Did you try vinegar and water, that might help. Soak them a bit and then wash them with soap. If you hang them in an enclosed space like a closet will intensify the smell and may transfer to other things.

Yes, the smell of mildew means there's mildew. This is what I would do, keeping in mind I HATE mildew and wouldn't wear bike shorts with mildew, so would otherwise throw them out.

I would soak them in HOT water with OxiClean and a little dab of laundry detergent, for 6 hours or overnight. Rinse and sniff. Everything I soak in this mixture emerges smelling incredibly fresh and clean. Mildew and bacteria cannot survive the alkalinity of the washing soda, the oxidizing of the oxygen bleach, or the enzymes of the detergent. Hot water makes all those cleaners much more active, and is itself inhospitable to the mildew. Hanging them in the sun to dry would also be good, as sunlight kills mildew and bacteria as well.

andersons, I did pretty much what you stated. I soaked the clothes for at least 6 hours in Oxiclean, then washed them in the washing machines with detergent. The mildew smell did disappear!

Awesome! It's so gratifying to fix something that's all but ruined.

Hang them in the sun. It is a completely natural anti-mold agent. My grandmother used three things for fighting mold-sunlight, fresh air and lemon juice.

For mildew, add about 1/8 to 1/4 cup of ammonia to wash cycle (depending on size of load), along with your detergent, and wash as usual. The ammonia kills the mildew and the odor as well. Never fails!