proc av_ripemd_alloc(): ptr AVRIPEMD {.importc, cdecl, ...raises: [], tags: [],
                                       forbids: [].}

proc av_ripemd_final(context: ptr AVRIPEMD; digest: ptr uint8) {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}

proc av_ripemd_init(context: ptr AVRIPEMD; bits: cint): cint {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}

proc av_ripemd_update(context: ptr AVRIPEMD; data: ptr uint8; len: csize_t) {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}