Texture packer with cocos2dx

hey,guys, i have a intersting problem. i use texture packer to package all of my resources, and it works well on cocos2d, now i’m porting my game to cocos2d-x, but i found out that the every picture is twice larger than that in the cocos2d. here is the source code.

CCSpriteFrameCache * cache = CCSpriteFrameCache::sharedSpriteFrameCache();
cache~~>addSpriteFramesWithFile;
CCSprite* bird = CCSprite::createWithSpriteFrameName;
bird~~>setPosition(ccp(x, y));
this->add child(bird);

please help! thanks a lot