Dear 磊 胡,
thank you for contacting.
Currently, is it possible to learn more about your use-case?
Based on Bing translation, I understand you are doing multi-threaded recognition ? Is it possible to learn more about your implementation?
Also, you have callbacks that are frozen after several recognitions?
First, how many threads do you have? Indeed, our recommendation is that you create one recognition thread per PHYSICAL core, e.g. your CPU has 4 physical cores you shall not create more than 4 threads in order to get the best performance.
Then, how do you ensure the recognitions is finished? Can you confirm you are calling "waitForIdle" before exporting the result? Indeed, with the latter, you will ensure that teh result is not gotten before the recognition process is on-going?