I applied RATT's fix and it works well with the Video Player Component in 2017.4.1f1.If you want a simple breakdown:

- In Project Window: Create > Shader > Unlit Shader

- Underneath the line: fixed4 col = tex2D(_MainTex, i.uv);
add the following line:
col.rgb = LinearToGammaSpace(col.rgb);

- Create a new material: Create > Material
- Select the new Shader
- Drag that Material onto the GameObject where your Video Player Component is.
- Enjoy life!

Remember that if you upgrade your project to 2018.2 or above in the future, you might need to swap the shader back to the default Unlit Shader.

ergh, I meant "private RenderTexture myRTTarget;" OFC, but couldn't modify the comment once it was posted in an "oh no second" :)

Mark-Davis Mar 20, 2018 22:37 <--- LIFE SAVER, THANKS!

For all those who just want to copypaste, create a class level "private RenderTexture targetRT;", have your UI RawImage ready, then in Awake()

RenderTextureDescriptor rtDesc = new RenderTextureDescriptor([int_vidclip_width], [int_vidclip_height], RenderTextureFormat.Default, 24);
rtDesc.sRGB = false; //Thank this to Mark Davis! :)
myRTTarget = new RenderTexture(rtDesc);
myRTTarget.Create();
[your_ui_rawimage].texture = myRTTarget;

And when you want to play a clip:
myVideoPlayer.targetTexture = myRTTarget;

Tada, untested joke-engine bug million-th workaround applied!

FYI - This issue is definitely fixed in Unity 2018.1.0b12. I just upgraded from 2017.3 and had the dark videos, and they look great now.

Hey guys - I just ran into the same issue, but found a workaround. Maybe this will help someone.

Try using a RenderTexture as the target. An easy way to handle this is to link the RenderTexture to a RawImage. When you create the RenderTexture, in the RenderTextureDescriptor,
set: desc.sRGB = false;

Good luck!

The issue still exists in 2017.3.1f1 please fix asap.

Still exists in 2017.2.1f1

Tried both workaround but on dark areas, there are bad artifacts and you can clearly see the difference in quality if you play the video outside of unity.
Any idea if this will be fixed soon or if there is a better workaround?

We ran into the same issue, we fixed it by making a custom shader based on the default Unity UI shader.

We added:

fixed4 col = tex2D(_MainTex, i.uv); //this is the line before, should be in the shader
col.rgb = LinearToGammaSpace(col.rgb); //this is the line we added

And then make a material with that, put it as the material for the VideoPlayer and you should be good to go

I'm trying to get a workaround going.
Another thread mentioned it might be lacking gamma correction so I wrote a quick shader to try and add in gamma correction using a formula I found online.

// Where _GammaFactor is a range of 1-2.4
col.rgb = pow( col, 1.0 / _GammaFactor);

This brings the color and some brightness back but it up introducing some weird artifacting.
Anyone else had any luck with this?