Vector image as background

I am making a video using chroma key effect. The foreground would be a movie file and the background would be a vector image created with "pdflatex" (initially the image is a pdf), so it is a pdf file.

In the compositing context of blender, I add a node "image" so that I could import my pdf background. However I can't import such file.

A pdf file contains both raster and vector elements so I tried to raster the file with inkscape as mentionned here or here but it doesn't work and I find this method a bit messy (I have a lot of pdf files).

I try to change the compilation of my latex document to a format compatible with blender.... on-going