what causes this stuter and how can i fix it ?

[zanzar]

what causes this stuter with a simple script like this

https://forum.videohelp.com/images/imgfiles/QvMhEUN.jpg
https://forum.videohelp.com/images/imgfiles/3EQSq0W.jpg

v = LWLibavVideoSource("d:\4.mp4", fpsnum=30000, fpsden=1001, format="YUV420P8")
a = LWLibavAudioSource("d:\4.mp4")
AudioDub(a,v)
ConvertToYV12()
ColorMatrix(mode="Rec.601->Rec.709")
ColorYUV(cont_u=20, cont_v=20)
nnedi3_rpow2(2, cshift="Spline36Resize", fwidth=1280, fheight=720)


i guess it doesnt take the source really well

any suggestions?

[jagabo]

Stuter? You mean stutter? How can one see stutter with two still frames? What are the two images showing us?

[zanzar]

Stuter? You mean stutter? How can one see stutter with two still frames? What are the two images showing us?

sorry that i wast clear do you see the difference in the images?
they are identical exept one is the original and one is encoded by the script you see how it resulted in some kind of back ground noise and became less clear

that is what i am asking

for example look at the glasses
after the encode they became like less straight i can say

[sneaker]

But the output screenshot is not directly from the script, is it? You probably encoded using a lossy encoder (x264?) that introduced additional quality loss - that's what lossy encoders do. If you want less quality loss you need to put in more bitrate and/or CPU time (different preset or even x265) and/or otherwise better tuning.

Of course your process is questionably anyways. You aren't really filtering out any artifacts. It's not worth re-encoding that way IMHO.

[pandy]

sorry that i wast clear do you see the difference in the images?

Stutter is term related to motion as such single picture can't have stutter at all - it is static...

[jagabo]

So the first image is the original video upscaled to 1920x1080 by the player and the second image is the video upscaled to 1280x720 via nnedi3, encoded with a lossy codec, then upscaled to 1920x1080 by the player? I'd agree with sneaker, you made no attempt to reduce artifacts in your source so they were accentuated by the first upscale. Then the encoding was at too low a bitrate for the material, generating more artifacts. Then player upscaled and accentuated the artifacts even more.

In the future it would be better if you uploaded a sample of your source, and a sample of your final video.

[zanzar]

So the first image is the original video upscaled to 1920x1080 by the player and the second image is the video upscaled to 1280x720 via nnedi3, encoded with a lossy codec, then upscaled to 1920x1080 by the player? I'd agree with sneaker, you made no attempt to reduce artifacts in your source so they were accentuated by the first upscale. Then the encoding was at too low a bitrate for the material, generating more artifacts. Then player upscaled and accentuated the artifacts even more.

In the future it would be better if you uploaded a sample of your source, and a sample of your final video.

i now see that if i mimp up the bit rate like to 3000 in x265 it looks better
also how do i remove some of the artifacts and why are they caused?
why if i put it trough the encoder and spit it out at the same bit rate why doesnt it come the same?

sorry i really dont know about this stuff

thank you for trying to help me

[jagabo]

also how do i remove some of the artifacts and why are they caused?

They are caused by the lossy compression of your source. DCT ringing and blocking artifacts.
https://en.wikipedia.org/wiki/Compression_artifact

why if i put it trough the encoder and spit it out at the same bit rate why doesnt it come the same?

The bigger frame needs more bitrate. Each round of lossy compression adds more artifacts.

[zanzar]

also how do i remove some of the artifacts and why are they caused?

They are caused by the lossy compression of your source. DCT ringing and blocking artifacts.
https://en.wikipedia.org/wiki/Compression_artifact

why if i put it trough the encoder and spit it out at the same bit rate why doesnt it come the same?

The bigger frame needs more bitrate. Each round of lossy compression adds more artifacts.

so what is the solution to minimize it ?
encode with higher bit rate?

[jagabo]

You can reduce ringing artifacts with de-ringing filters, blocking artifacts with deblocking filters. Use higher bitrates to keep such artifacts from coming back when you re-compress. And better encoder settings.

Look into Toon() or Deen() for animated material. Your video probably needs levels adjustments too.

[zanzar]

You can reduce ringing artifacts with de-ringing filters, blocking artifacts with deblocking filters. Use higher bitrates to keep such artifacts from coming back when you re-compress. And better encoder settings.

Look into Toon() or Deen() for animated material. Your video probably needs levels adjustments too.

umm it looks like i dont understand nothing in this stuff

should i encode something with like 10000 bit rate x265 and then use something like handbrake?

because with even with 5000 bit rate it looks grate and even the artifacts that were present in the original video disappeared and it looks smooth