proc av_crc(ctx: ptr AVCRC; crc: uint32; buffer: ptr uint8; length: csize_t): uint32 {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}

proc av_crc_get_table(crc_id: AVCRCId): ptr AVCRC {.importc, cdecl, ...raises: [],
    tags: [], forbids: [].}

proc av_crc_init(ctx: ptr AVCRC; le, bits: cint; poly: uint32; ctx_size: cint): cint {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}