video.py read_video_timestamps (follow-up PR #2202) (#2268)

* get pts directly instead of storing full frames to get pts later

* fix linting

* add initial pts value
sort pts

* catch decoding errors for read_video_timestamp

torchvision/io/video.py

@@ -329,11 +329,16 @@ def read_video_timestamps(filename, pts_unit="pts"):
         if container.streams.video:
             video_stream = container.streams.video[0]
             video_time_base = video_stream.time_base
+            try:
                 if _can_read_timestamps_from_packets(container):
                     # fast path
                     pts = [x.pts for x in container.demux(video=0) if x.pts is not None]
                 else:
-                pts = [x.pts for x in container.decode(video=0) if x.pts is not None]
+                    pts = [
+                        x.pts for x in container.decode(video=0) if x.pts is not None
+                    ]
+            except av.AVError:
+                warnings.warn(f"Failed decoding frames for file {filename}")
             video_fps = float(video_stream.average_rate)
         container.close()