Aliasing when I compress .flv with deinterlacing

[Daniel Low]

Was the source video shot progressive?

__________________________________________________________________
“There’s no chance that the iPhone is going to get any significant market share. No chance.”
Steve Ballmer To USA Today: 30 April 2007

“We and Apple are neck and neck and we’re chasing the two
other players,”
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009

[Eric Olson]

Yes, the original footage is progressive as it was created in After Effects. The footage looked bad in the Avid window but the QT movie export looked fine.

EO

[Daniel Low]

I think you just answered your own question! No point interlacing/deinterlacing progressive material.

__________________________________________________________________
“There’s no chance that the iPhone is going to get any significant market share. No chance.”
Steve Ballmer To USA Today: 30 April 2007

“We and Apple are neck and neck and we’re chasing the two
other players,”
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009

[Eric Olson]

Yeah, but it doesn’t really solve my problem.

[Daniel Low]

OK, a few things:

1. Your Avid project should be set to progressive and you export from there as progressive.

2. The frame size you are exporting at is not correct, each side should be equally divisible and ideally by 16 or by 8, so 856×480 would be much better.

3. The same applies to your Flix encode, a frame size of 688×384 would be ideal.

There’s not really much else you can do. The bottom line is that you have imported progressive material into an interlaced avid project, exported it as LFF interlaced and then you are trying to deinterlace it, of course you are going to see problems!

__________________________________________________________________
“There’s no chance that the iPhone is going to get any significant market share. No chance.”
Steve Ballmer To USA Today: 30 April 2007

“We and Apple are neck and neck and we’re chasing the two
other players,”
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009

[Eric Olson]

I see your point about bringing the footage into a progressive Avid project. In this case, that would have worked because it is a purely animation project. And I’ll do that with similar projects in the future.

However, I also have projects that are a combination of DV footage and AE footage. When you import into Avid it asks the field order of your project and non-interlaced is an option. It should then apply the correct field order to the AE footage on import and from there on out it should be treated no differently than the DV footage. Yes/no?

Thanks,

Eric

[Eric Olson]

I understand your point about the divisible by 16 thing. Although I don’t think it would matter on export as I’m using the Animation (lossless) codec but would be important for the flash encoding.

https://www.flashsupport.com/books/fvst/files/tools/video_sizes.html

Man, could they make this stuff anymore complicated!!! You have to be a broadcast engineer these days just to get your stuff on the web and looking good.

EO

[Daniel Low]

Div 16 is important but not as important as using even numbers, which all codecs need in order to work properly.

__________________________________________________________________
“There’s no chance that the iPhone is going to get any significant market share. No chance.”
Steve Ballmer To USA Today: 30 April 2007

“We and Apple are neck and neck and we’re chasing the two
other players,”
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009

[Daniel Low]

[Eric Olson] “However, I also have projects that are a combination of DV footage and AE footage”

In those cases, render out of AE as interlaced.

__________________________________________________________________
“There’s no chance that the iPhone is going to get any significant market share. No chance.”
Steve Ballmer To USA Today: 30 April 2007

“We and Apple are neck and neck and we’re chasing the two
other players,”
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009

[Eric Olson]

Ok, the plot thickens.

1) I create an AE project 720×480 and 24fps, D1/DV PAR

2)I animate a line drawing and export QT with same settings using Animation codec. The QT looks great at this point.

3)I import to Avid Project at 24p NTSC, import settings RGB, 601 non-square, Ignore Alpha. At this point the video looks pixelated in Avid monitor window (don’t have my CRT monitor hooked up as I’m running a minimal set up right now)

4)Add clip to timeline and export as QT, 24 fps, Animation Codec, 640×480 sq px

…essentially, I brought it into Avid and exported at exactly the same setting, aside from converting from D1/DV PAR to square pixels.

The pixelated result can be seen in the image below, even though the QT looked great coming out of AE. Essentially, there is no interlacing going on in this process at all and yet I’m getting interlacing effects.

Anyone have an idea of what is going on here?