Patent Description:
The present disclosure describes embodiments generally related to methods and apparatuses for dynamic adaptive streaming over hypertext transfer protocol (DASH).

Work of the presently named inventor, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

Moving Picture Expert Group (MPEG) dynamic adaptive streaming over hypertext transfer protocol (DASH) provides a standard for streaming multimedia content over IP networks. In MPEG DASH, a single manifest can represent a single storyline of a story map. It is possible to update the manifest to change the storyline. However, the story map needs to be maintained outside of the manifest by an application.

Emmanuel Thomas (TNO): "[OMAF] Signalling of viewport-driven DASH playback for interactive storytelling" discloses DASH signalling to enable the creation of storyline paths as called by the Virtual Realty Industry Forum.

The invention is defined in the appended claims and the scope of protection of the invention is determined by these claims. The invention relates to apparatuses for receiving media data including processing circuitry that receives a media presentation description (MPD) file that includes an MPD event indicating a plurality of branches of a story map. The processing circuitry receives a user selection of one of the plurality of branches of the story map during an active duration of the MPD event. The user selected branch corresponds to a next period that is connected to a current period. The processing circuitry receives, from a server, media data of the next period corresponding to the user selected branch. The processing circuitry stores period information of a period for each of the plurality of branches indicated by the MPD event and generates a local MPD file based on the received MPD file and the user selected branch.

In an embodiment, the MPD event includes a start time of the active duration.

In an embodiment, the processing circuitry sends, to the server, selection information that indicates the user selected branch.

In an embodiment, the selection information includes a period identification (ID) of the next period corresponding to the user selected branch.

In an embodiment, the processing circuitry sends the selection information to the content server based on uniform resource locator (URL) information included in the MPD event and the period ID.

In an embodiment, the MPD file is updated to include period information of the next period.

The invention relates to methods for receiving media data. In one method, a media presentation description (MPD) file that includes an MPD event indicating a plurality of branches of a story map is received by processing circuitry. A user selection of one of the plurality of branches of the story map is received by processing circuitry during an active duration of the MPD event. The user selected branch corresponds to a next period that is connected to a current period. Media data of the next period corresponding to the user selected branch is received by processing circuitry from a server. The period information of a period for each of the plurality of branches indicted by the MPD event is received by the processing circuitry. A local MPD file based on the received MPD file and the user selected branch is generated by the processing circuitry.

Aspects of the disclosure also provide non-transitory computer-readable mediums storing instructions which when executed by a computer for receiving media data cause the computer to perform any one or a combination of the methods for receiving the media data.

Dynamic adaptive streaming over hypertext transfer protocol (DASH) is an adaptive bitrate streaming technique that enables streaming of media content using hypertext transfer protocol (HTTP) infrastructures, such as web servers, content delivery networks (CDNs), various proxies and caches, and the like. DASH supports both on-demand and live streaming from a DASH server to a DASH client, and allows the DASH client to control a streaming session, so that the DASH server does not need to cope with an additional load of stream adaptation management in large scale deployments. DASH also allows the DASH client a choice of streaming from various DASH servers, and therefore achieving further load-balancing of the network for the benefit of the DASH client. DASH provides dynamic switching between different media tracks, for example, by varying bit-rates to adapt to network conditions.

In DASH, a media presentation description (MPD) file provides information for the DASH client to adaptively stream media content by downloading media segments from the DASH server. The MPD file can be fragmented and delivered in parts to reduce session start-up delay. The MPD file can be also updated during the streaming session. In some examples, the MPD file supports expression of content accessibility features, ratings, and camera views. DASH also supports delivering of multi-view and scalable coded content.

The MPD file can contain a sequence of one or more periods. Each of the one or more periods can be defined by a period element in the MPD file. The MPD file can include an availableStartTime attribute for the MPD and a start attribute for each period. For media presentations with a dynamic type (e.g., used for live services), a sum of the start attribute of the period, the MPD attribute availableStartTime, and the duration of the media segment can indicate the availability time of the period in coordinated universal time (UTC) format, in particular the first media segment of each representation in the corresponding period. For media presentations with a static type (e.g., used for on-demand services), the start attribute of the first period can be <NUM>. For any other period, the start attribute can specify a time offset between the start time of the corresponding period relative to the start time of the first period. Each period can extend until the start of the next period, or until the end of the media presentation in the case of the last period. Period start times can be precise and reflect the actual timing resulting from playing the media of all prior periods.

Each period can contain one or more adaptations sets, and each of the adaptation sets can contain one or more representations for the same media content. A representation can be one of a number of alternative encoded versions of audio or video data. The representations can differ by encoding types, e.g., by bitrate, resolution, and/or codec for video data and bitrate, and/or codec for audio data. The term representation can be used to refer to a section of encoded audio or video data corresponding to a particular period of the multimedia content and encoded in a particular way.

Adaptation sets of a particular period can be assigned to a group indicated by a group attribute in the MPD file. Adaptation sets in the same group are generally considered alternatives to each other. For example, each adaptation set of video data for a particular period can be assigned to the same group, such that any of the adaptation set can be selected for decoding to display video data of the multimedia content for the corresponding period. The media content within one period can be represented by either one adaptation set from group <NUM>, if present, or the combination of at most one adaptation set from each non-zero group, in some examples. Timing data for each representation of a period can be expressed relative to the start time of the period.

A representation can include one or more segments. Each representation can include an initialization segment, or each segment of a representation can be self-initializing. When present, the initialization segment can contain initialization information for accessing the representation. In some cases, the initialization segment does not contain media data. A segment can be uniquely referenced by an identifier, such as a uniform resource locator (URL), uniform resource name (URN), or uniform resource identifier (URI). The MPD file can provide the identifiers for each segment. In some examples, the MPD file can also provide byte ranges in the form of a range attribute, which can correspond to the data for a segment within a file accessible by the URL, URN, or URI.

Each representation can also include one or more media components, where each media component can correspond to an encoded version of one individual media type, such as audio, video, or timed text (e.g., for closed captioning). Media components can be time-continuous across boundaries of consecutive media segments within one representation.

In some embodiments, the DASH client can access and download the MPD file from the DASH server. That is, the DASH client can retrieve the MPD file for use in initiating a live session. Based on the MPD file, and for each selected representation, the DASH client can make several decisions, including determining what is the latest segment that is available on the server, determining the segment availability start time of the next segment and possibly future segments, determining when to start playout of the segment and from which timeline in the segment, and determining when to get/fetch a new MPD file. Once the service is played out, the client can keep track of drift between the live service and its own playout, which needs to be detected and compensated.

The present disclosure includes embodiments directed to storyline events and presents methods for conveying an interactive storyline in DASH media streaming. A streaming service can provide a user with a plurality of story branches of a story. The user can make a choice of one of the plurality of story branches and provide the choice back to the streaming service, and the streaming service can continue with the chosen branch of the story.

In an interactive storyline, at certain moments of a presentation of the storyline, the user can make a choice among possible branch choices provided by a story map. Then the storyline changes according to the user-choice. An example of an interactive storyline use-case is Netflix's Black Mirror published in <NUM>.

In the DASH standard, a manifest can be updated. Therefore it is possible to create a manifest with a single period in which an application can provide a choice to the user. In an example, the choice can be provided at or close to the end of period. The choice can provide to the user a plurality of different story branches, each branch corresponding to a period. Then the user can select one of the plurality of story branches. Depending on the user selection, the manifest can be updated with a new period, which carries the content of the story corresponding to the user selection. Such a manifest can be referred to as a dynamic manifest. Since the content is on demand, all period elements are stored in a server, and the dynamic manifest can be created by adding these periods one after another according to the user selection. In this solution, however, the story map is not provided, and if the user decides to go back and makes another choice, the server has to navigate to the desired point and author another manifest. A client system that presents the story does not have any view of the story map of the story.

This disclosure presents embodiments to provide the story map along with the manifest. So when the user makes a selection, the client system can maintain the story map and navigate through different branches of the storyline.

<FIG> shows an exemplary DASH system (<NUM>) according to an embodiment of the disclosure. In the DASH system (<NUM>), an MPD file is sent from a DASH server (<NUM>) (e.g., a content server) to a DASH client (<NUM>). The DASH client (<NUM>) can receive media segments from the DASH server (<NUM>) based on the MPD file. The MPD file can provide a choice for a user to select a next interested period of the current period through a user interface (<NUM>). In an example, the selection of the next interested period can be sent back to the DASH server (<NUM>) by using a callback function. The DASH server (<NUM>) can update the MPD and send media content corresponding to the next interested period to the DASH client (<NUM>).

In an embodiment, the DASH server (<NUM>) provides an initial MPD and MPD updates as well as media segments to DASH client. The initial MPD, MPD updates, and/or media segments can be provided by different servers in other embodiments. Whenever the DASH client (<NUM>) receives a storyline event as part of MPD updates, the DASH client (<NUM>) can provide the storyline event to the user through the user interface (<NUM>). Then the user interface (<NUM>) informs the DASH client (<NUM>) of the user selection of an interested story branch, and the DASH client (<NUM>) can provide the user selection to the DASH server (<NUM>) so that the DASH server (<NUM>) can update the MPD accordingly.

<FIG> shows an exemplary DASH client architecture according to an embodiment of the disclosure. The DASH client (or DASH player) can be configured to communicate with an application (<NUM>) and process various types of events, including (i) MPD events, (ii) inband events, and (iii) timed metadata events.

A manifest parser (<NUM>) can parse a manifest (e.g., an MPD). The manifest can be provided by the DASH server (<NUM>) for example. The manifest parser (<NUM>) can extract event information about MPD events, inband events, and timed metadata events embedded in timed metadata tracks. The extracted event information can be provided to a DASH logic (<NUM>) (e.g., DASH player control, selection, and heuristic logic). The DASH logic (<NUM>) can notify the application (<NUM>) of event schemes signaled in the manifest based on the event information.

The event information can include event scheme information for distinguishing between different event streams. The application (<NUM>) can use the event scheme information to subscribe to event schemes of interest. The application (<NUM>) can further indicate a desired dispatch mode for each of the subscribed schemes through one or more subscription application programming interfaces (APIs). For example, the application (<NUM>) can send a subscription request to the DASH client that identifies one or more event schemes of interest and any desired corresponding dispatch modes.

If the application (<NUM>) subscribes to one or more event schemes that are delivered as part of one or more timed metadata tracks, an inband event and 'moof' parser (<NUM>) can stream the one or more timed metadata tracks to a timed metadata track parser (<NUM>). For example, the inband event and 'moof' parser (<NUM>) parses a movie fragment box ("moof") and subsequently parses the timed metadata track based on control information from the DASH logic (<NUM>).

The timed metadata track parser (<NUM>) can extract event messages embedded in the timed metadata track. The extracted event messages can be stored in an event and timed metadata buffer (<NUM>). A synchronizer/dispatcher module (<NUM>) (e.g., event and timed metadata synchronizer and dispatcher) can dispatch (or send) the subscribed events to the application (<NUM>).

MPD events described in the MPD can be parsed by the manifest parser (<NUM>) and stored in the event and timed metadata buffer (<NUM>). For example, the manifest parser (<NUM>) parses each event stream element of the MPD, and parses each event described in each event stream element. For each event signaled in the MPD, event information such as presentation time and event duration can be stored in the event and timed metadata buffer (<NUM>) in association with the event.

The inband event and 'moof' parser (<NUM>) can parse media segments to extract inband event messages. Any such identified inband events and associated presentation times and durations can be stored in the event and timed metadata buffer (<NUM>).

Accordingly, the event and timed metadata buffer (<NUM>) can store therein MPD events, inband events, and/or timed metadata events. The event and timed metadata buffer (<NUM>) can be a First-In-First-Out (FIFO) buffer, for example. The event and timed metadata buffer (<NUM>) can be managed in correspondence with a media buffer (<NUM>). For example, as long as a media segment exists in the media buffer (<NUM>), any events or timed metadata corresponding to that media segment can be stored in the event and timed metadata buffer (<NUM>).

A DASH Access API (<NUM>) can manage the fetching and reception of a content stream (or dataflow) including media content and various metadata through an HTTP protocol stack (<NUM>). The DASH Access API (<NUM>) can separate the received content stream into different dataflows. The dataflow provided to the inband event and 'moof' parser (<NUM>) can include media segments, one or more timed metadata tracks, and inband event signaling included in the media segments. In an embodiment, the dataflow provided to the manifest parser (<NUM>) can include an MPD.

The DASH Access API (<NUM>) can forward the manifest to the manifest parser (<NUM>). Beyond describing events, the manifest can also provide information on media segments to the DASH logic (<NUM>), which can communicate with the application (<NUM>) and the inband event and 'moof' parser (<NUM>). The application (<NUM>) can be associated with the media content processed by the DASH client. Control/synchronization signals exchanged among the application (<NUM>), the DASH logic (<NUM>), the manifest parser (<NUM>), and the DASH Access API (<NUM>) can control the fetching of media segments from the HTTP Stack (<NUM>) based on information regarding media segments provided in the manifest.

The inband event and 'moof' parser (<NUM>) can parse a media dataflow into media segments including media content, timed metadata in a timed metadata track, and any signaled inband events in the media segments. The media segments including media content can be parsed by a file format parser (<NUM>) and stored in the media buffer (<NUM>).

The events stored in the event and timed metadata buffer (<NUM>) can allow the synchronizer/dispatcher (<NUM>) to communicate to the application (<NUM>) the available events (or events of interest) related to the application (<NUM>) through an event/metadata API. The application (<NUM>) can be configured to process the available events (e.g., MPD events, inband events, or timed metadata events) and subscribe to particular events or timed metadata by notifying the synchronizer/dispatcher (<NUM>). Any events stored in the event and timed metadata buffer (<NUM>) that are not related to the application (<NUM>), but are instead related to the DASH client itself can be forwarded by the synchronizer/dispatcher (<NUM>) to the DASH logic (<NUM>) for further processing.

In response to the application (<NUM>) subscribing to particular events, the synchronizer/dispatcher (<NUM>) can communicate to the application (<NUM>) event instances (or timed metadata samples) corresponding to event schemes to which the application (<NUM>) has subscribed. The event instances can be communicated in accordance with a dispatch mode indicated by the subscription request (e.g., for a specific event scheme) or a default dispatch mode. For example, in an on-receive dispatch mode, event instances may be sent to the application (<NUM>) upon receipt in the event and timed metadata buffer (<NUM>). On the other hand, in an on-start dispatch mode, event instances may be sent to the application (<NUM>) at their associated presentation time, for example in synchronization with timing signals from the media decoder (<NUM>).

It is noted that, in the DASH client architecture, the thick dataflow lines indicate media dataflow, the narrow dataflow lines indicate even and timed metadata dataflow, and the dash dataflow lines indicates control and synchronization. In addition, the same processing model can be used for CMAF events.

<FIG> shows an exemplary story map of a story according to an embodiment of the disclosure. In the story map, the story starts with period P0. At the end of the period P0, the story map provides a selection point S0, indicating that the story has three branches P1, P2, and P3. At the end of period P1, the story map provides a selection point S1, indicating that the story has two branches P4 and P5. The rest of the story P6 and P7 occurs at a merging of various branches.

It is noted that a number of choices at each selection point can be set to <NUM> or more. A duration of each branch is not necessarily equal to each other. Some or all of the branches can merge at certain moments, and the merged branches can have different durations. In addition, the story can have one or more endpoints.

According to aspects of the disclosure, an MPD storyline event can be an MPD event indicating one or more selection points in the story map. An event scheme of the MPD event can be identified with a schemeIdUri such as "urn:mpeg: dash: manifest-storyline-event:<NUM>". In an MPD file, only one EventStream element is allowed per period, and thus the events that are carried in the only one EventStream element should use the same URI in their scheme attributes (e.g., @schemeIdUri). In addition, the sub-scheme attributes (e.g., @value) of these events in the EventStream can be ignored by the DASH client (<NUM>). That is, no sub-schemes are defined for the events in the EventStream.

An exemplary MPD event element is shown in Table <NUM>. In Table <NUM>, start time information such as the attribute @presentationTime indicates a start time of the MPD event and duration information such as the attribute @duration indicates a duration of the MPD event. From the start time and during the duration, the user can make a selection. In addition, the MPD event element includes URL information such as an attribute @callbackUrl, which provides a URL for the client system (<NUM>) to make a request (e.g., HTTP GET request). The client system (<NUM>) can add a query to the URL based on the user selection. For example, the query can be "nextPeriod=id", in which id is a period identification (ID) (e.g., @id) value selected by the user through the user interface (<NUM>). The MPD event element includes replacement information such as an attribute @replace. If the attribute @replace is set 'true', then the MPD event is an update of all previous events in this session and a connection map (or story map) replaces previous connection maps. The MPD event includes a connection element specifying the connection map. The connection element can include a set of simple links in the connection map. For example, one link can be a connection from P0 to P1 in the story map shown in <FIG>, and another link can be a connection from P0 to P2 or a connection from P0 to P3.

Table <NUM> shows an exemplary connection element. In the exemplary connection element, one or more links from a first period to one or more second periods can be indicated. For example, a link can be indicated by an attribute @from and an attribute @to. The attribute @from indicates a period from which the link starts. The attribute @to indicates one or more periods to which the link can be connected. Values of the attributes @from and @to can be period IDs. It is noted that the attribute @to can include one or more period IDs, each corresponding to a different link. In addition, a default value of the attribute @from can be a period ID of a parent period of the event. For example, the connection element of the storyline event at period P0 in the exemplary story map shown in <FIG> can be represented by <Connection to ="<NUM><NUM><NUM>"> or <Connection from ="<NUM>" to ="<NUM><NUM><NUM>">. In this example, it is assumed that P0@id="<NUM>", P1@id="<NUM>", P2@id="<NUM>", and P3@id="<NUM>".

According to aspects of the disclosure, one or more connection elements can be included in one storyline event. Multiple connection elements can provide a part of or an entire connection map of a current session. However, it is noted that only the part of the connection map at or close to the end of the current period element is active for selection during the duration of the event. For example, the entire story map as shown in <FIG> can be represented in Table <NUM>. In this example, it is assumed Pi@id= "i". When the current period is P1, only the connection element <Connection from ="<NUM>" to ="<NUM><NUM>"> is active during the duration of the event. So the user can select P4 or P5 as a next period.

According to aspects of the disclosure, the manifest (e.g., MPD) can be updated based on the user selection. The user selection can be provided to the DASH server (<NUM>) by using an out of band method or a callback function. The out of band method can be a method that is not based on the DASH standard. The callback function can allow the DASH client (<NUM>) to issue an HTTP GET request to a given URL. For example, after the user makes a selection, the DASH client (<NUM>) can make an HTTP GET request to the URL address indicated by the callback attribute (e.g., @callbackUrl) in the MPD event element. The selected period ID can be included in the query parameter of the request. Table <NUM> shows an exemplary callback function.

In this disclosure, choices can be provided using MPD events which are simple to parse and pass to the application/user interface. In addition, the upcoming choices, the partial story map, or the entire story map can also be provided, and the story map can be updated. If the story map is delivered to the DASH client (<NUM>) a selection point by another selection point, the DASH client (<NUM>) can only have one selection at a time and not have the entire story map. The story map can be updated at each event (e.g., by including the past and future connections). An event can provide a start time and a duration (e.g., event active period) in which the user is allowed to make the selection. If the user does not make the selection, the presentation may continue with a default branch storyline. Since the event active duration can be set ahead of a transition to a next period, the client system (<NUM>) can have time to buffer the content of the next period for continuous playback. It is noted that the client system (<NUM>) can store the story map as well as period information of all periods and be able to build an interactive local MPD for playback.

The disclosure presents methods for delivering interactive storyline streaming content. A plurality of choices can be provided to the user at certain moments in the timeline of the story. The user can make a choice among the provided choices to change the story direction. An MPD event can be used to convey the plurality of choices for each period. The MPD event can be activated before the actual transition from the current period to the next period. The MPD event can have a duration for the client system (<NUM>) to buffer the selected next period and playback the content with no interruption or re-buffering. One or more selection points in the story map can be provided per MPD event, or the entire story map can be provided in any MPD event. Part of or the entire story map can be updated with each or some MPD events. The MPD event can also provide the URL for the client system (<NUM>) to send back the user choice. The MPD can be updated at the end of each period by adding the next period selected by the user. The DASH client (<NUM>) can build the story map gradually, or in one step if the story map is fully provided. The DASH client (<NUM>) can also store the corresponding periods, and therefore be able to build the entire interactive storyline and manufacture the MPD updates locally with no need to contact the DASH server (<NUM>) for MPD. The DASH server (<NUM>) can only stream the media content while the DASH client (<NUM>) plays the interactive story.

<FIG> shows a flow chart outlining a process (<NUM>) according to the invention. The process (<NUM>) is executed by processing circuitry, such as the processing circuitry in the DASH client (<NUM>). In some embodiments, the process (<NUM>) is implemented in software instructions, thus when the processing circuitry executes the software instructions, the processing circuitry performs the process (<NUM>). The process (<NUM>) starts at (S410), where the process (<NUM>) receives an MPD file that includes an MPD event indicating a plurality of branches of a story map. Then, the process (<NUM>) proceeds to step (S420).

At step (S420), the process (<NUM>) receives, from processing circuitry of an information processing apparatus, a user selection of one of the plurality of branches of the story map during an active duration of the MPD event. The user selected branch corresponds to a next period that is connected to a current period. Then, the process (<NUM>) proceeds to step (S430).

At step (S430), the process (<NUM>) receives, from a server, media data of the next period corresponding to the user selected branch. The process (<NUM>) stores period information of a period for each of the plurality of branches indicated by the MPD event and generates a local MPD file based on the received MPD file and the user selected branch. Then, the process (<NUM>) terminates.

In an embodiment, the process (<NUM>) sends, to the server, selection information that indicates the user selected branch.

In an embodiment, the selection information includes a period ID of the next period corresponding to the user selected branch.

In an embodiment, the process (<NUM>) sends the selection information to the content server based on URL information included in the MPD event and the period ID.

For example, <FIG> shows a computer system (<NUM>) suitable for implementing the invention.

Input human interface devices may include one or more of (only one of each depicted): keyboard (<NUM>), mouse (<NUM>), trackpad (<NUM>), touch screen (<NUM>), data-glove (not shown), joystick (<NUM>), microphone (<NUM>), scanner (<NUM>), and camera (<NUM>).

These visual output devices (such as screens (<NUM>)) can be connected to a system bus (<NUM>) through a graphics adapter (<NUM>).

Computer system (<NUM>) can also include a network interface (<NUM>) to one or more communication networks (<NUM>). The one or more communication networks (<NUM>) can for example be wireless, wireline, optical. The one or more communication networks (<NUM>) can further be local, wide-area, metropolitan, vehicular and industrial, real-time, delay-tolerant, and so on. Examples of the one or more communication networks (<NUM>) include local area networks such as Ethernet, wireless LANs, cellular networks to include GSM, <NUM>, <NUM>, <NUM>, LTE and the like, TV wireline or wireless wide area digital networks to include cable TV, satellite TV, and terrestrial broadcast TV, vehicular and industrial to include CANBus, and so forth. Certain networks commonly require external network interface adapters that attached to certain general purpose data ports or peripheral buses (<NUM>) (such as, for example USB ports of the computer system (<NUM>)); others are commonly integrated into the core of the computer system (<NUM>) by attachment to a system bus as described below (for example Ethernet interface into a PC computer system or cellular network interface into a smartphone computer system). Using any of these networks, computer system (<NUM>) can communicate with other entities. Such communication can be uni-directional, receive only (for example, broadcast TV), uni-directional send-only (for example CANbus to certain CANbus devices), or bi-directional, for example to other computer systems using local or wide area digital networks. Certain protocols and protocol stacks can be used on each of those networks and network interfaces as described above.

These devices, along with Read-only memory (ROM) (<NUM>), Random-access memory (<NUM>), internal mass storage such as internal non-user accessible hard drives, SSDs, and the like (<NUM>), may be connected through the system bus (<NUM>).

As an example and not by way of limitation, the computer system having architecture (<NUM>) and specifically the core (<NUM>) can provide functionality as a result of processor(s) (including CPUs, GPUs, FPGA, accelerators, and the like) executing software embodied in one or more tangible, computer-readable media. Such computer-readable media can be media associated with user-accessible mass storage as introduced above, as well as certain storage of the core (<NUM>) that are of non-transitory nature, such as core-internal mass storage (<NUM>) or ROM (<NUM>). The software implementing various embodiments of the present disclosure can be stored in such devices and executed by core (<NUM>). A computer-readable medium can include one or more memory devices or chips, according to particular needs. The software can cause the core (<NUM>) and specifically the processors therein (including CPU, GPU, FPGA, and the like) to execute particular processes or particular parts of particular processes described herein, including defining data structures stored in RAM (<NUM>) and modifying such data structures according to the processes defined by the software. In addition or as an alternative, the computer system can provide functionality as a result of logic hardwired or otherwise embodied in a circuit (for example: accelerator (<NUM>)), which can operate in place of or together with software to execute particular processes or particular parts of particular processes described herein. Reference to software can encompass logic, and vice versa, where appropriate. Reference to a computer-readable media can encompass a circuit (such as an integrated circuit (IC)) storing software for execution, a circuit embodying logic for execution, or both, where appropriate. The present disclosure encompasses any suitable combination of hardware and software.

Claim 1:
A method for receiving media data, wherein the method comprises:
receiving, by processing circuitry of an information processing apparatus, a media presentation description, MPD, file that includes an MPD event indicating a plurality of branches of a story map (S410);
receiving, by the processing circuitry of the information processing apparatus, a user selection of one of the plurality of branches of the story map during an active duration of the MPD event, the user selected branch corresponding to a next period that is connected to a current period (S420); and
receiving, by the processing circuitry of the information processing apparatus from a server, media data of the next period corresponding to the user selected branch (S430), characterized in, that the method further comprises:
storing, by the processing circuitry of the information processing apparatus, period information of a period for each of the plurality of branches indicated by the MPD event; and
generating, by the processing circuitry of the information processing apparatus, a local MPD file based on the received MPD file and the user selected branch.