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-   -   Is Fx1 Cineframe 30 stored as Interlaced or Progressive Mpeg2? (https://www.dvinfo.net/forum/sony-hvr-z1-hdr-fx1/120453-fx1-cineframe-30-stored-interlaced-progressive-mpeg2.html)

Anna Uio April 27th, 2008 08:56 PM

Is Fx1 Cineframe 30 stored as Interlaced or Progressive Mpeg2?
 
Hi,

I'm a software developer and I'm working on code to upsample the chroma in mpeg2 video. I was wondering if anybody here knows if the Fx1 in Cineframe 30 mode writes out interlaced or progressive mpeg2. The obvious choice would be to write out progressive, but I know that some cameras in "progressive" mode still break the frame into two interlaced fields and store them as interlaced so that software expecting interlacing will decode them correctly.

Thanks in advance,
Anna

Jonathan Shaw April 28th, 2008 12:33 AM

I believe that it is interlaced.

Jon

Craig Irving April 28th, 2008 07:20 AM

Yes. Interlaced.

Martin Pauly April 28th, 2008 09:11 AM

Anna,

Here is some information that may be helpful to you:
http://www.adamwilt.com/HDV/cineframe.html

In general, the Cineframe modes don't really change as much as their name may suggest. They create a different look, but without altering the output format significantly (such as switching between progressive/interlaced video).

- Martin

Chris Barcellos April 28th, 2008 10:43 AM

There is also a difference in apparent, if not actual resolution. Forgive my lack of technical explanation, but it is my understanding is that due to the methods employed to process the image, less information is actually used create the 30p Cineframe image, or the 24P Cineframe image, which affects the actual resolution.

Incidentally, Cineform will convert these to true 30p and 24p files for editing purposes.

Anna Uio April 28th, 2008 11:55 AM

Interesting. In my tests with Fx1 footage in CF30, upsampling chroma as progressive looks great and interlaced look bad (has the telltale alternating horizontal lines from incorrect chroma upsampling). I'd love to post a couple of images, but I don't have permission to use attachments in the forum :(

Cheers,
Anna

Chris Barcellos April 28th, 2008 12:49 PM

Anna, I suggest to you that when you are viewing interlaced on a computer system, seeing the interlaced footage as intended is a matter of setting up your player or preview properly. If I ever have an interlacing issue on playback, in can use VLC, for instance, and order that it deinterlace the footage as it plays.

Anna Uio April 28th, 2008 08:03 PM

By the way, here is a fairly frequently referenced article on incorrect chroma upsampling. It refers to DVD players, but the issue is the same. I'm sure many here are already familiar with this, but I thought those who weren't might appreciate the article.

http://www.hometheaterhifi.com/volum...ug-4-2001.html

Note that the issue is not a matter of deinterlacing an interlaced image, but rather of properly interpreting to stored frame/fields as either interlaced or progressive.

I wonder has anyone here actually done a test and physically confirmed for themselves that CF30 is stored as interlaced and not progressive? As opposed to taking the word of Sony. Just curious. If someone has done the test and confirmed interlaced, I'll be more inclined to wonder about the results I am getting.

Cheers,
Anna


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