I would remove the validate method and do some modifications:

About validate method:

• Check argc and argv outside the class, just provide the filename to the getData method.
• You also need to check when argc is less than 2, the user may forget to supply the filename.
• Openning the file in the validate method and closing it again does not guarantee that it will be still available when you call getData, so it is better to open the file only there and handle any errors there.

About getData:

• I would rename it to loadData
• for each line loaded you insert a value in time_ms and text_info vectors, call reserve before the loop to pre-allocate the needed memory.
• no need to call close on the stream, it will close when its scopes end

validateFileExtention

• use rfind instead of find and just grab the last "." from the string.
• I would instead create a function to copy the fileExtension and check both extensions at once, instead of finding the extension each time.
• also I would not even bother about file extension at all, I would just let the parser validate it.

About generateXML:

• memory leak: you never delete doc, also, if you need it just inside the method, why you use dynamic memory? Just create it on stack
• also, check if tinyxml deletes everything that you insert on the document, if not, you will have to handle this too.

Thats all that I could figure out.

Cheers

I would remove the validate method and do some modifications:

About validate:

• Check argc and argv outside the class, just provide the filename to the getData method.
• You also need to check when argc is less than 2, the user may forget to supply the filename.
• Opening the file in the validate method and closing it again does not guarantee that it will be still available when you call getData, so it is better to open the file only there and handle any errors there.

About getData:

• I would rename it to loadData.
• For each line loaded you insert a value in time_ms and text_info vectors, call reserve before the loop to pre-allocate the needed memory.
• No need to call close on the stream, it will close when its scopes end.

About validateFileExtention:

• Use rfind instead of find and just grab the last "." from the string.
• I would instead create a function to copy the fileExtension and check both extensions at once, instead of finding the extension each time.
• I would also not even bother about file extension at all. I would just let the parser validate it.

About generateXML:

• Memory leak: you never delete doc. Also, if you need it just inside the method, why you use dynamic memory? Just create it on stack.
• Also, check if tinyxml deletes everything that you insert on the document. If not, you will have to handle this too.