Fix pyav 14 error (#8776)

Author: NicolasHug

torchvision/io/video.py

@@ -26,6 +26,10 @@
 install PyAV on your system.
 """
         )
+    try:
+        FFmpegError = av.FFmpegError  # from av 14 https://github.com/PyAV-Org/PyAV/blob/main/CHANGELOG.rst
+    except AttributeError:
+        FFmpegError = av.AVError
 except ImportError:
     av = ImportError(
         """\
@@ -155,7 +159,13 @@ def write_video(
 
         for img in video_array:
             frame = av.VideoFrame.from_ndarray(img, format="rgb24")
-            frame.pict_type = "NONE"
+            try:
+                frame.pict_type = "NONE"
+            except TypeError:
+                from av.video.frame import PictureType  # noqa
+
+                frame.pict_type = PictureType.NONE
+
             for packet in stream.encode(frame):
                 container.mux(packet)
 
@@ -215,7 +225,7 @@ def _read_from_stream(
     try:
         # TODO check if stream needs to always be the video stream here or not
         container.seek(seek_offset, any_frame=False, backward=True, stream=stream)
-    except av.AVError:
+    except FFmpegError:
         # TODO add some warnings in this case
         # print("Corrupted file?", container.name)
         return []
@@ -228,7 +238,7 @@ def _read_from_stream(
                     buffer_count += 1
                     continue
                 break
-    except av.AVError:
+    except FFmpegError:
         # TODO add a warning
         pass
     # ensure that the results are sorted wrt the pts
@@ -350,7 +360,7 @@ def read_video(
                     )
                     info["audio_fps"] = container.streams.audio[0].rate
 
-        except av.AVError:
+        except FFmpegError:
             # TODO raise a warning?
             pass
 
@@ -441,10 +451,10 @@ def read_video_timestamps(filename: str, pts_unit: str = "pts") -> Tuple[List[in
                 video_time_base = video_stream.time_base
                 try:
                     pts = _decode_video_timestamps(container)
-                except av.AVError:
+                except FFmpegError:
                     warnings.warn(f"Failed decoding frames for file {filename}")
                 video_fps = float(video_stream.average_rate)
-    except av.AVError as e:
+    except FFmpegError as e:
         msg = f"Failed to open container for {filename}; Caught error: {e}"
         warnings.warn(msg, RuntimeWarning)