I just read an article in the May issue of DV magazine about HDV and it was a bit depressing: the article basically says HDV will exhibit generation artifacts over repeated dubbing of only a few times, that motion artifacts are evident in "high frequency detail and/or abrupt complex motions" and that these cause "noticeable degradation in the form of poserization, blocking, and psuedo-random noise." Adding that "HDV's artifacts can permeate the entire frame."

Finally, when talking about dubbing your edited program back to HDV "shows more artifacts than the camera original does".

How expensive are small sized HD monitors anyway? Monitor issues are another whole ball of wax...

"that motion artifacts are evident in "high frequency detail and/or abrupt complex motions" and that these cause "noticeable degradation in the form of poserization, blocking, and psuedo-random noise." Adding that "HDV's artifacts can permeate the entire frame."
"

This so far this problem has only been mentioned in regards to the 12GOP interlaced cams.
The problem with "generalizing" HDV is that they are doing so using only two cams. The progressive JVC HD1/10 made two years ago, and the recent Sony FX1/Z1 interlaced release. Imagine if someone generalized DV after the first two cams were released.

Not only that, but because of the nature of the HDV compression, results can vary dramatically based on workflow. It's pretty easy to reduce the quality of the footage to zero if you lack an understanding of generational losses etc... so it really depends on who the author is.

-Steve

I have always edited in native format (JVC-KDDI, MSP), and I have never seen anything like that described. Artifacts are WAY below that seen on broadcast. And even then I prefer that to SD television.

At Best Buy recently I saw a 27" (I think) monitor in the TV section (not computer) that was at least 1280 x 720 LCD panel. This was Westinghouse (a name I didn't expect to see). It was as good as the best on display, and was the lowest priced - $890 as I recall.

I agree with Stephen. IT is very easy to totally mess up an MPEG file with the wrong work flow/computer system. IF by dubbing they mean copying then HDV is a data stream and should have no degradation in copying at all. So this comment alone makes me very suspicious of the author. For your information a PC that is only just capable of decoding a HDV image for display will find it difficult to capture with any of the programs that have a preview screen and will likely only be able to capture a m2t native file ( which is 25mbs just like DV) For instance on my AMD XP2500 I have to capture native m2t with capDVHS, then import into Edius Pro 3 ( HDlink from Cineform will also do this capture). Any attempt to capture using Premiere Pro 1.5.1 which simultaneously encodes to the CFHD intermediate codec will result in blockies and other defects in the data stream aand in my case system just locks up with not enough power!!!!. The question is how powerful a machine can ensure that there are no defects on capture? Having had this problem with my admittedly low power PC and will continue to adopt the same approach latter this summer when I get a dual core PC and then encode to intermediate afterwards for editing if needed.

Ron Evans

The author is Adam Wilt. Perhaps the best known and most respected DV Guru around. It's a positive review, he just points out the limitations inherent in the format, along with it's strengths. I think it's an excellent article, worth reading before discounting.

IF by dubbing they mean copying then HDV is a data stream and should have no degradation in copying at all.
Ron, the author was talking about recording the edited program (timeline) back to tape, and that the generationl loss was a result of essentially recompressing because of the HDV compression scheme. He was saying that HDV compresses at 32:1 to start with, then dubbing it back to tape results in yet another 32:1 compression. Ouch!

I have just found and read the article and it is very good as usual from Adam. I was thrown by the use of the word dubbing which I could not find in the article. To me dubbing is copying. Generation loss was the only comment I could find Adam was talking about, this is repeated decode for editing on the computer and then re-encode to MPEG----absolutely agree, which is why I made my comment about work flow as being even more critical than DV. Adam even made similar comments about the high power requirments for the PC. In my 5 months with my FX1 I am almost convinced that staying in native m2t may be the answer for highest quality even editing with a proxy then final render with the source HDV m2t, to absolutely limit the generation losses as Adam points out. For a lot of people this will mean a different work flow to what they are used to now. My interest is using HDV to create a multi camera 4x3 SD output mixed with DV camera video. That is, just two cameras on a shoot could look like many after editing. In Edius it is possible to use the Layout ( Motion in Premiere) feature to crop 4x3 image from the HDV frame and in experimenting with this I found it just as easy to scrub the timeline using the m2t file and as long as I didn't need to see realtime playback all was well on my meagre XP2500. Rendered output was about 2.5 times realtime to DV file with about 50% mix of HDV and DV on the timeline. I am hoping that come my PC upgrade late summer(wife and bank account willing!!) to dual core PC this render will be close to realtime.

Ron Evans

I'm wondering how you render the HDV out from a proxy timeline. I read another post by a guy in Europe, talking about editing with a DV proxy and rendering the m2t- I think on Premiere Pro 1.51. As he describes the process:
1) Download a single long clip as m2t
2) Use the camera to downconvert and download the same long clip as DV
3) Make sure the timecodes on the two clips match
4) Edit the DV in the usual fashon
5) Break the link between the clip file icon in the editor and the DV file
5) Relink the clip file icon to the m2t file
6) Render the timeline out to the camera on firewire (using exactly what command??)
Would this actually work? All the cuts, xsitions, effects, filters, etc. would integrate into the GOPs?
Sounds too easy
Bob

Robert, if you're a Vegas user, this is exactly what the GearShift plugin does.
Capture HDV
Gearshift converts HDV to two of 3 options; DVWidescreen proxy, 4:2:2 YUV HD, or Cineform 4:2:2 avi.
You can edit the proxy, which is calibrated for the correct 709 colorspace, then press a single button which "shifts" out the proxy for the HD, whether it's the m2t, or 4:2:2 file, and all titles, filters, transitions, framerate conversions, etc all take place. Set it to render and go have dinner.
For a while, proxy-based editing is going to be common. It's an ironic return to what we used to do with MJPEG or other formats when computers were slow and acceleration was horrendously expensive.

Bob,

Just noticed your location. I have a wonderful sunset shot at the 5 gate Kona airport, taken in November 2003 with my then four month old JVC HD10. I'm ready to come back!

Anybody! What is the GOP structure of the FX1? Six frames like the JVC? Did I mention how much I liked Hawaii?

Surprise, surprise. Got my copy of "Videography" mag the day after my DV mag arrived in the mail, and they too have an HDV article. This one entitled :"Is HDV right for your editing workflow?"

Covers most of the same aspects, and comes to much the same conclusions: "HDV is not for everyone, but it may be perfect for you"...'

and

"Is HDV right for you? Well if your goal is to make money now, probalby not. The lack of any viable distribution format makes commecialization of HDV difficult..."

Both articles are fair representations of where the work flow is RIGHT NOW versus where it promises to be in the future.

The 6-GOP path that JVC choose is much better. Your not going to see issues at 6 GOP in my opinion. HDV/MPEG is a very advanced Codec that is getting a bad wrap as an acquisition format in the public arena.

I think people are going to be very surprised how well the HD100u is going to perform. As well future HDV systems.



Current article on the HVX200 removable Lens possibility

http://www.pbase.com/aghvx200/do_hvx200s_dream_of_lenses

Michael Pappas



I just read an article in the May issue of DV magazine about HDV and it was a bit depressing: the article basically says HDV will exhibit generation artifacts over repeated dubbing of only a few times, that motion artifacts are evident in "high frequency detail and/or abrupt complex motions" and that these cause "noticeable degradation in the form of poserization, blocking, and psuedo-random noise." Adding that "HDV's artifacts can permeate the entire frame."

Finally, when talking about dubbing your edited program back to HDV "shows more artifacts than the camera original does".

How expensive are small sized HD monitors anyway? Monitor issues are another whole ball of wax...