add_stream_from_template with different codec?

[caffeinism]

My understanding is that add_stream_from_template is primarily used to create an equivalent stream for the input container. However, input containers often use codecs that are specific to decoding. I want to create a stream from a template but change the codec.

with open("av1.webm", "r") as i: # It opens with libdav1d by default.
  with open("out.webm", "w") as o:
    o.add_stream_from_template(i.streams.video[0], codec_name="libaom-av1") 

The other attributes appear to be changeable, but the codec only seems to be generated by the codec name in the template.

PyAV/av/container/output.pyx

Lines 132 to 147 in bf41ee0

	def add_stream_from_template(self, Stream template not None, **kwargs):
	"""
	Creates a new stream from a template. Supports video, audio, and subtitle streams.
	:param template: Copy codec from another :class:`~av.stream.Stream` instance.
	:param \\**kwargs: Set attributes for the stream.
	:rtype: The new :class:`~av.stream.Stream`.
	"""
	cdef const lib.AVCodec *codec
	cdef Codec codec_obj
	if template.type != "video":
	codec_obj = template.codec_context.codec
	else:
	codec_obj = Codec(template.codec_context.codec.name, "w")
	codec = codec_obj.ptr

It would be nice to have a path similar to the one below.

     def add_stream_from_template(self, Stream template not None, codec_name=None, **kwargs): 
         """ 
         Creates a new stream from a template. Supports video, audio, and subtitle streams. 
  
         :param template: Copy codec from another :class:`~av.stream.Stream` instance. 
         :param \\**kwargs: Set attributes for the stream. 
         :rtype: The new :class:`~av.stream.Stream`. 
         """ 
         cdef const lib.AVCodec *codec 
         cdef Codec codec_obj 
  
         if template.type != "video": 
             codec_obj = template.codec_context.codec 
         else: 
             codec_obj = Codec(codec_name or template.codec_context.codec.name, "w") 
         codec = codec_obj.ptr 

[WyattBlue]

This is possible for a new template function, but not possible for add_stream_from_template()