WO2005051020A1

WO2005051020A1 - Method and device for sharing real-time information

Info

Publication number: WO2005051020A1
Application number: PCT/IB2004/052411
Authority: WO
Inventors: Declan P. Kelly; Bei Wang
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2003-11-18
Filing date: 2004-11-12
Publication date: 2005-06-02

Abstract

Communication devices like mobile phones (42,43) may have a storage unit and a playback function for rendering real-time information like audio or video. Such devices are equipped to exchange auxiliary data for remotely affecting the retrieval of the real-time information from a storage medium (45,46). A first user generates on the first device (42) auxiliary data relating to the stream, for example a playlist indicating a selection of tracks. The auxiliary data is transferred via the network to a second device (43) at a different location. The second device is equipped to receive the auxiliary data and, while rendering the stream of real-time data, apply the auxiliary data received from the first device to adapt or synchronize the playback. The storage medium may comprise predefined messages to allow the user to generate his auxiliary data.

Description

Method and device for sharing real-time information

The invention relates to a method of exchanging auxiliary data for controlling retrieval of real-time information on rendering devices that are connectable via a network. The invention further relates to a rendering device and a storage medium for use in the method, and a computer program product exchanging auxiliary data. The invention relates to the field of rendering real-time data such as a stream of digitally encoded audio or video, and in particular to affecting rendering real-time data by auxiliary data exchanged via a network.

US2002/0165024 describes a system and method for mobile terminal users to communicate with each other. The device has a communication unit, such as a wireless receiver/transmitter, for communicating via a network such as the mobile telephone network or the internet. Further the terminal is provided with the capability of displaying real-time information such as video, also called multimedia information. Messages to be sent between users are predefined either by a user or at system level, and are related by subject matter to an on-line service to which the user is connected for receiving the real-time information. The messages that are communicated may include voice, text, sound, an image, or video, and may be stored at a mobile terminal or at a network-based message database. The system allows a game to be shared and to be played with several players via respective terminals. Further users may communicate with one another using predefined messages which are related to the multimedia content an on-line service or database. A problem of the system is that the amount and variety of multimedia information that the user can control and share is limited to on-line data such as websites.

It is an object of the invention to provide a communication system that allows flexible selection, availability and sharing of multimedia information. For this purpose, the method as described in the opening paragraph comprises the steps of providing a storage medium containing at least one stream of real-time information, retrieving at least part of the stream from the storage medium in a first rendering device at a first location, generating on the first rendering device auxiliary data relating to the stream, transferring the auxiliary data via the network to a second rendering device at a second location, rendering on the second rendering device a representation of at least part of the stream in dependence of the auxiliary data received from the first rendering device. For this purpose, the rendering device as described in the opening paragraph comprises transceiver means for connecting the device to a network, read means for retrieving data from a storage medium containing at least one stream of real-time infonnation, and control means for generating auxiliary data relating to the stream, and for transmitting the auxiliary data via the network to a further rendering device at a different location, and/or for receiving auxiliary data via the network from a further rendering device at a different location, and for controlling retrieval of the real-time information in dependence of the auxiliary data received from the further rendering device. For this purpose, the storage medium as described in the opening paragraph comprises at least one stream of real-time information and predefined auxiliary message data related to the stream. The measures have the effect that the real-time information, such as video or audio, and predefined messages, are provided on a storage medium for rendering the multimedia content for the user of the first rendering device. The storage medium may be an optical disc, e.g. a small form factor optical disc (SFFO) for which a disc drive unit is fitted in a mobile phone. The user may enjoy the multimedia content without being connected to an on-line service, and generate auxiliary data, e.g. selecting predefined message data, create a playlist, or generate samples of the multimedia content. The playlist indicates a selection or order of tracks of the storage medium to be played. Advantageously the user may transfer his auxiliary data to another rendering device at a second location for a second user to share. This has the advantage that the second user may share the experience of the first user, while only a relatively small amount of auxiliary information needs to be transferred via the network, while no on-line service is needed. The invention is also based on the following recognition. Although accessing multimedia content is possible via a network, there are several limitations to overcome, such as limited speed of the network, interruption of access, cost of data transfer, etc. In particular limitations arise due to the use of a shared website or server to provide the multimedia content and/or related auxiliary messages. Providing multimedia content via a storage medium, such as a small format optical disc, to a user does not suffer from such limitations. The inventors have seen that by transferring only auxiliary control data that represents preferences or selected samples of a first user to a second user allows sharing of the experience of consuming the multimedia content. In particular when the second user also has a copy of the optical disc the way of playback may be shared with the other user. In an embodiment of the device the control means are arranged for retrieving from the storage medium predefined auxiliary message data related to the stream and for including the predefined auxiliary message data in the auxiliary data. This has the advantage that the user has predefined messages available for sharing with other users of such rendering devices. In an embodiment of the device the control means are arranged for including identification infonnation in the auxiliary data, and for verifying that the storage medium present in the device contains similar data as the storage medium in the further rendering device in dependence of the identification infonnation. This has the advantage that the device detects that real-time data is available in a remote rendering device which is related to the transferred auxiliary data. In an embodiment of the device the control means are arranged for generating playlist data in the auxiliary data, the playlist data representing a selection of, or order of, parts of the stream to be played. This has the advantage that the user shares his preferences and selections with other users. In an embodiment of the device the control means are arranged for synchronizing the playback of the stream of real-time data to playback of the stream at the further rendering device in dependence of the auxiliary data received from the further rendering device. This has the advantage that users of different rendering devices share the same multimedia content simultaneously, without transferring large amounts of data via the network. Further embodiments are given in the dependent claims.

These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which Figure 1 shows a record carrier, Figure 2 shows a communication device, and Figure 3 shows communication devices connected via a network. Corresponding elements in different Figures have identical reference numerals.

Figure 1 shows a disc-shaped record carrier 11 having a track 9 and a central hole 10. The track 9, being the position of the series of (to be) recorded marks representing information, is arranged in accordance with a spiral pattern of turns constituting substantially parallel tracks on an information layer. The record carrier may be optically readable, called an optical disc. In a read-only type of record carrier the marks are provided during manufacture, e.g. as pits and lands pressed in a substrate layer. Examples of read-only optical discs are the CD (Compact Disc) or the DVD (Digital Versatile Disc) ROM or Video. Further details about the DVD disc can be found in reference: ECMA-267: 120 mm DVD - Readonly Disc - (1997). In an embodiment the record carrier has an information layer of a recordable type. Examples of a recordable disc are the CD-RW, and rewritable versions of DVD, such as DVD+RW, and the high density writable optical disc using blue lasers, called Blu-ray Disc (BD). The information is represented on the information layer by recording optically detectable marks along the track, e.g. crystalline or amorphous marks in phase change material. The track 9 on the recordable type of record carrier is indicated by a pre- embossed track structure provided during manufacture of the blank record carrier, for example, by a pregroove which enables a read/write head to follow the track during scanning. The record carrier 11 is intended for carrying digital information in blocks according to a predefined recording format. The recording format may include a file management system. An example of the predefined recording format is the Blu-ray Disc (BD), which defines recording of real-time data. For the application in small devices such as mobile phones a small form factor optical disc (SFFO) is proposed. Real-time information is information to be rendered continuously, in particular information representing digitally encoded video according to a standardized format like MPEG2 or MPEG4. The recording format usually defines meta-data for rendering the real-time data, such as navigation information or characteristic point information. Navigation information is provided for allowing a user to easily access a part of the recorded real-time data stream. Characteristic point information provides access to points in the encoded data stream where reproduction can be started. An example of Characteristic point information is described in WO 00/28544. For use in communication devices as described below the record carrier is provided with at least one stream of real-time data such as video or music and with predefined auxiliary message data related to the stream. Mobile phone networks such as GPRS (an extension of GSM, sometimes called 2.5 G) and CDMA20001X now support Multimedia Messaging System (MMS) that allows users send messages that include pictures and music instead of just text (as in SMS). The 3G networks such as W-CDMA and CDMA2000 can support much higher bit rate which makes it possible to also transfer video fragments. The publisher of SFFO discs includes pre-defined MMS messages on the disc. MMS means the message can be a photo, a piece of music or a short video clip. A person using SFFO in a mobile phone will have the option to send these MMS messages to friends. The intention is that the MMS messages relate to the content on disc e.g. for an audio disc the MMS message may correspond to a picture of the singer plus a low resolution segment of the audio. This feature has clear benefits. In an embodiment, besides the copy-protected content on the disc, the messages contain some copy- free content for sending to other communication devices. Each customer can send the predefined messages including the copy-free content to their friends. Advantageously the publisher controls how the content is presented in the sent message. For the customer it also has benefits. When they buy a new SFFO they can share parts of the content with their friends and send very elaborate MMS messages. The mobile phone that supports SFFO provides a function for the user to preview and send the MMS from the disc. The MMS messages could also be linked directly to the content e.g. while playing a particular song you can choose to send the MMS associated with this song. No explicit support for SFFO is required in the receiving phone. As well as the real content, the disc includes files that correspond to the MMS format defined for the mobile phone network. In an embodiment for supporting multiple different mobile phone network standards (e.g. GPRS, CDMA20001X, iMode) the same content is stored as predefined messages in multiple formats. Because the size of MMS messages is small (compared to the capacity of an optical disc), storing multiple MMS messages in many formats takes only a negligible part of the disc capacity. In an embodiment the predefined (MMS) messages are customizable e.g. the sender can add some text with the content to include a personal message in the predefined message. MMS messages on disc contain placeholders for customization where the sender can add his auxiliary information, such as text or pictures. The mobile phone that creates the final MMS to send has an application function to customize the predefined messages. Figure 2 shows a communication device. The device has a network interface 27, for example an antenna to communicate via a wireless network. In an embodiment the network interface may be a wired or wireless interface to a local area network (LAN, e.g. Ethernet), or to a wired telephone network. The network interface 27 is coupled to a transceiver unit 28 for sending and receiving data to/from other communication devices according to the transmission protocols of the network, such as the mobile phone network standards mentioned above. The device has a rendering unit 29 for multimedia data, such as a display screen for video and a microphone and telephone for audio. A camera may also be included for input of still pictures or video. In addition the device has a storage unit for reading information from a record carrier 11. The storage unit is provided with means for scanning the track on the record carrier which means include a drive unit 21 for rotating the record carrier 11, a head 22, a positioning unit 25 for coarsely positioning the head 22 in the radial direction on the track. The head 22 comprises an optical system of a known type for generating a radiation beam 24 guided through optical elements focused to a radiation spot 23 on a track of the information layer of the record carrier. The radiation beam 24 is generated by a radiation source, e.g. a laser diode. The head further comprises (not shown) a focusing actuator for moving the focus of the radiation beam 24 along the optical axis of said beam and a tracking actuator for fine positioning the spot 23 in a radial direction on the center of the track. The tracking actuator may comprise coils for radially moving an optical element or may alternatively be arranged for changing the angle of a reflecting element. For reading the radiation reflected by the information layer is detected by a detector of a usual type, e.g. a four-quadrant diode, in the head 22 for generating a read signal and further detector signals including a tracking error and a focusing error signal for controlling said tracking and focusing actuators. The read signal is processed by read processing unit 30 of a usual type including a demodulator, deformatter and output unit to retrieve the information. In an embodiment the storage unit is arranged for recording information on record carriers of a recordable (write-once or re- writable) type. Such a storage unit comprises write processing means for processing the input information to generate a write signal to drive the head 22, which means comprise an (optional) input unit, a formatter and a modulator. During the writing operation, marks representing the information are formed on the record carrier. The marks are formed by means of the spot 23 generated on the recording layer via the beam 24. The device has a control unit 20 which is arranged to be controlled by the user, e.g. via a keyboard or a touch screen. The control unit 20 is connected via control lines 26, e.g. a system bus, to said transceiver unit 28 and rendering unit 29, and in the storage unit to the read processing unit 30, and to the drive unit 21, and the positioning unit 25. The control unit 20 comprises control circuitry, for example a microprocessor, a program memory and control gates, for performing the procedures and functions according to the invention as described below. The control unit 20 may also be implemented as a state machine in logic circuits. In an embodiment the communication device is constituted by a standard computer device provided with network communication facilities, such as a laptop or PDA having a wireless network connection unit. In such a device the function of exchanging auxiliary data related to rendering of real time data is implemented in a computer program product for controlling retrieval of the real-time information. The program is operative to cause the processor of the standard computer device to perform the steps of retrieving at least part of a stream of real-time information from a storage medium, generating auxiliary data relating to the stream, transmitting auxiliary data via the network to a rendering device at a different location, or receiving auxiliary data via the network from a rendering device at a different location, and rendering a representation of at least part of the stream in dependence of the auxiliary data received. For example a selection from the real time data to be retrieved is based on the auxiliary data received. Further examples of auxiliary data and control of retrieval are given below. Figure 3 shows communication devices connected via a network. A network 41 is provided for connecting communication devices 42,43,44 such as mobile phones. The network supports transferring messages from a first user device 42 to further user devices 43,44. The first user device is provided with a storage unit as described above with Figure 2. A storage medium 45, for example a SFFO, is entered by the first user in the device 42 and real-time data is rendered, e.g. a video clip. The first user generates auxiliary data, like a selection of video fragments to be played, or text comments, or karaoke type singing as audio data. The first user assembles a message containing the auxiliary data and transmits the message to a second user at device 44. The first user may select some samples from his storage medium and transmit the samples, for example after data reduction by a compression algorithm, to the device 44 of the second user. The second user may for example enjoy the selected video fragments. In an embodiment the message including the auxiliary data is received at a third user device 43, where a third user enters a same storage medium 46 in his device for locally rendering the same real-time data. The auxiliary data generated by the first user may be enjoyed together with the same real-time information without transferring the real-time information via the network. Hence two mobile phone users, who both have the same SFFO disc, share the experience of the content of this disc using the mobile phone network. The existing network features of transferring messages like SMS and MMS are used so that a new feature on the phone can be presented without requiring an extension to the network infrastructure software. In an embodiment the first user creates a playlist for a published SFFO disc. The playlist indicates a selection or order of tracks of the storage medium to be played. The playlist data may be generated automatically as auxiliary data, the playlist data representing a selection of, or order of, parts of the stream as played. Note that the application function on the phone may automatically send/receive SMS/MMS messages and the user not need to be aware of how it is implemented. Alternatively the user may enter a playlist manually, e.g. via the keyboard. The playlist is send via SMS/MMS to one or more other users. The receiver can then choose to play this playlist and so listen to the recommendations of their friend. This has the advantage that the user shares his preferences and selections with other users. The playlist exchange feature can be implemented in a basic way, e.g. the playlist information is exchanged and it is up to the users to ensure that they each have the correct discs. Preferably the same real-time data is available in the receivers drive, and the system checks that the correct disc is loaded, i.e. a disc containing the same real-time data. This ensures that no wrong disc is in the player and so the playlist is not used with a wrong disc. In an embodiment the control unit is arranged for including identification information in the auxiliary data, and for verifying that the storage medium present in the device contains similar data as the storage medium in the further rendering device in dependence of the identification information. In fact the actual representation may be different, e.g. at one side an uncompressed audio file and at the other side an MP3 encoded file of the same piece of music. For example the real-time content may be free of rights, and the receiver may have his own copy, e.g. on a recordable type of SFFO. Or a user of a mobile device (e.g. a phone in a car) may exchange auxiliary data with a stationary device, e.g. at home. For identification song titles, etc. may be included, or a code for the storage medium and/or the track at the sending device. However, preferably, a same original disc is available in the receivers drive. In an embodiment the control means 20 are arranged for including authentication information in the auxiliary data, and for verifying that the storage medium present in the remote device (at least at the time the auxiliary data is used by the remote user) is a copy of the storage medium in the sending device in dependence of the authentication information, and in particular that the copy is authentic and/or that the device complies with rights due for rendering the real-time information. In a digital rights management (DRM) environment the transmitted auxiliary data may include DRM data for verifying that the storage medium at both sides is an original version of the disc and not an illegal copy. For example to ensure that the disc is present e.g. use a random location on disc as a seed for an encryption key and encrypt the MMS using the data from this location as a key, and indicate the location on disc in the MMS. If the receiving player does not contain a perfect bit copy of the storage medium then they can't decrypt the MMS. A basic encryption system is sufficient, since only a playlist is protected. In a different example a storage medium may already contain the real-time data, but a payment has to be made first to the rights owner before rendering is allowed. Such a payment may automatically be performed via the network. In an embodiment the control unit 20 is arranged to allow two mobile phone users choose to link up, so that one user can control playback of the others disc remotely. The remote user actually allows his device to be controlled via the received messages, e.g. for setting a selection of tracks to be played based on a playlist received. For straightforward playback SMS may be used, and MMS may be used to allow some additional features, such as a video comment or disc authentication. In an embodiment the control unit 20 is arranged for synchronizing rendering of real time data at a first device to rendering the same data at the same time at a second device. The auxiliary data in the message includes a request for synchronization, and some timing information. If the receiver accepts the offer to sync then they will hear the same content as the sender at substantially the same time. If the sender skips songs etc. the receiver's player will also skip the songs. So every time the sender takes an action, a

SMS/MMS is send to the receiver to cause the same action. Both users enjoy the same realtime information at the same time, and may both interactively share comments via the network. Although the invention has been explained mainly by embodiments based on a playlist as auxiliary data, it is noted that in the current document auxiliary data indicates any type of data that is related to real-time data and can be shared by users enjoying the real-time data. The invention may be used for various predefined recording formats like the SFFO or Blu-ray Disc recording format, the CD-RW or DVD+RW. Also for the information carrier an optical disc has been described, but other media, such as a magnetic hard disc, can be used. It is noted, that in this document the word 'comprising' does not exclude the presence of other elements or steps than those listed and the word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that the invention may be implemented by means of both hardware and software, and that several 'means' may be represented by the same item of hardware. Further, the scope of the invention is not limited to the embodiments, and the invention lies in each and every novel feature or combination of features described above.

Claims

CLAIMS:

1. Method of exchanging auxiliary data for controlling retrieval of real-time information on rendering devices that are connectable via a network, the method comprising the steps of - providing a storage medium containing at least one stream of real-time information, - retrieving at least part of the stream from the storage medium in a first rendering device at a first location, generating on the first rendering device auxiliary data relating to the stream, - transferring the auxiliary data via the network to a second rendering device at a second location, - rendering on the second rendering device a representation of at least part of the stream in dependence of the auxiliary data received from the first rendering device.

2. Rendering device for use in the method of claim 1, which device comprises - transceiver means (28) for connecting the device to a network, - read means (22) for retrieving data from a storage medium containing at least one stream of real-time information, and - control means (20) for generating auxiliary data relating to the stream, and for transmitting the auxiliary data via the network to a further rendering device at a different location, and/or for receiving auxiliary data via the network from a further rendering device at a different location, and for controlling retrieval of the real-time information in dependence of the auxiliary data received from the further rendering device.

3. Device as claimed in claim 2, wherein the control means (20) are arranged for retrieving from the storage medium predefined auxiliary message data related to the stream and for including the predefined auxiliary message data in the auxiliary data.

4. Device as claimed in claim 2, wherein the control means (20) are arranged for including identification information in the auxiliary data, and for verifying that the storage medium present in the device contains similar data as the storage medium in the further rendering device in dependence of the identification information.

5. Device as claimed in claim 4, wherein the control means (20) are arranged for including authentication information in the auxiliary data, and for verifying that the storage medium present in the device is a copy of the storage medium in the further rendering device in dependence of the authentication information, and in particular that the copy is authentic and/or that the device complies with rights due for rendering the real-time information.

6. Device as claimed in claim 2, wherein the control means (20) are arranged for generating playlist data in the auxiliary data, the playlist data representing a selection of, or order of, parts of the stream to be played.

7. Device as claimed in claim 2 or 6, wherein the control means (20) are arranged for synchronizing the playback of the stream of real-time data to playback of the stream at the further rendering device in dependence of the auxiliary data received from the further rendering device.

8. Storage medium for use in the method of claim 1 , characterized in that the storage medium comprises at least one stream of real-time information and predefined auxiliary message data related to the stream.

9. Storage medium as claimed in claim 8, wherein the predefined auxiliary message data comprises placeholders for customization.

10. Computer program product for exchanging auxiliary data for controlling retrieval of real-time information on rendering devices that are connectable via a network, which program is operative to cause a processor to perform the steps of - retrieving at least part of a stream of real-time information from a storage medium, - generating auxiliary data relating to the stream, - transmitting auxiliary data via the network to a rendering device at a different location, or receiving auxiliary data via the network from a rendering device at a different location, and rendering a representation of at least part of the stream in dependence of the auxiliary data received.