HK1176769A - Play-out control for a media data stream - Google Patents

Abstract

A technique for controlling a play-out of a media data stream at a receiving device is provided. The media data stream comprises one or more programs, and each pro-gram comprises one or more program components. In a method implementation of the technique, a zone description is defined. The zone description is defined for a media zone for at least one program or at least one program component in the me-dia stream and identifies the media zone for the at least one program or the at least one program component. In a next step, the zone description is associated to a program specific information data segment. The program specific information data segment is part of the media stream and comprises data specifying information at least regarding to the at least one program or at least one program component. The method also comprises transmitting the media data stream towards the receiving device.

Description

Play-out control for media data streams

Technical Field

The present disclosure relates generally to methods, devices and computer program products for controlling the playout of media data streams. The media data stream comprises one or more programs.

Background

Forced playout is a function that may be used, for example, to control the inability of a user to skip particular portions of an advertisement while viewing a video clip or other content. By ensuring this, advertisers may be willing to subsidize the cost of content access.

For example, open IPTV forum standardization (OIPF) is making a demand for this type of functionality. In this regard, reference is made to the open IPTV Forum "Functional Architecture V2.0", http:// www.openiptvforum.org/docs/OIPF-Functional _ Architecture _ v2_0-2009-09-08. pdf.

To meet these requirements, the Marlin Developer Community (MDC), which developed one of the OIPF-recommended content protection schemes, created an extension of Marlin, referred to as the Dynamic Media Zone (DMZ) Specification (http:// www.marlin-community.com; see "Marlin dynamic Media Zones", Version1.0, Final, Marlin development Community, 25 January2008 (hereinafter reference [1]), and Version1.0.1, Final, Marlin development Community, 13November 2009). OIPF is considering solutions that employ forced playout control based on Marlin DMZ. However, in addition to being applicable to MP4 files, there is a need for solutions that can be applied to unprotected content (http:// member. OIPF. tv/Application/documetpp/downloadimediate/default. aspxdocID. 3410; see open IPTV Forum, "OIPF-IPP-SOL-107-Navigation _ constructs _ in _ OIPF" (hereinafter referred to as reference [2])) and moving Picture experts group-2 (MPEG-2) Transport Stream (TS)).

The Marlin DMZ solution does not provide mapping to MPEG-2 TS. At the conference of 11 months in 2009, proposals were made on how to carry DMZ information in MPEG-2TS streams (see marlin-dynamic media components specification-v1.1 — 20091102.doc, non-public subscription to November2009 MDC meeting, from syelong Keoh, Philips (hereinafter referred to as reference [4 ])). This proposal is not adopted and is not applicable to unprotected content because it carries the DMZ information in Entitlement Control Messages (ECMs), i.e. key messages only for protected content. No other proposals so far suggest a flexible solution to the problem of signaling DMZ information in MPEG-2 or other TSs so that this solution can be used for both protected/encrypted and unprotected/unencrypted content.

In addition, previous proposals suffer from other drawbacks (e.g., precise start and end point labeling with respect to zones).

Disclosure of Invention

There is a need for techniques that allow media zone related signaling in MPEG-2 or other media data streams.

According to a first aspect, there is provided a method of controlling playout of a media data stream at a receiving device, the media data stream comprising one or more programs, each program comprising one or more program components. The method comprises the following steps: for at least one of the one or more programs or at least one of the one or more program components in the media data stream, defining a zone description for the media zone, the zone description identifying the media zone of the at least one program or at least one program component in the media stream; associating a region description with a program specific information data segment, the program specific information data segment being part of a media data stream and comprising data specifying information relating at least to the at least one program or the at least one program component; and transmitting the media data stream to a receiving device.

For example, defining the zone description may include creating a new zone description or updating a zone description. Further, associating the zone description with the program specific information data segment may be performed, for example, by inserting the zone description into the data segment or including the zone description in the data segment. The program specific information data segment may be any MPEG-2 table.

The method may further comprise: an identifier for identifying a media zone in the media stream is determined and the identifier is inserted into the zone description. The identifier may be an area identifier.

The method may further comprise: determining at least one other element of a group of other elements, the group of other elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream (e.g., zone start, zone end or zone duration, etc.),

play-out control instructions regarding the play-out of the media zone (e.g., indicating usage-allowed and/or limited information) (e.g., zone characteristics),

information for inserting media data into the media zone (e.g., outer zone reference),

rights management information regarding the media zone (e.g., digital rights management or DRM system information, DRM content ID, and/or DRM rights issuer Uniform resource locator or RI URL), and

integrity protection information for protecting the integrity of the media zone and at least one of the zone descriptions or parts thereof (e.g. the signing key ID, the signing algorithm, and/or the signing value),

and inserting the at least one other element into the region description or a region descriptor including the region description.

The broadcast control command may convey the zone type information according to the Marlin dynamic media zone specification. The play-out control instruction may be part of the zone description, but is not necessary. For example, for a system where there is only a single playout control instruction for a media zone, the single playout control instruction does not have to be declared in the zone description, as the remote receiving device may be configured to apply the unique (single) playout control instruction known in the system, e.g. retrieved from the data storage of the remote receiving device, when detecting the media zone (e.g. by analyzing the zone description).

The method may further comprise: protection integrity information about the zone description is determined. Determining protection integrity information may include: a cryptographic signature is performed on the zone description to obtain a signature value. The cryptographic signing may be performed using a cryptographic key transmitted in the entitlement control message or ECM, or derived therefrom. The encryption key may be a key used to protect the media stream.

The method may further comprise: determining that at least one of the one or more program components is protected, setting a zone indication parameter according to the protection determination, and associating (e.g., inserting or including) the zone indication parameter with a data segment that prevents unauthorized playout of at least one of the one or more program elements, the data segment being part of a media data stream. Integrity protection of the zone indication parameter may be performed. The data segments that prevent unauthorized play-out may be ECMs. The region indication parameter may be a region information notification flag or a region descriptor counter.

The method may further comprise: the definition of the program specific information data segment is triggered whenever an update of the zone description occurs.

According to another aspect, a method is provided for controlling playout of a media data stream at a receiving device, the media data stream comprising one or more programs, each program comprising one or more program components. The method comprises the following steps: receiving a media data stream comprising a program specific information data segment associated with a zone description of a media zone defined for at least one of the one or more programs or at least one of the one or more program components, the program specific information data segment further comprising: data specifying information at least relating to said at least one program or said at least one program component, a zone description identifying a media zone of said at least one program or said at least one program component in the media stream; detecting a program specific information data segment including a zone description in a media data stream; identifying the media zone and determining a playout control instruction for playout of the media zone based on the analysis of the zone description; and playing out the identified media zone according to the determined play-out control instruction.

In one embodiment already discussed above (single playout control instruction), once a zone description is detected, the receiving device may conclude the only possible playout control instruction defined in the application system from the mere presence of the zone, so that no explicit instruction command may be specified in the zone description. However, explicit specification may be a more frequent and likely scenario.

The program specific information data segment may be any MPEG-2 table. Furthermore, the media zone may be identified from an identifier in the zone description.

The method performed at the receiving device may further include: determining at least one other element of a group of other elements from the zone description, the group of other elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream (e.g., zone start, zone end or zone duration, etc.),

play-out control instructions regarding the play-out of the media zone (e.g., indicating usage-allowed and/or limited information) (e.g., zone characteristics),

information for inserting media data into the media zone (e.g., outer zone reference),

rights management information about the media zone (e.g., DRM system information, DRM content ID, and/or DRM rights issuer Uniform resource locator or RI URL), and

integrity protection information for protecting the integrity of the media zone and at least one of the zone descriptions or parts thereof (e.g. the signing key ID, the signing algorithm, and/or the signing value).

Based on the determined other elements, at least one of a group of operations may be performed, the group of operations including:

based on the other identification information, the start, end or duration of a media zone in the media data stream is identified,

performing the play-out of the media zone according to the play-out control instructions determined from the zone description,

determining media data consistent with the information for inserting the media data into the media zone, and inserting the media data into the media zone,

determining copyright management data and operations based on the copyright management information and applying the determined copyright management data and operations to the media zone, an

Verifying said integrity protection information for verifying the integrity of at least one of the media zone and the zone description or parts thereof.

The method performed at the receiving device may further include: integrity protection information about the zone description is determined. Further, the method performed at the receiving device may further comprise: an ECM is received. The ECM may contain a cryptographic key, and the integrity protection information may be a signature value obtained by performing a cryptographic signature on the area description using the cryptographic key.

The method performed at the receiving device may further comprise the steps of: detecting in the media stream a zone indication parameter associated with a data segment preventing unauthorized playout of at least one of said one or more programs or said one or more program elements, and performing a security operation with respect to at least one of said one or more programs, said one or more program elements, the media zone and the zone description. Further, an integrity protection verification process of the region indication parameter may be performed.

The data segment for preventing unauthorized play-out may be an ECM, and the zone indication parameter may be a zone information notification flag or a zone descriptor counter. In this case, the method performed at the receiving device may further include: a zone information notification flag in the ECM is received, the zone information notification flag signaling that the program specific information data segment contains a zone description. The program specific information data segment may be checked to determine whether the region information notification flag is set.

The method performed at the receiving device may further include: the integrity protection information is verified based on the encryption key received in the ECM. The encryption key may be a key used to protect the media stream.

The method performed at the receiving device may further include: the detection of the media zone and the determination of the playout control instructions are performed whenever an update of the program specific information data segment is detected.

The disclosure also relates to a computer program comprising software code portions for implementing any of the methods described herein when operating at a transmitting or receiving device. The computer program may be stored on a computer readable medium. The computer readable medium may be permanent or rewritable memory within the transmitting or receiving device or external. The computer program may also be transferred to the respective device as a sequence of signals, e.g. via a cable or a wireless link. Accordingly, a computer program may be provided comprising code adapted to perform any of the methods described herein when executed by a computer. A computer program product may comprise the computer program.

According to another aspect, a transmitting device for controlling the playout of a media data stream at a receiving device is provided, the media data stream comprising one or more programs, each program comprising one or more program components. The transmission apparatus includes: a processing unit or any other component adapted to define a zone description of a media zone for at least one of said one or more programs or at least one of said one or more program components in the media data stream, said zone description identifying the media zone of said at least one program or at least one program component in the media stream, wherein said processing unit or other component is further adapted to associate the zone description with a program specific information data segment, said program specific information data segment being part of the media data stream and comprising data specifying information at least relating to said at least one program or said at least one program component; and a transmitting unit or any other component adapted to transmit the media data stream to a receiving device.

The transmitting device may be adapted to determine an identifier for identifying a media zone in the media stream and to insert the identifier into the zone description. The transmitting device is further adapted to determine at least one other element of a group of other elements, the group of other elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof.

The transmitting device may be adapted to insert the at least one further element into the zone description or a zone descriptor comprising the zone description. The broadcast control command may convey the zone type information according to the Marlin dynamic media zone specification.

Furthermore, the transmitting device may be adapted to determine protection integrity information regarding the zone description. Determining the protection integrity information may include performing a cryptographic signature on the zone description to obtain a signature value. The cryptographic signing may be performed using the encryption key transmitted in the ECM, or derived therefrom. The encryption key may be a key used to protect the media stream.

The sending device may be adapted to determine that at least one of the one or more program components is protected, set a zone indication parameter according to the protection determination, and associate the zone indication parameter with a data segment preventing unauthorized playout of at least one of the one or more program elements, the data segment being part of a media data stream. The sending device may be further adapted to perform integrity protection of the zone indication parameter.

The data segments that prevent unauthorized play-out may be ECMs. Also, the region indication parameter may be a region information notification flag or a region descriptor counter.

In a variant, the device is adapted to trigger the definition of the program specific information data segment whenever an update of the zone description occurs.

According to another aspect, a receiving device for controlling playout of a media data stream at the receiving device is provided, the media data stream comprising one or more programs, each program comprising one or more program components. The receiving apparatus includes: a receiver unit or any other component adapted to receive a media data stream comprising program specific information data segments associated with a zone description of a media zone defined for at least one of said one or more programs or at least one of said one or more program components, said program specific information data segments further comprising: data specifying information at least relating to said at least one program or said at least one program component, a zone description identifying a media zone of said at least one program or said at least one program component in the media stream; a processing unit or any other component adapted to detect program specific information data segments comprising zone descriptions in the media data stream and, based on an analysis of the zone descriptions, to identify the media zone and to determine playout control instructions for playout of the media zone; and an output unit or any other component adapted to play out the identified media zone according to the determined play-out control instruction.

The receiving device may be adapted to identify the media zone based on an identifier in the zone description. Furthermore, the receiving device may be adapted to determine at least one further element of a further group of elements from the zone description, the further group of elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof.

Based on the determined other elements, at least one of a group of operations may be performed, the group of operations including:

based on the other identification information, the start, end or duration of a media zone in the media data stream is identified,

performing the play-out of the media zone according to the play-out control instructions determined from the zone description,

determining media data consistent with the information for inserting the media data into the media zone, and inserting the media data into the media zone,

determining copyright management data and operations based on the copyright management information and applying the determined copyright management data and operations to the media zone, an

Verifying said integrity protection information for verifying the integrity of at least one of the media zone and the zone description or parts thereof.

The receiving device may be adapted to determine integrity protection information about the zone description. Furthermore, the device may be adapted to receive an ECM. The ECM may contain a cryptographic key, and the integrity protection information may be a signature value obtained by performing a cryptographic signature on the area description using the cryptographic key.

Furthermore, the receiving device may be adapted to detect a zone indication parameter associated with a data segment preventing unauthorized play-out of at least one of the one or more programs or the one or more program elements in the media stream and to perform a security operation with respect to at least one of the one or more programs, the one or more program elements, the media zone and the zone description. An integrity protection verification process of the zone indication parameter may also be performed.

In general, the data segment for preventing unauthorized play-out may be an ECM, and the zone indication parameter may be a zone information notification flag or a zone descriptor counter. In this case, the receiving device may be adapted to receive a zone information notification flag in the ECM, the zone information notification flag signaling that the program specific information data segment contains a zone description. The program specific information data segment may be checked to determine whether the region information notification flag is set.

The receiving device may be adapted to verify the integrity protection information based on a cryptographic key received in the ECM. In one example, the encryption key is a key used to protect the media stream.

The receiving device may perform the detection of the media zone and the determination of the playout control instructions whenever an update of the program specific information data segment is detected.

Further, a system comprising a transmitting device and a receiving device is provided. The two devices may be configured to perform any of the method aspects disclosed herein.

Any of the operations, steps or functions of the disclosed method aspects, when performed by a transmitting device or a receiving device, may be performed by one or more elements of the transmitting device or the receiving device. As an example, any of the process-related operations, steps or functions may be performed by the respective processing units, such as "define", "associate", "determine", "insert", "execute", "set", "trigger", "identify", "verify", and the like. The processing unit may be a monolithic device or comprise separate sub-units.

The following considerations apply to all of the method and apparatus aspects disclosed herein.

The media data stream may typically be a transport stream according to the MPEG-2 transport stream format. The program specific information data segment may be a table (e.g. at least one of a program map table or PMT, a conditional access table or CAT, a program association table or PAT, e.g. a newly defined private table of the transport stream).

The information may be included in both the PMT and entitlement control message or ECM. The program specific information data segment may be a PMT, the zone description may be included in a (e.g. newly defined) private table, and the PMT may be associated with the private table and the zone description included in the private table via a first packet identifier or PID. Additionally or alternatively, the program specific information data element may be a PMT, wherein the PMT may be associated with the entitlement control message or ECM via a second packet identifier or PID. The zone description may typically be a descriptor of a table.

In one embodiment, a media zone is a segment of a media data stream with specific properties that cannot be skipped or must be played from beginning to end. The media zone may typically be a media zone according to the Marlin dynamic media zone specification.

Drawings

Other details, aspects, and advantages of the disclosure will become apparent from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

fig. 1 schematically illustrates an embodiment of data entities in an MPEG-2 transport stream comprising media zones;

FIG. 2 illustrates an embodiment of a system including a transmitting device and a receiving device;

FIG. 3 shows a flow chart illustrating a first method embodiment of the operation of the transmitting device of FIG. 2;

FIG. 4 shows another flow chart illustrating a second method embodiment of the operation of the receiving device of FIG. 2;

fig. 5 is a diagram illustrating a first embodiment of a program specific information data segment; and

fig. 6 is a diagram illustrating a second embodiment of a program specific information data segment.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as specific device configurations and specific signaling scenarios, in order to provide a thorough understanding of the present disclosure. It will be apparent to those skilled in the art that the techniques presented herein may be practiced in other embodiments that depart from these specific details. Those skilled in the art will appreciate that the techniques discussed herein may be practiced, for example, in conjunction with other device configurations and different signaling steps.

Those skilled in the art will also appreciate that the methods, steps, and functions described herein below may be implemented using individual hardware circuits, using software functions in conjunction with a programmed microprocessor or general purpose computer, using one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), and/or one or more Field Programmable Gate Arrays (FPGAs). It will also be understood that the methods, steps, and functions disclosed herein may be embodied in a processor and a memory coupled to the processor, where the memory stores one or more programs that when executed by the processor perform the steps discussed herein.

The following description will mainly relate to the combination of the Marlin DMZ concept and the MPEG-2 TS. It will be appreciated that the techniques presented herein are not limited to media areas according to the Marlin specification and transport streams according to the MPEG-2 specification.

Fig. 1 schematically illustrates an embodiment of data entities in an MPEG-2 TS. As shown in fig. 1, the TS includes one or more tables including at least one Program Map Table (PMT) discussed in more detail below with reference to fig. 5 and 6. Furthermore, one or more Entitlement Control Messages (ECMs) are optionally included in the TS, especially in the case of transmission of protected content. The content of the TS may include one or more Elementary Streams (ESs). In the example shown in fig. 1, a single video ES and a single audio ES are shown. In video and audio ESs, according to the Marlin DMZ (or any other) specification, a media zone ("zone 1") is defined that has certain attributes (e.g., regarding play-out).

As shown in fig. 1, the media zone may be defined for a program (i.e., for the entire program with all program components), but there may also be applications where the media zone is defined for a subset of the program components of the program (e.g., the media zone is defined for a video stream only and not for an audio stream — this is useful for live broadcasts of, inter alia, sporting events so that users may still listen to the reporter during the period of the video-based media zone (including, for example, video-based advertisements). More than one media zone may also be defined and processed.

The basic concept of the present disclosure will be best illustrated by the following example for the MPEG-2TS shown in fig. 1 to provide play-out information on "media zones" within the MPEG-2TS, which information is included as e.g. regularly repeated descriptors within the PMT as part of each MPEG-2TS (for MPEG-2 systems, see ISO/IEC13818-1, also published as ITU-T h.222.0 (hereinafter reference [5 ])).

For unprotected content, the descriptor is typically not protected from modification. For protected content, the descriptors can be supplemented by some information carried in the ECM. The detailed description that follows accurately describes information included, for example, in the PMT (or other tables) and (optionally) the ECM. Furthermore, some policy/compatibility rules are defined that a receiving device with playout capability can follow. In addition, it is described how the key can be updated to ensure that the system does not replay old PMTs (or other tables).

In the simplest case, the media zone is a usage rule. For example, a user is not allowed to use trick modes (e.g., fast forward) during commercial breaks. Thus, a Set Top Box (STB) receives a content (or media) stream and media zone information describing usage rules. As described above, the concept of the present disclosure is to provide information on a "media zone" within an MPEG-2 transport stream as shown in fig. 1 (see reference [1 ]).

Such a transport stream may comprise one or more programs (e.g., TV or and/or radio programs), each program comprising one or more program components. For example, a radio program may include an audio program component, and a TV program may include an audio program component and a video program component.

The MPEG-2 transport stream format is defined in reference [5 ]. This includes PMT, PAT and other table definitions. In the following, some characteristics of MPEG-2 (taken from http:// en. wikipedia. org/wiki/MPEG _ transport _ stream andhttp:// en. wikipedia. org/wiki/Program _ Specific _ Information) are described for illustration, where the term "elementary stream" (or ES, see FIG. 1) is used as an example for the term "Program component". In the uncertain cases, the description in reference [5] is valid.

In the following, various terms in the MPEG context will be explained in more detail to provide a better understanding of the embodiments discussed herein.

The transport stream (TS, TP, MPEG-TS, or M2T) is a communication protocol for audio, video, and data. The type of digital container format encapsulates packetized elementary streams and other data. The TS is specified in MPEG-2Part1, Systems (ISO/IEC standard 13818-1). Also known as ITU-T rec.h.222.0. The design goal is to allow multiplexing of digital video and audio and to synchronize the output. Transport streams provide error correction features for transmission over unreliable media and are used for broadcast applications such as DVB and ATSC. As opposed to MPEG program streams designed for more reliable media such as DVDs.

PID

Each table or elementary stream in the transport stream is identified by a 13 bit packet id (pid). The demultiplexer partially extracts elementary streams from the transport stream by looking for packets identified by the same PID. In most applications, time division multiplexing will be used to determine the frequency with which a particular PID appears in the transport stream.

Program and method for providing a program

Transport streams have the concept of programs. Each individual program is described by a Program Map Table (PMT) with a unique PID and the elementary streams associated with that program have the PIDs listed in the PMT. For example, a transport stream for digital television may contain three programs to represent three television channels. Each channel is assumed to include one video stream, one or two audio streams, and any necessary metadata. A receiver that wants to decode a particular "channel" only has to decode the payload of each PID associated with its program. The contents of all other PIDs may be discarded. A transport stream with more than one program is called an MPTS-multi-program transport stream. A single program transport stream is called an SPTS.

Program Specific Information (PSI)

The PSI table includes Program Association (PAT), Program Map (PMT), Conditional Access (CAT), and Network Information (NIT). The MPEG-2 specification does not specify the formats of CAT and NIT.

Program Specific Information (PSI) is metadata about a program (channel) and a portion of an MPEG transport stream.

The PSI data may include, for example, the following table:

PAT (program association table)

CAT (conditional access Table)

PMT (program map table)

NIT (network information Table)

TDT (time and date table)

The PSI is carried in the form of a table structure. The table structure may span multiple transport stream packets. The adaptation field is also present in the TS packet carrying PSI data. PSI data is typically not scrambled so that a decoder at the receiving end can easily recognize the characteristics of the stream.

PAT, CAT, and TDT tables are associated with predefined PIDs. There may be multiple independent PMT tables in the stream; these tables are assigned a given user-defined PID number (e.g., PES (packetized elementary stream) packets). The PMT table PID is defined in the PAT and is the unique PID defined there (the PES PID is defined in the PMT). Each table has a predefined structure.

PAT

PAT represents a program association table. It lists all programs available in the transport stream. Each of the listed programs is identified by a 16-bit value called program _ number. Each program listed in the PAT has an associated value of PID for its Program Map Table (PMT).

A program _ number of a value of 0x0000 is reserved to specify a PID in which a Network Information Table (NIT) is found. If no program is present in the PAT, the default PID value (0x0010) will be used for NIT.

PMT

The Program Map Table (PMT) contains program related information. There is one PMT for each program. While the MPEG-2 standard allows more than one PMT portion to be transmitted on a single PID, most MPEG-2 "users" such as ATSC and SCTE require that each PMT be transmitted on a separate PID that is not used for any other packet. The PMT provides information about each program present in the transport stream, including program _ number, and lists elementary streams including the described MPEG-2 program. There are also locations of optional descriptors that describe the entire MPEG-2 program, and optional descriptors for each elementary stream. Each elementary stream is marked with a stream _ type value.

CAT (conditional access meter)

The table is used for conditional access to the stream. This table provides the association with the EMM stream. When the TS is scrambled, this portion contains the EMM PID. The EMM PID is encrypted using the smart card number. The PID value is 0x 0001.

PCR

To enable the decoder to present synchronized content (e.g., matching the soundtrack of the associated video), the program clock reference or PCR is sent at least once every 100ms in the adaptation field of the MPEG-2 transport stream packet. The PID with PCR for the MPEG-2 program is identified by associating the PCR _ PID value in the program map table. When used correctly, the values of the PCR are used to generate a system _ timing _ clock in the decoder. When it is really current, STC decoders provide a highly accurate time base for synchronizing audio and video elementary streams. The timing in MPEG2 is referenced to the clock, e.g., Presentation Time Stamps (PTS) are intended to be related to the PCR. The first 33 bits are based on a 90kHz clock. The last 9 are based on 27MHz clocks. The maximum jitter allowed for PCR is +/-500 ns.

NIT (network information meter)

The table provides information relating to the multiplexing and transport streams over a given network.

The information on the current network uses table _ id0x40, and the information on the other network uses table _ id0x 41.

The information is split into a network information part and carried on PID0x 0010. [ see EN300468 ].

In addition, the table also contains private flow information. Such as TeleText, Subtitle, and MHEG.

TDT (time and date watch)

UTC (universal time) encoded as MJD (modified Julian date) is provided. The PID value is 0x 0014.

For TDT, table ID is 0x 70; for TOT, the table ID is 0x 73.

In the following, various terms in the context of a media zone will be explained in more detail to provide a better understanding of the embodiments discussed herein.

A media zone is a part of a media stream that has certain properties (e.g. cannot be skipped, or must be played from head to tail). Typical uses of media zones are advertisements that a user cannot skip in a program, or legal information that a user must view before a program starts.

The zone description describes attributes of one or more media zones.

In one embodiment, this is done by including information (region description) in descriptors in the regularly repeated PMT as part of each MPEG-2 TS.

Alternatively, other MPEG-2 tables may be used to carry the zone description (e.g., PAT or CAT or a newly defined "private table" such as "zone map"). In the following, even if reference is made to a PMT table, it is to be understood that another table type is possible.

MPEG-2TS allows new descriptors to be defined (see tables 2-39 in reference [5 ]). This newly defined descriptor (referred to herein as a region descriptor) will contain the following elements in one embodiment:

region descriptor counter (identifier of current region descriptor) [ optional ]

For each area

O zone identifier

O zone start (time code and optional byte offset) [ optional ]

End of O zone [ optional ]

O zone Attribute [ optional ]

Reference to outer zone [ optional ]

Orifice DRM system identification [ optional ]

DRM content ID [ optional ]

DRM RI URL [ optional ]

O signature-Key-ID [ optional ]

O signature-Algorithm [ optional ]

O signature-value [ optional ]

·}

signature-Key-ID [ optional ]

signature-Algorithm [ optional ]

Signature-value [ optional ]

The structure of the PMT including the region descriptor will be described later with reference to the accompanying drawings.

Hereinafter, the respective fields of the region descriptor according to the above-described embodiment will be discussed in more detail Means of。

Region identifier: id of region, e.g. in reference [1]]As defined in (1). For DRM and CA systems that know the media zone this can be used to assign permissions and zone specific usage restrictions, e.g. no fast forward. (typically there is also a default usage limit defined for a particular zone type, which may be supplemented or replaced by more specific usage limits).

Zone start: reference to the start of a region in MPEG 2-TS. This may be, for example, a value representing the System Time Clock (STC) as defined in MPEG2-TS and transmitted to the client (receiving device) by means of a Program Clock Reference (PCR).

Alternatively, this could also be any other time reference or other reference to a point in the MPEG2-TS, such as a Presentation Time Stamp (PTS) or byte offset. Note that the reference may point to any point in the MPEG2-TS, such as a future or past point. The start of the zone is optional. If it does not appear in the region descriptor, the region may be started once the associated PMT is valid, i.e., the region may start with data immediately following the PMT in the MPEG 2-TS.

The PMT table may also include a byte offset (optional) that describes the number of bytes between the start of the media zone and the current location in the stream. The user can jump to the middle of the media zone time-shifted while watching the live program. Therefore, the STB has to find the start of the media zone. Another option to find the start of a media zone is the zone start information.

End of zone: reference to the end of the indication area in the MPEG 2-TS. The item is optionalSince it may not yet be available in some cases, for example in case of live programs. If this value does not occur, the receiving device must assume that the zone has not yet ended (assuming that the zone has indeed started). The reference may be absolute, i.e. directly pointing to the end of the zone, or relative, i.e. representing e.g. a duration, and pointing to the end of the zone together with some other information, e.g. a reference in the zone start field. This may be, for example, a value representing the System Time Clock (STC) as defined in MPEG2-TS and transmitted to the client by means of a Program Clock Reference (PCR). Alternatively, this could also be any other time reference or other reference to a point in the MPEG2-TS, e.g. to a Presentation Time Stamp (PTS) or byte offset.

Region attribute: this field may be used to signal zone attributes. This may be, for example, a usage restriction such as no fast forward for unprotected content, or a similar default restriction (which may be overwritten by a license) for protected content. For example, this field may be passed on in reference [1]]The property or region type information defined in (1). (e.g. there are so-called "trick" and "magnetic" zones; after entry, the "trick" zone cannot be left until full play; the "magnetic" zone cannot be skipped).

Outer zone reference: references to outer regions, e.g. in reference [4]]The URL and corresponding information described in (1), by which the content that should be shown when in the zone can be obtained.

DRM system identification [ optional ]]: reference to DRM or Conditional Access (CA) systems used.

DRM content ID: DRM or CA system specific identifiers for permissions that may be used to access the content of the zone.

DRMRIURL [ optional)]: DRM or CA system specific information for obtaining a license.

signature-Key-ID: for protection describeThe integrity of the information of the zone defined here, a cryptographic signature can be used. This field may contain a reference to identify the key used for the signature. This may be an indication, for example, of whether odd or even scrambling codes used to protect content in the MPEG2-TS can be used to verify the signature. Alternatively or additionally, this field may contain a reference to a key (e.g. a content key) sent in the (DRM/CA) license.

signature-Algorithm [ optional ]]: this field may be used to signal a cryptographic algorithm (signature algorithm) for protecting the integrity of the zone description. For example, this may be directed to a MAC algorithm, such as an HMAC that relies on a secure hash function such as a SHA-1 or SHA-2 family member.

Signature-value [ optional ]]: the value of the cryptographic signature described for that zone, i.e. if there is one signature per zone; or the value of the cryptographic signature described for a plurality of zones, i.e. if one signature exists for a set of zones. The signature may be obtained, for example, using an HMAC algorithm and a key as described above with reference to the above. This key may be, for example, an (odd/even) key for protecting the media stream and is transmitted in the ECM. The signature may also be derived from the key, for example, using an encryption key derivation algorithm (e.g., based on HMAC) or any other key (e.g., a key transmitted in a license of the DRM/CA system).

There may be multiple zone descriptions delivered in MPEG2-TS, for example, with reference to different DRM systems. This may be the case, for example, in a simulcrypt MPEG-2 transport stream, where the media is protected by a different CA or DRM system.

Optional signaling in ECM

For unprotected content, the descriptors are typically not protected from modification. For protected content, the descriptors can be supplemented by some information carried in the ECM. For example, the ECM information may contain the following:

zone information notification flag: if set to 1, the flag signals the PMT to contain the region descriptor, and the receiving device needs to check the PMT and extract the region descriptor

Note that the presence of the description in the PMT may also be signaled in other ways. For example, when evaluating a license, the DRM system may signal that the license is valid only if a zone description can be found.

Region descriptor counter: identifying a region descriptor valid for the ECM

Since ECMs may not get integrity protection for some DRM/CA systems and thus may be modified, there may be an additional mechanism to ensure that the zone information notification flag is not modified. For example, the protected key carried in the ECM may be exclusive-or (XOR) with the zone information notification flag (before protection/encryption). Therefore, even if the PMT is modified and the section information is deleted, the device sees the section information notification flag and thus notices that the section information is lost, or if the section information notification flag has been deleted or changed, the key derivation results in an erroneous key (because the XOR operation is not correctly applied), failing to correctly decrypt the audio/video ES.

PMT update

For example, the PMT including the zone map description may be updated when a new zone starts or an old zone ends. The PMT may contain descriptions for multiple zones (e.g., zero, one or more past zones, the current zone, and zero, one or more future zones). For example, once the end point of a zone is known, the zone description may also be updated during playback of the zone.

Key switching as PMT replay protection

It is to be avoided that old PMT entries may be replayed (without restriction) to tamper with the intended zone behavior. If an ECM is used, the ECM delivers a traffic key that, as described above, can also be used to derive a signature of the zone description in the PMT. To avoid tampering with the zone description (e.g. by replaying the old zone description), the player should only accept signatures calculated using the same key that is also used for service protection whenever the new zone starts to change the service key.

Compliance rules

Compliant receiving devices should typically follow some policies and rules to enforce the desired behavior:

for example, if a zone description is expected in the PMT, by signaling ECM or DRM permission or by other means, but if the description cannot be found, the stream should not be decrypted.

If integrity protection for the zone description is required (e.g. by a specific system specification or by an additional flag in the integrity protected ECM), the device should compute the signature value of the received zone description, e.g. using the encryption key indicated in the zone description. If the signature does not match the signature sent with the zone description, the stream should not be decrypted. As described above, the signature may be calculated based on information of one region alone, or may be calculated together based on descriptions for a plurality of regions.

If replay protection as described above is used, the stream should not be decrypted if the key used to protect the integrity of the zone description is different from the key used to protect the actual media stream.

The device should evaluate the zone descriptors in the PMT and enforce the zone behavior described herein.

If an ECM is sent, the device should verify that the ECM signalling and PMT signalling do not contradict. If they contradict each other, the stream should not be decrypted.

If the ECM is sent and an (optional) additional protection mechanism as described above is used, the device should perform an XOR operation on the zone information notification flag and the key signaled (in protected form) in the ECM. If decryption fails, this is an indication that the information has been tampered with, and after a number of failures, the device should not decrypt the stream further.

Hereinafter, an embodiment of a playout control system including the transmitting device 100 and the receiving device 200 will be described with reference to fig. 2. The media zone description described above may be embedded by the sending device 100 in an MPEG2-TS and evaluated by the receiving device 200.

The transmitting device 100 comprises a processing unit P1, a transmitting unit T1, a receiver unit R1 and a control unit C1, and typically a data storage unit (not shown in fig. 2). For example, the sending device 100 receives content (e.g., encoded video and/or audio content) from some other device or from other units in the same device, such as storage units, via the receiver unit R1. For example, the content unit C1 receives control information associated with the content and specifying a media zone by the media zone id, usage restriction, and/or zone attributes that should be applied to the received content (note that the programs or program elements include the content, respectively, and the received content may be for one or more program elements of one or more programs). Alternatively or additionally, control information and/or content may be stored and/or generated at the transmitting device 100 and retrieved therefrom to define the region descriptors and program components of the program of the media data stream. Note that C1 and R1 may also be integrated into a single cell.

The following section describes an embodiment of the operation of the transmitting apparatus 100. This operation will be described with reference to the flowchart 300 of fig. 3.

Receive content and corresponding control information.

For example

If the control information is changed for the corresponding content,

o if the key in the ECM changes (optionally for protected content)

After a period of time or interval of time (optionally)

A PMT update is initiated via P1.

At PMT update, for example, if a previously unknown zone end reference is now available, the processing unit P1 creates a new zone description and/or updates an existing (stored) zone description. According to step 302, a zone description (a media zone for at least one program or at least one program component) is thus defined. As explained with reference to the zone descriptor embodiments described above, the zone description identifies a media zone of a program or program component in the media stream.

If the content is protected, processing unit P1 may now compute one or more cryptographic signatures on the zone description, for example using a MAC algorithm such as an HMAC that relies on a secure hash function (e.g., SHA-1 or SHA-2 family members). The encryption key may be the same encryption key as sent in the ECM or may be derived from this key. A key, which may be part of the control information or may be generated (randomly) by P1, may be extracted from the received ECM (for already received protected content).

Using the above information, P1 generates one or more region descriptors and embeds them into existing or newly generated PMTs. The zone description is thus associated with the PMT (i.e., with the program specific information data segment), pursuant to step 304. By embedding, the PMT becomes part of the MPEG 2-TS.

The T1 transmits the content to the receiving device 200 in step 306 as an MPEG2-TS (shown in FIG. 1) with embedded PMTs.

Using the above information, P1 optionally generates additional information and embeds them in existing or newly generated ECMs.

T1 sends ECMs to the receiving device 200.

The receiving device 200 comprises a processing unit P2, a receiver unit R2, an optional storage unit S2 and an output unit O2.

For example, the reception apparatus 200 receives the content packaged in the MPEG2-TS shown in fig. 1 from the transmission apparatus 100 or from another unit (e.g., a hard disk) in the same apparatus 200 via the reception unit R2.

The following sections describe embodiments of the operation of the receiving apparatus 200. This embodiment will be described with reference to the flowchart 400 of fig. 4.

MPEG2-TS including PMTS is received by R2 and processed by P2 according to step 402.

According to step 406, the table in the MPEG2-TS detected according to step 404 is checked. If the PMT contains a zone description, the zone description is analyzed, the information therein is evaluated and optionally stored in S2. As shown by step 406, an analysis of the zone description is performed to identify the media zone and determine play-out control instructions (or rules) for play-out of the media zone.

If an ECM is received, the received ECM is also checked. If the ECM contains information relating to the zone description, the information is analysed, the information therein evaluated and optionally stored in S2. The information in the ECM is used to verify the information previously retrieved from the PMT. For example, the key in the ECM is used to verify the signature in the zone description.

If the information in the PMT or the information in both the PMT and the ECM generate an error condition (e.g., according to a compliance rule as described in the previous section), P2 stops further processing and presentation of the media.

Otherwise, the media received through R2 is decrypted and decoded and sent to O2 for playout according to applicable rules for media zones (e.g., non-skipped zones) (see step 408).

Two embodiments of associating a zone description (as defined in the zone descriptor) with a program specific information data segment will be described below with reference to fig. 5 and 6.

Fig. 5 shows the structure of a PMT including a region descriptor, and various elements of the PMT include a region description and a signature value. A signature value for verifying the signature value may be received with the ECM. The PMT and ECM may be embedded in MPEG2-TS as shown in FIG. 1.

Fig. 6 illustrates another embodiment for associating a zone description with a PMT. As shown in fig. 6, the zone description (zone map) is included in the private section of the MPEG-2 private table (which may include one or more additional private sections for other purposes). The PMT is associated with the private part (and thus the private table) and the zone description included in the private table via the first PID. The PMT is also associated with the ECM via a second PID. As described above, the ECM transmits a signature key required to verify a signature value (not shown in fig. 6) included in the zone map. The private table and PMT and ECM are transmitted together in an MPEG2-TS (as shown in fig. 1).

As is apparent from the above description of exemplary embodiments, the techniques presented herein provide a solution to the requirements/requirements of supporting MPEG2-TS and being usable for forced playout of encrypted or unencrypted content (as discussed in OIPF).

Although the techniques presented herein have been described with respect to particular embodiments, those skilled in the art will recognize that the present invention is not limited to the particular embodiments described and illustrated herein. It will be understood that this disclosure is only intended for illustrative purposes. Accordingly, the invention is to be limited only by the scope of the following claims.

Claims (75)

1. A method of controlling playout of a media data stream at a receiving device, the media data stream comprising one or more programs, each program comprising one or more program components, the method comprising:

-defining, for at least one of said one or more programs or at least one of said one or more program components in the media data stream, a zone description for the media zone, said zone description identifying the media zone of said at least one program or at least one program component in the media stream;

-associating the zone description with a program specific information data segment, said program specific information data segment being part of the media data stream and comprising data specifying information at least relating to said at least one program or said at least one program component; and

-transmitting said media data stream to a receiving device.

2. The method of claim 1, further comprising:

-determining an identifier for identifying a media zone in a media stream, an

-inserting the identifier into the zone description.

3. The method of claim 1 or 2, further comprising:

-determining at least one other element of a group of other elements, the group of other elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof,

and

-inserting the at least one other element into a region description or a region descriptor comprising the region description.

4. The method of claim 3, further comprising: protection integrity information about the zone description is determined.

5. The method of claim 4, wherein determining protection integrity information comprises: a cryptographic signature is performed on the zone description to obtain a signature value.

6. The method according to claim 5, wherein the cryptographic signing is performed using a cryptographic key transmitted in the entitlement control message or ECM, or derived therefrom.

7. The method of claim 6, wherein the encryption key is a key used to protect the media stream.

8. The method according to any of claims 3 to 7, wherein the playout control instructions convey the zone type information according to the Marlin dynamic media zone specification.

9. The method of any preceding claim, further comprising:

-determining that at least one of the one or more program components is protected,

-setting a zone indication parameter in dependence of the protection determination, an

-associating a zone indication parameter with a data segment preventing unauthorized playout of at least one of said one or more program elements, said data segment being part of a media data stream.

10. The method of claim 9, further comprising:

-performing integrity protection of the zone indication parameter.

11. The method according to claim 9 or 10, wherein the data segment preventing unauthorized play-out is an entitlement control message or ECM.

12. The method according to any of claims 9 to 11, wherein the zone indication parameter is a zone information notification flag or a zone descriptor counter.

13. The method of any preceding claim, further comprising: the definition of the program specific information data segment is triggered whenever an update of the zone description occurs.

14. A method for controlling playout of a media data stream at a receiving device, the media data stream comprising one or more programs, each program comprising one or more program components, the method comprising:

-receiving a media data stream comprising a program specific information data segment associated with a zone description of a media zone defined for at least one of the one or more programs or at least one of the one or more program components, the program specific information data segment further comprising: data specifying information at least relating to said at least one program or said at least one program component, a zone description identifying a media zone of said at least one program or said at least one program component in the media stream;

-detecting a program specific information data segment comprising a zone description in the media data stream;

-identifying the media zone and determining play-out control instructions for play-out of the media zone based on the analysis of the zone description; and

-playing out the identified media zone according to the determined play-out control instruction.

15. The method of claim 14, further comprising:

-identifying the media zone based on the identifier in the zone description.

16. The method of claim 14 or 15, further comprising:

-determining at least one further element of a further group of elements from the zone description, the further group of elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof,

and

-performing at least one operation of a group of operations based on the determined other elements, the group of operations comprising:

based on the other identification information, the start, end or duration of a media zone in the media data stream is identified,

performing the play-out of the media zone according to the play-out control instructions determined from the zone description,

determining media data consistent with the information for inserting the media data into the media zone, and inserting the media data into the media zone,

determining copyright management data and operations based on the copyright management information, and applying the determined copyright management data and operations to the media area,

verifying said integrity protection information for verifying the integrity of at least one of the media zone and the zone description or parts thereof.

17. The method of claim 16, further comprising: integrity protection information about the zone description is determined.

18. The method of any of claims 14 to 17, further comprising: an entitlement control message or ECM is received.

19. The method according to claims 17 and 18, wherein the ECM contains a cryptographic key, and the integrity protection information is a signature value obtained by performing a cryptographic signature on the zone description using the cryptographic key.

20. The method according to any one of claims 14 to 19, further comprising the step of:

-detecting in the media stream a zone indication parameter associated with a data segment preventing unauthorized play-out of at least one of said one or more programs or said one or more program elements,

-performing a security operation with respect to at least one of the one or more programs, the one or more program elements, the media zone and the zone description.

21. The method of claim 20, further comprising:

-performing an integrity protection verification procedure of the zone indication parameter.

22. The method according to claim 20 or 21, wherein the data segments preventing unauthorized play-out are entitlement control messages or ECMs.

23. The method according to any of claims 20 to 22, wherein the zone indication parameter is a zone information notification flag or a zone descriptor counter.

24. The method according to claims 22 and 23, further comprising: receiving a zone information notification flag in the ECM, the zone information notification flag signaling that a program specific information data segment contains a zone description.

25. The method of claim 23 or 24, further comprising: the program specific information data segment is checked to determine whether the region information notification flag is set.

26. The method according to at least claims 21 and 22, further comprising: verifying integrity protection information based on a cryptographic key received in the ECM.

27. The method of claim 26, wherein the encryption key is a key used to protect the media stream.

28. The method of any of claims 14 to 27, further comprising:

the detection of the media zone and the determination of the playout control instructions are performed whenever an update of the program specific information data segment is detected.

29. The method according to any of the preceding claims, wherein the media data stream is a transport stream according to the MPEG-2 transport stream format.

30. A method according to any one of the preceding claims, wherein said program specific information data segments are tables.

31. The method according to claims 29 and 30, wherein said table is at least one of a program map table or PMT, a conditional access table or CAT, a program association table or PAT, and a transport stream specific table.

32. The method according to claim 30 or 31, wherein said program specific information data segment is a PMT, said zone description is comprised in a private table, and said PMT is associated with the private table and the zone description comprised in the private table via a first packet identifier or PID.

33. The method according to claim 31 or 32, wherein the program specific information data element is a PMT, and the PMT is associated with an entitlement control message or ECM via a second packet identifier or PID.

34. The method of any of claims 30 to 33, wherein the zone description is a descriptor of a table.

35. The method according to any of the preceding claims, wherein a media zone is a media data stream segment having specific properties that cannot be skipped or must be played from beginning to end.

36. The method according to any of the preceding claims, wherein the media zone is a media zone according to the Marlin dynamic media zone specification.

37. A computer program comprising code adapted to perform the method of any of claims 1 to 36 when executed by a computer.

38. A computer program product comprising a computer program according to claim 37.

39. A transmitting device (100) for controlling playout of a media data stream at a receiving device (200), the media data stream comprising one or more programs, each program comprising one or more program components, the transmitting device (100) comprising:

-a processing unit (P1) adapted to define, for at least one of said one or more programs or at least one of said one or more program components in the media data stream, a zone description for the media zone, the zone description identifying the media zone of said at least one program or at least one program component in the media stream,

-wherein said processing unit (P1) is further adapted to associate a zone description with a program specific information data segment being part of a media data stream and comprising data specifying information at least relating to said at least one program or said at least one program component; and

-a sending unit (T1) adapted to send the media data stream to a receiving device (200).

40. The apparatus according to claim 39, adapted for

-determining an identifier for identifying a media zone in a media stream, an

-inserting the identifier into the zone description.

41. A device according to claim 39 or 40, adapted to

-determining at least one other element of a group of other elements, the group of other elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof,

and

-inserting the at least one other element into a region description or a region descriptor comprising the region description.

42. The apparatus according to claim 41, said apparatus being adapted to determine protection integrity information on a zone description.

43. The apparatus of claim 42, wherein determining protection integrity information comprises performing a cryptographic signature on the zone description to obtain a signature value.

44. The apparatus according to claim 43, wherein the cryptographic signing is performed using a cryptographic key transmitted in the entitlement control message or ECM, or derived therefrom.

45. The apparatus of claim 44, wherein the encryption key is a key used to protect the media stream.

46. The apparatus according to any of claims 41 to 45, wherein the playout control instructions convey the zone type information in accordance with the Marlin dynamic media zone specification.

47. The device according to any of claims 40 to 46, the transmitting device being adapted to

-determining that at least one of the one or more program components is protected,

-setting a zone indication parameter in dependence of the protection determination, an

-associating a zone indication parameter with a data segment preventing unauthorized playout of at least one of said one or more program elements, said data segment being part of a media data stream.

48. The apparatus according to claim 47, adapted for

-performing integrity protection of the zone indication parameter.

49. The apparatus according to claim 47 or 48, wherein the data segments preventing unauthorized play-out are entitlement control messages or ECMs.

50. The apparatus according to any one of claims 47 to 49, wherein the region indication parameter is a region information notification flag or a region descriptor counter.

51. Apparatus according to any one of the preceding claims, adapted to trigger the definition of a program specific information data segment whenever an update of a zone description occurs.

52. A receiving device (200) for controlling playout of a media data stream at the receiving device (200), the media data stream comprising one or more programs, each program comprising one or more program components, the receiving device (200) comprising:

-a receiver unit (R2) adapted to receive a media data stream comprising program specific information data segments associated with a zone description of a media zone defined for at least one of said one or more programs or at least one of said one or more program components, said program specific information data segments further comprising: data specifying information at least relating to said at least one program or said at least one program component, a zone description identifying a media zone of said at least one program or said at least one program component in the media stream;

-a processing unit (P2) adapted to detect program specific information data segments comprising zone descriptions in the media data stream, and based on an analysis of the zone descriptions, to identify the media zone and to determine playout control instructions for the playout of the media zone; and

-an output unit (O2) adapted to play out the identified media zone according to the determined play-out control instruction.

53. The apparatus of claim 52, further adapted for

-identifying the media zone based on the identifier in the zone description.

54. The device of claim 52 or 53, the receiving device being adapted to

-determining at least one further element of a further group of elements from the zone description, the further group of elements comprising:

other identification information for identifying the start, end or duration of a media zone in the media data stream,

play-out control instructions regarding play-out of the media zone,

information for inserting media data into the media zone,

copyright management information on the media area, and

integrity protection information for protecting the integrity of at least one of the media zone and the zone description or parts thereof,

and

-performing at least one operation of a group of operations based on the determined other elements, the group of operations comprising:

based on the other identification information, the start, end or duration of a media zone in the media data stream is identified,

performing the play-out of the media zone according to the play-out control instructions determined from the zone description,

determining media data consistent with the information for inserting the media data into the media zone, and inserting the media data into the media zone,

determining copyright management data and operations based on the copyright management information and applying the determined copyright management data and operations to the media zone, an

Verifying said integrity protection information for verifying the integrity of at least one of the media zone and the zone description or parts thereof.

55. The apparatus according to claim 54, adapted to determine integrity protection information about a zone description.

56. The device according to any of claims 52 to 56, adapted to receive entitlement control messages or ECMs.

57. The apparatus according to claims 55 and 56, wherein the ECM contains a cryptographic key, and the integrity protection information is a signature value obtained by performing a cryptographic signature on the zone description using the cryptographic key.

58. Apparatus according to any one of claims 52 to 57, adapted for use with a human being

-detecting in the media stream a zone indication parameter associated with a data segment preventing unauthorized play-out of at least one of said one or more programs or said one or more program elements, and

-performing a security operation with respect to at least one of the one or more programs, the one or more program elements, the media zone and the zone description.

59. The apparatus according to claim 58, adapted for

-performing an integrity protection verification procedure of the zone indication parameter.

60. The apparatus according to claim 58 or 59, wherein the data segments preventing unauthorized play-out are entitlement control messages or ECMs.

61. The apparatus according to any of claims 58 to 60, wherein the region indication parameter is a region information notification flag or a region descriptor counter.

62. Apparatus according to claims 60 and 61, said apparatus being adapted to receive a zone information notification flag in the ECM, said zone information notification flag signaling that the program specific information data segment contains a zone description.

63. Apparatus as claimed in claim 61 or 62, adapted to examine a program specific information data segment to determine if a zone information notification flag is set.

64. The device according to at least claims 59 and 60, adapted to verify integrity protection information based on a cryptographic key received in the ECM.

65. The apparatus of claim 64, wherein the encryption key is a key used to protect a media stream.

66. Apparatus according to any one of claims 52 to 65, adapted for use with a human being

The detection of the media zone and the determination of the playout control instructions are performed whenever an update of the program specific information data segment is detected.

67. The apparatus according to any of claims 39 to 66, wherein the media data stream is a transport stream according to the MPEG-2 transport stream format.

68. Apparatus according to any one of claims 39 to 67, wherein said program specific information data segments are tables.

69. The apparatus according to claims 67 and 68, wherein said table is at least one of a program map table or PMT, a conditional access table or CAT, a program association table or PAT, and a transport stream private table.

70. The apparatus according to claim 69, wherein said program specific information data segment is a PMT, said zone description is included in the private table, and said PMT is associated with the private table and the zone description included in the private table via a first packet identifier or PID.

71. The apparatus according to claim 69 or 70, wherein the program specific information data element is a PMT and the PMT is associated with an entitlement control message or ECM via a second packet identifier or PID.

72. The apparatus of any of claims 68-71, wherein the zone description is a descriptor of a table.

73. The apparatus according to any of claims 39 to 72, wherein a media zone is a media data stream segment having specific properties that cannot be skipped or must be played from head to tail.

74. The apparatus according to any of claims 39 to 73, wherein the media zone is a media zone according to the Marlin dynamic media zone specification.

75. A system comprising the transmitting device (100) according to any one of claims 39 to 51 and 67 to 74 and the receiving device (200) according to any one of claims 52 to 74.