有人能帮我理解这个错误在pdfminer的pdf2txt中的含义吗：AttributeError:'PDFObjRef'对象没有属性'decode'

Question

我正在使用pdfminer的pdf2文本.py从不同的pdf文件中提取文本。该算法在很多情况下都能很好地工作，但我遇到了这个错误，我不知道我能做些什么让pdfminer工作。你知道吗

AttributeError:“PDFObjRef”对象没有“decode”属性

我已经在其他文档上运行了相同的命令，这是唯一一个出现此错误的文档。你知道吗

我只是在命令行之外运行这个，因此没有其他代码可以显示：

pdf2txt.py -t xml -F -1.0 test.pdf

这是pdf2的完整输出文本.py你知道吗

<?xml version="1.0" encoding="utf-8" ?>
<pages>
Traceback (most recent call last):
  File "/usr/local/bin/pdf2txt.py", line 116, in <module>
    if __name__ == '__main__': sys.exit(main(sys.argv))
  File "/usr/local/bin/pdf2txt.py", line 110, in main
    interpreter.process_page(page)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdfinterp.py", line 834, in process_page
    self.render_contents(page.resources, page.contents, ctm=ctm)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdfinterp.py", line 844, in render_contents
    self.init_resources(resources)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdfinterp.py", line 350, in init_resources
    self.fontmap[fontid] = self.rsrcmgr.get_font(objid, spec)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdfinterp.py", line 200, in get_font
    font = self.get_font(None, subspec)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdfinterp.py", line 191, in get_font
    font = PDFCIDFont(self, spec)
  File "/Library/Python/2.7/site-packages/pdfminer2-20151206-py2.7.egg/pdfminer/pdffont.py", line 643, in __init__
    self.cidcoding = '%s-%s' % (self.cidsysteminfo.get('Registry', b'unknown').decode("latin1"),
AttributeError: 'PDFObjRef' object has no attribute 'decode'

任何见解都将不胜感激！你知道吗