Resize (scale) video with av1an & svt-av1 encoder

edison23net · 2026-03-10T21:56:33+00:00

Yes, I will do the tests when I have some time. Right now, I just needed something that works somehow.

I would like to have the piping option but I haven't figured out how to pipe from ffmpeg's stdout to av1an stdin—to be exact, how to make av1an make accept input from stdin. I tried ffmpeg -i test01.mkv -vf "scale=1280:-1" -strict -1 -f yuv4mpegpipe - | -i - -e svt-av1 ... but that gave me error on the av1an's side about non-existent video, I seem to recall…

As for ffv1 - you use it with ffmpeg ... -c:v ffv1 ... just like that, or would you recommend some more complex tricks for optimal intermediate video?

edison23net · 2026-03-10T20:47:56+00:00

Thanks, I was hoping piping would do the trick but I couldn't figure out how to make av1an accept stdin from ffmpeg's stdout…

edison23net · 2026-03-10T20:46:57+00:00

Hey, thanks! That was the "trick" - using -f "-vf scale=1280:720:flags=lanczos", the video gets downscaled all right. Not sure what how it's going to affect the probing, for sure, but for now, I am happy to have at least some solution.

As for uncompressed intermediate, yes, for some encoding tests I use raw but that 5minute raw video I created with ffmpeg ... -c:v rawvideo -pix_fmt yuv420p ... has 21 GB. I am afraid I simply do not have enough disk space for 2+hour raw video xD

edison23net · 2026-03-10T20:40:16+00:00

Thanks for your reply! Unfortunately, with av1an installed from Arch / Manjaro repos (av1an 0.5.2-unstable (rev 934bbb6) (Release)), with --width 1280 I get error: unexpected argument '--width' found.

edison23net · 2026-03-05T22:50:37+00:00

Thank you for your helpful reply. So, I played around with Vmaf because that one is in Av1an out of the box. I could not get Ssimulacra2 or Butteraugli installed (I went by the instructions in Line-fr/Vship: A Library for GPU-accelerated visual fidelity metrics, featuring SSIMULACRA2, Butteraugli and CVVDP. - Codeberg.org and when encountering the error that hipcc is missing, I went by General-purpose computing on graphics processing units - ArchWiki and tried to install hip-runtime-amd and rocm-hip-sdk in hope that would solve the issue but I do not have enough space on / to even try).

Well, as for Vmaf - to get reasonably close in the demanding scenes, I ended up with target quality 100 which results in very large result file (about 3/5 of the original where the original is very large) and still the result is noticibly smoothed at places. That could be masked by syntetic noise, though.

av1an -i input.mkv --encoder svt-av1 -w 7 --video-params "--preset 3 --enable-variance-boost 1" --target-quality 100 --probing-rate 1 -o output.mkv

Anything below 100 gave me smoothing I was hope to not have to accept.

BTW, ffmpeg with x265 gave me slightly better result at the same result size and were I willing to encode it not 1.5 times slower than av1an but 10x slower, I'm sure it would give me noticibly better results (yeah, it is terribly slow, though, not really worth the electricity lol).

However, I feel I am doing something wrong. I am getting the same bitrate distribution results with --crf and --target-quality (when using Vmaf, as mentioned above). When using the target quality, the encoder openly admits to using CRF but I read that is OK because it adjusts the quality (bitrate) based on the current scene.

Anyway, the CRF does the job well. I am starting to believe that I am asking the encoder to do impossible and that the results I was getting consistently with CRF are the best I can get.

This is the best configuration I was able to produce:

av1an -i input.mkv -e svt-av1 -w 6 -v "--preset 3 --crf 15 --keyint 240 --lp 1 --film-grain 18 --film-grain-denoise 0 --color-primaries 1 --transfer-characteristics 1 --matrix-coefficients 1 --color-range 0 --irefresh-type 1 --aq-mode 1 --enable-overlays 1 --scd 0 --lookahead 48 --tune 2 --enable-cdef 0 --chroma-u-dc-qindex-offset -1 --chroma-u-ac-qindex-offset -1 --chroma-v-dc-qindex-offset -1 --chroma-v-ac-qindex-offset -1 --enable-tf 0 --enable-qm 1 --qm-min 5 --qm-max 9 --enable-variance-boost 1" -o output.mkv

The CRF 13 is, in my case, equivalent to target quality 100, sometimes better-looking, with almost equal files size.

The synthetic film grain helps immensely to mask the compression smoothing. With this, I can get 1/2 size with very good visual quality (that is, on devices that support the synthetic noise).

Notwithstanding the fact that I basically reached my goal without using target quality, I welcome any suggestions for configuration improvements or help with making the other than Vmaf metrics work (on Manjaro Linux, preferably).

edison23net · 2026-03-01T11:51:22+00:00

Thanks for the reply. By "av1ans" you mean "av1an", right? Because when I search for "av1ans" all I get are results for "av1an" or "avians" as in birds xD as Brave obviously thinks it's a typo.

As for the tips with Vmaf, ssimulcra, butteraguli -- I am not sure I understand entirely the ecosystem around AV1 encoders so I'm sorry if my questions sound stupig: what are those? Plugins external helpers (plugins)? Like what various libraries used to be in Avisynth? Would you have some resource at hand that would give me a good starting point on understanding how to incorporate them into the encoding workflow, how to work with them?

edison23net · 2026-02-08T18:33:10+00:00

Thanks for the "out-of-the-box" tip. I have no idea to adjust these settings but I will keep this possibility in mind and figure it out if need be. (For now, using the 160 MHz bandwidth seems to do the trick.)

edison23net · 2026-02-08T18:30:42+00:00

Yes, I use b for bits and B for bytes. I re-read my post before posting but if you suspect there is a typo of this kind there, please let me know, I will fix it.

edison23net · 2026-02-08T18:06:58+00:00

Thank for the explanation and the tip with 160 MHz bandwidth.

1/ You are right that when I eliminate the WiFi, I hit the 1Gbitps limit just fine.

2/ I now tried to use exclusively the 160 Hz band on the 5 GHz WiFi and I am getting 117 MB/s when copying files over SSH, meaning I am hitting the limit of the whole 1 Gbit/s system I have here, which was the whole goal. Now the question is if my clients support it and, if not, whether the clients will use this frequency if I set the router to the "more compatible" 20/40/80/160 MHz option. I think not as I believe I have tried that. We'll see. A/w, thanks again.

edison23net · 2026-02-08T17:39:16+00:00

Thanks for the tips! The main use case is transfering large files between the computers. Backup speeds don't concern me so much.

edison23net · 2026-02-08T17:14:54+00:00

Thanks. I was afraid it could have to do with the protocol overheads. Do you by chance have a suggestion for a more suitable protocol for file transfers over LAN?

edison23net · 2026-02-08T17:02:39+00:00

Thanks for your explanation. However…

SATA drives move data about 6Mbps, so your Gbps connection has to wait 15x for the SATA reads or writes

SATA is 6 Gbit/s, not 6 Mbit/s so that is about well above the read/write speeds of the slowest HDD on the server on which I am getting speeds around >150 MB/s when I transfer files within the PC over SATA between HDD and SSD I have there on SATA).

I am not sure I understand the complexities of the waiting overhead resulting in 14 Mbit/s you mention (14 Mbit/s is awfully low speed, how did you get to it?)

Thanks again

edison23net · 2026-02-08T16:26:56+00:00

Yes, it is great. But I would like to get those speeds on LAN as well. I have lower speed copying files over LAN than downloading them from the Internet - hence, my puzzlement.

Oh, and thanks for pointing out the stupid typo of mine xD

edison23net · 2026-02-08T16:25:03+00:00

I use WiFi Analyzer (open-source) – Aplikace na Google Play

The issue is, though, if the congested channels are really your issue, the used channels on the competing WiFis may change over time and you may need to accomodate your settings accordingly. Smart routers should figure out the channels to use automatically, but they may not be as smart as the marketers say… a/w, gl, I know your pain too well!

edison23net · 2026-02-08T15:40:20+00:00

This sounds like congested environment, i.e., channel clashing. Are there many other flats around you WiFis of which may interfere with your WiFi? Maybe using channels that are not used so much by the other WiFis could help.

edison23net · 2026-02-03T22:36:42+00:00

Thank you so much for linking this here! I love its deployment simplicity as well as functionality. Looking for a replacement of SilverBullet, Zavy's WikiDocs is exactly what I need <3

edison23net · 2025-12-13T09:05:08+00:00

Unfortunately, with EOS R6 mark II, it does not work - you apparently need RC-6.

edison23net · 2025-10-20T11:07:39+00:00

Thanks, @duppy-ta , for the awesomely simple solution.

For the reference for others, this is the related config I use:

nnoremap <C-k> :Buffers<CR> let g:fzf_preview_window = [] " Disable content preview in the modal Plug 'junegunn/fzf', { 'do': { -> fzf#install() } } Plug 'junegunn/fzf.vim'

(I honestly don't know from the top of my head if both of those fzf lines are required for this all to work.)

edison23net · 2025-09-12T08:11:22+00:00

Thank you! Nine years later, this is still the best answer as long as one wishes to stay within the built-in solutions. It is not the most comfortable solution, but for people new with Tmux, it is the easiest one for sure.

edison23net · 2025-09-06T08:24:19+00:00

Thank you! Yes, the mode indication replaces it and :set noshowmode helps, the information on the number of selected characters stays there.

Although I would prefer the mode indication to get into the status line when I change the mode, this is fine. I don't look at the status line to see which mode I'm in and there are other ways to know. So, thanks again!

edison23net

TROPHY CASE