Output file is "de-interlaced" though the input file is progressive

Nozzle wrote on 3/17/2021, 2:34 PM

Without going in to detail about why I'm trying what I'm trying (though I can add this detail if required) - in brief, I have a *progressive* h.264 file which I simply want to sharpen a little, add a different sound track to then downsize to 1280x720; and I want to use Vegas Movie Studio to do it. I add the .WAV file and it's allready the correct length so there is no problem with lip-sync etc.

However, the output file seems to have had a de-interlace applied, no matter what settings I try.

In "Project - Properties" I've tried all 3 settings "Deinterlace method" None, Blend, Interpolate and with and without "Adjust source media to better match project or render settings"

(left side is the original, right side is the output having had "None" de-interlacing, both displayed from VLC)

In the Make Movie menu I always choose save MP4 to HD then MAGIX AVC/AAC MP4 then chose a custom template and here I am resizing from from 1080 down to 720. I am careful to make the frame rate is the same by choosing 23.976 which is same as source. Field order has no other options that "None - progressive Scan" which is what I want.

I've tried 3 different outputs in the "Project - Properties" menu and each resultant output is EXACTLY the same file size, no matter what if I choose for "Deinterlace method" (None, Blend or Interpolate). Which suggest to me that the encoder is ignoring this parameter of the project properties.

What is the wisdom on this, is it a known bug?

Regards, Nozzle

Comments

EricLNZ wrote on 3/17/2021, 4:15 PM

Please upload images directly to the forum using the upload button

I don't notice any interlacing in your image. There would be combing if there was. What you probably have is ghosting caused by resampling which is adding extra frames which are a blend of adjacent original frames. You must be altering the play speed somewhere?

Go to the clip and in Switches or Properties select "Disable Resampling".

Former user wrote on 3/17/2021, 4:16 PM

And deinterlacing has nothing to do with file size. The only things that affect file size are length of program and bitrate.

Nozzle wrote on 3/17/2021, 4:29 PM

Please upload images directly to the forum using the upload button

I don't notice any interlacing in your image. There would be combing if there was. What you probably have is ghosting caused by resampling which is adding extra frames which are a blend of adjacent original frames. You must be altering the play speed somewhere?

Go to the clip and in Switches or Properties select "Disable Resampling".

Thanks for this tip, I have switched to "Disable Resample" from "Smart Resample", which must be the default setting. Ghosting describes what I see and it looks like extra fames, as if it were interpolated from one either side - which is how I came to the conclusion it was related to a de-interlacing function

A new file is now being produced as I type..

I'm new to Vegas and the learning curve is steep. Very steep

Nozzle wrote on 3/17/2021, 4:31 PM

And deinterlacing has nothing to do with file size. The only things that affect file size are length of program and bitrate.

My thinking here is that the file size would be different, even if only marginally if the frames are processed differently even if encoded with exactly the same parameters. The chances of the outputs being the same size, if one was "blended" and another "interpolated" are vanishingly small.

Nozzle

Former user wrote on 3/17/2021, 4:33 PM

Nope, no difference. Bitrate and length only. (it could be minor but that could be encoding logarithm rather than interlace vs. non.)

Musicvid wrote on 3/17/2021, 5:28 PM

Deinterlacing does nothing to progressive files.

Progressive = Not Interlaced

If you will post your file properties for both source and render, you will find that @EricLNZ is correct, and you will not need to speculate.

https://www.vegascreativesoftware.info/us/forum/faq-how-to-post-mediainfo-and-vegas-pro-file-properties--104561/

Nozzle wrote on 3/18/2021, 3:28 AM

I accept what EricLNZ has told me about the sampling switch and now know what I see in the output is a result of ghosting and not as a result of de-interlacing. One thing is for sure, it's a temporal effect between one frame and the next.

I have now re-encoded and the result is great, the new "stereo" sound track is in sync and there's no temporal bluring/ghosting.

My next job... search this forum to learn more about these switches!

Nozzle

3POINT wrote on 3/18/2021, 7:35 AM

This "ghosting" is a result of rendering (with smart resampling enabled) to a different framerate than the framerate of your footage. Disabling resampling will eliminate this "ghosting" but could add "stuttering" instead.

When rendering to the correct framerate, the setting of resampling doesn't matter and no "ghosting" or "stuttering" is added.

Nozzle wrote on 3/18/2021, 8:30 AM

When rendering to the correct framerate, the setting of resampling doesn't matter and no "ghosting" or "stuttering" is added.

This is interesting, as my input file is 23.976fps and that's what I'm requesting the encode is at too. (and Media info is confirming both to be true).

3POINT wrote on 3/18/2021, 8:55 AM

When rendering to the correct framerate, the setting of resampling doesn't matter and no "ghosting" or "stuttering" is added.

This is interesting, as my input file is 23.976fps and that's what I'm requesting the encode is at too. (and Media info is confirming both to be true).

Does Media info also say that your input file is CFR and not VFR? Another reason could be that you timestreched the clip on the timeline.

Nozzle wrote on 3/18/2021, 10:45 AM

The plot thickens! It says my input file is VFR, which is odd as this input file is infact an output file of Handbrake which I've needed to use as an intermediate step since the original file I have to work with is .mkv and Movie Studio won't play nicely with .MKV . I was sure I had set the frame rate in Handbrake to CFR and "same rate as source" so to see it on Media info as VFR means I've messed that up, or the nvidia codec in Handbrake is playing tricks.

I realise using Handbrake as in intermediary is not ideal, but I've set the Quality Factor quite high as I'm not interested if the file size is large. Speaking of Quality factor, that reminds me of another thread I need to start...

Nozzle