函数 avio_closep 

pub unsafe extern "C" fn avio_closep(
    s: *mut *mut AVIOContext,
) -> c_int

Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL. This function can only be used if s was opened by avio_open().

The internal buffer is automatically flushed before closing the resource.

@return 0 on success, an AVERROR < 0 on error. @see avio_close