I just got a copy and while it's subtitled, the voices don't match the mouth movements, I'm guessing that it's been re-dubbed into Cantonese rather than the original Mandorin? Does anyone know if this is common with a lot of Chinese films? It seems that way for a few I've seen of late.
shareThe Shaw Bros. movies up until about the 1950s were all in Cantonese, then they switched over to Mandarin and stayed with it from that point on. They never recorded in one and then dubbed it later with the other. In subtitled versions those are the actual actor's voices you hear, and the voices might not exactly match the mouth movements because the soundtrack was entirely re-recorded in the studio.
For some reason in the 60s this was not uncommon, not just for Shaw Bros. movies but in Italy and France, among other countries. I don't know if they just had crappy sound systems but they thought it sounded better that way. If you have ever seen a Sergio Leone "spaghetti western" (nicknamed that because they were made in Italy) you will notice the same thing. It's Clint Eastwood's voice but it's been dubbed in the studio and doesn't match the mouth movement exactly.