Attn.: Jan C. – AJ-SPC700 Questions

[Toke]

Hmmm…

I’ve been one decade in impression that dv has field based compression in its codec.
In many NLEs you can even choose which field to preview or both.

So these fields are compressed individually and separately.

If the reverse-pull-down software coder understands this, I see now reason why to touch the compression inside a field. With reverse pull-down you are dropping fields away, not touching the content of a field.

So if you have to decompress fields to change their order, that’s only a very bad programming.

[Graeme Nattress]

I think in the decompression you can choose to only decompress one field, or even just do a rough / fast decompress, but I don’t know if there’s a way to extract the raw data from one field and combine that with the raw data from the other field and create a new frame from them. It would certainly be nice if you can, but again, I go back to my point earlier that 24pA a) avoids this issue entirely, and b) is easier as the frames are flagged.

Graeme

– http://www.nattress.com – Film Effects for FCP

[Deleted User]

Hi Jan. First off, thanks again for your detailed reply. I hope your boss realizes your spending time with folks online is worth millions in terms of sales! 🙂

[Jan Crittenden Livingston] “… Actually since the majority of the 24P NLEs now get the 2:3:3:2 removal on the fly, you may get looks that are analogous to having two heads. Like, what do you mean this camera doesn’t do 24PA? that is dumb. Even Sony’s Vegas does 2:3:3:2 removal. …”

Yes, my thoughts exactly. The next thing I’m going to do is attempt to get some sort of confirmation from Sony concerning whether the DSR-450WS really does operate the lame way it seems to in regards to 24p. I agree with Jan (she’s not biased in any way, is she? >grin<): Sony has had 2 or 3 years to get with the program regarding how to handle 24p. If it's true their newest, redesigned, top-of-the-line DVCAM camcorder really does handle 24p only in the most basic "standard" way, and not also offer advanced pulldown, then I stand by my description of Sony as "dumb*ss". I'll call Sony tomorrow and see what they have to say. [Jan Crittenden Livingston] “… >Peter wrote: The AJ-SPC700 is much less expensive than the $18K Sony DSR-450WS, and I’d primarily record the AJ-SPC700’s output via Firewire to a Sony GV-D1000 “DV walkman” portable recorder.< But you would be relegating the camera to DVCAM level? it is a DVCPRO50 camcorder, why do 4:1:1 when it can do 4:2:2? ..."

For most of my work (longform corporate video), DV25 4:1:1 is all my current clients want/need/will pay for. My clients (present & future) may eventually want DVCPRO-50 4:2:2 — hopefully sooner rather than later — and the AJ-SPC700 & other Panasonic cams give us that option. However, DV25 4:1:1 is my bread & butter. Periodically I’d take advantage of the AJ-SPC700’s DV25 & DVCPRO-50 P2 capabilities and Firewire interface with external devices on special projects initially, and with increasing frequency going forward.

However, I’d be _much_ happier if 24p and an SDI output option was offered for the AJ-SPC700. I could use SDI to record 4:2:2 to a wider array of external devices. But Jan has indicated these features are not available for this cam model. Sigh. 🙁

[Jan Crittenden Livingston] “… You should take a few minutes and down load the operations manual on the SPX or even the SDX … Take a look a the SDX900 website and spend a few minutes looking at the downloadable scene file area … You could probably get closer to your price on a demo SDX900. And then there is the Goodman’s Guide to the SDX900, which by far is the best book written on working with the digital cameras …”

Believe me, if I could afford complete AJ-SPX800 or AJ-SDX900 camera systems — even demo units — I wouldn’t hesitate. But my near-term need for DV25 tape (and 2/3″ CCDs & lenses) may unfortunately out-weigh my somewhat lesser need for 24p.

That’s why it’s so frustrating that the AJ-SPC700 doesn’t do 24p. If it did, with the addition of a $1,000 miniDV portable recorder, I’d be “done”.

I’ll let you know what Sony has to say for themselves.

Thanks to all for a very helpful discussion of these issues. It’s _so_ refreshing to participate in a dialog about Panasonic & Sony products without people (shills?) screaming & yelling. Thanks! 🙂

All the best,

– Peter

Just a friendly reminder to all: Please consider filling-in your COW user profile information so we have a better idea who you are, where you’re from, and so forth. It’s the friendly thing to do. Thanks!

[Toke]

[Graeme Nattress] “I don’t know if there’s a way to extract the raw data from one field and combine that with the raw data from the other field and create a new frame from them.”

What’s there to combine?
Dv-stream is field based. It’s just field after another. All you have to tell the software which field is upper or lower.
When you drop fields away you don’t even have to change the order of remaining fields.

[Graeme Nattress]

I can only get the quicktime API to give me frames of video, no matter what the codec, not fields. Perhaps if you want to access the raw DV stream with your own code you might be able to do that, but that’s not a very easy way of working. If you can only access frames, you have to be able to combine a field from one frame with a field from the next to recreate the frame.

Graeme

– http://www.nattress.com – Film Effects for FCP

[Toke]

Limitations of quicktime always amazes me.
So with qt you really have to decompress fields to one framme for combining two fields from different frames
to be new one frame?
Apple hasn’t cared a lot about picture quality past days…
Their mp4 encoding is propably worst in a planet…
So they never understood interlacing…

[Deleted User]

Jan: How does one go about acquiring a B-Stock or Demo SPX800 camcorder? Do I go through a Panasonic dealer, or is there a more direct channel? Pricing & availability?

And can you put in a good word for me? 🙂

All the best,

– Peter

Just a friendly reminder to all: Please consider filling-in your COW user profile information so we have a better idea who you are, where you’re from, and so forth. It’s the friendly thing to do. Thanks!

[Jan Crittenden livingston]

Hi Peter,

Just contact me of line, let me know where you are geographically, and we will go from there.

Best,

jan

Jan Crittenden Livingston
Product Manager, DVCPRO, DVCPRO50, AG-DVX100
Panasonic Broadcast & TV Systems

[Deleted User]

[Jan Crittenden Livingston] “Just contact me offline, let me know where you are geographically, and we will go from there.”

Thanks, Jan, but I don’t have your contact info (it’s not in your COW profile).

Do you work in Panasonic’s offices in Secaucus, NJ?

My contact info is in my COW profile (I’m in the SF Bay Area, zip 94530).

Thanks again for your assistance,

– Peter

Just a friendly reminder to all: Please consider filling-in your COW user profile information so we have a better idea who you are, where you’re from, and so forth. It’s the friendly thing to do. Thanks!

[Jan Crittenden livingston]

Hi Peter,

My email address is in my profile and yes I work in our Headquarters in NJ. Phone calls are expensive and frankly I get too many of those anyhow, which is why I do not list that. Just send me an email. But now that I have a hint as to where you are, let me see what I can do, but please send me an email with your contact info in it and I will send it along to my guy in the SF area.

Best,

Jan

Jan Crittenden Livingston
Product Manager, DVCPRO, DVCPRO50, AG-DVX100
Panasonic Broadcast & TV Systems