If the error code is set to non-zero, av_thread_message_queue_recv() will
return it immediately when there are no longer available messages.
Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used
to cause the receiving thread to stop or suspend its operation.
Set the receiving error code.
If the error code is set to non-zero, av_thread_message_queue_recv() will return it immediately when there are no longer available messages. Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used to cause the receiving thread to stop or suspend its operation.