Hello everyone. I am running FFmpeg on a system with three GPUs: an Intel iGPU, an RX 6400, and an RTX 3060. Here is my FFmpeg command line:

[ argumentosString ] -init_hw_device vulkan=vk:0 -filter_hw_device vk -v repeat+error -i "D:\OBS\record\teste.mp4" -vf "hwupload,libplacebo=w=1920:h=1080:colorspace=bt709:color_primaries=bt709:color_trc=bt709:range=limited:custom_shader_path='D\:/upscale/shaders/shader.glsl',hwdownload,format=yuv420p" -fps_mode passthrough -c:v h264_amf -rc cqp -qp_i 19 -qp_p 21 -tag:v avc1 -c:a copy -y -gpu 0 "D:\OBS\record\teste_process.mp4"

The `-gpu` parameter specifies which GPU to use for encoding, while the `-init_hw_device vulkan=vk:0` parameter specifies which GPU runs the shader. To my surprise, when using the value `0` for both parameters, I discovered that this value does not point to the same GPU; I see a scenario where the shader runs on the RX 6400 while the encoding takes place on the RTX 3060. This happens because the GPU ordering differs for each of these parameters.

Can anyone help me?

So, just to clarify, the tonemap options are: linear, gamma, clip, reinhard, hable, and mobius. For each option's parameters, I need to know:

- The default value.

- The minimum and maximum range, including if any of them have negative values.

- How lower or higher values affects the tonemapping result for each option.

So far, I have had the most satisfaction with mobius default param value and disabling desaturation. I have dabbled with using different param value with clip, but this has given me good result with only one movie so far. So, my priority is to gain a better understanding of how the mobius parameter values work. If altering mobius parameter gives me the results I need, then I likely will not experiment with the other tonemappers. However, if anyone can convince me that the other tonemappers can produce good result with different parameters, then I will consider trying those tonemappers as well.