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  embedding-shape
  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 latter.Would have been nice if these "MUST KNOW BEFORE" advises were structured in a way so one could easily come back and use it as a reference, like just a list, but instead it's like a over-dinner conversation with your "expert and correct but socially-annoying" work colleague, who refuses to elaborate on the how's and why's, but still have very strong opinions.
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  EdNutting
  Interesting read, it’s a shame the ranty format makes it 3x longer than necessary.Not sure why it takes a dump on VLC - it’s been the most stable and friendly video player for Windows for a long time (it matters that ordinary users, like school teachers, can use it without special training. I don’t care how ideological you are about Linux or video players or whatever lol).
• buzer
  I would disagree somewhat on his stance that video quality is not affected by container format (especially on part "Here is a list of things that people commonly associate with a video's quality"). Different container formats have different limitations regarding what video (and audio) formats they support. And while it subtitles support doesn't directly affect video quality, it does do so indirectly. If you cannot add subtitles without hardsubbing or subtitle formats are so limited that you end up needing hardsubbing anyway then the choice of the container format ends up affecting the video quality.
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  happytoexplain
  I'm always amazed when I see how many people are unfamiliar with VLC hate. It was notorious (to the point of it being a popular meme topic) for video artifacts, slow/buggy seeking, bloated/clumsy UI/menus, having very little format support out of the box, and buggy subtitles. I assume nowadays it's much better, since it seems popular, but its reputation will stick with me forever.
• mmcclure
  Shameless plug for anyone that wants to go deeper on specific video topics: I've been organizing a conference for video devs for 11 years now and there's a wealth of info in the recordings. A talk from the most recent one on hacking a Sega Genesis to stream video might not seem that practical, but there were some fascinating bits on compression (or, rather, not being able to use actual compression). https://www.youtube.com/watch?v=GZdxdpw-3nIIf folks want to get involved, there's also a chat community that's pretty active: https://video-dev.org.
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  weinzierl
  "Don't use Topaz AI, Anime4k, RealESRGAN, RIFE, etc. Trust me, just don't."Why? I only know Topaz and I always thought it had its narrow but legitimate uses cases for upscaling and equalizing quality?
• coppsilgold
  MPV plugins can actually do frame-perfect cuts and crops for you (+ whatever ffmpeg filters you want), something that would generally require the hassle of opening editing software. And those cuts can be done in h264 lossless (for additional processing later at no additional quality loss from this step).https://github.com/occivink/mpv-scriptsThere is also a way to losslessly cut preserving the original encoding but you give up the precision of the cuts due to keyframes. The MPV script above can do that too: script-opts/encode_slice.conf
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  jokoon
  I wish he talked about avidemux.It's a simple tool which is great for many things, it has filters and there are most of the formats. I think it uses ffmpeg under the hood.It's an old tool but it's fine for most things, when ffmpeg is to fastidious to use. ffmpeg is still what I use, but some more complex tasks are just more comfortable with avidemux.
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  craftkiller
  Something I've never been able to find satisfactory information on (and unfortunately this article also declares it out of scope), is what is the actual hard on-the-wire and on-disk differences between SDR and HDR? Like yes, I know HDR = high dynamic range = bigger difference between light and dark, but what technical changes were needed to accomplish this?The way I understand it, we've got the YCbCr that is being converted to an RGB value which directly corresponds to how bright we drive the R, G, and B subpixels. So wouldn't the entire range already be available? As in, post-conversion to RGB you've got 256 levels for each channel which can be anywhere from 0 to 255 or 0% to 100%? We could go to 10-bit color which would then give you finer control with 1024 levels per channel instead of 256, but you still have the same range of 0% to 100%. Does the YCbCr -> RGB conversion not use the full 0-255 range in RGB?Naturally, we can stick brighter backlights in our monitors to make the difference between light and dark more significant, but that wouldn't change the on-disk or on-the-wire formats. Those formats have changed (video files are specifically HDR or SDR and operating systems need to support HDR to drive HDR monitors), so clearly I am missing something but all of my searches only find people comparing the final image without digging into the technical details behind the shift. Anyone care to explain or have links to a good source of information on the topic?
• kwar13
  Pretty good writeup but not sure why VLC is not recommended...?
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  Jabrov
  What's wrong with VLC?
• eviks
  > I would recommend you to just learn basic ffmpeg usage instead > but ffmpeg is fine for beginnersNo, that's just nonsense for any guide targetting beginners, it's not fine, it's too error-prone and complicated and requires entering the whole unfriendly land of the cli!> If you must use a GUIOf course you must! It's much better to provide beginners with your presets in Handbrake that avoid the footguns you mention (or teach them how to avoid them on their own) rather than ask them to descend into the dark pit of ffmpeg "basics"> Before you start complaining about how complicated ffmpeg is and how arcane its syntax is, do yourself a favor and read the start of its documentation. It turns out that reading the (f.) manual actually helps a lot!It turns out that wrapping the bad UI in a simpler typed GUI interface wastes less of the collective time than asking everyone to read dozens of pages of documentation!
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  netsharc
  The second technical definition in this document is wrong. Great way to put the "the author is opinionated but is clueless" marker right near the top.> Actual video coding formats are formats like H.264 (also known as AVC) or H.265 (also known as HEVC). Sometimes they're also called codecs, short for "encode, decode".Codec is coder/decoder. It's not the format.There's a footnote claiming people mix the 2 terms up (a video format is apparently equal to a video codec according to this "expert") but apparently acknowledging the difference is seemingly only what nitpickers do. Sheesh. If you want to educate, educate with precision, and don't spread your misinformation!
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  swiftcoder
  Really good quickstart guide
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  g4zj
  I'm curious what the issue is with using Handbrake? I use it all the time on macOS and it's generally a simple and effective tool for my purposes.
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  weinzierl
  The article talks about image comparisons but does not say what the best way to extract an image is.If I want the best possible quality image at a precisely specified time, what would I do?Can I increase quality if I have some leeway regarding the time (to use the closest keyframe)?Is there a way to "undo" motion blur and get a sharp picture?
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  perching_aix
  I've had a lot of misconceptions that I had to contend with over the years myself as well. Maybe this thread is a good opportunity to air the biggest one of those. Additionally, I'll touch on subbing at the end, since the post specifically calls it out.My biggest misconception, bar none, was around what a codec is exactly, and how well specified they are. I'd keep hearing downright mythical sounding claims, such as how different hardware and software encoders, and even decoders, produce different quality outputs.This sounded absolutely mental to me. I thought that when someone said AVC / H.264, then there was some specification somewhere, that was then implemented, and that's it. I could not for the life of me even begin to fathom where differences in quality might seep in. Chief of this was when somebody claimed using single threaded encoding instead of multi threaded encoding was superior. I legitimately considered I was being messed with, or that the person I was talking to simply didn't know what they were talking about.My initial thoughts on this were that okay, maybe there's a specification, and the various codec implementations just "creatively interpret" these. This made intuitive sense to me because "de jure" and "de facto" distinctions are immensely common in the real world, be it for laws, standards, what have you. So I'd start differentiating and going "okay so this is H.264 but <implementation name>". I was pretty happy with this, but eventually, something felt off enough to make me start digging again.And then, not even a very long time ago, the mystery unraveled. What the various codec specifications actually describe, and what these codecs actually "are", is the on-disk bitstream format, and how to decode it. Just the decode. Never the encode. This applies to video, image, and sound formats; all lossy media formats. Except for telephony, all these codecs only ever specify the end result and how to decode that, but not the way to get there.And so suddenly, the differences between implementations made sense. It isn't that they're flaunting the standard: for the encoding step, there simply isn't one. The various codec implementations are to compete on finding the "best" way to compress information to the same cross-compatibly decode-able bitstream. It is the individual encoders' responsibility to craft a so-called psychovisual or psychoacoustic model, and then build a compute-efficient encoder that can get you the most bang for the buck. This is how you get differences between different hardware and software encoders, and how you can get differences even between single and multi-threaded codepaths of the same encoder. Some of the approaches they chose might simply not work or work well with multi threading.One question that escaped me then was how can e.g. "HEVC / H.265" be "more optimal" than "AVC / H.264" if all these standards define is the end result and how to decode that end result. The answer is actually kinda trivial: more features. Literally just more knobs to tweak. These of course introduce some overhead, so the question becomes, can you reliably beat this overhead to achieve parity, or gain efficiency. The OP claims this is not a foregone conclusion, but doesn't substantiate. In my anecdotal experience, it is: parity or even efficiency gain is pretty much guaranteed.Finally, I mentioned differences between decoder output quality. That is a bit more boring. It is usually a matter of fault tolerance, and indeed, standards violations, such as supporting a 10 bit format in H.264 when the standard (supposedly, never checked) only specifies 8-bit. And of course, just basic incorrectness / bugs.Regarding subbing then, unless you're burning in subs (called hard-subs), all this malarkey about encoding doesn't actually matter. The only thing you really need to know about is subtitle formats and media containers. OP's writing is not really for you.
• anon
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• tmaly
  This is a great write up. Thank you for sharing.
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  webdevver
  video format world is one where you nope out pretty quick once you realize how many moving pieces there are.ffmpeg seems ridiculously complicated, but infact its amazing the amount of work that happens under the hood when you do ffmpeg -i input.mp4 output.webm and tbh theyve made the interface about as smooth as can be given the scope of the problem.
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  pandemic_region
  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.