Many webm didn't played smooth. I solved it by reducing the number of processes are taken at the same time when more tabs are open with firefox but why do webm even take sometimes so much RAM?

Because decoding WEBMs to display images and play audio is a complicated process.

This is a problem with your computer, not with e621.

go to about:support and check the Graphics section
see if anything looks out of place, particularly anything that might indicate FF is not making use of your graphics card

lafcadio said:
Because decoding WEBMs to display images and play audio is a complicated process.

This is a problem with your computer, not with e621.

hmm... maybe I'm just missing too much knowledge about this but shouldn't bufferings solve such problems? The video is moving on while the frame stays. Very frustrating sometimes.

I know that it's because of my hardware but I thought there'll maybe be people more knowledgeable about this and would/could elaboarte maybe. Also I thought if there are some other people having similar problems, they could maybe find the solution in this post

agiant said:
hmm... maybe I'm just missing too much knowledge about this but shouldn't bufferings solve such problems? The video is moving on while the frame stays. Very frustrating sometimes.

I know that it's because of my hardware but I thought there'll maybe be people more knowledgeable about this and would/could elaboarte maybe. Also I thought if there are some other people having similar problems, they could maybe find the solution in this post

well you were complaining about RAM usage; increasing buffer lengths would lead to *higher* memory consumption

i haven't seen anyone else mention having trouble with webms; i guess reducing the content-process limit will be a solution to keep in mind for the future then 🤷

bipface said:
well you were complaining about RAM usage; increasing buffer lengths would lead to *higher* memory consumption

i haven't seen anyone else mention having trouble with webms; i guess reducing the content-process limit will be a solution to keep in mind for the future then 🤷

Buffering was kinda stupid question. You're right.
But maybe I should:ve thoguht more before i posted this and wrote my comment.
My problem was that webm did play with freezing at one frame. If there was sound that would not stop. Also the bar would move on.
2 things got me to the conclusion that webms take too much RAM sometimes
-it looks like webms do something else than videos on youtube. I believed that youtube videos got temporary downloaded(buffered) and got shown. That means if I "buffered" all the video i could jump to the spot I want. Somehow it looked like webms do the processing for the specific time at which the video is while deleting what was processed already: waiting and jumping didn't solve anything and while jumping lead to that loading symbol.
-I think it's that what you call content-processes. That's set to 8 with firefox as a default. There is also stated that a higer count could lead to more RAM usage but better performance with many tabs. I set it to 4 and had no problems so far. So I thought it's RAM

So, yes, my problem is solved at the time being and I should've thought and researched (what I will certainly do) before writing difficult to understand gibberish here XS.

PS: I didn't understand what you mean with about:support. Sorry XS
And thank you very much :)

agiant said:
-it looks like webms do something else than videos on youtube. I believed that youtube videos got temporary downloaded(buffered) and got shown. That means if I "buffered" all the video i could jump to the spot I want. Somehow it looked like webms do the processing for the specific time at which the video is while deleting what was processed already: waiting and jumping didn't solve anything and while jumping lead to that loading symbol.

Youtube does default to VP9/Opus WebM, yes, but additionally they are also using DASH. This was contriversal back in the day they introduced this as people had issues initially and even now for compatibility they do serve videos up to 720p as non-DASH variations.
So what this means is that the video is actually literally in tens and hundreds of parts and when you scroll around the video, it's starting to load up the parts you actually need, instead of trying to buffer single individual video file from specific part. Makes things not only faster, but harder to rip for example, even now you do need ffmpeg on your %PATH% on windows if you use youtube-dl and want anything over 720p MP4 file.

agiant said:
My problem was that webm did play with freezing at one frame. If there was sound that would not stop. Also the bar would move on.

This is generally a result of not enough CPU power to decode the video. Either you have a weaker CPU that can't decode the video fast enough, or firefox is not configured to use what it otherwise could. This happens often to me with 60fps videos or 1080p videos, and sometimes 720p videos. In my case, I know it's because my processor has trouble keeping up. Youtube often works better because it recompresses the video at different sizes/rates, 1080p60, 720p60, 480p30, 360p, etc, and tries to automatically select the version that works on your system (it will even dynamically change it during playback, reducing the quality if it detects the video is stuttering, or increase the quality if it detects you have power to spare for a higher quality version).

Unless you're on a computer from 2010 or earlier your RAM should not be too slow for webm files below 1080p or below. You could check if flipping the switch on hardware acceleration changes anything for you, that's usually the more realistic problem if you have a dated PC.
Alternatively, the amount of process limits are more heavily tied to your core and hyperthread capabilities of your CPU than to RAM.

As such, you may want to check if your CPU is getting hotter than it should, and if so clean out the thermal paste and replace it with new one. If it throttles due to excessive heat it might very well lead to stutters, but you'd also likely see that happening when playing video games.

Funny story. My computer has heatsinks on the RAM and you're supposed to have a fan pointing at them and the voltage regulator as well. It's not a gaming PC but a repurposed server. Had issue when I let a RAM module get to 95 degrees Celsius! XD

Yeah, newer CPUs will throttle down if overheated, while ancient ones just crashed and burned (literally, almost). I've seen this issue on older systems with too high of resolution of specific codecs in VLC or other players, and only solutions were to try it on a faster system. Note though, that you can also get issues with not having proper video drivers installed or the like, failing hardware, or running things with almost no free RAM left (swap doesn't count!). It would be funny if the problem vanishes when cleaning the CPU heatsink as mentioned above. :)

Thank you so much everyone. I already had fun reading your posts and also got some pointers. I'll surely do my own research first before I further elaborate it here with my halfbaked knowledge.
My notebook dates to 2011. Was at that time not the best but good one but slowly too old for many things :D. Also yeah I should have done the cleaning a few more times already XD

Another interesting story. I heared from an acquaintance that he knew somebody who wanted to install a big programm or something but the processors overheated. After the third try or so they understood the problem, opened the case and got a cup with water. They droped every few minutes a water drop on the heatsink and got it to install :D