Video Rendering Video Quality Problem

We are developing a project in unity in which we are taking pixels from the picture, change their colour and put them back in a texture. We keep updating each frame and at the end we get a video. For video rendering we use Unity’s Media Encoder but the video that comes out is much more compressed than the original picture that we put in. And we can’t understand why is it happening. We don’t apply any compression to the original texture.

We have two theories for why its happening. First, when rendering using Media Encoder, we use h.264 codec and causes our texture to compress. So if we use a different codec (i.e. h.265), there is a chance that the quality of the video will get better. BUT! We could not find how to use different codecs in unity, so would be very appreciate for any help with that.

Second theory is that we use a wrong texture format for the drawing of our texture. Right now we are using TextureFormat.RGBA32, so could anyone please suggest a better format to use.

However, we can be completely wrong and none of these are the reasons why the quality of our video falls. So if there are any other solutions to our problem, we will be very thankful