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Comment by brucethemoose2 | Hacker News Reader

Meanwhile, I've been enjoying threaded filter processing in VapourSynth for nearly a decade.

Not that this isn't great. Its fantastic. But TBH its not really going to change my workflow of VapourSynth preprocessing + av1an encoding for "quality" video encodes.

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Interesting! I'm among today's lucky 10,000 in learning for the first time about VapourSynth.

How come it only has 4 measly entries in HN, and none got any traction. I've posted a new entry, just for the curiosity of others.

FFMPEG does so much more than just video encoding. I use ffmpeg all day every day, and only a fraction of the time do I actually make a video.

Can you run doom on it?

Vapoursynth can be used for image processing too (albeit more clumsily with variable size input), and its also a great way to hook into PyTorch.

Does it can fix broken files?

It reads image sequences with imagemagick or ffmpeg, but in place repair is not its thing, no.

Like what do you do?

One can use it instead of cat to display text files. Easy syntax to remember.

  ffmpeg -v quiet -f data -i file.txt -map 0:0 -c text -f data -

I use dd for that.

    dd if=./file.txt

Can you also format your drive with ffmpeg? I'm looking for a more versatile dd replacement..

It can't create partition tables or filesystems, so no, but

  ffmpeg -f data -i /dev/zero -map 0:0 -c copy -f data - > /dev/sda

is roughly equivalent to to

  dd status=progress if=/dev/zero of=/dev/sda

you might need a -disposition default type option, otherwise, it introduce some abnormal behavior

I'm dying.

https://www.youtube.com/watch?v=9kaIXkImCAM

"Do you know ffmpeg supports OCR? I haven't found the command yet, but it does support it."

This is probably 80% of my experience with ffmpeg, to be honest, but the other 20% is invaluable enough anyway.

I thought this was a joke, but it really exists! https://ffmpeg.org/ffmpeg-filters.html#ocr

Lol what. I have a bot that processes ~50 videos a day, burning in translated whisper-generated subtitles. It also translates images using Tesseract, then overlaying texts in-place. I once thought of exporting frames as images to maybe do this for video too, I actually did not even start to think FFMPEG would have tesseract support on top of everything.

Later on though I've realized the quality of tesseract's OCR on arbitrary media is often quite bad. Google translates detection and replacement is so much ahead my current image system I'd think I would just somehow reutilize that for my app, either thru public API or browser emulation ...

I'm glad we've reached a point where there is quality parody content online for our industry.

Check out Krazam. I quote their Microservices video on a regular basis (https://youtu.be/y8OnoxKotPQ)

THIS!!! It was so refreshing!

That was one of the funniest things I've seen in a while!!!! I had to stop drinking my decaf for fear of spitting it all over my computer I was laughing out loud so much!

(ps: and no, it's not Rick Astley/Never Gonna Give You Up)

The artfully inserted, corrupted predicted frames was :chefskiss:

Good thing it's now multi-threaded so it can process all those command line arguments in parallel!

I bet ffmpeg special cases that combination of flags and calls cat.

Ah now I can replace all my useless uses of cat with ffmpeg

That doesn't work[1], but

  ffmpeg -v quiet -f data -i file.txt -map 0:0 -c copy -f data -

does.

[1] “Encoder 'text' specified, but only '-codec copy' supported for data streams”

can I use ffmpeg to embed a gif in a Hacker News comment, because I want that so much right now

No, but you can use ffmpeg to create a GIF from ASCII art embedded in a Hacker News comment:

  $ ffmpeg -v quiet -codecs | egrep -i 'gif|ascii'
   D.V.L. ansi                 ASCII/ANSI art
   DEV..S gif                  CompuServe GIF (Graphics Interchange Format)

(“D” and “E” in the first field indicate support for decoding and encoding)

Beside video conversion/compression ? Sound extraction or processing, image processing, video casting or streaming, anything related to image/multimedia format, basically

I've used it for video and audio concatenation of laserdisc game segments, transcoding audio clips for gamedev, programmatically generating GIFs of automatically generated video clips from tests in a CI pipeline, ripping songs and audio clips from YouTube videos to ogg/mp3, creating GIFs from burst-shot and time-lapse photography (and decimating them), excerpting clips from a video without re-encoding, and compressing or transforming audio on remote servers where VLC wasn't and couldn't be installed.

Sounds like you already have a process for most of this, but I found https://github.com/mifi/editly to be incredibly helpful to run ffmpeg and make my little time lapse video. Could be useful for others

I use ffmpeg everytime I download a YouTube video.

ffmpeg can produce an amazing amount of analysis

you can make gif's with it

I'm guessing from context that VapourSynth is a frame-server in the vein of avisynth? If so, does it run on Linux? Avisynth was the single biggest thing I missed when moving to Linux about 20 years ago.

[edit]

found the docs; it's available on Linux[1]. I'm definitely looking into it tonight because it can't be worse than writing ffmpeg CLI filtergraphs!

1: http://www.vapoursynth.com/doc/installation.html#linux-insta...

20 years ago, the best feature of avisynth was running random plugin dlls downloaded from doom9, none with source code and all running on an XP Administrator account.

The frameserver is one thing, but an ecosystem of (trustable! open source!) plugins is harder to replicate.

At least we don't need deinterlacers so badly any more, though.

They have pretty much all been ported, and much more! VapourSynth can do a lot more than AviSynth can.

Yep, and its so much better than ffmpeg CLI that its not even funny.

This is a pretty good (but not comprehensive) db of the filters: https://vsdb.top/

I believe I have too with gstreamer's pipe framework for threading, but ffmpeg's syntax has stuck in my mind far longer than any of the elaborate setups I built with gstreamer. I'm excited for this development

I don't understand why you would want to piggyback on this story to say this.

are people just itching for reasons to dive into show & tell or to wax poetic about how they have solved the problem for years? I really don't understand people at all, because I don't understand why people do this. and I'm sure I've done it, too.

Not gonna lie, I think VapourSynth has been flying under the radar for far too long, and is an awesome largely unused alternative to ffmpeg filter chains in certain cases. I don't see any harm in piggybacking on an ffmpeg story to bring it up, especially if readers find it useful.

It's been threaded since its inception, so it seems somewhat topical.

There is hype for FEAT. People who have achieved similar FEAT perk up their heads but say nothing.

Hype for FEAT is beyond sensibility. People with similar FEAT are bristled by this and wish that their projects received even a fraction of FEAT's hype.

I think it's normal.

not gonna define FEAT, then? ok.

...in this case, multi-threading. In other cases; AI workflows that others commercialize, a new type system in a language that already exists in another, a new sampling algorithm that has already existed by another name for decades, a permaculture innovation that farmers have been using for aeons, the list goes on...

just say "feature".

language is for communicating. don't impede that communication by using unnecessary terms.

I was trying to generalise a concept so I used a placeholder word. I feel that most people got that.

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