Project propretore: when blend/none For a DVD?

[Marcus Martell]

Hallo,

I m converting a file shot in hdv1080 50i to DVD. Setting the properties what should i set on the deinterlace method:blend of none?
In 40 minutes of video there are about 5 min of pictures with pan & crop

Thx

[Marco Ba]

Anything except "None" is fine for your purpose. Select either "Blend fields" or "Interpolate fields". Blend field is the most common standard setting.

[Marcus Martell]

When do you use none?

[Eric Olson]

Originally Posted by Marcus Martell

When do you use none?

None means force progressive chroma and scaling on interlaced footage and is usually not what you want. The only time you might set it to none is when the source is 30psf, the output will be 30psf and everything is wrapped as 60i.

Blend fields will reduce motion stutter in a 60i to 30p conversion at the expense of making things blurry. The only time to use this is when tests indicate interpolate fields has objectionable stutter. Note that stutter is seldom noticable when video is watched on relatively small screens such as computer displays and cell phones. Moreover, if the video is intended for TV delivery then it makes more sense to keep it 60i.

[David Jimerson]

Originally Posted by Marcus Martell

Hallo,

I m converting a file shot in hdv1080 50i to DVD. Setting the properties what should i set on the deinterlace method:blend of none?
In 40 minutes of video there are about 5 min of pictures with pan & crop

Thx

If you're exporting as standard PAL (which you will be doing for DVD), there's no deinterlacing. It doesn't matter what you set it to; it won't be done.

Now, if you WANT to deinterlace, as in, convert to 25p first, then you'd use Interpolate Fields. But there's no need to do this unless you want the motion of 25p instead of the motion of 50i ("live").

[Jerry Amende]

Internally, Vegas deinterlaces when resizing interlaced footage. Therefore, if you are resizing interlaced footage, you should set a deinterlace method.

The other (rather obvious) situation that a deinterlace method should be used is when you are actually rendering an interlaced project to progressive.

I've made it a habit of always using a deinterlace method when working with interlaced footage as there is no penalty for setting it.

Some people recommend using "interpolate" for fast moving footage. "Blend" for slow moving footage. Frankly, I've seen little difference in the output.

...Jerry

[David Jimerson]

"Internally, Vegas deinterlaces when resizing interlaced footage."

I've never heard that it does this -- where is there info about this?

The manual says it deinterlaces to apply FX, but it doesn't say anything about it for resizing.

In any case, Interpolate Fields is better for faster motion because it creates frames out of single fields. Blend Fields takes two fields and (more or less) stitches them together, which can create exaggerated ghosting. This isn't a problem if something isn't moving much, but for a lot of motion, it can create a lot of ghosting and other horrible problems.

[Jerry Amende]

Originally Posted by David Jimerson

"Internally, Vegas deinterlaces when resizing interlaced footage."

I've never heard that it does this -- where is there info about this?

Well, here's one place: Resizing on Render Second post down.

Don't believe it? Run a test. Here I've rendered 1080 60i footage to NTSC WideScreen. First, with Deinterlace=None, next with Deinterlace=Interpolate.

...Jerry

Edit: BTW always set Rendering Quality to "Best" which specifies Bi-Cubic resizing algorithm. See: https://www.custcenter.com/app/answers/detail/a_id/334

[David Jimerson]

Just asking. If John Rofrano says so, then I believe him. I had simply never heard of this before. I haven't edited any interlaced footage for probably 9 years or so, so I never had reason to come across it.

[Eric Olson]

Originally Posted by Jerry Amende

Some people recommend using "interpolate" for fast moving footage. "Blend" for slow moving footage. Frankly, I've seen little difference in the output.

Scaling of interlaced source to interlaced output is done using the same interlace aware scaling algorithm when deinterlace mode is set to either blend or interpolate fields. The only difference between blend and interpolate fields is when the source is interlaced and the output is progressive.

[Marco Ba]

If you scale interlaced footage with deinterlace method set to "none" it will result in visible interlace artifacts. As mentioned above there are very, very rare cases where it makes sense to use "none". Another one (in addition to the one mentioned above) is when you use a 3rd party plug-in for deinterlacing. I'm not aware of any other cases where it would be useful to leave the standard setting of "blend" or "interpolate".