.dm 文件扩展名
开发商：
Open Mobile Alliance
文件类型：
Message File
你在这里因为你有，有一个文件扩展名结尾的文件 .dm. 文件与文件扩展名 .dm 只能通过特定的应用程序推出。这有可能是 .dm 文件是数据文件，而不是文件或媒体，这意味着他们并不是在所有观看。
什么是一 .dm 文件？
对DM的文件扩展名是被称为DRM传递消息的数据格式。 DM文件一般编码使用DRM（数字版权管理）复制保护的音频文件，它们由开放移动联盟被发明。这些都是定制的铃音和媒体剪辑只为选定授权的手机下载。根据OMA DRM V1.0，糖尿病文件包含要传递邮件的内容和权利。对于索尼爱立信的用户，这些文件在DRM打包程序创建。但是，如果它是为诺基亚用户，这些文件都可以从网上的诺基亚Ovi商店，并使用SIS.DM或SISX.DM文件扩展名。在DM格式的文件可以打开与索尼爱立信DRM打包，并在基于Microsoft Windows的系统的SISContents。这些文件可以被转换成MP3或MIDI格式和解锁DM铃声的方法之一是通过记录和保存铃声为不同的格式。
如何打开 .dm 文件？
推出 .dm 文件，或者你的电脑上的任何其他文件，双击它。如果你的文件关联的设置是否正确，这意味着应用程序来打开你的 .dm 文件将其打开。这是可能的，你可能需要下载或购买正确的应用程序。这也有可能是你有正确的应用程序在PC上，但 .dm 文件还没有与它相关联。在这种情况下，当您尝试打开一个 .dm 文件，你可以告诉Windows的应用程序是正确的该文件。从这时起，打开 .dm 文件将打开正确的应用程序。 点击这里修复.dm文件关联错误
打开一个应用程序 .dm 文件
Sony Ericsson DRM Packager
Sony Ericsson DRM Packager
Digital Rights Management is a technology that is used in securing the distribution, promotion and sales of a digital media. It protects digital content through limited usage, like for instance in 3G, where operators and content providers need a method that will allow then to sell content without freely distributing it between devices. DRM is defined by the standards of Open Mobile Alliance (OMA). OMA DRM enables controlled consumption of digital media objects by letting content providers express usage rights like the ability to preview DRM content, to prevention of illegally forwarding downloaded DRM content from to other users, and in enabling super distribution of DRM content. Usage rights are controlled with DRM, these are defined for all types of content. Different rights from different users may be applied on the same content. DRM controls usage rights like the number of times it can be used, the period it can be used and the length of time it can be used. This kind of control enables content providers to create more subscriptions and pay-per-use models and will also stimulate mobile content based services.
SISContents
SISContents
SISContents is software used in unpacking, editing and signing of Symbian 9 SIS packages. It inspects the files that are contained in the package, and checks for certificates it was signed to and view the PKG script which describes the process of on-device installation. The contents of these packages may be edited and signed after the installation. Packages may be edited by modifying the name, vendor, version, type of installation, supported platforms for devices, software dependencies, and the files and components contained in the package may be added, replaced, deleted and change capabilities, UID3, SID of executables. Signed packages show information on certificates, its validity period, issuer, subject, and others, and they may be deleted from the package. It can also view and save installation PKG script, create SIS packages from PKG scripts, read and unpack contents and files from N-Gage packages, and also view, edit and extract images from multibitmap files embedded in the sis packages. It is compatible with Windows XP, Windows 2003 Server, Windows Vista, windows 2008 Server and Windows 7. Nokia S60 3rd, 5th Edition and Sony Ericsson UIQ 3.x platforms are also supported.提醒一句
要小心，不要重命名扩展 .dm 文件，或任何其他文件。这不会更改文件类型。只有特殊的转换软件可以从一个文件类型更改一个文件到另一个。
什么是文件扩展名？
文件扩展名是一组三个或四个字符在文件名的末尾，在这种情况下， .dm. 文件扩展名告诉你它是什么类型的文件，并告诉Windows哪些程序可以打开它。窗户经常关联一个默认程序的每个文件的扩展名，这样，当你双击该文件，程序会自动启动。当该程序不再是您的PC上，有时可以得到一个错误，当您试图打开相关的文件。
