At several sites there has been concern expressed about HDCAM being in an EOL (End of Life) phase.

Folks are waking up to the fact that Sony was absolutely serious when several years ago their NAB theme was the "Welcome to the World of MPEG-2."

Naturally, we are seeing the same BS posted about "data rates" as appeared when HDV was first announced.

I'm in the process of writing the next installment of "Much More About 720p24 HDV" for the HDV@Work Newsletter. (The best option, as we approach NAB, is to subscribe -- it's free -- at www.videosystems.com).

However, in light of the panic that some are expressing at the thought MPEG-2 will replace HDCAM -- and likely DVCPRO HD -- here is the beginning of the coming story:


In the last Newsletter, we calculated that 720p24 HDV has an effective 46.8Mbps data rate verses the 36.9Mbps rate of 720p24 (24PA) DVCPRO HD. This calculation, which may surprise some, is a reminder that:

1) When an intra-frame codec writes a fraction of 50/60fps to a non-tape media, the format’s specified data rate must be reduced by this fraction. (720/24P DVCPRO HD verses 720/24PA)

2) You cannot compare inter- and intra-frame rate codecs on the basis of their data rates. You must factor-in inter-frame rate codec compression efficiency. (HDV verses DVCPRO HD)

3) Intra-frame codecs are compared by their "compression ratios."

4) Inter-frame codecs are compared by their "bit-rate reduction ratios."

5) The image quality of inter-frame codecs (HDV) cannot be inferred from their data rates unless you also take into account both frame size and frame rate. (1080i60 verses 720p30 HDV)

6) You cannot compare CBR and VBR inter-frame codecs on the basis of data rates. (HDV verses XDCAM HD)

Moved here from the HD100 forum.

I think there's two kinds of people, those who already understand exactly what you're saying and those that never will.

Actually, there's another two kinds of people: those who seek out 24P and those who really, really .... don't!

So ... um ... is that 4 kinds of people? Or are they all just the same people?

Sorry, it's late :)

You cannot compare inter- and intra-frame rate codecs on the basis of their data rates. You must factor-in inter-frame rate codec compression efficiency. (HDV verses DVCPRO HD)

Does interlacing have any impact on this? Looking at a frame of two fields that include motion, and thinking of the way that JPEG compression works (breaking up areas of image, using higher compression on areas of low detail, subdividing blocks to isolate detail, etc)... The 'fine-tooth comb' edges would add a lot more 'work' to the compression per frame. So, would a 60p MPEG engine be more efficient than a 60i engine?

Does interlacing have any impact on this? Looking at a frame of two fields that include motion, and thinking of the way that JPEG compression works (breaking up areas of image, using higher compression on areas of low detail, subdividing blocks to isolate detail, etc)... The 'fine-tooth comb' edges would add a lot more 'work' to the compression per frame. So, would a 60p MPEG engine be more efficient than a 60i engine?

I don't have anything to back it up but yes!

Hopefully Steve can give some data to help me back it up.

In the last Newsletter, we calculated that 720p24 HDV has an effective 46.8Mbps data rate

yes, there are indeed two kinds of people... those who subscribe to videosystems, and those who know better ;-)

Those are strong words Dan. Would you care to back up your opinion with an explanation, or do you think a cheap shot such as this, in a public forum, is adequate?

Ken, just for the record, there are much worse "cheap shots" on other public forums elsewhere on the web... as an example, just recently I've been amused by the most disgusting and slanderous allegations about me and the way that I choose to run this site. They're not worth repeating, nor worth pointing to, except to say that I was not at all surprised given the tabloid journalism aspect of that so-called "report" and the stultifying ignorance of the person who wrote it. Equally amusing is the dismal lack of traffic on that particular site, which is clearly indicative of its overall value, but that isn't surprising either.

Now I'll be the first to admit that DV Info Net is obviously far above such baseless tactics, and clearly we hold the moral and ethical high ground here, relative to the sort of trash which other online communities choose to propagate. So in a sense, yes, there's no doubt that we're to be held to a higher standard, to the point where Dan's humor at first glance might seem out of place. But look at it this way... if I can easily shrug off a few nasty barbs aimed at me (not too hard to do considering where they came from), then surely a writer for Video Systems can easily take a well-natured joke, correct? So let's please not escalate things or blow them out of proportion. Dan's jibe was harmless.

I don't subscribe to Video Systems either, but Steve's free newsletter is well worth signing up for.