[Request] Any Guides to FFMPEG, Transcoding, Codecs, and Metadata?
[Request] Any Guides to FFMPEG, Transcoding, Codecs, and Metadata?
I have a collection of about ~110 4K Blu-Ray movies that I've ripped and I want to take the time to compress and store them for use on a future Jellyfin server.
I know some very basics about ffmpeg and general codec information, but I have a very specific set of goals in mind I'm hoping someone could point me in the right direction with:
- Smaller file size (obviously)
- Image quality good enough that I cannot spot the difference, even on a high-end TV or projector
- Preserved audio
- Preserved HDR metadata
In a perfect world, I would love to be able to convert the proprietary HDR into an open standard, and the Dolby Atmos audio into an open standard, but a good compromise is this.
Assuming that I have the hardware necessary to do the initial encoding, and my server will be powerful enough for transcoding in that format, any tips or pointers?
Just FYI, despite what media companies would like you to believe, making copies of media you own for your own use is not piracy. It's allowed by law under fair use.
Mhm, I'm aware. I just figured the nice folks here would likely have more experience with codecs and such than elsewhere!
(That, and, if I can build my own replacement Disney+, I would definitely want to share with friends.)
I'm sure you're right.
Depending on your jurisdiction. Big asterisk.
True, good catch.
Unmanic is way easier to understand than Tdarr. I use it to transcode DVR recordings recorded using Plex and a HDHomeRun tuner. Digital TV uses MPEG2 which has pretty large file sizes.
You're about to embark on a massive journey and I wish you the best of luck :D
Compressing 110 4K movies is going to be a long encode time, but it will be so nice to digitize that collection.
First question: if you already have them ripped and stored, do you even need to re-encode them? If you have a powerful enough Jellyfin server for transcoding, that may be enough.
That said, if you're looking to optimize for space and quality, there's some questions to ask:
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proprietary (but ubiquitous) HEVC or the emerging open standard AV1? It's going to be a lot easier finding tips/guides for HEVC.
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Constant Rate Factor (CRF), or Average Bit Rate (ABR). CRF tends to be more straightforward if you have a varied collection of content because it let's the encoder choose settings to deliver consistent quality. 2-pass average bit rate is good if you have a target size or compatibility in mind - great for squeezing out the absolute optimal quality if you're trying to fit on a Blu-Ray disc or meet certain streaming criteria, but 2x the encode time (hence "2-pass") can be a tough sell.
Stick with software encoding, steer clear of hardware solutions like NVENC. They're crazy fast, but inconsistent quality.
There's some guides out there on converting DV to HDR 10+ etc, but I don't have a lot of experience with that process.
The issue is storage costs. Currently they (and some Blu-ray shows I ripped) are taking up just over 12TB. I bought all of these movies when I had money to spend on stuff like that, but money is short and times are tough. "Storage is cheap" but my wallet is cheaper right now, aha.
Look, I definitely get it, but just a note, encoding 100+ 4k HEVC movies is going to take months of time at full PC loads. It's a subtle cost, but depending on your electricity rate, running a 200W PC 24/7 for 3 months straight may hurt your bottom line more than it helps.
If you already have the storage, the cheapest option may be just to keep it. If you're looking to increase the size of your collection it may be about even to save 6 TB via encode and to buy an extra 6TB disc, depending on your setup
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I did a comparison trying to find where my personal "good enough" and techinically indistinguishable crf levels were at a little while ago. It may be worth looking into as a start. I've never really touched hdr before though.
oh hey I've actually done this recently so a lot of this is fresh for me. Now I had a slightly different use case than you, I had a bunch of AV1 files that wouldn't run on my pi so I had to convert them to something less GPU intensive. I was finding x265 was indistinguishable for me from AV1, and had a HUGE file size drop, close to a half or even a third. x264 had a larger file size than 265 and looked worse so I don't recommend it. I did not try VP9 once I was satisfied with 265 but you could try it out and see how it compares. My recommendation is to pick one (shorter) file and run a couple of different transforms on it till you're satisfied before trying to transform your entire library
Preserving audio and metadata is trivial, just use -c:a copy for audio and -c:d copy for metadata
EDIT: I feel dishonest not mentioning the important caveats regarding my own experiments. My files were 1080p, so the difference between codecs might be less noticeable at that resolution. It was also anime, which is similarly going to be easier to compress and be less distinct between codecs. This is why I cannot recommend x264 because if you can ruin 1080p anime it'll ruin whatever you're working with. This is why I recommend picking a sample video and spend a day running a couple test transformations on it to see what you like
Skipping the audio encode from a blu-ray will lose op out on a surprisingly large amount of space, especially with 110 source disks. I checked one of my two hour blu-ray backups. Audio will net you about nine audio tracks (english, french, etc). A single 5.1 448kbs audio track will take about 380MB of space per movie. Multiply that by nine (the number of different tracks in my sample choice) and you'll get 3420MB per disk. That means about 376GB of space is used on audio alone for ops collection. A third of a terabyte. You can save a lot of space by cutting out the languages you don't need, and also by compressing that source audio to ogg or similar.
By running the following ffmpeg command;
ffmpeg -i out-audio.ac3 -codec:a libvorbis -qscale:a 3 small-audio.ogvI got my 382MB source audio track down to 200MB. Combine that with only keeping the language you need, and you end up dropping from 376GB down to 22GB total.You can likely save even more space by skimping on subtitles. They're stored as images, so they take up a chunk of space too.
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Since you're talking about anime, how did you solve the subtitles problem? My pi doesn't transcode fast enough but I haven't found a tdarr extension to do that automatically (nor a command)
I'm sorry my subtitles worked fine from the beginning so I don't know what to tell you. I've got a pi4 running osmc as my media center if that makes any difference.
If you want to do an open codec, use AV1 codec and Opus for audio.
https://github.com/master-of-zen/Av1an and use aomenc for the av1 codec.
Ffmpeg doesn't have good av1 support.
With current hardware support I would advise against using AV1 or even H.265.
I'd recommend to experiment with H.264 and low CRF values to see what quality loss and file size OP is comfortable with: https://trac.ffmpeg.org/wiki/Encode/H.264
Are those your own blurays? Then share them before compressing.
Transcoding is hard. There is no way that your transcoding settings are going to be a one size fits all. I am currently encoding the famous iKaos Dragonball release and I did 48 samples before deciding what configuration to use.
You are better off downloading stuff from torrent, especially for newer media. You'll find a community that put 100x your time collectively on transcoding. That will also save from your tremendous electricity costs.
Also look into vmaf for quality metrics. Consider that switching to uncompressed 1080 might bring you close to your goal with very very low effort.
Btw, can you share the title list?
Yeah, sure thing.
Abominable Ad Astra Aladdin (Live Action) Aladdin Alien - Covenant Alien Ant-Man and the Wasp Ant-Man Aquaman Arrival Austin Powers In Goldmember Austin Powers - International Man of Mystery Austin Powers - The Spy Who Shagged Me Avengers - Endgame Avengers - Infinity War Baby Driver Batman and Robin Batman Forever Batman Batman Returns Big Hero 6 Black Panther Bohemian Rhapsody Brave Captain Amercia - Civil War Captain America - The First Avenger Captain America - The Winter Soldier Captain Marvel (2019) Cars 2 Cars 3 Cars Cinderella (Live Action) Close Encounters of the Third Kind 40th Anniversary Edition Deadpool 2 Deadpool Detective Pikachu Doctor Sleep Doctor Strange Everything Everywhere All At Once Fantastic Beasts - The Crimes of Grindelwald Finding Dory Finding Nemo First Man From Up on Poppy Hill Frozen II Frozen Gemini Man Godzilla (1998) Godzilla - King of the Monsters Gremlins Guardians of the Galaxy Vol 1 Guardians of the Galaxy Vol 2 Halloween Harry Potter and the Chamber of Secrets Harry Potter and the Deathly Hallows - Part 1 Harry Potter and the Deathly Hallows - Part 2 Harry Potter and the Goblet of Fire Harry Potter and the Half-Blood Prince Harry Potter and the Order of the Phoenix Harry Potter and the Prisoner of Azkaban Harry Potter and the Sorcerer's Stone Howl's Moving Castle Incredibles 2 Incredibles Inside Out Interstellar Iron Man 2 Iron Man 3 Iron Man IT (2018) John Wick 3 - Parabellum John Wick - Chapter 2 John Wick Joker (2019) Jumanji (1995) Jurassic Park III Jurassic Park Jurassic Park - The Lost World Jurassic World - Fallen Kingdom Jurassic World Kiki's Delivery Service Kingsman - The Golden Circle Kingsman - The Secret Service Logan Maleficent - Mistress of Evil Maleficent Mary Poppins Returns Moana Monsters, Inc Monsters University My Neighbor Totoro Pacific Rim Uprising Paprika Ponyo Ratatouille Robin Hood Spider-Man - Homecoming Spider-Man - Into the Spider-Verse Spirited Away Starship Troopers Star Trek - Beyond Star Trek - Into Darkness Star Trek (2009) Tangled The Cat Returns The Expendables 2 The Expendables 3 The Expendables The Good Dinosaur The Hulk The Jungle Book The Karate Kid (1984) The Lion King (Live Action) The Lion King The Little Mermaid The Matrix The Matrix - Reloaded The Matrix - Revolutions The Predator The Princess and the Frog The Secret Life of Pets 2 The Secret World of Arrietty The Shining The Wizard of Oz Thor Thor - The Dark World Toy Story 2 Toy Story 3 Toy Story 4 Toy Story Turning Red Up Us Venom (2018) Wall-E Waterworld (2019) Wonder Woman Wreck-It Ralph Zootopiayeah, I would redownload all of those instead of transcoding. They are all available with very good encodes publicly
Consider online file converters. Just pay for a month or two, obviously need a good internet connection.