Cineform from Interlaced AVCHD?
 

Hey people,
Can someone tell me where I am going wrong here.
I normally capture all 1080p progressive footage, convert to Cineform, edit, render out a Cineform master, then down size with HD Link to 1024x576 (square pixel Pal). Then put that in a Vegas Pal widescreen sequence and render to Mpg 2 elementary streams for DVD authoring.
This works great for me, especially the HD Link resizing.
Now for reasons that I wont go in to I have to capture a multicam show with interlaced footage.
I want to use the same workflow to continue the interlacing all the way through to DVD.
Now the problem, Ive been testing a bit of 1 min interlaced footage from one of the cams Ill be using.
If I try to convert in Cineform studio I cant trim it (why?)
I managed to render it from the Vegas timeline to Cineform and maintain the interlacing (even though Mediainfo says its progressive?).
When trying to downsize to 1024x576 in HD Link it then turns it progressive, no matter what I set in preferences.
Resizing in Virtual dub does the same, I assume (read- guess) its because the 1080i file thinks its progressive.
Does Cineform support interlaced workflow?

Re: Cineform from Interlaced AVCHD?
 

OK then.
Can someone just confirm that they have no trouble with interlaced resizing in HD LInk?
At least then I will know it is my workflow rather than a limitation of the software.
If it does work for you, can I maybe get a screen shot of your settings in the Cineform preferences window.
Thanks
:)

Re: Cineform from Interlaced AVCHD?
 

I'm not sure that I totally understand your workflow, and I have no experience with PAL formats.
However, 90% of my editing is 1080 60i- XDCam, AVCHD, etc.
I use HD Link to convert the raw footage to 1080 CFHD.avi, which I then edit in Premiere Pro.
I then render the finished timeline to whatever delivery format is needed- 60i Blu Ray and/or DVD, 30p for web formats.
I've never had any problems using an interlaced workfolw
Here is an example of 60i HD Link Preference settings:

Re: Cineform from Interlaced AVCHD?
 

Thanks Robert,
The work flow you use is not a problem for me either.
The trouble I'm having is using HD Link to do the resize from HD to SD, it is turning the footage progressive at that point.
I can render from the Vegas timeline to DVD compatible formats as you do in Premiere Pro,
However, the resizing algorithm used by HD LInk (Lanczos) is far superior to the Bicubic or Bilinear that is used by Vegas or Premiere.

Re: Cineform from Interlaced AVCHD?
 

Got it...
If I use HDLink to resize from 1080 60i to 480 60i, I just change the "Resize Video" pull down to SD NTSC 16:9.
When I import the new file after the conversion, Premiere Pro reads it as 60i UFF.
I have converted 1080 60i CF masters to 480 60i CF masters specifically for DVD production workflow.
I usually use Adobe Media Encoder which I believe accesses the CF engine (Lanczos) for the conversion, but I have done it using HDLink as well.
I have never had a problem with HD Link changing any field parameters unless there was an incorrect setting somewhere.

Re: Cineform from Interlaced AVCHD?
 

Is this documented anywhere Robert? If true, would that be the same with Sony Vegas, doing Cineform resizes?

Re: Cineform from Interlaced AVCHD?
 

My recollection is that David Newman made a point of this in a post on this forum several years ago.
I just tried to search for it, but no luck.
The issue dates back to maybe CS3 era when the Adobe native downscaling was rather poor.
I think that the point was being made that if you stayed in the CF codec (CF HD source, outputting to CF SD 480 x 720), you could stay within Premiere (or AME) and the downscaling would be performed by the CF engine, rather than the Adobe rescaler.
I had not given the topic much thought since then- now you have me wondering...
Is this info correct, or is it a misunderstanding???

Re: Cineform from Interlaced AVCHD?
 

Would be great to a confirm or deny from David or Jake on this.
Do they still participate in this forum?

Re: Cineform from Interlaced AVCHD?
 

Gerald
Check this recent thread.
http://www.dvinfo.net/forum/cineform...n-stopped.html
Although he doesn't directly address the issue of downscaling, David seems to be saying that a CFHD encode done with AME is equivalent to an HD Link encode.

Re: Cineform from Interlaced AVCHD?
 

Thanks Robert.
That is one very vague conversation though.
David doesn't seem to know if AME upgrades the color space to 422 or not.
Unrelated, out of interest I did my own test from Sony Vegas with a 1080p short edit.
All footage was AVCHD and MXF converted to Cineform 1080p.
I rendered a 1080p Cineform Master.
From that I-
1.Rendered to mpg2 720x576 from the Vegas timeline.
2.Down converted 1080p master in HDLink to 1024x576, then rendered that to mpg2 720x576 on the Vegas timeline.
3.Used the 1080p master in Promedia Carbon to render to mpeg2 720x576. It uses Lanczos resizing like HDLink.
Then I dropped the 3 files in Vegas, Masked them to give me a third of each track, so I was looking at all three playing at the same time.
Put resolution on Best Full and previewed to a 30" external monitor.
I have to say I could not pick a visible difference in quality on any one encode. Certainly nothing to justify extra steps in rendering.
There was a slight color shift in the Carbon coder version, but hardly noticeable.
Looks like from now on I just render in Vegas.
:)

Re: Cineform from Interlaced AVCHD?
 

Is it possible to transcode MVC 1080i50 (60) to get the output interpolated cineform 1080p50 (60)?

Or only addition to the original 1080i50 (60) we can have a 1080p25 (30) by mixing the fields?

For MVC 1080i50 (60) is very tempting to get the output in cineform 1080p50(60) half Over-Under.

Re: Cineform from Interlaced AVCHD?
 

I don't believe that there has ever been a dedicated flag in the header of an AVI file to designate interlaced or progressive, nor is there a flag to indicate aspect ratio. It also doesn't store upper or lower field first in the case of interlaced footage. Without the flag in the AVI header, neither Mediainfo nor Vegas has any way of knowing, so it just reports progressive as a default.

I use Vegas and I simply set the clip's properties to the correct field dominance and aspect ratio. Vegas also has a mechanism so you can tell it how to set the properties the next time it sees a file using a specific codec at a specific frame size and frame rate*. Chances are that your footage is indeed still interlaced despite Vegas and Mediainfo not being able to tell.

Keep in mind that interlaced HD footage is almost always upper field first and you will need to maintain that field dominance throughout the project.

(* When you right-click on a clip and go to "Properties" and then the "Media" tab, there is a small disk icon next to the "Stream" box, if you set the properties correctly and then click on the disk icon, that will tell Vegas to use those same properties the next time it encounters a file of this type.)