A method and a device for processing a multimedia file are provided. In some embodiments, for a multimedia file to be processed, payload data in the multimedia file is acquired, and the payload data includes multi-frame data forming the multimedia file. Some pieces of frame data are selected from the payload data as frame data to be encrypted, and the frame data to be encrypted is encrypted. New payload data is formed by the encrypted frame data and unencrypted frame data, and the new payload data is encoded to obtain an encoded multimedia file. Therefore, the protection of the copyrights of the multimedia file is achieved.

A method and system for controlling implementation of dynamic content modification. The disclosure provides for using at least one steganographically-encoded timestamp in a media stream transmitted to a media client as a basis to determine a transmission delay for media-stream transmission to the media client, and for providing the determined transmission delay as a basis to facilitate control over whether to have the media client implement dynamic content modification. In addition, the disclosure provides for receiving respectively from each of various media clients a report indicating transmission delay determined for the media client based on such steganographically-encoded timestamp data, and using the transmission delays for the media clients to establish a dynamic-content-modification footprint that could be used to control whether, where, and to what extent dynamic content modification will be applied.

A method of processing supplementary content in a digital receiving apparatus, includes connecting to an external device being different from a broadcaster; receiving uncompressed audio/video (A/V) content from the external device being different from the broadcaster; extracting audio watermark from the uncompressed A/V content, wherein the audio watermark includes domain type information, time information and event flag, further the event flag is used to signal when an event is available, and the event flag is 1-bit; constructing a first uniform resource locator (URL) based on the audio watermark; transmitting a request to a remote server based on the first URL; receiving a second URL for the supplementary content from the remote server; and presenting the supplementary content based on the second URL.

The present invention provides a method of transmitting broadcast signals. The method includes, receiving an uncompressed broadcast content from an external receiving unit, wherein an watermark is embedded in a frame of the uncompressed broadcast content; extracting the embedded watermark from the uncompressed broadcast content; parsing the extracted watermark; generating an URL by using information in the parsed watermark; and launching an application by using the generated URL, wherein the application provides the interactive services related to the uncompressed broadcast content.

A device (40) for generating a watermarked stream (39), comprising: at least one input interface (41) configured to receive encrypted control messages (20) and conditional access streams (30) including a main stream (33) and protected watermarking data streams (35) from which a watermarking information (38) can be embedded in said watermarked stream (39); a security module (43) configured to process said control messages (20) and to control access to said conditional access streams (30); a descrambler (45) configured to remove protection applied on at least some of said conditional access streams (30); a watermarking unit (47) configured to generate the watermarked stream (39) from said conditional access streams (30) by selectively processing said watermarking data streams (35) depending on access data (AC, AR) included in some of said control messages (20).

A method can include receiving, at a given node, a continuous stream of input media from a media source. A value can be computed as a function of each of a plurality of data blocks of the continuous stream of input media received by the given node. The method can also include receiving, at the given node, values computed for a plurality of data blocks of the continuous stream received by another node. A set of the received values from the other node can be correlated with a set of the computed values for the given node to determine an offset between the blocks of the continuous stream of input media that are received by the given node and the blocks of the continuous stream of input media that are received by the other node.

Dynamic control by a source device of sink buffer size for audio and/or video streaming over an error-prone channel. The sink buffer size may be determined based on a type of application for a media stream being transmitted from the source device to the sink device for presentation. The techniques may select a buffer size that is smaller for gaming applications, larger for interactive media applications, and even larger for non-interactive media types. The techniques adjust the time delta between a shared clock reference and time reference values of a transport stream that are used by the sink device to determine decoding or presenting of media frames of the transport stream relative to a shared clock reference. In addition, the techniques may account for transceiver latency at the source device due to scanning or multiple concurrent connections.

Techniques are disclosed for measuring propagation delay of a media distribution system based on content output by rendering devices. An output from an output device of the media distribution system may be captured and a token may be detected from the captured content. A timecode may be derived from the detected token. The system's propagation delay may be determined from the derived timecode and may provide a basis to analyze system delays and other processing artifacts. In this manner, propagation artifacts may be estimated between multiple rendering devices that lack controls to synchronize their operation.

A portable device, such as a cell phone, is used to “forage” media content from a user's environment. For example, it may listen to a television viewed by a traveler in an airport lounge. By reference to digital watermark or other data extracted from the content, the device can identify the television program, and enable a variety of actions. For example, the device may instruct a DVR to record the remainder of the television program—or determine when the program will be rebroadcast, and instruct the DVR to record the program in its entirety at that later time. The device may also identify content that preceded (or follows) the foraged content. Thus, a user who tunes-in just at the end of an exciting sporting event can capture one of the following commercials, identify the preceding program, and download same for later viewing. In other aspects, a cell phone can be used as a “second screen,” through which a user can interact with ambient content—such as reviewing electronic program guide data, or enjoying interactive television features. A great variety of other functions and arrangements are also detailed.

A method is provided for delivering a streaming media asset to a client device. For the method, a request is received over a communication network from a client device for playing a media asset in accordance with a streaming media technique. Prior to fully authorizing the client device to play the media asset, the client device is provided with access to a first cryptographic key that decrypts a subset of the media asset so that the client device is able to render the subset of the media asset before completion of the authorization. The subset of the media asset is less than all of the media asset. Subsequent to successfully fully authorizing the client device to play the media asset, the client is provided with access to at least one additional cryptographic key that decrypts a remainder of the media asset.