Cineform ConnectHD & smartrendering

[Laurence Kingston]

I just noticed that when using the Cineform Codec in Vegas, it only smartrenders video that was already rendered at least once in Vegas. In other words, if you capture M2T and generate your Cineform codec avis using Gearshift, the rendered Cineform avis will smartrender but if you capture directly to Cinform avis using ConnectHD, Vegas will render everything. This seems to me to mean that using Gearshift instead of ConnectHD will save a generation of rendering by the time you complete a project. Am I missing something or is this the case?

[Laurence Kingston]

A few more tests and I can now say the following:

Vegas won't smartrender Cineform codec avis rendered by anything other than Vegas. Any Cineform codec avis captured by ConnectHD or rendered by VirtualDub or DVfilm will be completely rerendered. It is probably a flag issue that Sony needs to fix.

[John Rofrano]

Originally Posted by Laurence Kingston

It is probably a flag issue that Sony needs to fix.

It might be more than just a flag fix. Connect HD uses the DirectShow CineForm codec while Sony Vegas uses the VFW (Video for Window) CineForm codec. Since the DirectShow files are smaller than their VFW counterparts, I’ve got to believe the encoding itself is different which is probably why Vegas can’t smartrender them (because it only understands the VFW version).

~jr

[Laurence Kingston]

How about DVFilm and VirtualDub? Do they use the DirectShow Cineform codec or the VFW one? I can't make Cineform codec files from either of these programs smartrender either.

[John Rofrano]

I think VirtualDub only works with VFW drivers. I don’t know about DVFilm.

~jr

[Laurence Kingston]

Well if VirtualDub is working with the VFW driver, then it's likely to be a flag issue. I know that DVFilm requires that you render RGB rather than YUV, so I believe that it is using the VFW driver as well.

The smart-rendering of the Cineform Codec is one of it's main features IMO. The rerendered quality still looks pretty good, but I like to save a generation whenever I can. It is pretty important to me to get this working.

[David Newman]

The CineForm codec comes in various flavors to handle progressive vs interlaced, 8-bit vs 10-bit, and I-frame vs 2-frame GOP. Every decoder we release, from the one bundled in Vegas to the decoders with Prospect HD, will handle all the different internal formats. Yet the VFW encoder can only produce an I-frame version of the CineForm compression, which is a little less efficient (bigger files.) Vegas uses the VFW codec, is it produces I-frame CFHD files, as does GearShift, VirtualDub and DVFilm. Connect HD defaults to producing a 2-frame GOP with the DirectShow encoder for the greater efficiency and fast conversion times. The Vegas smartrender unfortunately is not smart enough for an I,P compression structure so it chooses to render those elements. Now generation loss with the CineForm codec is not an issue to worry about, see quality tests here http://www.cineform.com/technology/quality.htm. However, if you doing a lot of timeline flattening (I'm curious why) the smart rendering is a nice time saver. We could offer fast I-frame conversion within Connect HD if this is of great interest.

[Laurence Kingston]

From the tests I've done, I don't see any resolution loss from rerendering Cineform codec video. I'm still worried about resolution loss though. I have a friend who just recently got a huge HD widescreen TV. On his setup I can see all kinds of focus, compression and resolution problems that I never could see on my own 37" HD setup. This has me concerned about even the smallest quality loss, especially if there is an easy way to avoid it. Smartrendering really sets my mind at ease quality-wise

Then there is the time issue. With my P4 3.06 processor, rendering time can be quite an issue. Smartrendering makes the difference between a trailing edge PC such as mine and a cutting edge dual core system largely moot (at least on an original format Cineform AVI render). I would love to be able to smartrender whenever possible.

As far as the I-Frame option from ConnectHD goes, what I am really worried about is smartrendering. If I had a choice between smaller sized files and no smartrendering, or larger sized files and smartrendering, I would go for for the larger sized files and smartrendering.

Remember that this is also important when you archive projects (which I do on every project). You archive a project and a subdirectory with only the video footage used is created. All these clips are smartrendered. I also like to keep a complete project avi on file use in whatever format I might need in the future. A smart-rendered avi is perfect for this.

I do "flatten" quite a bit. I do documentary style production and like everyone who does this genre, I record huge amounts of footage. I don't see how you can do a documentary style piece without constant timeline flattening.

I'm not convinced that this is entirely an I-Frame issue. I can't smart render anything that wasn't originally rendered by Vegas. If it was just an I-Frame issue, I would be able to smart-render files generated by VirtualDub or DVfilm, but I can't.

[Michael Liebergot]

Laurence, I have Vegas 6 and was wondering what Smartsampling is? I am looking into getting the Sony A1to edit and mix with my VX2100's to render for standard DVD.
I was debating between the Connect HD way (capture directly to the Cineform Codec). compared to the GearShift way (Capture and convert to Cineform or Proxy). The Connect HD would definitely save me time as like you I have a P3.4 HT Processor which wouldn't render nearly as fast as a Dual Core system. (The new system is later down the raod after I purchase a couple of HD cameras.

Does Smartsampling bypass any renderring where the video wasn't modified (color corrrected, pan crop etc) in any way?
I would also assume that Smartsampling would only apply when keeping the final output in HD. So if you were downresing to Standard DVD then there would be no time savings.

[Laurence Kingston]

Originally Posted by Michael Liebergot

Laurence, I have Vegas 6 and was wondering what Smartsampling is? I am looking into getting the Sony A1to edit and mix with my VX2100's to render for standard DVD.
I was debating between the Connect HD way (capture directly to the Cineform Codec). compared to the GearShift way (Capture and convert to Cineform or Proxy). The Connect HD would definitely save me time as like you I have a P3.4 HT Processor which wouldn't render nearly as fast as a Dual Core system. (The new system is later down the raod after I purchase a couple of HD cameras.

Does Smartsampling bypass any renderring where the video wasn't modified (color corrrected, pan crop etc) in any way?
I would also assume that Smartsampling would only apply when keeping the final output in HD. So if you were downresing to Standard DVD then there would be no time savings.

Aside from the name "smartsampling" you are correct. The correct term is "smart-rendering" and it works exactly the way you describe it.

[Laurence Kingston]

I am kind of happy to see that with version 3.0, ConnectHD captured footage can now smart-render in Vegas (if you select that option).

It is entirely possible that the new soon-to-be-released Vegas 7 will smart render regular Cineform codec footage (hopefully).

Anyway, thanks Cineform! I do documentary type stuff and go through an amazing amount of footage on my projects. I am constantly flattening the timeline and rendering little segments to use later. I also am also using a 3.06 P4, which was screamingly fast not so long ago, but now considered something of a slouch. This one feature alone makes more of a difference to my rendering time than upgrading to the latest dual-core AMD screamer would.

[Paul Kepen]

I hadn't heard about there being a new vegas in the immediate future. Do you have any more info, like when it will be out and what the new features will be? Thanks - PK

[Laurence Kingston]

Vegas 7? I'm just guessing, but it's about time wouldn't you say!