[Nottingham] [Misc] Breaking Youtube with Slow Mo Glitter - The Slow Mo Guys

[Martin]

Folks,

Part 2 of the glitter experiment:


It looks like the problem for my system at least is the VP9 codec decode
and rescaling... Likely mostly the rescaling...

Using ffmpeg to transcode to native resolution gives spectacular results :-)


Hence, trying a cautious:

ffmpeg -i BtYKDamqo2I.mkv -r 25 -s 3840x2160
slow-mo-glitter-25fps-3840x2160.mkv

and then the less cautious:

ffmpeg -i BtYKDamqo2I.mkv -r 50 -s 3840x2160
slow-mo-glitter-50fps-3840x2160.mkv

both displayed spectacularly fine, until occasional hiccups towards the
end for the more colourful bits...


Interestingly, despite the 8k res -> 4k res rescale/transcoding, the
file sizes remain similar at:

2.5G BtYKDamqo2I.mkv (50fps)
2.2G slow-mo-glitter-25fps-3840x2160.mkv
2.4G slow-mo-glitter-50fps-3840x2160.mkv


all for example:

  Stream #0:0 -> #0:0 (vp9 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> vorbis (libvorbis))

  Duration: 00:14:32.88, start: 0.000000, bitrate: 23938 kb/s
    Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv, bt709),
7680x4320, SAR 1:1 DAR 16:9, 50 fps, 50 tbr, 1k tbn, 1k tbc (default)

->

    Stream #0:0(eng): Video: h264 (libx264) (H264 / 0x34363248),
yuv420p, 3840x2160 [SAR 1:1 DAR 16:9], q=-1--1, 50 fps, 1k tbn, 50 tbc
(default)
frame=43641 fps=4.1 q=-1.0 Lsize= 2505363kB time=00:14:32.87
bitrate=23513.1kbits/s speed=0.0814x


OK... So the transcoding speed was only "speed=0.0814x", but hey, it now
plays at full speed.

Very glittery! All good fun :-)


Enjoy!
Martin


On 20/04/2020 19:37, Martin via Nottingham wrote:
> Folks,
> 
> I've been breaking multiple things recently... (More on the other
> breakage for another post...)
> 
> 
> So... For the firefox/video breakage I tried:
> 
> 
> Breaking Youtube with Slow Mo Glitter - The Slow Mo Guys
> https://www.youtube.com/watch?v=BtYKDamqo2I
> 
> And all looks fine at the default viewing.
> 
> 
> However, increase the settings to display the higher resolutions and my
> single threaded firefox certainly can't cope - immediate freeze-frame
> non-action.
> 
> Running a media player for the video, I get such as:
> 
> 
> MPlayer 1.3.0-9.2.0 (C) 2000-2016 MPlayer Team
> 
> Playing Breaking Youtube with Slow Mo Glitter - The Slow Mo Guys - The
> Slow Mo Guys-BtYKDamqo2I.mkv.
> 
> libavformat version 58.29.100 (external)
> libavformat file format detected.
> [lavf] stream 0: video (vp9), -vid 0
> [lavf] stream 1: audio (aac), -aid 0, -alang eng
> VIDEO:  [VP90]  7680x4320  0bpp  50.000 fps
> 
> 
>            ************************************************
>            **** Your system is too SLOW to play this!  ****
>            ************************************************
> 
> 
> 
> ... And trying VLC gives:
> 
> VLC media player 3.0.8 Vetinari (revision 3.0.8-0-gf350b6b5a7)
> 
> avcodec decoder error: more than 5 seconds of late video -> dropping
> frame (computer too slow ?)
> 
> 
> Note that the full 8k res version is a whopping 2.5GBytes of video. The
> quality is stunning! (If you can see it!!)
> 
> 
> I may try downscaling it with ffmpeg for giggle...
> 
> 
> Enjoy?
> Martin