Function JxlEncoderSetUpsamplingMode 

pub unsafe extern "C" fn JxlEncoderSetUpsamplingMode(
    enc: *mut JxlEncoder,
    factor: i64,
    mode: i64,
) -> JxlEncoderStatus

Sets the upsampling method the decoder will use in case there are frames with ::JXL_ENC_FRAME_SETTING_RESAMPLING set. This is useful in combination with the ::JXL_ENC_FRAME_SETTING_ALREADY_DOWNSAMPLED option, to control the type of upsampling that will be used.

@param enc encoder object. @param factor upsampling factor to configure (1, 2, 4 or 8; for 1 this function has no effect at all) @param mode upsampling mode to use for this upsampling: -1: default (good for photographic images, no signaling overhead) 0: nearest neighbor (good for pixel art) 1: ‘pixel dots’ (same as NN for 2x, diamond-shaped ‘pixel dots’ for 4x/8x) @return ::JXL_ENC_SUCCESS if the operation was successful, ::JXL_ENC_ERROR otherwise