Deinterlacing HD videos

[Gio21stri]

Hi, I have 13 gb tv show episode (here's excerpt https://drive.google.com/file/d/1SrlqOcT1tcD2TIMdeSJb7d8fYZ1zEo8e/view?usp=sharing),
I want to compress it in avidemux - but every deinterlacing filter i tried gives bad result - video is not smooth like original, movements looks like there is frames missing from every second - best example in ending titles -titles flickering while scrolling -here is excerpt of that render -  https://drive.google.com/file/d/1RIL2MV5fbUJgRSyrdQJ-n-RJUAo7DG4K/view?usp=sharing

Can it be fixed?

[eumagga0x2a]

Please ensure that you use the latest nightly build (vsWin64 or win64) --> https://avidemux.org/nightly/

The result of deinterlacing carried out by the Yadif video filter (mode: field, temporal & spacial check; order: top field first) looks perfectly for me with Avidemux built from the current code.

[Gio21stri]

Thanks, looks good - i'll try to render full episode like that

[Gio21stri]

Yes that works - file becomes bigger than with libavdec - but i think its the only way (im sitting of the forums for 4 days now), thanks

[eumagga0x2a]

Not sure what you mean by libavdec here, at least libavcodec doesn't do any filtering / deinterlacing. Yadif in that particular mode creates a full frame out of each field, so obviously there is more data to be compressed by a codec later. Doubling the frame rate is necessary to achieve smooth motion.

[dosdan]

Not sure what you mean by libavdec here, at least libavcodec doesn't do any filtering / deinterlacing. Yadif in that particular mode creates a full frame out of each field, so obviously there is more data to be compressed by a codec later. Doubling the frame rate is necessary to achieve smooth motion.

Thankfully, for years, I haven't had to worry about deinterlacing. But it's interesting to experiment with this "Drake" clip.  YADIF in a FIELD mode doubles the frame rate, but it isn't duplicating frames.



If you load this clip into a program that shows frame numbers, and then single-step between frames, (I used Virtualdub2), and look at the top of the "PRODUCED BY" credit at the start, it takes 37 frames to reach the top of the frame in FIELD mode and 18.5 frames in FRAME mode (Frame 18 is not quite there, while Frame 19 is just over the top).  The frames in FIELD mode are all different so it's not straight duplication. The vertical movement of the credits is larger between each frame at the lower frame-rate, which is why 59.94fps looks smoother here.  Individual deinterlaced frames, at both frame rates, when stopped, look fine, so the smoothness is to due to the amount of changed position of an object BETWEEN frames.

The vertical deinterlaced motion inside ADM, when previewing, showed small amount of jerkiness, which I believe is due to processing load (My PC is old). But I confirmed the 29.97 vs 59.94 fps smoothness by saving FRAME/FIELD deinterlaced MP4s with different names and them comparing them in MPC-BE or VLC against the original clip.

Dan.

[eumagga0x2a]

The frames in FIELD mode are all different so it's not straight duplication.

A deinterlacer in frame-for-field (bob) mode is never supposed to duplicate frames. It fills missing lines in each field based on the other field and the previous field pair (in principle, it can use a list of past and future frames for a better motion estimation).

The vertical deinterlaced motion inside ADM, when previewing, showed small amount of jerkiness, which I believe is due to processing load (My PC is old).

Additionally, we have a big problem when frame rate is equal or very close to display refresh rate which often happens to be 60 fps. The GUI may become unresponsive.