Test subtitle muxing

av/container/output.pyx

@@ -144,14 +144,15 @@ cdef class OutputContainer(Container):
         :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 not template.codec_context:
-            raise ValueError("template has no codec context")
-
-        cdef Codec codec_obj = Codec(template.codec_context.codec.name, "w")
-        cdef const lib.AVCodec *codec = codec_obj.ptr
+        if template.type == "subtitle":
+            codec_obj = template.codec_context.codec
+        else:
+            codec_obj = Codec(template.codec_context.codec.name, "w")
+        codec = codec_obj.ptr
 
         # Assert that this format supports the requested codec.
         if not lib.avformat_query_codec(self.ptr.oformat, codec.id, lib.FF_COMPLIANCE_NORMAL):
@@ -182,13 +183,6 @@ cdef class OutputContainer(Container):
         cdef Stream py_stream = wrap_stream(self, stream, py_codec_context)
         self.streams.add_stream(py_stream)
 
-        if template.type == "video":
-            py_stream.time_base = kwargs.pop("time_base", 1 / template.average_rate)
-        elif template.type == "audio":
-            py_stream.time_base = kwargs.pop("time_base", 1 / template.rate)
-        else:
-            py_stream.time_base = kwargs.pop("time_base", Fraction(0, 1))
-
         for k, v in kwargs.items():
             setattr(py_stream, k, v)
 

tests/test_encode.py

@@ -222,6 +222,29 @@ def test_transcode(self) -> None:
             assert stream.sample_rate == sample_rate
 
 
+class TestSubtitleEncoding:
+    def test_subtitle_muxing(self) -> None:
+        input_ = av.open(fate_suite("sub/MovText_capability_tester.mp4"))
+        in_stream = input_.streams.subtitles[0]
+
+        output_bytes = io.BytesIO()
+        output = av.open(output_bytes, "w", format="mp4")
+
+        out_stream = output.add_stream_from_template(in_stream)
+
+        for packet in input_.demux(in_stream):
+            if packet.dts is None:
+                continue
+            packet.stream = out_stream
+            output.mux(packet)
+
+        output.close()
+        output_bytes.seek(0)
+        assert output_bytes.getvalue().startswith(
+            b"\x00\x00\x00\x1cftypisom\x00\x00\x02\x00isomiso2mp41\x00\x00\x00\x08free"
+        )
+
+
 class TestEncodeStreamSemantics(TestCase):
     def test_stream_index(self) -> None:
         with av.open(self.sandboxed("output.mov"), "w") as output:

tests/test_streams.py

@@ -135,10 +135,3 @@ def test_data_stream(self) -> None:
         assert repr.startswith("<av.DataStream #0") and repr.endswith(">")
 
         container.close()
-
-    # def test_side_data(self) -> None:
-    #     container = av.open(fate_suite("mov/displaymatrix.mov"))
-    #     video = container.streams.video[0]
-
-    #     assert video.nb_side_data == 1
-    #     assert video.side_data["DISPLAYMATRIX"] == -90.0