Disable resample? What exactly does it do?

Warper wrote on 12/26/2014, 6:52 AM

I hope you are talking about video events property (if not, please clarify).
Smart/forced resample (smart, forced, disabled) comes into play when your video has different fps (frames per second, modified by playback speed and speed envelope) is different from project settings.
Sony Vegas works with regular image sequences on track level. Frequency of frames is defined by project settings. For example, if you set up 25 fps, each 40 milliseconds new frame comes out. You can imagine it as momentary flashes of pictures and void between them. Void is here to emphasize that anything in between is lost, track have no information of what happened between frames after it processed video events.
If source media fps and synchronization time is exactly the same as of project, you get frame by frame correlation, in this case you need no resample to get frames from track - Vegas can simply fetch input frames and process them.
If source media has different fps, to generate something similar to what would be in desired time Vegas needs to invent something. There are two ways:
1) no resample: you get previous/nearest frame; here source frames that don't fit into project fps are simply lost - no single bit of their information goes to project preview/rendering, sometimes it's not acceptable - for example if you have quick flash of light of about 1 frame length
2) resample: you mix few frames (through blending in case of Vegas), I believe that blending takes into account the difference in time, so more close frame will less transparent and farer one will be more transparent in combined picture. As a result you get a picture with "ghosts". It is not a problem for static pictures as they are quite similar and produces movement effect for slow motion, but makes quite visible ghosts for fast motion.

Smart resample applies resample in case of different fps and does not apply resample if source and media are of same fps.

Speed envelope, playback speed and undersample rate can affect this. If you speed up 20 fps media with 150% playback rate, you deal with 30fps media as result. Speed envelope works similar, but it speeds up frames from keypoint to keypoint, not video events as one. Both can produce this ghosting.
Undersample rate sets up still image barriers, similar to additional "no-resample" change of fps, but it does not change fps itself, just copies one of frames with set up intervals, replacing other frames with previous that appeared in "fixed time".

Calculations become more complicated if you deal with interlaced and progressive media in the same project or change speed, size, sometimes position and do other transformations with interlaced source. In this case field control comes into play - Vegas sometimes combines fields to get one frame, then transforms this frame and then splits it back to fields. But it's another story...

Rendering with different fps can do resampling as well. Generally if you have x1, x2 fps in project it's not a problem, but if you render into fractional fps or bigger fps than that of project, you can see ghosts of frames...

If you don't use speed envelope, playback rate and work with same fps in source, project and render, you can forget about resampling.
If you speed up something or work with different fps, you should make a choice - drop some frames to even fps(disable resampling) or mix some frames (forced resampling). I do prefer disable resampling, but sometimes it's indeed not optimal.

musicvid10 wrote on 12/26/2014, 8:51 AM

Disable resample prevents frames from being blended when the source and render frame rates differ.
So frames are either dropped or duped.

JohnnyRoy wrote on 12/26/2014, 11:55 AM

The reason many tutorials tell you to disable Smart Resample is because the resample function is old and outdated. It was originally intended to blend frames between 29.970 and 23.976 (in both directions) when 60i, 50i, and 24p were the only frame rates there were. Smart Resample detected the need for frame bending and applied it when needed and did a very good job.

Unfortunately, Smart Resample hasn't gotten any "smarter" since the whole world moved to 60p and it very "unintelligently" tries to blend frames when going from 60p to 30p when all it really needs to do is drop every other frame. That's why people tell you to disable it, because it's not very smart any more and it usually makes a mess out of 60p video delivered as 60i or 30p.

~jr

OldSmoke wrote on 12/26/2014, 12:05 PM

JR

All true BUT it does a good job converting 60i to 60p or any interlaced to progressive.

set wrote on 12/26/2014, 4:30 PM

You need to know exactly when you are using this and know exactly your FINAL project video spec, especially on Interlaced and Progressive setting.

I usually leave it Smart since my works are still interlaced-based and rarely makes any speed changes, but I know I have to turn it off when exporting 60p (50p) directly to 30p (25p). This will make ghosting.

Pete L wrote on 12/26/2014, 7:34 PM

Thanks everyone, so it is mainly to help with Ghosting & using different Frame Rates.
I have had projects where I had 2 separate Frame rates from different cameras & I couldn't render it out but once I disabled the resample then it worked fine.
I have gotten into the habit of disabling on every clip as I started this from the very beginning.
Should I be disabling it when I am slowing Footage down?
I appreciate everyones time answering my questions :)
Cheers Pete.

kb_de wrote on 12/27/2014, 5:07 AM

I doubt you still havent got the point. Let me explain it again with ny non-motherlanguage hand:
1, what is resample
set a project means set a fixed framerate, lets say you have a PAL project so a event on the timeline with 2 seconds length MUST contain exactly 50 frames.
if the event comes from a NTSC source (its origing ist 60f), 10 frames must be subtacted away.
if the event is squeesed from 3 seconds (its origins is 75f), 15 frames must be also away, or, if it ist lengthend from 1 second event, additional 25 frames must be added.
2, how to subtract or add the existing/nonexisting frames there are 2 ways:
A, DISABLE RESAMPLE: simply take them away or repeat the frame, in a certain sequence, say every 3rd ones -- this gives clear pictures but also jumps.
B, FORCE RESAMPE: merge or creat frames so the motion smoothness will be kept, but we see something like ghost pictures.
So, its rather an effect than a decision.
What about the slow/quick motion its just nonsence! Because you cannot adjust it in a project.
And the smart resample module ist Vegas' brain. Others if you want certain effect, this brain brings you the best result.

JohnnyRoy wrote on 12/27/2014, 7:02 AM

> "Should I be disabling it when I am slowing Footage down?"

It depends. If you are slowing it down by 1/2 I would disable resample and just drop the frames. If you are slowing down by some arbitrary amount, I would enable resample so that frames can be blended to make new frames.

Here are the guidelines:

- If you disable it and the motion looks jerky, enable it.

- If you enable it and the frames show annoying ghost images, disable it.

~jr

Chienworks wrote on 12/27/2014, 9:41 AM

Just my 2.3 cents, but i have never found the jerkiness objectionable, in fact have never even noticed it. On the other hand, the ghosting looks terrible in all situations.

I've never encountered a situation in which resampling looked good, or in which disabling it looked worse.

wwjd wrote on 12/27/2014, 12:03 PM

"I've never encountered a situation in which resampling looked good, or in which disabling it looked worse."

HERE HERE!! I'm totally shocked this is turned on by default ALWAYS. Sony ought to shut if off. I've seen some amateur youtubes where you can totally see it, and I just shake my head.... maybe it should be on in the $29 version of HOME MOVIE MAKER 3000, but not in Vegas "Pro" where skilled people are actually working hard to produce decent videos. Sad.

When I first started using Vegas, I thought I had broken my camera somehow! thanks to the auto resample crap

Spectralis wrote on 12/27/2014, 12:40 PM

I use Vegas to composite animation and always turn resample OFF. In every case, even when combining footage that has the same frame rate, ghosting is a PITA with it on. I agree with others that it should be set to OFF by default or completely got rid of/kept as legacy and some more advanced system introduced. I've never found it useful even when combining footage with different frame rates. What I think is very counter-productive is the fact that it is set to ON by default - it took me ages and many posts on this forum to finally figure out why my animation footage kept ghosting. By simply turning resample off the ghosting went away completely.

JohnnyRoy wrote on 12/27/2014, 12:56 PM

> "I've never encountered a situation in which resampling looked good, or in which disabling it looked worse."

Then you've never worked with converting 24p to 60i or 60i to 24p. Vegas Pro resampling looks great when making these conversions. The process is called Telecine, and Inverse Telecine (IVTC) respectively and it's a well know algorithm that actually blends FIELDS and not FRAMES to minimize ghosting. Vegas Pro does this extremely well. That was the original intent of this function and probably how most people use it back in the day. There were several 3rd party plug-ins that claimed to do this and those of us using Vegas Pro never needed them because Vegas handled it so well.

In that same example disabling it looks worse because you either double 6 frames every 30 or loose 6 frames out of 30 every second!!! (that's 1/5th of your video missing or being doubled) It makes any quick motion very jerky and unwatchable. Smart Resample uses telecine/inverse telecine to make it look smooth again.

Remember I said that all of this was developed before 60p existed so none of it works well with 60p video.

~jr

Tim Stannard wrote on 12/27/2014, 1:00 PM

What a great thread.Cleared up a few things for me. Thanks guys.
I'll even forgive you, JR, for your US-centric point of view that the whole world has gone to 60p. :)

wwjd wrote on 12/27/2014, 3:08 PM

I agree, I am sure it has its place, but Sony believes more people are converting than not converting. hmmmmm okay. I personally don't believe that with all the modern cameras out there.

set wrote on 12/27/2014, 4:02 PM

When I did my first 'test' of NEX-VG20 (probably 2012), I recording one of the event in 50p, edit, then render in 720-25p, didn't check before upload...

After finished uploading, why it is so blurry....why I feel there's a motion blur on the movement (for this thread's word now - Why there is ghosting appear??).
I can watch it, but I get sick with those blur, I felt like my eyes have trouble seeing that.

Finally, found the problem... Disable Resample! - Rerender, Reupload.... done. Much better...

--------------

On the other side,
I found it useful for making graphic lower3rd motion for my interlaced finish video (Concert and Choir performance video) in DVD.

I create the nice Lower3rd animation in 50p, render to 50p PNG image sequence, then in my MAIN project, I put the PNG sequence in 50p frame rate and leave the resample do its' job on 'converting' it to 50i. Smooth motions.
*Did the same thing too if I need all motion graphics 'zoomed in'. Make motion graphic project VEG in 4K resolution, 50p, so when nested in final 50i project, the motion still smooth for interlaced video format needs.

Pete L wrote on 12/27/2014, 7:21 PM

Ok guys this is very informative.
Thankyou to all the contributions.
I think I am starting to get my head around it now.
I have disabled resample pretty much from day one of learning Vegas but I could never find out why.
Maybe with most new cameras coming out now, people working with Interlaced footage will become a thing of the past so maybe Vegas will eventually be set to disable as default.

I can't say that I have ever seen Ghosting but the one time I did notice its effect was using both 25p & 30p footage together & I could not render it for the life of me.
Once I selected Disable resample on the clips as I had forgotten to do it, it worked fine.

I am happy to hear anyone else's knowledgeable contributions if you want to add any.
Cheers Pete.

JohnnyRoy wrote on 12/27/2014, 8:25 PM

> "I'll even forgive you, JR, for your US-centric point of view that the whole world has gone to 60p. :)"

Forgive me... 60p or 50p. It just seems that all of the people who are complaining about Smart Resample being the default have probably gone 60p/50p because I like it as the default. The only time I could see me using 60p/50p is recording auto racing. I like to go to Lime Rock Park and my 60i videos get quite a bit of motion blur as the cars speed by. But for every day shooting I don't see the need.

~jr

Spectralis wrote on 12/27/2014, 10:42 PM

Having it set to on as default wouldn't be a problem if it switched itself off when not relevant to a project. For those new to editing or still developing their skills it's incredibly frustrating not knowing why a project is ghosting. Perhaps Vegas could ask whether to leave it on when adding clips so that at least there would be some indication that it might significantly effect footage in certain circumstances. The reminder could then be switched off if necessary. This is the only setting that has had a repeated impact on my projects so its not like there needs to be dozens of reminders for other settings.

Peter Riding wrote on 12/28/2014, 4:53 AM

I searched for a way of disabling resampling by default - no go - but found this discussion on Creative Cow:

https://forums.creativecow.net/thread/24/975063

It links to this script which you can use to disable resampling on all clips:

http://www.mediafire.com/download/jy34bsx4flyzb42/Smart+rerender+Disable.cs

Just download it to a suitable holding location.

I then had to remind myself how to install a script and found the end of this old article by Sony's Gary R useful:

http://www.sonycreativesoftware.com/scripting_in_vegas_pro_and_sound_forge

I am on Vegas Pro 13 Windows 64 bit of course, but it was easy to find the "Script Menu" location:

Program Files > Sony > Vegas Pro 13.0 > Script Menu

Just copy the download to there.

Then in Vegas go Tools > Scripting > Rescan Script Menu Folder

It will now appear in your list of scripts.

To add it to your Toolbar, double click the toolbar and find the "Smart rerender Disable" script listed in the Available toolbar buttons on the left. Select it and click Add. Then click Close.

It will now appear in your Toolbar and one click of it will disable smart resample on all your clips.

Note that it is called "rerender" rather than "resample" but it has the effect of disabling resample.

Sorry to those in the know for the longwinded explanation!

Pete

Kimberly wrote on 12/28/2014, 9:49 AM

Great thread all. Thanks Peter for the link to the script. I will load that up when I'm at my machine.

Regards,

Kimberly

Rich Parry wrote on 1/8/2015, 9:15 PM

I thought the free Timeline Tools Command Extension Utility by Gary James for Vegas Pro would be a great platform to DISABLE RESAMPLE with just a few clicks. I requested the feature only to find Timeline Tools already supports it. It works perfectly and it's easy.

Below is a cut and paste from Gary's email to me. If you don't have the tool, I encourage you to give it a try. Gary has excellent support including a user manual and even a video tutorial. The tool has a ton of features.

http://www.nfatoys.com/moasoftwarellc/Default.htm

==== The follow is from Gary, unfortunately I can't include his screen shots ===
Timeline Tools already can do what you ask. You can set the Resample mode properties of your event(s) in one of two ways. By editing the events Highlighted in the Timeline Tools main grid. Or by editing the Selected events in the selected Vegas Track. Right click-on the main Grid, then choose the appropriate item in the context menu shown.

In my example I clicked on the menu item to edit Highlighted Events. This brings up the Property editor. Look down through all the Properties listed until you find “Resample Mode” in the Event Properties Group. Clicking on the list drops down three selections: Smart, Force and Disable. Make your choice, then click on the “X” in the upper right corner of the editor to close the window. All the Highlighted Events will now have their Resample Mode settings changed to your selection.

Hope this helps.
Gary …

Gary James wrote on 1/8/2015, 9:29 PM

I'll add the screenshots I sent to you Rich.

#1. This is where the Properties Editor is opened to edit either Highlighted or Selected Events.

#2 is how you change the Resample mode property of all your chosen Events.

WayneM wrote on 3/15/2015, 4:09 PM

JUST TO CONFIRM I didn't miss something in all these messages. . .

It looks like there is no way in Options or anyplace else to have RESAMPLE Default to Off when a clip is added to the timeline.

I didn't see mention of it, but is there be a Script that would do a blanket change to all video clips on a timeline and set Resample to Disable? I'd like to also find a script to uncheck the LOOP option while I'm at it. . . .

UPDATE: Found a script at "http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=917168"

Thanks JohnMeyer!

Wayne

johnmeyer wrote on 3/15/2015, 4:24 PM

JUST TO CONFIRM I didn't miss something in all these messages. . .Well, you did, and you didn't. You didn't miss anything about a global setting: there isn't one. You DID miss the various links to scripts that will do exactly what you are requesting, namely changing every event so that resample is turned on or off. This includes the post immediately prior to yours.

Just use Ctrl-F in your browser to search this thread for the word "script" and you'll find all the links to scripts you can use.