master-of-zen

Dangers of the Zone

Emission/Radiation Storm

You will be informed when it starts, emmission is dangerous and lethal, as soon as you see the warning - find shelter, it could be a tent, building, bunker.

You have around 4 minutes before emmision starts killing you and will end in around 5 minutes after radiation stage started.

Emmision is lethal, you will not survive staying outside.

master-of-zen

Video is messy

I speak on stuff that i noticed, if you have questions message me directly on discord Master Of Zen#7693

Video encoding is messy and a lot of stuff is poorely explained online, which leaves people with bad framework to understand and deal with video.

Base

• Coding Standarts and Video encoders are different things. aomenc, rav1e, SVT-AV1 are all video encoders for AV1.

• Coding standarts define how encoded video should be as a binary(file) and decoded(made back into pixels, usually to play it or feed into another program as pixels).

master-of-zen

Slow

>  Using y4m decoder: 1920x1080p @ 25/1 fps, 4:2:0, 8-bit
>  Using 16 tiles (4x4)
>  encoded 250 frames, 5.239 fps, 2482.74 Kb/s, elap. time: 47s
>  ----------
>  Key frame:             3 | avg QP:  79.00 | avg size:   38309 B
>  Inter frame:         247 | avg QP: 138.00 | avg size:   12099 B
>  Intra only frame:      0 | avg QP:   0.00 | avg size:       0 B
>  Switching frame:       0 | avg QP:   0.00 | avg size:       0 B

master-of-zen

---- api::test::output_frameno_no_scene_change_at_multiple_flashes stdout ----
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false
[src/scenechange/mod.rs:186] scenecut = false

master-of-zen

• Install python
• Install rustup
• Install rust nightly

git clone https://github.com/master-of-zen/Av1an
cd Av1an
python3 -m venv env
source env/bin/activate
pip install maturin

master-of-zen

Total wall time difference on speed 9

Version	Time
old:	47,783.666
new:	44,202.432

-8% wall time diffrence

1080p is ~7 times faster

new | old

master-of-zen

filmgrn1
E 0 834166 1 7391 1
	p 3 8 0 11 0 1 128 192 256 128 192 256
	sY 8  0 43 13 43 27 51 40 68 54 82 67 90 81 93 255 93
	sCb 8 0 41 13 41 40 51 54 58 67 63 81 65 94 65 255 65
	sCr 4 0 26 13 26 54 32 255 35
	cY 1 0 -1 8 3 0 1 0 3 -1 -21 -12 2 1 1 0 -21 83 19 -10 2 17 -42 108
	cCb 3 2 0 8 2 2 2 3 1 2 -16 -5 5 3 0 6 -16 73 8 -3 5 20 -37 90 -2
	cCr 2 1 1 6 3 1 2 1 5 -2 -6 -8 4 1 2 -3 -14 85 15 -1 3 11 -12 87 -1
E 834166 1251250 1 0 1

master-of-zen

# Fields meanings: <source root>/av1/encoder/firstpass.h
fields = [
    "frame",
    "weight",
    "intra_error",
    "frame_avg_wavelet_energy",
    "coded_error",
    "sr_coded_error",
    "tr_coded_error",
    "pcnt_inter",

master-of-zen

Goals and motivation

Current fast scene detection in rav1e relatively slow to compared methods of scene detection, and have proclivity to show false results or don't detect scene changes where they appear

This pr reworks fast scene detection algorithm, making it faster, better, and more accurate

Achieved goals are:

• Faster decision making ( Both less and more efficient computations )
• More accurate scene detection, by adjusting threshold based on previous frames
• Frame downscale for faster decisions.

master-of-zen

  for x in 1..=scale {
    let src_row = &data_origin[(src.cfg.stride * 2 + x)..];
    let local_sum: usize = (1..scale)
      .into_par_iter()
      .map(|y| u32::cast_from(src_row[col * 2 + y]) as usize)
      .sum();
    sum += local_sum;
  }