摘要:
Systems and/or methods (“tools”) are described that enable a digital rights management policy to be associated with digital media having an arbitrary content type or transfer control protocol. In some embodiments, the tools encrypt data segments of a media file and add a descriptor to each of those segments. These descriptors can enable a receiver of the encrypted media file to decrypt the file and consume it according to the correct digital rights management policy.
摘要:
Various embodiments utilize methods of protecting content, such as Digital Rights Management (DRM), to enable secure playback of content on machines and devices within a local network, such as a home media network. In at least some embodiments, messages and content are delivered using, respectively, a control protocol for streaming and a transport protocol. In at least some embodiments, the control protocol for streaming is Real Time Streaming Protocol (RTSP), and the transport protocol is Real Time Transport Protocol (RTP).
摘要:
Fast startup for streaming media includes one or both of a technique for predictive start and a technique for switching delivery channel(s) during streaming. Predictive start allows a media content source to predict which media stream(s) are desired by the requesting client device and begin streaming those predicted media stream(s) to the client device. The delivery channel switching technique allows the media content source to begin streaming the media stream(s) using one delivery channel (e.g., using the Transmission Control Protocol (TCP)), and then check whether another delivery channel (e.g., using the User Datagram Protocol (UDP)) will work and switch to that other delivery channel if it will work.
摘要:
Various embodiments permit policy updates, such as DRM policy updates, to be delivered and updated for a given piece of protected content. In at least some embodiments, various protocols can be extended to permit policy updates to be represented and carried by the protocol. In one embodiment, Hypertext Transport Protocol or HTTP is utilized to carry the policy updates. In another embodiment, Real Time Streaming Protocol or RTSP is used to carry policy updates.
摘要:
Multimedia presentations are multicast using an announcement channel that includes presentation description information along with multiple channels for multiple streams of multimedia data to accommodate clients of different multimedia resources. Clients can use the announcement channel to select channel(s) appropriate for their multimedia resources. The channels are created in a predetermined manner (e.g., preselected logical addresses, preselected ports of an IP address, etc.) so that clients can immediately join a channel without (or concurrently with) joining the announcement channel to reduce startup latency. An acceleration channel may be created that provides blocks of data containing a preselected number of previous units, which may be transmitted at at a bit rate that is “faster than real-time”. This feature allows clients with suitable resources to more quickly buffer sufficient data to begin presenting the multimedia data to users.
摘要:
Protecting elementary stream media content is described. In one aspect, data segments within elementary stream media content are identified. Each data segment includes a single video or audio frame. Encryption boundaries for protecting the payload packets are selected to correspond to data segment boundaries. The elementary stream media content is then protected using the selected encryption boundaries.
摘要:
Methods and apparatuses are provided for use with a client and server device connected through a communication link. The client device sends a startup request to the server device. The startup request identifies a streamable media content that is to be provided to the client device, a communication link bandwidth associated with the communication link, and an amount of the desired streamable media content that is to be provided at a bitrate greater than the encoded bitrate but no greater than about the communication link bandwidth. The server device buffers at least the amount of the streamable media content, and transmits the amount of the buffered streamable media content at the higher bitrate. The server device locates a discrete rendering point in the amount of the buffered streamable media content and initiates transmission beginning with the discrete rendering point. After transmitting the amount of the buffered streamable media content, the server device transmits subsequent portions of the streamable media content to the client device at a bitrate about equal to the encoded bitrate. The client device buffers received streamable media content, and subsequently renders the buffered streamed media content.
摘要:
A system and method for embedding a streaming media format header within a session description message. The streaming media format header is encapsulated within a session description message as a header attribute. The streaming media format header describes complex relationships between available media streams. The session description message also includes a list of content description attributes storing metadata about the media streams. A media description field in the session description message stores a stream attribute identifying a media stream associated with the media description field.
摘要:
Various functionality with respect to streaming media content is made available to users. Such functionality includes one or more of: streaming media content at a rate independent of the encoded bit rate of the content, allowing streaming of content to continue even when the user has selected various shuttle control options (e.g., pause, stop, fast forward, seek, rewind, etc.), allowing streaming content to be recorded for playback at a later time, and allowing streaming content to be time-shifted.
摘要:
Protecting elementary stream media content is described. In one aspect, Media Access Units (MAUs) of elementary stream content are identified. Each MAU includes one or more data segments representing a single video or audio frame. Encryption boundaries are selected for each MAU. The encryption boundaries are based on one or more data segments associated with the respective MAU. Portions of each MAU are encrypted based on corresponding encryption boundaries. Each MAU is mapped to a MAU Payload Format. The MAU Payload Format allows a media consumer to process each elementary stream associated with the elementary stream content independent of any different elementary stream. The MAU Payload Format also allows a media consumer to process each MAU in an elementary stream independent of any other MAU.