ytdl-org/youtube-dl · error · ExtractorError

Cannot find function %s.%s

Error message

Cannot find function %s.%s

What it means

Error "Cannot find function %s.%s" thrown in ytdl-org/youtube-dl.

Source

Thrown at youtube_dl/swfinterp.py:447

        if call_cinit and hasattr(res, 'cinit_idx'):
            res.register_methods({'$cinit': res.cinit_idx})
            res.methods['$cinit'] = self._all_methods[res.cinit_idx]
            cinit = self.extract_function(res, '$cinit')
            cinit([])

        return res

    def extract_function(self, avm_class, func_name):
        p = self._patched_functions.get((avm_class, func_name))
        if p:
            return p
        if func_name in avm_class.method_pyfunctions:
            return avm_class.method_pyfunctions[func_name]
        if func_name in self._classes_by_name:
            return self._classes_by_name[func_name].make_object()
        if func_name not in avm_class.methods:
            raise ExtractorError('Cannot find function %s.%s' % (
                avm_class.name, func_name))
        m = avm_class.methods[func_name]

        def resfunc(args):
            # Helper functions
            coder = io.BytesIO(m.code)
            s24 = lambda: _s24(coder)
            u30 = lambda: _u30(coder)

            registers = [avm_class.variables] + list(args) + [None] * m.local_count
            stack = []
            scopes = collections.deque([
                self._classes_by_name, avm_class.constants, avm_class.variables])
            while True:
                opcode = _read_byte(coder)
                if opcode == 9:  # label
                    pass  # Spec says: "Do nothing."
                elif opcode == 16:  # jump

View on GitHub (pinned to 956b8c5855)

Solutions

1. Update youtube-dl; the SWF calls a function the interpreter cannot find.

When it happens

Trigger: Thrown at youtube_dl/swfinterp.py:447 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/d72af8db6364dc46. Report an issue: GitHub.