Understanding Interlacing and export through Premiere

[kktk1]

I have my videos shot through my PAL camcorder(HI8).
I transfer this to my computer and I have an avi file.
Its a PAL clip - so its 720 X 576 I believe at 25 FPS.
The audio is in PCM format at 48 khz.

I import this into premiere, do my editing.

Now the export(I know I read many posts on this already)....is where I get overwhelmed with options.

When I try to export as a m2v file, I get horizontal lines(which i believe is an issue because of interlacing?)

So let me try and understand a few things first. I know there is a lot that can be done with audio, but I want to stick to understanding the video aspect for now.

Questions for exporting:
1. What should the file type be?
Microsoft DV AVI? or Microsoft AVI?

2. If I choose just the AVI, what compressor should I pick?

3. If I use the Mainconcept's encoder....what settings should I use?
Do I need to deinterlace this? is this a trial and error thing or would some preset always work right given my source file?

I am learning a lot through trial and error, but still cant figure out why I am doing something the way I am to get a result?!?

Thanks
K

[/u]

[jagabo]

Each frame from your DV camcorder contains two pictures, taken at 1/50th second intervals. Actually only half of each picture is present -- all the even numbered scanlines from one, all the odd numbered scanlines from the other. Each of these is called a field.

When you view interlaced video on the computer you will see comb artifacts where there is motion. If you don't see any comb artifacts then the player is hiding them from you.

When you view interlaced video on a standard definition TV you only see one field at a time. The player has to know which of the two fields to display first. Otherwise the two fields will be displayed in the wrong temporal order making for very jerky motions. There are two possible "field orders": Top Field First (TFF) and Bottom Field First (BFF). Some programs use different nomenclature A/B, Even/Odd, etc. The field that contains the topmost scanline is called the top field. The field that starts with the second scanline is called bottom field. DV camcorders always produce BFF video.

What format you save to depends on what you plan to do with your video. If you are editing and want to send the video back to tape, or plan on more editing later, save it as DV AVI. (AVI is a container, it can contain video and audio compressed with any number of codecs.) If you are making a DVD save it as MPEG 2. Make sure the MPEG encoder knows the video is BFF so that it can pass the field order on to the DVD player correctly. Do not deinterlace unless you need a video that will be played on the computer and you can't control what player is used.

[kktk1]

" If you are making a DVD save it as MPEG 2. Make sure the MPEG encoder knows the video is BFF so that it can pass the field order on to the DVD player correctly. Do not deinterlace unless you need a video that will be played on the computer and you can't control what player is used."

---This is what I need clarification on.

My end goal is to make a DVD out of this. So I would need to send it out as an MPEG.

But when I do export as MPEG or AVI---and dont deinterlace, I always see have problems when there is any motion on the video---dont know what the technical term is...but horizontally there are lines visible.


K

[jagabo]

But when I do export as MPEG or AVI---and dont deinterlace, I always see have problems when there is any motion on the video---dont know what the technical term is...but horizontally there are lines visible.

Computer displays are progressive so you see both fields at the same time. You should see interlace comb artifacts on the computer unless you are using a player that deinterlaces on the fly. After burning the file to a DVD the DVD player will send one field at a time to your TV, exactly the same way your camcorder plays the DV file. On the TV you see 50 fields per second, not 25 frames per second. You never see both fields at the same time. If the field order is wrong you will see fast jerky motions -- 25 jerks per second.

[kktk1]

If its ok for the computer display to show interlace comb artifacts, I can ignore it there.

But when I burn a DVD and watch it on my TV, I still see lines whenever there is a rapid left to right OR right to left movement.

Isnt this not supposed to happen?
And if I understand correctly, this is an interlacing issue?

[Scorpion King]

Sounds like wrong field order. Check your files. Burn a few short clips, with different settings, onto an RW disk and try them on your TV.

Good luck.

[kktk1]

I was going to do that today.

I just wanted to make sure that this is not being caused by all the decoding and encoding OR because of some compression technique that I had used....and its actually an interlacing issue that wouldnt be corrected by the steps I have taken already.

[lordsmurf]

In Premiere, you have to set the project to interlace, and with bottom field first. If you use a DV project template, it should be set already, but check anyway. I've found it NOT SET a few times. I use Premiere 6.5, other versions may slightly vary in location.