Could flashing lights be the new blue light? Even for non epileptics, flashing lights might be associated with eye strain, sleep disruption, migraines, and stress. I may turn this feature on.

This. I know I'm page-rage and even navigate away from webpages or videos with too much flash (whether by accident due to loading issues or by design).

I'm not epileptic.

I basically only encounter this when I use a machine without an ad blocker. (And holy ** is the Internet bad without one.)

I’m not epileptic but I find flashing lights extremely unpleasant and will always avoid or look away if I encounter them.

Like most accessibility features, you don’t need to have a condition to find value in this one

Are there any comparable tools or filters you find useful now? I have an old epileptic cat on my couch, and I’m always worried subjecting her to my horrible old anime. I was just yesterday thinking a filter like this was probably out there, and if not, might be easy to make. Looking for VLC plugins, though, I don’t see anything

VLC:

Tools > Effects and Filters > Video Effects > Advanced > Anti-Flickering

Tools > Preferences > Show settings: All > Search: antiflicker

  mpv --vf=deflicker,scale=960x540,pixscope 'https://github.com/apple/VideoFlashingReduction/blob/main/VideoFlashingReduction_Mathematica/Resources/movie.mp4?raw=true'

(generate test video):

  ffplay -f lavfi -i "color=777777[x],color=cccccc,
    [x]framepack=frameseq,settb=AVTB,
    setpts=N/TB/${flickerrate:-12},framerate=${interpolated:-24},
    deflicker=size=5:mode=am,scale=640x480,pixscope"

antiflicker and deflicker are different implementations

Doh! there's a better filter for this: photosensitivity. It detects local brightness changes that sum to 0, unlike deflicker and apparently the Apple algorithm.

drawgraph can be bodged to convert metadata to frames, and signalstats the opposite. This enables silly things like a self-contained filtergraph mimicking Apple's demo with plots and usable in mpv.

  frames=5
  sensitivity=1.5
  dim_range=2
  dim_intercept=-0.4
  smoothing=10
  smoothtype=am
  decay=0.9
  min_contrast=0.0
  min_brightness=0.0
  min_saturation=0.0
  
  ffplay -vf "split[original],  crop=640:360:0:0,
  split=5[i1][i2][i3][i4][i5];
  [i1]photosensitivity=$frames :$sensitivity,
    drawgraph='bg=black@0 :r=60 :s=1x1 :m1=lavfi.photosensitivity.factor
        :fg1=0x010101*round(0xff*clip(VAL*$dim_range+$dim_intercept,0,1))',
 split[sensedat],  deflicker=$smoothing :$smoothtype,
 negate,  lagfun=$decay,  negate,  split[mit1][mit2];
      [mit1][i2]scale2ref[mask][i2];  [i2][mask]alphamerge[m];
      [mit2]signalstats[mitdat];
  [i3]eq=$min_contrast :$min_brightness :${min_saturation}[a];
    [a][m]overlay,  split[output1][output2];
  [sensedat]drawgraph=lavfi.photosensitivity.badness :0xffff0000
      :bg=white :r=60 :slide=scroll :size=512x256 :min=0 :max=7[bad];
    [bad][i5]scale2ref[badout][reuse];
      [badout]drawtext=fontcolor=2222dd:text='frame     %{metadata\:lavfi.photosensitivity.frame-badness}'[badout];
      [badout]drawtext=fontcolor=0000ff:y=1.2*lh:text='badness %{metadata\:lavfi.photosensitivity.badness}'[badout];
      [badout]drawtext=fontcolor=777700:y=2.4*lh:text='factor      %{metadata\:lavfi.photosensitivity.factor}'[badout];
    [mitdat]drawgraph=lavfi.signalstats.YAVG :0xff00ccdd
        :bg=00000000 :r=60 :slide=scroll :size=512x256 :min=0 :max=255,  vflip[factor];
    [factor][badout]scale2ref[factorout][badout];
      [factorout]drawtext=fontcolor=999900:y=3.6*lh:text='smoothed %{metadata\:lavfi.signalstats.YAVG}'[factorout];
    [badout][factorout]overlay[rplot];
  [i4]signalstats,  drawgraph=lavfi.signalstats.YAVG :0xffff0000
      :bg=white :r=60 :slide=scroll :size=512x256 :min=0 :max=255[lum];
    [lum][reuse]scale2ref[lumout][reuse];
      [lumout]drawtext=fontcolor=ff0000:text='%{pts\:hms} %{pts} %{eif\:n\:d\:5}'[lumout];
      [lumout]drawtext=fontcolor=0000ff:y=1.2*lh:text='avg luma %{metadata\:lavfi.signalstats.YAVG}'[lumout];
  [output1]signalstats,  drawgraph=lavfi.signalstats.YAVG :0xff00ccdd
      :bg=00000000 :r=60 :slide=scroll :size=512x256 :min=0 :max=255[mlum];
    [mlum][lumout]scale2ref[mlumout][lumout];
      [mlumout]drawtext=fontcolor=999900:y=2.4*lh:text='mitigated %{metadata\:lavfi.signalstats.YAVG}'[mlumout];
    [lumout][mlumout]overlay[lplot];
  [reuse][output2][rplot][lplot]xstack=4 :0_0|w0+30_0|w0+30_h0+20|0_h0+20,  [original]hstack" \
  'https://web.archive.org/web/0id_/https://developer.apple.com/accessibility/downloads/video-flashing-reduction-fig12.mp4'

There’s this chrome plugin for YouTube videos. It stops the video before trigger scenes so you might find it a bit interruptive depending on your (or your cat’s) sensitivity.

https://chrome.google.com/webstore/detail/seizafe-epilepsy-a...

To the best of my knowledge, there's nothing else that's realtime like this for end users?

There are other offline tests like the Harding test that are run by the content creators (and why you see the epilepsy warnings at the start of shows)

FWIW, I'm not sure if this actually would benefit cats. I'm not up to speed on feline perception, but I know dogs see at a different frame rate than humans so things that won't trigger us might trigger them differently

This might be helpful: https://www.doesthedogdie.com/are-there-flashing-lights-or-i...

I was so happy and pleasantly surprised to see this feature come out today! I just spent the last week telling a client they can’t put their flashy new brand video on their website and still meet AA guidelines.

I told them to do a Harding Test and get the company who made it to do the edits because WCAG doesn’t leave any wiggle room when it comes to potential seizures (rightfully so).

Glad to see Apple leading in this front. These features aren’t sexy but they make a real difference in people’s lives!

Some more documentation on this api is here: https://developer.apple.com/accessibility/#whats-new