PyAVReader can't work when num_workers is not set to 0

[huge3286]

it seems there are some problems about multiprocess when reading a single video.
this is the error message I encountered.
I wonder if PyAVReader is being used in the wrong way or is there a long-standing problem?
I searched other issues still not get the answer.

Invalid NAL unit size (-961680302 > 9279).
missing picture in access unit with size 9283
Invalid NAL unit size (-961680302 > 9279).
Error splitting the input into NAL units.
Invalid NAL unit size (-1966654939 > 7227).
missing picture in access unit with size 9283
Invalid NAL unit size (-1966654939 > 7227).
Error splitting the input into NAL units.
Invalid NAL unit size (1674551080 > 8532).
missing picture in access unit with size 8536
Invalid NAL unit size (1674551080 > 8532).
Error splitting the input into NAL units.
Invalid NAL unit size (-961680302 > 9279).
missing picture in access unit with size 9283
Invalid NAL unit size (-961680302 > 9279).
Error splitting the input into NAL units.
Invalid NAL unit size (-1966654939 > 7227).
missing picture in access unit with size 9283
Invalid NAL unit size (-1966654939 > 7227).

av.error.InvalidDataError: [Errno 1094995529] Invalid data found when processing input; last error log: [h264] Error splitting the input into NAL units.