Add opaque param to add_stream_from_template

av/container/output.pyi

@@ -38,7 +38,9 @@ class OutputContainer(Container):
         options: dict[str, str] | None = None,
         **kwargs,
     ) -> VideoStream | AudioStream | SubtitleStream: ...
-    def add_stream_from_template(self, template: _StreamT, **kwargs) -> _StreamT: ...
+    def add_stream_from_template(
+        self, template: _StreamT, opaque: bool | None = None, **kwargs
+    ) -> _StreamT: ...
     def add_data_stream(
         self, codec_name: str | None = None, options: dict[str, str] | None = None
     ) -> DataStream: ...

av/container/output.pyx

@@ -129,20 +129,24 @@ cdef class OutputContainer(Container):
 
         return py_stream
 
-    def add_stream_from_template(self, Stream template not None, **kwargs):
+    def add_stream_from_template(self, Stream template not None, opaque=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 opaque: If True, copy opaque data from the template's codec context.
         :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":
+        if opaque is None:
+            opaque = template.type != "video"
+
+        if opaque:  # Copy ctx from template.
             codec_obj = template.codec_context.codec
-        else:
+        else:   # Construct new codec object.
             codec_obj = Codec(template.codec_context.codec.name, "w")
         codec = codec_obj.ptr
 
@@ -164,10 +168,8 @@ cdef class OutputContainer(Container):
         if self.ptr.oformat.flags & lib.AVFMT_GLOBALHEADER:
             codec_context.flags |= lib.AV_CODEC_FLAG_GLOBAL_HEADER
 
-        # Initialise stream codec parameters to populate the codec type.
-        #
-        # Subsequent changes to the codec context will be applied just before
-        # encoding starts in `start_encoding()`.
+        # Initialize stream codec parameters to populate the codec type. Subsequent changes to
+        # the codec context will be applied just before encoding starts in `start_encoding()`.
         err_check(lib.avcodec_parameters_from_context(stream.codecpar, codec_context))
 
         # Construct the user-land stream