AV_MUTEX_INITIALIZER   68 libavcodec/utils.c static AVMutex codec_mutex = AV_MUTEX_INITIALIZER;
AV_MUTEX_INITIALIZER  550 libavformat/allformats.c static AVMutex avpriv_register_devices_mutex = AV_MUTEX_INITIALIZER;
AV_MUTEX_INITIALIZER   54 libavformat/utils.c static AVMutex avformat_mutex = AV_MUTEX_INITIALIZER;
AV_MUTEX_INITIALIZER   44 libavutil/log.c static AVMutex mutex = AV_MUTEX_INITIALIZER;