Procs

proc av_display_matrix_flip(matrix: ptr int32; hflip, vflip: cint) {.importc,
    cdecl, ...raises: [], tags: [], forbids: [].}

proc av_display_rotation_get(matrix: ptr int32): cdouble {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}

proc av_display_rotation_set(matrix: ptr int32; angle: cdouble) {.importc,
    cdecl, ...raises: [], tags: [], forbids: [].}