Patent Description:
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) provides a standard for streaming multimedia content over Internet Protocol (IP) networks. The standard is referred to as dynamic adaptive streaming over hypertext transfer protocol (DASH) standard. The DASH standard includes a part for session-based DASH operation. In the session-based DASH operation, while a media presentation file (MPD) is generic for all clients, a client can get a side file, which can provide instructions for the client to make the MPD file specific for a session of the client. The side file is referred to as a session-based description (SBD) file.

The document ("<NPL>) outlines a URL customization applied after segment URL substitution rules applied so that a SBD client's operation stays after a DASH client generates a segment address and right before making a HTTP request for that segment.

The document ("<NPL>) discloses a MPD signaling, a query template , a key value pair and a SBD file format in relation to a session based DASH operation.

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 also be 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 and 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.

It is noted that the MPD file can be generic for all DASH clients. In order to make the MPD file specific for a session of the DASH client, moving picture expert group (MPEG) provides session-based DASH operations. In session-based DASH operations, the DASH client can receive a side file, such as a session-based description (SBD) file, which provides instructions for the DASH client to customize the MPD file per session and possibly per client. However, in some related examples, the session-based DASH operation is application-specific. That is, for each new application, a new SBD format is required.

This disclosure includes methods for customizing or modifying a URL in a session-based DASH.

<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 a server, such as the DASH server (<NUM>), based on the MPD file. The DASH client (<NUM>) can send a request to the DASH server (<NUM>) for updating the MPD file. The DASH server (<NUM>) can provide a content stream, including primary content (e.g., a main program) and one or more timed metadata tracks. In addition, the DASH client (<NUM>) can receive an SBD file from a server, such as the DASH server (<NUM>) or a third party (e.g., session controller).

According to aspects of the disclosure, the SBD file can include a plurality of time ranges and corresponding key-value pairs (or name-value pairs), along with additional metadata. The SBD file can be referenced in the MPD file by, for example, a URL. The SBD file can be used to customize the MPD file received by the DASH client (<NUM>) to be specific for a session of the DASH client (<NUM>). For example, the SBD file can allow adding session-specific elements to segment URLs without generating unique per-session MPDs.

<FIG> shows another exemplary session-based DASH operation architecture <NUM> according to an embodiment of the disclosure. In the session-based DASH operation architecture <NUM>, multimedia content is prepared and generated by a content generation device (<NUM>) (e.g., smartphone) which can include an audio source (e.g., microphone) and a video source (e.g., video camera). The multimedia content can be stored by the content generation device (<NUM>) or sent to a content server (<NUM>) which can store various multimedia contents. The content server (<NUM>) can receive a request from client devices, such as a DASH access client (<NUM>), for one or more media segments of the multimedia content. The multimedia content is described by an MPD file, which can be stored and updated by the content server (<NUM>) and accessed by the client devices including the DASH access client (<NUM>) to retrieve the media segments.

In order to retrieve a session-specific media segment, the DASH access client (<NUM>) can send a request to an SBD client (<NUM>) (e.g., session client) to access an SBD file that is received by the SBD client (<NUM>) and includes a plurality of time ranges and corresponding key-value pairs for the current session. For example, the DASH access client (<NUM>) can send a key name and a time range to the SBD client (<NUM>), which then parses the key name and the time range and returns a value corresponding to the key name and the time range to the DASH access client (<NUM>). The DASH access client (<NUM>) can include the value in a query of a segment URL which can be sent to the content server (<NUM>) for requesting the session-specific media segment when the segment request is a HTTP GET or partial GET request.

It is noted that the SBD client (<NUM>) can receive multiple SBD files from different session controllers, such as a session controller (<NUM>) and a session controller (<NUM>).

According to aspects of the disclosure, any or all of the features of the content server (<NUM>) (e.g., DASH server) can be implemented on one or more devices of a content delivery network (CDN), such as routers, bridges, proxy devices, switches, or other devices. The content server (<NUM>) can include a request processing unit configured to receive network requests from the client devices (e.g., DASH access client (<NUM>)). For example, the request processing unit can be configured to receive HTTP GET or partial GET requests and provide data of multimedia contents in response to the requests. The requests can specify a segment using a URL of the segment. In some examples, the requests can also specify one or more byte ranges of the segment, thus comprising partial GET requests. The request processing unit can further be configured to service HTTP HEAD requests to provide header data of a segment.

In some embodiments, the content generation device (<NUM>) and the content server (<NUM>) can be coupled by a wireless network or a wired network, or can be directly communicatively coupled.

In some embodiments, the content generation device (<NUM>) and the content server (<NUM>) can be included in a same device.

In some embodiments, the content server (<NUM>) and the session controllers (<NUM>)-(<NUM>) can be included in a same device.

In some embodiments, the content server (<NUM>) and the DASH access client (<NUM>) can be coupled by a wireless network or a wired network.

In some embodiments, the SBD client (<NUM>) and the session controllers (<NUM>)-(<NUM>) can be coupled by a wireless network or a wired network, or can be directly communicatively coupled.

In some embodiments, the DASH access client (<NUM>) and the SBD client (<NUM>) can be included in a same device.

According to aspects of the disclosure, in order to link multiple SBDs to an MPD, one or more essential property descriptors for session-based DASH can be used at an MPD level and each essential property descriptor for session-based DASH includes similar or same essential property descriptor attributes. Note that presentation descriptor can be either an essential property descriptor or a supplemental property descriptor. For an essential property, the media presentation author expresses that the successful processing of the descriptor is essential to properly use the information in the parent element that contains this descriptor unless the element shares the same @id with another EssentialProperty element. By contrast, for a supplemental property, the media presentation author expresses that the descriptor contains supplemental information that may be used by the DASH Client for optimized processing.

<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 p 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 p 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 p 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.

In the DASH standard, a general usage of an SBD file or document is provided. For example, the SBD file can be used to generate a URL query for a request URL. The request URL can be generated by a DASH access client and/or modified by an SBD client. In some cases, the URL query generation needs service information of one or more services of a device that the DASH access client and/or the SBD client runs on. For example, the service information of the device can be user identification (ID) information, device ID information, device hardware information, software information, operating system information, and/or application program information of the device. However, the DASH standard does not provide a method for the URL query generation based on the service information of the service(s) running on the device.

This disclosure includes methods of generating a URL query based on service information of service(s) of a device. The methods are based on session-based DASH operation. The service information of the service(s) can be gathered and updated dynamically.

<FIG> shows an exemplary session-based DASH system according to an embodiment of the disclosure. In <FIG>, a DASH access client (<NUM>) running on a device (<NUM>) can access a manifest file such as an MPD file and media segments through a CDN (<NUM>). In order to request a resource such as a media segment from the CDN (<NUM>), the DASH access client (<NUM>) can provide a request URL and an SBD URL (and associated information) to an SBD client (<NUM>), which also runs on the device (<NUM>). The SBD client (<NUM>) can download an SBD file based on the SBD URL and modify the request URL based on the SBD file. Then, the modified request URL can be returned to the DASH access client (<NUM>), which sends the modified request URL to the CDN (<NUM>) to request the resource.

In an embodiment, the SBD file can be an SBD1 document, which is located and provided by an external device or server such as a cloud session controller (CSC) (<NUM>). In this embodiment, the DASH access client (<NUM>) can provide an SBD URL pointing to a remote address in the CSC (<NUM>) for the SBD1 document. The SBD client (<NUM>) can download the SBD1 document from the CSC (<NUM>) based on the remote address in the CSC (<NUM>) and modify the request URL based on the SBD1 document.

In an embodiment, the SBD file can be an SBD2 document, which is located in a local cache of the device (<NUM>) and provided by a local session controller (LSC) (<NUM>) running on the device (<NUM>). In this embodiment, the DASH client (<NUM>) can provide an SBD URL pointing to a local address in the local cache for the SBD2document. The SBD client (<NUM>) can access the SBD2 document through the LSC (<NUM>) based on the local address in the local cache and modify the request URL based on the SBD2 document.

In an embodiment, the request URL can be modified based on both the SBD1 and SBD2 documents. In this embodiment, the DASH access client (<NUM>) can provide two SBD URLs to the SBD client (<NUM>). One SBD URL is used to address the SBD1 document and the other one is used to address the SBD2 document. The SBD client (<NUM>) can access both SBD documents based on the SBD URLs and modify the request URL based on both SBD documents.

According to aspects of the disclosure, the LSC (<NUM>) can access information of different services, functions, and/or programs running on the device (<NUM>). For example, the LSC can access user ID information of the device (<NUM>), device ID information of the device (<NUM>), user ID information of an application program running on the device (<NUM>), application information of the application program (e.g., an application profile or an user profile), device capability information (e.g., device screen size or screen resolution) of the device (<NUM>), operating system information of the device (<NUM>) (e.g., operating system version), and/or device location information of the device (<NUM>). The information of the services, functions, and/or programs can vary from device to device and be accessed based a user permission. The SBD2 document can be generated and updated based on the information of the services, functions, and/or programs that run on the device (<NUM>).

In the DASH standard, an MPD file can include an essential property descriptor, referred to as an SBD essential property descriptor, to indicate an address of an SBD file. For example, a value of an attribute (e.g., @value) of the SBD essential property descriptor can be set as an SBD URL, based on which the SBD client (<NUM>) can access an SBD file.

In an embodiment, the SBD2 document can be located in a local cache of the device (<NUM>). In order to access the SBD2 document, the value of the attribute @value in the SBD essential property descriptor can be set as a local URL address, such as 'locolhost/SBD2. js' or ` <NUM>. <NUM>/sessionbased/SBD2.

The SBD2 document can include one or more key-value pairs. Each key of the one or more key-value pairs can indicate a different device or user characteristic. Examples of the keys can include different aspects of device hardware information (e.g., memory size or memory type), device firmware information (e.g. firmware version), device software information (e.g., media player version), operating system information (e.g., operating system version), device capabilities (e.g., device screen size or screen resolution), user partial or full information depending on a user permission, application information of application program(s) running on the device (<NUM>), and/or device location information of the device (<NUM>).

Depending on the nature of the information, a corresponding key-value pair can be either static or dynamic. A static key-value pair is a constant key-value pair, such as a key-value pair corresponding to the device screen size information. A dynamic key-value pair can be updated based on a change of the corresponding information, such as a key-value pair corresponding to the device location information.

In an embodiment, a key-value pair can be generated once, for each MPD, for each period, or with each request URL (e.g., a media segment request). A key-value pair can be generated and updated based on an event. For example, a key-value pair corresponding to the device location information can be updated whenever the location of the device (<NUM>) changes.

In an embodiment, a frequency of updating the key-value pair(s) in the SBD2 document can be managed by the LSC (<NUM>).

Table <NUM> shows exemplary settings for a key-value object in the SBD2 document according to an embodiment of the disclosure. In Table <NUM>, a type of the SBD2 document can be set as a dynamic type, indicating that the key-value pair(s) in the SBD2 document can be updated every ttl seconds. A timeline model instead of an orderline model can be used for an arrangement of the key-value pairs in the SBD2 document, indicating the key-value pairs in the SBD2 document are time-based arranged. A loop attribute of the SBD2 document can be set as 'true', indicating that after running out of all timeline elements, a new set of timeline element(s) can be added by repeating the same element(s) until the session ends.

Table <NUM> shows exemplary settings for the timeline model of the SBD2 document according to an embodiment of the disclosure. In Table <NUM>, an attribute @n is set as <NUM>, indicating the starting (sub)segment is the first (sub)segment in the corresponding MPD or period element. An attribute @d is a duration of the timeline model and can be set as a very large value.

With the above settings, for each request sent from the DASH access client (<NUM>), the SBD client (<NUM>) can access the LSC (<NUM>) to get an updated SBD2 document. The LSC (<NUM>) can make inquiries to each module, function, program, and/or service running on the device (<NUM>) and then update the corresponding key-value pair(s) in the SBD2 document. Then, the LSC (<NUM>) can provide the updated SBD2 document to the SBD Client (<NUM>). Based on the updated SBD2 document, the SBD client (<NUM>) can modify a URL provided by the DASH access client (<NUM>) and send the modified URL back to the DASH access client (<NUM>). The DASH access client (<NUM>) can send the modified URL to the CDN (<NUM>) to request a resource.

In an embodiment, the MPD and manifest information can be provided to the LSC (<NUM>). For example, the LSC (<NUM>) can have the latest MPD and manifest information such as MPD URL information, MPD query information, MPD publish time information, period ID information, adaptation set ID information, and/or representation set ID information. Other information, such as specific information in various descriptors included in the MPD file can also be provided to the LSC (<NUM>) if needed. The LSC (<NUM>) can set the information as various keys in the SBD2 document. Therefore, the MPD and manifest information can be added as a part of a URL query to request a resource from the CDN (<NUM>).

In an embodiment, for the URL provided by the DASH access client (<NUM>), the SBD client (<NUM>) can modify the URL by adding one or more key-value pairs in the SBD2 document to a URL query of the URL. The one or more key-value pairs can be determined based on a time range corresponding to a media segment that the URL requests. Each of the one or more key-value pairs can correspond to information of a different service running on the device (<NUM>). For example, a first key-value pair can correspond to a first service including the device screen size information and a second key-value pair can correspond to a second service including the device screen resolution information. If the device (<NUM>) has a screen size of <NUM> inches and a screen resolution of 1600x1200, the first key-value pair can be set as 'screen_size=21inches' and the second key-value pair can be set as 'screen_resolution=<NUM>×<NUM>'. These two key-value pairs can be combined as 'screen_size=21inches& screen_resolution=<NUM>×<NUM>', which can be added as the URL query.

In an embodiment, for the URL provided by the DASH access client (<NUM>), the SBD client (<NUM>) can modify the URL by customizing one or more URL parts of the URL based on the SBD2 document. For example, one or more of a host part, a port part, a path part, and/or a fragment part of the URL can be customized by the SBD client (<NUM>) based on the key-value pair(s) in the SBD2 document.

In an embodiment, the URL used to request a resource from the CDN (<NUM>) can be one of a media segment request, an MPD request, an Xlink resolution request, a callback request that is triggered by a callback event, a chaining request for a chained-to MPD, or a fallback request for a fallback MPD.

This disclosure includes a method for adding one or more of various device, user, application, and/or streaming session parameters dynamically as a query to a request URL such as a media segment request URL. These parameters can be generated by an LSC such as the LSC (<NUM>) and be included in different services running on a device such as the device (<NUM>). The LSC can access these parameters by accessing the services including these parameters. Based on these parameters, the LSC can generate a dynamic SBD document (e.g., SBD2) including key-value pair(s) with each corresponding to one different parameter. The dynamic SBD document can be stored as a resource in a local cache of the device. The SBD document can be set up with a configuration that indicates it is dynamic and be updated with any change of the parameters. The SBD document can be accessed with every request received from an SBD client such as the SBD client (<NUM>). The SBD client can send a request to the LSC to access the SBD document, for example, when the URL query information is to be updated. An address value of the SBD document in the local cache can be included in an SBD essential property descriptor in an MPD file so that the SBD client can access the SBD document.

In an embodiment, a DASH access client such as the DASH access client (<NUM>) can send a key name and a time range to the SBD client. The SBD client can access the SBD document to determine a value corresponding to the key name and the time range. Then, the SBD client or the DASH access client can modify the URL based on the value, for example by adding the value as a URL query of the URL. If the DASH client sends the URL to the SBD client, the SBD client can modify the URL and return the modified URL to the DASH access client. Otherwise, the SBD client can return the value to the DASH access client, which then modifies the URL based on the value. In either way, the modified URL can be sent by the DASH access client to a remote server such as the CDN (<NUM>) to request a resource.

This disclosure includes a method of customizing one or more parts of a URL based on a dynamic SBD document (e.g., SBD2) stored in a local cache of a device such as the device (<NUM>). The one or more parts can include a host part, a port part, a path part, and/or a fragment part of the URL. The dynamic SBD document is generated by an LSC such as the LSC (<NUM>) and includes key-value pair(s) with each corresponding to service information of a different service running on the device.

This disclosure includes a method of acquiring a resource from a remote server based on a modified URL. The modification of the URL can be a URL query addition and/or a URL part(s) customization. The modified URL can be one of an MPD update request, an Xlink resolution request, a callback request, a chaining MPD request, or an MPD fallback request. Based on a type of the request of the modified URL, a corresponding resource can be acquired from the remote server such as the CDN (<NUM>).

<FIG> shows a flow chart outlining a process (<NUM>) according to an embodiment of the disclosure. In various embodiments, 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 (S510), where the process (<NUM>) receives an MPD file that includes an essential property descriptor for session-based DASH operation. The essential property descriptor indicates an SBD file that includes one or more key-value pairs dynamically generated by a local SBD session controller. Each key of the one or more key-value pairs indicates service information of a different service of a local device. Then, the process (<NUM>) proceeds to step (S520).

At step (S520), the process (<NUM>) modifies a URL based on the SBD file. Then, the process (<NUM>) proceeds to step (S530).

At step (S530), the process (<NUM>) acquires a resource from a remote server based on the modified URL. Then, the process (<NUM>) terminates.

In an embodiment, the essential property descriptor includes a local address of the SBD file.

In an embodiment, the service information includes at least one of device information, user information, application information, or location information.

In an embodiment, in response to a change in the service information of the local device, the process (<NUM>) updates one of the one or more key-value pairs corresponding to the service information of one of the services of the local device.

In an embodiment, the process (<NUM>) modifies at least one of a host part, a port part, a path part, or a fragment part of the URL based on the SBD file.

In an embodiment, the process (<NUM>) adds a query to the URL based on the SBD file.

In an embodiment, the URL is one of a media segment request, an MPD request, an XLink resolution request, a callback request that is triggered by a callback event, a chaining request for a chained-to MPD, or a fallback request for a fallback MPD.

In an embodiment, a type of the SBD file is a dynamic type and the one or more key-value pairs are arranged in a time-based order.

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 of receiving media data, comprising:
receiving (S510), by a device (<NUM>), a media presentation description, MPD, file that includes an essential property descriptor for session-based dynamic adaptive streaming over hypertext transfer protocol, DASH, operation, the essential property descriptor indicating an address of a session-based description, SBD, file, wherein the SBD file includes one or more key-value pairs dynamically generated by a local SBD session controller (<NUM>), each key of the one or more key-value pairs indicating service information of a different service of the device (<NUM>), and wherein the service information includes at least one of device information, user information, application information, or location information;
modifying (S520), by the device (<NUM>), a uniform resource locator, URL, based on the SBD file; and
acquiring (S530), by the device (<NUM>), a resource from a remote server based on the modified URL.