There seems to be a boundary error (bug)

[ilovevan]

I convert WMA files to MP3. From now and then, I see one output file with error. The output file cannot be opened by WMP. Here are my investigations:

 

a. I convert using batch processor. To eliminate the possibility that problem is caused by busy CPU caused by batch processor, I manually convert the file that has trouble. The same result; i.e. WMP cannot open the file. I made many attempts to manually convert and the result is always the same.

 

b. To eliminate the problem that the original WMA file is errornous, I open the input file by WMP and by another player. They can open the WMA file without problem.

 

c. To eliminate that the problem is caused by some specific bits/bytes, I use another converting tool from another vendor. The tool from that vendor can convert without problem. The output MP3 file generated by that vendor can be opened by WMP (or another player) without problem.

 

d. I use WavePad to convert the troubled file to WAV. There is no problem. The output can be played successfully.

 

e. I notice that the error rate is about 2%. That is, about 2 files in every 100 files have trouble. [To do this test, I convert some hundred files using WavePad batch processor, then use another tool to massively open output files in order to locate the troubled files.]

 

The observation above lead me to suspect that there is a boundary error (bug) in this tool. During my testing career at my work place, I saw similar problems. In the case at work, any file that was multiple of 512 bytes long would be troubled.