• Adobe Premiere Pro

  Anyway to legalize chroma and luma values for HTML5 player?

  Posted by Jakub Frišo on February 23, 2016 at 10:06 am

  Hello guys,
  I have recently found out that Vimeo and Youtube completely shifts the black levels of my video in Google Chrome browser using HTML 5 decoding. I wanted to ask if there is anyway of how can I legalize luma levels for web video browsing like you can do for TV broadcast inside Premiere or Speedgrade?
  thank you for suggestion, really appreciate your help

  here is the example shot, where you can see the luma shift most visible:
  original shot:
  https://www.mediafire.com/view/o2cvva82jg5c8mj/Original%20Shot.jpg
  after HTML 5 decoding in Vimeo:
  https://www.mediafire.com/view/atwjufxd6vn0s7x/Vimeo%20compression.jpg

  Chris Wright replied 10 years, 2 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Chris Wright

  February 23, 2016 at 5:22 pm

  chroma and luma are used for different stuff.

  chroma is how much saturation it can handle till it bleeds, luma is how bright. for example the color profile, (Rec. 709 16-235) is legal ntsc luma but could still have chroma(saturation issues)

  the easiest way to force color management interpretation is AE’s utility color profile converter. This is because youtube doesn’t support color management. set input as your project setting or view-simulate and output as Rec. 709 or Rec 709 16-235.
• 

  Jakub Frišo

  February 24, 2016 at 12:29 am

  I solved the problem by rendering DNxHD file with Rec709 colorspace and it fits to youtube perfectly. Is it because HTML5 decoding and player is set to this colorspace? Because when I uploaded h264 file with sRGB colorspace to youtube it looked washed out like I described but the original file image looked as it looked in Premiere Pro preview. DNxHD on the other side, had really strong contrast as rendered out file but when I uploaded it to youtube it looked like the h264 file looked originaly. Is it because difference of sRGB colorspace and Rec709 colorspace? It seems to me that when you upload mp4 file with h264 codec in sRGB colorspace to youtube the perfect gamma of the orignal file kinda washes out, but when you upload extremely contrasty .mov with DNxHD codec and Rec709 colorspace it kinda “washes” out that extreme contrast and as a result you have correct gamma and contrast as you had in Premiere timeline …
• 

  Chris Wright

  February 24, 2016 at 1:43 am

  hard to say, in actuality, sRGB and Rec. 709 are relatively pretty close.

  the most likely answer is that html 5 is trying to decode at Rec. 16-235 instead of 0-255 so un-contrasts the footage.
  But I’m glad at least one person believes me. Everyone else is still fiddling with curves adjustments and media encoder contrast/saturation, hahah.

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