Juddering in encoded HD video

[akkers]

w2testb.mpg

This is one sample. Wath carefully the moving scenes.

[akkers]

wcars2.mpg
Another example.

Both tghese clips are from original mpeg2 file and have been 'cut' using avidmux without audio to keep filesize down.

[poisondeathray]

w2testb.mpg has been deinterlaced at some point, so you are missing 1/2 the information. Top & bottom fields contain the same information, instead of different information

What do you mean by from "original mpeg2 file?" . Is the mpeg2 file the export from premiere?

Describe your exact steps you did to get w2testb.mpg or Post screenshots of your settings

[_Al_]

That looks all right, just low shutter speed, 1/25 ?, movement is blurred. With this setting you cannot pan, just to follow object etc.

edit, is it from Canon HV30 or so, shot as progressive but inside interlace wrapper ? In this case you need set progressive flags inside editor or ReStream....

[jagabo]

wcars2.mpg and w2testb.mpg are encoded 25 fps interlaced TFF but contain 25 fps progressive frames with mismatched pairs of fields. Open the files with VirtualDub and add the Field Delay filter (TFF). You'll see they now have no comb artifacts. Somewhere along the line your source was deinterlaced to progressive frames, then the fields were recombined out of phase*. So now we need to see samples of your intermediate files to determine where the problem(s) happened.



* Say you have progressive frames numbered:

 1 2 3 4 5...

You the split that into a sequence of top and bottom fields:

 1t 1b 2t 2b 3t 3b 4t 4b 5t 5b

then you discard the first field:

  1b 2t 2b 3t 3b 4t 4b 5t 5b

and recombine the remaining fields:

 (1b2t) (2b3t) (3b4t) (4b5t)

Each frame now contains one field from one frame and another field from another frame. Even though you started with progressive frames every frame now looks interlaced. This can be fixed by splitting the frames into fields again:

 1b 2t 2b 3t 3b 4t 4b 5t

throwing away the first field:

 2t 2b 3t 3b 4t 4b 5t

and recombining again:

 (2t2b) (3t3b) (4t4b)...

That's what VirtualDub's field delay filter does. It will restore the progressive frames. But it can't fix the fact that you lost half your temporal resolution when the video was deinterlaced.

[_Al_]

Is it possible that avidemux did this to that original, and that just original has fields in order (progressive inside interlace wrapper),
what camera would shoot like that?

The name of the camcorder would help.

[aedipuss]

the canon hv30/40 and many others record 25/30p in a 50/60i stream.

[_Al_]

the canon hv30/40 and many others record 25/30p in a 50/60i stream.

yes but the mpg posted are kind of out of faze, like jabago says,
I shoot progressive with HV30, and then set video to progressive inside Restream,
if I do the same thing with posted mpg it will introduce combing, so I presume it is out of faze like jagabo describes ...

[jagabo]

The OP uploaded a source file in this post:

https://forum.videohelp.com/threads/341052-Juddering-in-encoded-HD-video?p=2124863&view...=1#post2124863

Although he misnamed the file .AVI it's an mpeg transport stream with fully interlaced video (50 different fields per second).

[_Al_]

The uploaded a source file in this post:

https://forum.videohelp.com/threads/341052-Juddering-in-encoded-HD-video?p=2124863&view...=1#post2124863

Although he misnamed the file .AVI it's an mpeg transport stream with fully interlaced video (50 different fields per second).

thanks, ok

[akkers]

The original files from a HDV cam and were around 10gb each; hard to post anywhere. I used avidemux to 'copy' the small chunks of video to new files which I have posted above. As I said if I play these files in WMP they show large amount of combing - more than I have seen with any interlaced material.

If I loafd these files into CS4 and export to mpeg 1440i upper field and default settings - I get the following file:

wcars-pp-m2-default.mpg

[_Al_]

ok, I know now that the original is not recorded as progressive, I did not read the whole thread or forgot it already, sorry.

[jagabo]

The original files from a HDV cam and were around 10gb each; hard to post anywhere. I used avidemux to 'copy' the small chunks of video to new files which I have posted above.

If that's true then your camcorder is shooting 25p, and storing as 25i with fields combined out of phase. That seems very unlikely.

And then what is the file in this post:
https://forum.videohelp.com/threads/341052-Juddering-in-encoded-HD-video?p=2124863&view...=1#post2124863

[poisondeathray]

"wcars-pp-m2-default.mpg " has been deinterlaced (1/2 the original fields are missing) and processed improperly as jagabo described above

Post your sequence settings, export settings and file interpretation settings

Why are you exporting as mpeg program stream (mpg) , not HDV (.m2t) ? I'm assuming original footage was HDV

[akkers]

That was from file1 of the same batch cut using avidemux using the copy method (although erroreneously wrapped it in avi).

[akkers]

I have tried the Field Delay in VD and that has got rid of combing at least. Now I have to see this if this has got rid of teh judder on the tv.

[jagabo]

I have tried the Field Delay in VD and that has got rid of combing at least. Now I have to see this if this has got rid of teh judder on the tv.

No, it will still have the same flicker.

[akkers]

Sorry this is the correct file exported out of CS4 in mpeg2.

wcar3-pp-m2mpg.mpg

[akkers]

This is teh file exported out of CS4 in H264 with default settings and upper field first.

wcars-pp-h264.mp4

[poisondeathray]

Sorry this is the correct file exported out of CS4 in mpeg2.


[Attachment 10043 - Click to enlarge]

"wcar3-pp-m2mpg.mpg" has been processed in the same way (missing 1/2 the original fields)

Unless your original file was recorded incorrectly, it has to be your premiere settings

Unless, perhaps you accidentally recorded some clips at 50i, some at 25p

[_Al_]

Can you mention what kind of camcorder was used to record this ?

[akkers]

I am not sure what the cam was - I am trying to find out. I think it was some kind of semi-pro gear.

I am not changing any settings in CS4. I am just taking the default settings for Mpeg2 1440i.

I have also posted the h264 version above as well. Is that missing 1/2 the fields as well?

[_Al_]

Semipro would produce correct (50i upper field first) Are the project settings the same as export settings. Perhaps Premiere is influenced by it regards to export ? I do not have Premeire. Hopefully you do not have mixed 50i and 50p inside 50i wrapper on one tape if there could be such a thing.

[poisondeathray]

I am not sure what the cam was - I am trying to find out. I think it was some kind of semi-pro gear.

I am not changing any settings in CS4. I am just taking the default settings for Mpeg2 1440i.

I have also posted the h264 version above as well. Is that missing 1/2 the fields as well?

Yes same problem. Post the original cars clip ; if that is ok (a true interlaced 50i HDV stream, like the AVI clip you posted), then it has to be your premiere settings

[aedipuss]

The original files from a HDV cam and were around 10gb each; hard to post anywhere. I used avidemux to 'copy' the small chunks of video to new files which I have posted above. As I said if I play these files in WMP they show large amount of combing - more than I have seen with any interlaced material.

If I loafd these files into CS4 and export to mpeg 1440i upper field and default settings - I get the following file:


[Attachment 10041 - Click to enlarge]

something's severely mucked up. here is a vlc screenshot with de-interlacing turned off. i count part of 8 frames in this one field. count the number of index fingers.



i shoot 30p with canon HV30 all the time and have never had any problem. both fields of a 25/30p frame are recorded at the same time so it really doesn't make any difference if it's called progressive, tff, or bff. when combined all of those create the same frame in the 50/60i stream.

[akkers]

The footage was given to me on mpeg2. I believe it was a HDV tape camera and they probably captured it straight into mepg2 file.

btw I tried the fuield delay filter in VD - it makes a lot of difference on pc, the resulting footage lpooks more stable and cleaner. However, on tv the judder is still there. So the field delay has not did not do anything to get rid of the judder.

So have we discounted the theory that it may be a progressive stream in an interlaced wrapper? If it was how would you get teh progressive stream out?

[poisondeathray]

The footage was given to me on mpeg2. I believe it was a HDV tape camera and they probably captured it straight into mepg2 file.

Post the original file of the cars clip; this is the only way we can tell if it's ok or if it's something as simple as premiere setting

If it was given to you as .mpg , use mpg2cut2 to cut a section

btw I tried the fuield delay filter in VD - it makes a lot of difference on pc, the resulting footage lpooks more stable and cleaner. However, on tv the judder is still there. So the field delay has not did not do anything to get rid of the judder.

As jagabo described, this only helps the field offset, it's still 25p (half the information) , so it will still be jerky . You need true 50i for it to be smooth

So have we discounted the theory that it may be a progressive stream in an interlaced wrapper? If it was how would you get teh progressive stream out?

It doesn't affect you , because 25p in 50i is still 25p (will still be jerky compared to true 50i)

[_Al_]

I think aedipuss is right, even if it was 25p inside 50i, there would be regular results exporting and such, something else is going on here for sure,...hard to believe that premiere would do such an export,....,

I would just ask again what is project settings in Premiere?

[akkers]

A section cut of the original file is in post 62 (wcars2.mpg).

I used avidemux to cut the piece.

If I use meg2cut2 then it comes up with an error:

TS format inside .MPG file ***
Format not fully supported...

[poisondeathray]

A section cut of the original file is in post 62 (wcars2.mpg).

I used avidemux to cut the piece.

If I use meg2cut2 then it comes up with an error:

TS format inside .MPG file ***
Format not fully supported...

Then the problem is the original file. Whoever gave this to you screwed up. Ask them to recapture and send you the original .m2t HDV files

On the slight chance that avidemux screwed up, try tsmuxer (split & cut tab) to cut a piece, or tssniper

It's possible to repair or interpolate fields with avisynth, but there are side effects like motion artifacts, takes longer to process, and there is a bit of a learning curve. Better idea to get the original undamaged files