Nil check input file in AVEncoder's #swapFiles.
Nil check input file in AVEncoder's #swapFiles.

imton/openkickflip-ios-sdk,twinenginelabs/kickflip-ios-sdk,imton/openkickflip-ios-sdk,OpenKickflip/openkickflip-ios-sdk,pourhadi/OpenKickFlip,pourhadi/OpenKickFlip,twinenginelabs/kickflip-ios-sdk,OpenKickflip/openkickflip-ios-sdk