My Workflow: Please feel free to comment

[smrpix]

You can also encode to DNxHD in Adobe Media Encoder, If you choose the mxf type rather than mov it's much quicker because it bypasses the quicktime engine.

With ffmpeg, for 1920x1080 use a command line containing this: -vcodec dnxhd -b:v 145M -acodec pcm_s16le
Add any other parameters you like. If you don't specify a bitrate it defaults to 220. If you don't specify a raster size it defaults to source. Interlace/progressive also defaults to source.

[sophisticles]

But it looks like, to go from HD interlace to SD interlace one must double frame rate de-interlace before resizing to get footage to be up to par with some standards (not flickering on screen). Just leave it to NLE does not give expected result somehow.

This is the first time I have ever heard anyone make such a claim. Are you telling me back when DVD was the best we could get in the consumer market and the highest end cameras shot in 1080i that the professional studios would de-interlace the content, resize it, then re-interlace it for dvd?

Does this make any sense to you? Have you ever experienced any such problems because I sure haven't.

[Cornucopia]

Yes, that is 1 way to get around interlacing issues:
Temporarily convert the interlaced to progressive, resize, and then re-interlace.

There are a number of tools that don't anticipate the complications of working with interlaced footage, so this is a workaround to accommodate them.
In common use, even now.

If you haven't heard of it, I'm surprised, but it could be that you just didn't recognize it as such.

Scott

[_Al_]

This is the first time I have ever heard anyone make such a claim. Are you telling me back when DVD was the best we could get in the consumer market and the highest end cameras shot in 1080i that the professional studios would de-interlace the content, resize it, then re-interlace it for dvd?

Does this make any sense to you? Have you ever experienced any such problems because I sure haven't.

This subject discussed a lot, in any forum I basically came across, folks notice that using NLE and making DVD out of 1080i is flickering, shimmering etc. It was discussed even here. I found this to be a problem also.

There is a term used like "low pass filter" for video to handle this problem. Deinterlace 1080i into 1080p double frame rate, resize it to SD. Using some techniques like blurring vertical resolution, or other scripts to make it ready for re-interlacing, so it is not flickering that much after reinterlacing. Sure video is slightly blurred then, but overall feel is much better.

[SameSelf]

I don't see the need to upsize because YouTube will just re-encode anyway and in doing so will up and down size for you.

I don't see the need to de-interlace because of your 3 delivery formats, DVD, BluRay and Youtube, the first two support interlaced content just fine and the last re-encodes everything anyway and will de-interlace it for you.

QTGMC does significant processing on the source, it sharpens, it denoises, it puts your source through the ringer. Some people may like what it does, I don't, I prefer to use a straight de-interlacer and handle any sharpening and de-noising myself.

Perhaps I haven't been 100% clear. The "need" for upsizing arises from YouTube requiring square pixels. I don't understand fully what YouTube does with uploaded video, but Youtube does recommend basic settings for best results. IOW, YouTube doesn't say, "Don't worry if you give us non-square pixels, we will make them square." Rather they seem to want square pixels up front.

The "need" for deinterlacing arises from the fact that I don't like mixing native progressive with interlaced video on my NLE. Plus all of my video will end up on YouTube with little of any being burned to DVD or BluRay.

You obviously have a much better command of sharpening and de-noising than me. Right now I am very dependent on QTGMC doing the thinking for me. But could you be so kind as to post your deinterlacing workflow? It sounds quite bespoke and I am sure educational for this novice!

[SameSelf]

You can also encode to DNxHD in Adobe Media Encoder, If you choose the mxf type rather than mov it's much quicker because it bypasses the quicktime engine.

With ffmpeg, for 1920x1080 use a command line containing this: -vcodec dnxhd -b:v 145M -acodec pcm_s16le
Add any other parameters you like. If you don't specify a bitrate it defaults to 220. If you don't specify a raster size it defaults to source. Interlace/progressive also defaults to source.

Thanks very much. Very useful insights.

[SameSelf]

QTGMC is a bob deinterlacer that outputs 60p if your source is 30i. The SelectEven (or SelectOdd) filter is what drops it to 30p. If you have native 30p footage, it's usually converted to 60p simply by showing every frame twice. Any NLE should handle that the same way, unless you tell it to invent in-between frames.

Does upsizing the video from 1440 yourself actually look better than uploading it to YouTube as-is?

There is so much being discussed in this thread now it is hard for me to keep up. So forgive my late response. As you and poisondeathray point out QTGMC is a bob deinterlacer. However, I assumed that QTGMC was using motion and edge detection in combination with bob. IOW it is so much more than just bob. And as sophisticles has pointed out, it seems to do a fair bit of sharpening and de-noising as well. Puts your footage through the ringer to quote sophisticles.

I don't know the answer to the question about upsizing myself vs letting Youtube do it. Perhaps I will get a chance to test soon.