Welcome to this blog post, where I examine the HDR10 files captured by the Samsung Galaxy S10. This is an ongoing post, where I shall be updating my findings as I go on.
Video on consumer devices are usually 8-bit videos.
An 8-bit file works with RGB using 256 levels per channel. An 8-bit photo can only display 16.7 million colours.
While 10-bit jumps up to 1,024 levels per channel. This means a 10-bit image can display up to 1.07 billion colors.
When it comes to colour standards, HD TVs offer an 8-bit video specification known as Rec. 709, or BT.709. HDR steps up to 10- or 12-bit Rec. 2020, or BT.2020, which represents
60 times more colour combinations with smoother shade gradations.
Therefore, a HDR10+ recording has more colour values and a larger brightness range than normal 8-bit video.
HDR10+ is also a dynamic format, meaning it masters the video for every frame, adjusting brightness values for every pixel to appear the best.
I captured some videos on the Samsung Galaxy S10,
using the h.265 HEVC HDR10+ mode.
There are some caveats to doing so though.
The HDR10+ mode can only be activated only upto 30FPS, and can be natively played only in the Video Player app.
Trying to play the files anywhere else will result in a very flat and desaturated image.
The HDR10+ mode also only records to h.265 or HEVC codec, which is a highly compressed codec, meaning, trying to edit said files will be extremely CPU intensive.
I tried to import the HEVC files into Premiere, but Premiere did not recognise the HDR metadata. It resulted in a highly contrasty image, with blownout highlights and crushed blacks. I had to lower the exposure by 3.8 stops to gain the highlights back.
After hours of scouring through the settings and the internet, I gave up on Premiere as it did not seem to want to recognise my HDR10+ files.
The only way to get Premiere to display the 10-bit files correctly is to either capture it in a codec that Premiere can identify or to apply Conversion LUTS to bring the REC2020(BT.2020) colour space back to REC709(BT.709).
Feeling low, I opened up Davinci Resolve.
Upon importing the files into Davinci Resolve, they were very flat and desaturated.
I applied some basic color-space transforms to transform this REC2020 image into a REC709 image:
Not feeling good about it, I reset the CST(Colour Space Transform) and started to tweak the contrast curve and the saturation to a point where i felt it looked good.
Upon doing this, I proceeded to open the file inside VLC to be presented with this:
VLC's metadata viewer showed that the file was encoded in the REC2020(ST2084) color space, but Resolve's built in Color Space Transform tool absolutely destroyed the images when transforming from the correct colour space.
Taking the VLC Auto-Transformed file to be the correct version, I realised that my manual adjustments were closer. So, I then set up a controlled environment, where I could test the 10-bit and the 8-bit files side by side, to check if the hassle of capturing in HDR10+ was worth it compared to the 8-bit files.
(TEST RESUTS TO BE UPDATED)
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