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Re-encode video AND repair stuttering?

Started by thoste, January 31, 2023, 05:06:34 PM

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thoste

Occasionally I create a video with my 2 year old Samsung Galaxy Smartphone cam

Used Codecs: AVC and AAC LC
Bitrate 20 Mbps and 30 fps
MP4 container

The colors & sharpness is almost perfect.
But I can observe a little (!) stuttering.

Since this stuttering is visible on all my computers it means that the original from Smartphone is already created with stuttering. Maybe its because of only 30 fps (=maximum available for that resolution on my smartphone).

Now I want to "repair" it (by re-encoding it with Avidemux).
I can imagine that increasing from 30 fps to 60 fps could solve the problem.
If - and only if - Avidemux is able to smart calculate new intermediate inserted frames.

What do I have to consider when setting up Avidemux for this un-stuttering?

What else could help to smooth the video movements?

eumagga0x2a

You should analyze the nature of the problem first. Either the video has variable FPS with large gaps in PTS or PTS are wrong or there is a superposition of both.

If it is the former, you could try to fill the gaps using the "Resample" filter with motion compensation enabled (most probably, this won't produce satisfactory results but there is nothing else one could do in Avidemux).

If PTS are wrong, you could export a short selection as a series of JPEG images, load the generated pictures in Avidemux and see whether the video looks smooth with constant FPS.

Nothing will help in case of a mixture of irregular FPS and wrong PTS.

thoste

#2
I think not fast moves of peoples and cars are the problem but fast camera pans.

When I focus on slow-moving traffic or slowly walking people the smartphone is able to encoding it in good quality.

In contrast when the motif is almost fixed like mountains or landscape scenery and I move the smartphone to capture everything with in a 180 or 270 deg angle then the resulting video has problems with stuttering.

I am using a Samsung Galaxy A52s smartphone which is not top-ranking but pretty good and produced e.g. excellent photos.

So again any chance to "repair" the smartphone videos later?

eumagga0x2a

Quote from: thoste on June 18, 2023, 11:00:11 AMIn contrast when the motif is almost fixed like mountains or landscape scenery and I move the smartphone to capture everything with in a 180 or 270 deg angle then the resulting video has problems with stuttering.

Looks like image stabilizer feature in the smartphone ruining the day. This is IMHO not recoverable other than with advanced AI, disable the stabilizer when possible.