where you can get tighter with the action instead of staying near the tele end of the lens.
 
I shoot on F350s all the time in 35mbps mode and have NEVER EVER "broken" the codec. I have shot almost everything, including sports at night.

It has similarities to HDV, but this is a professional codec for sure.
 
brianluce said:
Is the purpose of SP mode to merely have longer record times?
Click to expand...
And to be compatible with HDV.

The EX 35mbps codec is more robust, as compared to HDV, than the mere difference in bitrate would suggest. In 720/60p or 1080p it's pretty darn solid. In 1080i, that's the most susceptible to image artifacting. So you'll have to determine based on what you're shooting; if you're planning to put it through challenging circumstances and do so in 1080i mode, you might want to test it so you know what you're really getting into. But if you're using 720p or 1080p mode I think you'll be fine in most any rational circumstance.
 
In what ways does XDCAM differ from HDV, besides the obvious differences (full raster, 35 vs. 25, no resolution subsampling, ect)

Is the LongGOP compression more efficient and advanced with more motion prediction and everything?

Because it was real easy for me to "break" hdv. Why is it harder to get poor results out of XDCAM EX?


(pardon my questions i'm not too familiar with sony formats/codecs)
 
One thing that has yet to be mentioned is the fact XDCAM at 35mbps has a VBR where as when its at 25mbps its got a CBR. This helps a lot.
 
1st: 40% more avaliable encoding data per second
2nd: 33% more pixels
3rd: Highest quality 6th generation MPG2 encoding technology (not all MPG is created equal even for the same data rate)
4: VBR vs CBR: Not sure how much the XDCAM EX is willing to go above 35Mbps using VBR. If it doesn't (ie 35Mbps is the peak), then VBR only helps to reduce file size, not improve quliaty over 35Mbps CBR.
 
Thats the info I was looking for, thanks. Out of interest, is this a published spec somewhere of just what someone told you?
 
It's been posted before..
But, you can check the bit rate yourself by using VLC media player and while playing back an EX1 mp4 file select:

Tools>Codec Information>Statictics
Look under "Input": "Stream bitrate"

It depends whats playing, but mine just hit over 40,303kbps (40mbps). It never goes below
35mbps.
 
Ok, so it is VBR with a min of 35Mbps and peak of 40Mbps. I wonder what the 'average' is set too.
 
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