Fix segfault when printing closed video_stream

Author: WyattBlue

av/audio/stream.pyi

@@ -18,6 +18,9 @@ class _Layout:
 
 class AudioStream(Stream):
     codec_context: AudioCodecContext
+    def encode(self, frame: AudioFrame | None = None) -> list[Packet]: ...
+    def decode(self, packet: Packet | None = None) -> list[AudioFrame]: ...
+
     # From codec context
     frame_size: int
     sample_rate: int
@@ -27,5 +30,5 @@ class AudioStream(Stream):
     type: Literal["audio"]
     format: _Format
     layout: _Layout
-    def encode(self, frame: AudioFrame | None = None) -> list[Packet]: ...
-    def decode(self, packet: Packet | None = None) -> list[AudioFrame]: ...
+
+    def close(self, strict: bool = True) -> None: ...

av/codec/context.pxd

@@ -49,8 +49,8 @@ cdef class CodecContext:
     cdef _setup_decoded_frame(self, Frame, Packet)
 
     # Implemented by base for the generic send/recv API.
-    # Note that the user cannot send without recieving. This is because
-    # _prepare_frames_for_encode may expand a frame into multiple (e.g. when
+    # Note that the user cannot send without receiving. This is because
+    # `_prepare_frames_for_encode` may expand a frame into multiple (e.g. when
     # resampling audio to a higher rate but with fixed size frames), and the
     # send/recv buffer may be limited to a single frame. Ergo, we need to flush
     # the buffer as often as possible.

av/codec/context.pyx

@@ -193,10 +193,11 @@ cdef class CodecContext:
 
     @property
     def extradata(self):
+        if self.ptr is NULL:
+            return None
         if self.ptr.extradata_size > 0:
             return <bytes>(<uint8_t*>self.ptr.extradata)[:self.ptr.extradata_size]
-        else:
-            return None
+        return None
 
     @extradata.setter
     def extradata(self, data):
@@ -222,10 +223,14 @@ cdef class CodecContext:
 
     @property
     def is_encoder(self):
+        if self.ptr is NULL:
+            return False
         return lib.av_codec_is_encoder(self.ptr.codec)
 
     @property
     def is_decoder(self):
+        if self.ptr is NULL:
+            return False
         return lib.av_codec_is_decoder(self.ptr.codec)
 
     cpdef open(self, bint strict=True):

av/container/streams.pyi

@@ -16,7 +16,6 @@ class StreamContainer:
     other: tuple[Stream, ...]
 
     def __init__(self) -> None: ...
-    def add_stream(self, stream: Stream) -> None: ...
     def __len__(self) -> int: ...
     def __iter__(self) -> Iterator[Stream]: ...
     @overload

av/video/codeccontext.pyx

@@ -78,6 +78,8 @@ cdef class VideoCodecContext(CodecContext):
 
     @property
     def width(self):
+        if self.ptr is NULL:
+            return 0
         return self.ptr.width
 
     @width.setter
@@ -87,6 +89,8 @@ cdef class VideoCodecContext(CodecContext):
 
     @property
     def height(self):
+        if self.ptr is NULL:
+            return 0
         return self.ptr.height
 
     @height.setter

av/video/stream.pyi

@@ -17,6 +17,11 @@ class VideoStream(Stream):
     sample_aspect_ratio: Fraction | None
     display_aspect_ratio: Fraction | None
     codec_context: VideoCodecContext
+
+    def encode(self, frame: VideoFrame | None = None) -> list[Packet]: ...
+    def encode_lazy(self, frame: VideoFrame | None = None) -> Iterator[Packet]: ...
+    def decode(self, packet: Packet | None = None) -> list[VideoFrame]: ...
+
     # from codec context
     format: VideoFormat
     width: int
@@ -36,6 +41,4 @@ class VideoStream(Stream):
     colorspace: int
     type: Literal["video"]
 
-    def encode(self, frame: VideoFrame | None = None) -> list[Packet]: ...
-    def encode_lazy(self, frame: VideoFrame | None = None) -> Iterator[Packet]: ...
-    def decode(self, packet: Packet | None = None) -> list[VideoFrame]: ...
+    def close(self, strict: bool = True) -> None: ...

tests/test_streams.py

@@ -35,6 +35,41 @@ def test_selection(self) -> None:
         data = container.streams.data[0]
         assert data == container.streams.best("data")
 
+    def test_printing_closed_video_stream(self) -> None:
+        input_ = av.open(
+            fate_suite("amv/MTV_high_res_320x240_sample_Penguin_Joke_MTV_from_WMV.amv")
+        )
+        container = av.open("out.mkv", "w")
+
+        video_stream = container.add_stream("h264", rate=30)
+        # encoder = video_stream.codec.name + ""
+
+        video_stream.width = input_.streams.video[0].width
+        video_stream.height = input_.streams.video[0].height
+        video_stream.pix_fmt = "yuv420p"
+
+        for frame in input_.decode(video=0):
+            container.mux(video_stream.encode(frame))
+            break
+
+        encoder = "libx264"
+        repr = f"{video_stream}"
+        assert repr.startswith(f"<av.VideoStream #0 {encoder}, yuv420p 160x120 at ")
+        assert repr.endswith(">")
+
+        # repr = f"{video_stream}"
+        # assert repr.startswith(f"<av.VideoStream #0 {encoder}, yuv420p 160x120 at ")
+        # assert repr.endswith(">")
+
+        video_stream.close()
+
+        repr = f"{video_stream}"
+        assert repr.startswith(f"<av.VideoStream #0 {encoder}, yuv420p 0x0 at ")
+        assert repr.endswith(">")
+
+        container.close()
+        input_.close()
+
     # def test_side_data(self) -> None:
     #     container = av.open(fate_suite("mov/displaymatrix.mov"))
     #     video = container.streams.video[0]