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I have been converting my H265 (HVEC) collection to AV1. I am still trying to find the exact parameters for FFMPEG to produce the optimal output for the devices

I have been converting my H265 (HVEC) collection to AV1. I am still trying to find the exact parameters for FFMPEG to produce the optimal output for the devices I use plex on. Its been a little bit of whack a mole so far, but it seems ideal for file size when I get it right.

comrade1234 9mo ago
Do you know what plex clients can handle av1 without the server having to transcode? I started looking into converting stuff to AV1 but only confirmed that my gpu doesn't support AV1 but does support hevc so I stopped there...
- loufe 9mo ago
  IIUC, it's more about the client hardware that determines ability to play without transcoding. You'd have to check the mix of devices you have connecting to it and make a judgement call.
- blueside 9mo ago
  I started to convert a lot of my content in AV1 until I realized that my Nvidia Shield devices won't play AV1. My $30 firestick will play them but I do really prefer the Shield. I guess I'll wait it out and hope for a new Shield (it's been 2019 since Nvidia released one) but i'm not going to hold my breath.
  - breve 9mo ago
    > my Nvidia Shield devices won't play AV1 Put VLC on them. See if it works for your AV1 videos.
- hapticmonkey 9mo ago
  Google Streamer has hardware AV1 support, although I’m unsure if it can direct play with Plex. AppleTV with Infuse can direct stream and software decode AV1 at 4K 24fps. Not sure about AV1 HDR though.
  - breve 9mo ago
    VLC also works on Apple TV: https://www.videolan.org/vlc/download-appletv.html https://www.videolan.org/vlc/download-appletv.html
dragontamer 9mo ago
Because of conversion losses, I have to imagine this is subtly very bad. Every form of lossy compression deleted data. Yes AV1 is more efficient but only when working off of high quality originals. H265 already deleted a ton of data. It can never recover the quality loss. Compressing even further can only worsen the image.
- stefan_ 9mo ago
  Well its sure gonna get the filesize down though, great HECV -> AV1 transcoding success..
  - dragontamer 9mo ago
    Yes. Deleting data does wonders for the filesize. The question I'm bringing up is one of quality. If you must delete, delete starting from the 50GB+ original BluRays if at all possible, or some other very high quality source. That way the compression algorithm has the best chance of saving the important scene data. And keep an eye on the known hard to encode scenes. A lot of the typical shots of a movie are handled well on one set of settings, but suddenly screw up on other scenes (or other animation styles. Anime vs Cartoons vs 3D vs Live Action can have subtle differences leading to quality issues). It's not easy, and AV1 is our best bet at doing this well so far. But when the future algorithms come out, you need to start over from the best sources of you want AV2 to have a chance. You should *Never* double compress. (Blu-ray -> H265 -> AV1). This is horrible for the quality. You'll get better results from BluRay -> AV1 by a large margin.
- arnaudsm 9mo ago
  What's the optimal strategy then ? 50 GB Blu-ray remux => 3 GB AV1 ?
  - dragontamer 9mo ago
    50GB gives assurances that the BluRays are high quality (but not always. I've seen some horrible BluRay encodings...) As long as you are going from high quality sources, you should be fine. The issue is each transcoding step is a glorified loop-(find something we think humans can't see and delete it) In other words: the AV1 encoder in your example works by finding 47GBs of data TO DELETE. It's simply gone, vanished. That's how lossy compression works, delete the right things and save space. In my experience, this often deletes purposeful noise out of animation (there are often static noise / VHS like effects in animation and film to represent flashbacks, these lossy decoders think it's actually noise and just deleted it all changing the feel of some scenes). -------- More importantly: what is your plan with the 50GB BluRays? When AV2 (or any other future codec) comes out, you'll want to work off the 50GB originals and not off the 3GB AV1 compressed copies. IMO, just work with the 50GB originals. Back them up, play them as is. I guess AV1 compression is useful if you have a limited bandwidth (do you stream them out of your basement, across the internet and to your phone or something? I guess AV1 is good for that) But for most people just working with the 50GB originals is the best plan
loufe 9mo ago
I've been transcoding my media collection leaving my PC on overnight over months, it's great. My biggest issue is client support for native playback of AV1, naturally. For what it's worth, AB-AV1 [1] is a pretty awesome tool written in rust which compares random samples from a file at different parameters based on their VMAF score [2] (algorithm from Netflix for human-perceived visual likeness), choosing optimal parameters to save as much space as possible with the loss you're willing to stomach, on a file-by-file basis. Small plug: I made a nice little python GUI wrapper for ab-av1 [3]. [1] - https://github.com/alexheretic/ab-av1 https://github.com/alexheretic/ab-av1 [2] - https://github.com/Netflix/vmaf https://github.com/Netflix/vmaf [3] - https://github.com/Loufe/AB-AV1-GUI https://github.com/Loufe/AB-AV1-GUI
npodbielski 9mo ago
What is the difference in size of files? Around?
mannyv 9mo ago
I'd be surprised if there's any noticeable difference between 265 and AV1 when coming from the 265 encoding. 265 has already thrown a lot of stuff away, so there's not much for AV1 to work with. Maybe if you're going to a lower resolution it would be fine (ie: going from 4k 265 to 720p AV1).
Risse 9mo ago
I personally use av1an, and use VMAF target quality of 95 to 96. It's been really good and fast. https://github.com/rust-av/Av1an https://github.com/rust-av/Av1an
IgorPartola 9mo ago
Aside from video, audio compatibility is tricky as well. You can do AAC stereo and most things support that but AAC 5.1 seems to be supported by only some devices so all my video files end up getting stereo AAC, 5.1 AAC, and 5.1 DTS to avoid live transcoding.

comrade1234 9mo ago

Do you know what plex clients can handle av1 without the server having to transcode? I started looking into converting stuff to AV1 but only confirmed that my gpu doesn't support AV1 but does support hevc so I stopped there...

loufe 9mo ago
IIUC, it's more about the client hardware that determines ability to play without transcoding. You'd have to check the mix of devices you have connecting to it and make a judgement call.
blueside 9mo ago
I started to convert a lot of my content in AV1 until I realized that my Nvidia Shield devices won't play AV1. My $30 firestick will play them but I do really prefer the Shield. I guess I'll wait it out and hope for a new Shield (it's been 2019 since Nvidia released one) but i'm not going to hold my breath.
- breve 9mo ago
  > my Nvidia Shield devices won't play AV1 Put VLC on them. See if it works for your AV1 videos.
hapticmonkey 9mo ago
Google Streamer has hardware AV1 support, although I’m unsure if it can direct play with Plex. AppleTV with Infuse can direct stream and software decode AV1 at 4K 24fps. Not sure about AV1 HDR though.
- breve 9mo ago
  VLC also works on Apple TV: https://www.videolan.org/vlc/download-appletv.html https://www.videolan.org/vlc/download-appletv.html

dragontamer 9mo ago

Because of conversion losses, I have to imagine this is subtly very bad. Every form of lossy compression deleted data. Yes AV1 is more efficient but only when working off of high quality originals. H265 already deleted a ton of data. It can never recover the quality loss. Compressing even further can only worsen the image.

stefan_ 9mo ago
Well its sure gonna get the filesize down though, great HECV -> AV1 transcoding success..
- dragontamer 9mo ago
  Yes. Deleting data does wonders for the filesize. The question I'm bringing up is one of quality. If you must delete, delete starting from the 50GB+ original BluRays if at all possible, or some other very high quality source. That way the compression algorithm has the best chance of saving the important scene data. And keep an eye on the known hard to encode scenes. A lot of the typical shots of a movie are handled well on one set of settings, but suddenly screw up on other scenes (or other animation styles. Anime vs Cartoons vs 3D vs Live Action can have subtle differences leading to quality issues). It's not easy, and AV1 is our best bet at doing this well so far. But when the future algorithms come out, you need to start over from the best sources of you want AV2 to have a chance. You should *Never* double compress. (Blu-ray -> H265 -> AV1). This is horrible for the quality. You'll get better results from BluRay -> AV1 by a large margin.
arnaudsm 9mo ago
What's the optimal strategy then ? 50 GB Blu-ray remux => 3 GB AV1 ?
- dragontamer 9mo ago
  50GB gives assurances that the BluRays are high quality (but not always. I've seen some horrible BluRay encodings...) As long as you are going from high quality sources, you should be fine. The issue is each transcoding step is a glorified loop-(find something we think humans can't see and delete it) In other words: the AV1 encoder in your example works by finding 47GBs of data TO DELETE. It's simply gone, vanished. That's how lossy compression works, delete the right things and save space. In my experience, this often deletes purposeful noise out of animation (there are often static noise / VHS like effects in animation and film to represent flashbacks, these lossy decoders think it's actually noise and just deleted it all changing the feel of some scenes). -------- More importantly: what is your plan with the 50GB BluRays? When AV2 (or any other future codec) comes out, you'll want to work off the 50GB originals and not off the 3GB AV1 compressed copies. IMO, just work with the 50GB originals. Back them up, play them as is. I guess AV1 compression is useful if you have a limited bandwidth (do you stream them out of your basement, across the internet and to your phone or something? I guess AV1 is good for that) But for most people just working with the 50GB originals is the best plan

loufe 9mo ago

I've been transcoding my media collection leaving my PC on overnight over months, it's great. My biggest issue is client support for native playback of AV1, naturally. For what it's worth, AB-AV1 [1] is a pretty awesome tool written in rust which compares random samples from a file at different parameters based on their VMAF score [2] (algorithm from Netflix for human-perceived visual likeness), choosing optimal parameters to save as much space as possible with the loss you're willing to stomach, on a file-by-file basis. Small plug: I made a nice little python GUI wrapper for ab-av1 [3]. [1] - https://github.com/alexheretic/ab-av1 https://github.com/alexheretic/ab-av1 [2] - https://github.com/Netflix/vmaf https://github.com/Netflix/vmaf [3] - https://github.com/Loufe/AB-AV1-GUI https://github.com/Loufe/AB-AV1-GUI

npodbielski 9mo ago

What is the difference in size of files? Around?

mannyv 9mo ago

I'd be surprised if there's any noticeable difference between 265 and AV1 when coming from the 265 encoding. 265 has already thrown a lot of stuff away, so there's not much for AV1 to work with. Maybe if you're going to a lower resolution it would be fine (ie: going from 4k 265 to 720p AV1).

Risse 9mo ago

I personally use av1an, and use VMAF target quality of 95 to 96. It's been really good and fast. https://github.com/rust-av/Av1an https://github.com/rust-av/Av1an

IgorPartola 9mo ago

Aside from video, audio compatibility is tricky as well. You can do AAC stereo and most things support that but AAC 5.1 seems to be supported by only some devices so all my video files end up getting stereo AAC, 5.1 AAC, and 5.1 DTS to avoid live transcoding.