What you need to know before touching a video file • Hacker News Board

Re: What you need to know before touching a video file

#161

Post by memoriuaysj » Fri, Jan 02, 2026, 11:23 PM UTC

ErroneousBosh wrote: post #121

memoriuaysj wrote: post #96

Earlier quoted context omitted.

it's gone in a single still frame but across many consecutive frames, the information is spread out temporaly and can be recovered (partially) the same principle of how you can get a high resolution image from a short video, by extracting the same patch from multiple frames https://en.wikipedia.org/wiki/Video_super-resolution

No, it's not "restoring detail". The information is gone. It is predicting what the information might maybe have been like.

you are arguing with math proofs here, the information is not gone, if it was a real video (as opposed to adversarily generated video)

Re: What you need to know before touching a video file

#162

Post by COAGULOPATH » Fri, Jan 02, 2026, 11:24 PM UTC

Drybones wrote: post #116

Nearly this entire HN comment section is upset about VLC being mentioned once and not recommended. If you can not understand why this very minor (but loud?) note was made, then you probably do not do any serious video encoding or you would know why it sucks today and is well past its prime. VLC is glorified because it was a video player that used to be amazing back in the day, but hasn't been for several years now. I…

Thanks, I didn't realize the situation was so dire.

Re: What you need to know before touching a video file

#163

Post by RulerOf » Fri, Jan 02, 2026, 11:25 PM UTC

ambicapter wrote: post #154

usefulposter wrote: post #124

Earlier quoted context omitted.

Many HN readers won't be familiar with the fansub culture that this writeup originates from, so sharing a helpful resource in case anyone is interested in learning more: ENTRY LEVEL FANSUBBERS' BEGINNERS GUIDE: https://github.com/zeriyu/fansub-guide Hope this helps anyone interested in the ancient art of subbing Japanese animes! Be sure to read every link thoroughly, and don't worry, there are more link lists linked…

Wait, so this categorical dismissal of VLC is just coming from a specific fandom community?

I generally dislike anime and tend to reflexively roll my eyes when someone suggests I watch it, but I've been complaining about VLC for at least 15 years.

Its main claim to fame is that it "plays everything," and it rose to prominence in the P2P file sharing era. During this time, Windows users often installed so many "codec packs" that DirectShow would eventually just have an aneurysm any time you tried to play something. VLC's media stack ignored DirectShow, and would still play media on systems where it was broken.

We're past that problem, but the solution has stuck around because "installing codecs will break my computer, but installing VLC won't" is the zombie that just won't die.

Re: What you need to know before touching a video file

#164

Post by littlestymaar » Fri, Jan 02, 2026, 11:36 PM UTC

embedding-shape wrote: post #142

littlestymaar wrote: post #131

Earlier quoted context omitted.

No it doesn't. It says “don't, Unless you're extremely surgical with it and know exactly what you're doing ”. Which is a sensible piece of advice.

> Don't use Topaz AI, Anime4k, RealESRGAN, RIFE, etc. Trust me, just don't. Is what the submission says about Topaz and similar. > Applying any kind of post-processing[4] Is what the footnote you quoted is linked to.

There's no mistake, “Topaz and similar” == “any kind of postprocessing”.

Re: What you need to know before touching a video file

#165

Post by Agingcoder » Fri, Jan 02, 2026, 11:39 PM UTC

cruffle_duffle wrote: post #54

pandemic_region wrote: post #18

Could have used this in the nineties, where hunting a specific codec to play that video you downloaded off a BBS was an actual thing.

Oh man it extended well past the 90’s. Finding some weird windows video codec in a dodgy .ru domain was a time honored tradition for quite some time. I remember all the weird repackaged video codec installers that put mystery goo all over them machine. The article bashes VLC but I tell you what… VLC plays just about everything you feed it without complaint. Even horribly corrupt files it will attempt to handle. It mi…

I used mplayer ( the ancestor to mpv as I’ve just realized ) in the early 2000s which I think could handle everything under the sun back then.

Re: What you need to know before touching a video file

#166

Post by ro_bit » Fri, Jan 02, 2026, 11:42 PM UTC

I edit videos on a hobbyist level (mostly using davinci resolve to edit clips of me dying in video games to upload to a shareX host to show to friends). The big takeaway for me was reading that for quality/efficiency libx264 is better than nvenc for rendering h264 video. All this time I’ve assumed nvenc is better because it used shiny GPU technology! Is libx264 better for recording high quality videos too? I know it will run on CPU unlike NVENC but I doubt that’s an issue for my use case.

Edit: from some googling it looks like encoding is encoding, whether it’s used for recording or rendering footage. In that case the same quality arguments the article is making should apply for recording too. I only did a cursory search though and have not had a chance to test so if anyone knows better feel free to respond

Re: What you need to know before touching a video file

#167

Post by thegrim000 » Sat, Jan 03, 2026, 12:09 AM UTC

Drybones wrote: post #116

Nearly this entire HN comment section is upset about VLC being mentioned once and not recommended. If you can not understand why this very minor (but loud?) note was made, then you probably do not do any serious video encoding or you would know why it sucks today and is well past its prime. VLC is glorified because it was a video player that used to be amazing back in the day, but hasn't been for several years now. I…

I've really felt gaslit over the last decade from people continuing to promote VLC as such a great thing, when I've had nothing bug bugs, crashes, glitches, issues with it for a full decade now (on Linux). From 10-25 years ago I definitely used it for everything, all the time, but now even the default Ubuntu totem video player (or whatever it's called) seems like 2-3 times as likely to be able to play a random video file without an issue as VLC does.

Re: What you need to know before touching a video file

#168

Post by duskwuff » Sat, Jan 03, 2026, 12:09 AM UTC

zzo38computer wrote: post #120

cruffle_duffle wrote: post #54

Earlier quoted context omitted.

Oh man it extended well past the 90’s. Finding some weird windows video codec in a dodgy .ru domain was a time honored tradition for quite some time. I remember all the weird repackaged video codec installers that put mystery goo all over them machine. The article bashes VLC but I tell you what… VLC plays just about everything you feed it without complaint. Even horribly corrupt files it will attempt to handle. It mi…

I had found that VLC does not play a MPEG-TS file very well (although it recognizes the file and plays it, it does not work very well); converting it to another format first, will cause it to play better, in my experience.

MPEG-TS files are just a pain to play in general. It was never intended as a file format for prerecorded video, and lacks some features (like seek indexes) which are required for reasonable playback.

In most circumstances, a MPEG-TS file can be remuxed (without reencoding) to a more reasonable container format like MP4, and it'll play better that way. In some cases, it'll even be a smaller file.

Re: What you need to know before touching a video file

#169

Post by avidiax » Sat, Jan 03, 2026, 12:11 AM UTC

ro_bit wrote: post #166

I edit videos on a hobbyist level (mostly using davinci resolve to edit clips of me dying in video games to upload to a shareX host to show to friends). The big takeaway for me was reading that for quality/efficiency libx264 is better than nvenc for rendering h264 video. All this time I’ve assumed nvenc is better because it used shiny GPU technology! Is libx264 better for recording high quality videos too? I know it…

Yeah, this is a very common misconception. There are hardware encoders that might be distribution quality, but these are (to my knowledge) expensive ASICs that Netflix, Amazon, Google, etc. use to accelerate encode (not necessarily to realtime) and improve power efficiency.

GPU acceleration could be used to accelerate a CPU encode in a quality-neutral way, but NVENC and the various other HW accelerators available to end users are designed for realtime encoding for broadcast or for immediate storage (for example, to an SD card).

For distribution, you can either distribute the original source (if bandwidth and space are no concern), or you can ideally encode in a modern, efficient codec like x265 or AV1. AV1 might be particularly useful if you have a noisy source, since denoising and classification of the noise is part of the algorithm. The reference software encoders are considered the best quality, but often the slowest, options.

GPU is best if you need to temporarily transcode (for Plex), or you want to make a working copy for temporary distribution before a final encode.

Re: What you need to know before touching a video file

#170

Post by joe_the_user » Sat, Jan 03, 2026, 12:11 AM UTC

embedding-shape wrote: post #9

It seems really weirdly written. It's written with a lot of authority, like saying "Don't use VLC" and "Don't use Y" yet provides no reasoning for those things. Just putting "Trust me, just don't" doesn't suddenly mean I trust the author more, it probably has the opposite effect. Some sections seem to differ based on if the reader knows/doesn't know something, but I thought the article was supposed to be for the latt…

Yeah, as far as I know, to understand video formats, you need to understand encode-decode process, how film/video editor operate normally (keeping in mind film/video editing has levels from $100s to way beyond me), history, how optics and cameras work, etc. Then particular choices and confusions can be understood.

This indeed just seems to jump-in in the middle and give a bunch very specific recommendation. I have no idea if they're good or bad recommendations but this doesn't seem like the way to teach good procedures.