Patent Publication Number: US-2022217431-A1

Title: In-manifest update event

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. Ser. No. 17/008,898, filed Sep. 1, 2020, which claims priority to provisional application U.S. 62/897,228 filed on Sep. 6, 2019 which are both hereby expressly incorporated by reference, in their entirety, into the present application. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure is directed to an in-manifest update event signaling a streaming client that a manifest update is necessary. 
     2. Description of Related Art 
     In Dynamic Adaptive Streaming over HTTP (DASH), such as MPEG-DASH, an inband media presentation description (MPD) validity expiration event may be used to signal clients a need for updating a manifest. However, technical disadvantageous are experienced as an inband even is tied to media segments such that such events can only be received from a server providing the content, and therefore, when a client is streaming content from a separate server (e.g., an advertisement (ad) server), the main server cannot add the inband events to the media segments originating from the separate server. 
     During a live streaming of the content, there are certain moments that the ad can be inserted (e.g., at an ad-break). A nominal duration of ads is decided by the content server and is inserted into the manifest. During that period, the client goes to the ad-server and streams and/or plays back the ad. Such technical disadvantages noted above compounded when, for example during the live content event, the ad-server must provide the ad content for that exact duration that is indicated in the original manifest, and in real cases, the live server may want to early terminate the ads, because the event is back from a break, and the client needs to stop streaming the ads and switch back to the live content. However, since the inband MPD validity expiration event is included with the media segments, and since the client is not streaming the content from the live server, at least during the ad period, even if the live server inserts the MPD validity events, the client will not receive that update for at least the above reasons. 
     Therefore, there is a desire for a technical solution to such problems. 
     SUMMARY 
     The proposed method and apparatus herein may be used separately or combined in any order. Further, each of the features, encoder, and decoder may be implemented by processing circuitry (e.g., one or more processors or one or more integrated circuits). In one example, the one or more processors executes a program that is stored in a non-transitory computer-readable medium. 
     This disclosure introduces, among other things, an in-manifest event, which is inserted in an MPD, equivalent of an inband MPD validity expiration event. This in-manifest event may have the same properties of an inband MPD validity expiration event, and therefore the DASH client can process the in-manifest event in a way. There is also disclosed herein how the in-manifest event can be used for early termination of any of pre-roll and mid-roll ads. 
     There is included a method and apparatus comprising memory configured to store computer program code and a processor or processors configured to access the computer program code and operate as instructed by the computer program code. The compute program code includes publishing code configured to cause the at least one processor to publish media presentation description (MPD) data comprising main live program data and signaling code configured to cause the at least one processor to signal a client device about ad data and in-manifest data, where the ad data instructs the client device of an initial end time at which to end a display of an ad by switching a display at the client device from the ad to the main live program data, and where the in-manifest data instructs the client device to determine, during a streaming of the ad to the client device, an updated end time, prior to the end time, at which to end the streaming of the ad by switching the streaming at the client device from the ad to the main live program data. 
     According to exemplary embodiments, signaling the client device about the ad data and the in-manifest data comprises instructing the client device to stream the ad as a mid-roll ad in between segments of streaming of the main live program data. 
     According to exemplary embodiments, signaling the client device about the ad data and the in-manifest data further comprises instructing the client device to switch from an origin server, providing the main live program data, to an ad server separate from the origin server and to obtain the mid-roll ad from the ad server. 
     According to exemplary embodiments, the in-manifest data comprises instructions that the client device is to determine the updated end time by accessing a remote element, during streaming of the mid-roll ad by the client device, and determining whether the remote element indicates the updated end time. 
     According to exemplary embodiments, the in-manifest data comprises further instructions that the client device is to access the remote element at a predetermined frequency prior to the end time. 
     According to exemplary embodiments, the instructions of the in-manifest data instruct the client device to access the remote element via xlink data. 
     According to exemplary embodiments, signaling the client device about the ad data and the in-manifest data comprises instructing the client device to stream the ad as a pre-roll ad prior to streaming of the main live program data. 
     According to exemplary embodiments, the in-manifest data comprises instructions that the client device is to determine the updated end time by accessing a remote element, during streaming of the pre-roll ad by the client device, and determining whether the remote element indicates the updated end time. 
     According to exemplary embodiments, the in-manifest data comprises further instructions that the client device is to access the remote element at a predetermined frequency prior to the end time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, nature, and various advantages of the disclosed subject matter will be more apparent from the following detailed description and the accompanying drawings in which: 
         FIGS. 1-5  are schematic illustrations of diagrams in accordance with embodiments. 
         FIGS. 6 and 7  are simplified flow diagrams in accordance with embodiments. 
         FIG. 8  is a schematic illustration of a diagram in accordance with embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The proposed features discussed below may be used separately or combined in any order. Further, the embodiments may be implemented by processing circuitry (e.g., one or more processors or one or more integrated circuits). In one example, the one or more processors execute a program that is stored in a non-transitory computer-readable medium. 
       FIG. 1  illustrates a simplified block diagram of a communication system  100  according to an embodiment of the present disclosure. The communication system  100  may include at least two terminals  102  and  103  interconnected via a network  105 . For unidirectional transmission of data, a first terminal  103  may code video data at a local location for transmission to the other terminal  102  via the network  105 . The second terminal  102  may receive the coded video data of the other terminal from the network  105 , decode the coded data and display the recovered video data. Unidirectional data transmission may be common in media serving applications and the like. 
       FIG. 1  illustrates a second pair of terminals  101  and  104  provided to support bidirectional transmission of coded video that may occur, for example, during videoconferencing. For bidirectional transmission of data, each terminal  101  and  104  may code video data captured at a local location for transmission to the other terminal via the network  105 . Each terminal  101  and  104  also may receive the coded video data transmitted by the other terminal, may decode the coded data and may display the recovered video data at a local display device. 
     In  FIG. 1 , the terminals  101 ,  102 ,  103  and  104  may be illustrated as servers, personal computers and smart phones but the principles of the present disclosure are not so limited. Embodiments of the present disclosure find application with laptop computers, tablet computers, media players and/or dedicated video conferencing equipment. The network  105  represents any number of networks that convey coded video data among the terminals  101 ,  102 ,  103  and  104 , including for example wireline and/or wireless communication networks. The communication network  105  may exchange data in circuit-switched and/or packet-switched channels. Representative networks include telecommunications networks, local area networks, wide area networks and/or the Internet. For the purposes of the present discussion, the architecture and topology of the network  105  may be immaterial to the operation of the present disclosure unless explained herein below. 
       FIG. 2  illustrates, as an example for an application for the disclosed subject matter, the placement of a video encoder and decoder in a streaming environment. The disclosed subject matter can be equally applicable to other video enabled applications, including, for example, video conferencing, digital TV, storing of compressed video on digital media including CD, DVD, memory stick and the like, and so on. 
     A streaming system may include a capture subsystem  203 , that can include a video source  201 , for example a digital camera, creating, for example, an uncompressed video sample stream  213 . That sample stream  213  may be emphasized as a high data volume when compared to encoded video bitstreams and can be processed by an encoder  202  coupled to the camera  201 . The encoder  202  can include hardware, software, or a combination thereof to enable or implement aspects of the disclosed subject matter as described in more detail below. The encoded video bitstream  204 , which may be emphasized as a lower data volume when compared to the sample stream, can be stored on a streaming server  205  for future use. One or more streaming clients  212  and  207  can access the streaming server  205  to retrieve copies  208  and  206  of the encoded video bitstream  204 . A client  212  can include a video decoder  211  which decodes the incoming copy of the encoded video bitstream  208  and creates an outgoing video sample stream  210  that can be rendered on a display  209  or other rendering device (not depicted). In some streaming systems, the video bitstreams  204 ,  206  and  208  can be encoded according to certain video coding/compression standards. Examples of those standards are noted above and described further herein. 
       FIG. 3  may be a functional block diagram of a video decoder  300  according to an embodiment of the present invention. 
     A receiver  302  may receive one or more codec video sequences to be decoded by the decoder  300 ; in the same or another embodiment, one coded video sequence at a time, where the decoding of each coded video sequence is independent from other coded video sequences. The coded video sequence may be received from a channel  301 , which may be a hardware/software link to a storage device which stores the encoded video data. The receiver  302  may receive the encoded video data with other data, for example, coded audio data and/or ancillary data streams, that may be forwarded to their respective using entities (not depicted). The receiver  302  may separate the coded video sequence from the other data. To combat network jitter, a buffer memory  303  may be coupled in between receiver  302  and entropy decoder/parser  304  (“parser” henceforth). When receiver  302  is receiving data from a store/forward device of sufficient bandwidth and controllability, or from an isosychronous network, the buffer  303  may not be needed, or can be small. For use on best effort packet networks such as the Internet, the buffer  303  may be required, can be comparatively large and can advantageously of adaptive size. 
     The video decoder  300  may include a parser  304  to reconstruct symbols  313  from the entropy coded video sequence. Categories of those symbols include information used to manage operation of the decoder  300 , and potentially information to control a rendering device such as a display  312  that is not an integral part of the decoder but can be coupled to it. The control information for the rendering device(s) may be in the form of Supplementary Enhancement Information (SEI messages) or Video Usability Information parameter set fragments (not depicted). The parser  304  may parse/entropy-decode the coded video sequence received. The coding of the coded video sequence can be in accordance with a video coding technology or standard, and can follow principles well known to a person skilled in the art, including variable length coding, Huffman coding, arithmetic coding with or without context sensitivity, and so forth. The parser  304  may extract from the coded video sequence, a set of subgroup parameters for at least one of the subgroups of pixels in the video decoder, based upon at least one parameters corresponding to the group. Subgroups can include Groups of Pictures (GOPs), pictures, tiles, slices, macroblocks, Coding Units (CUs), blocks, Transform Units (TUs), Prediction Units (PUs) and so forth. The entropy decoder/parser may also extract from the coded video sequence information such as transform coefficients, quantizer parameter values, motion vectors, and so forth. 
     The parser  304  may perform entropy decoding/parsing operation on the video sequence received from the buffer  303 , so to create symbols  313 . The parser  304  may receive encoded data, and selectively decode particular symbols  313 . Further, the parser  304  may determine whether the particular symbols  313  are to be provided to a Motion Compensation Prediction unit  306 , a scaler/inverse transform unit  305 , an Intra Prediction Unit  307 , or a loop filter  311 . 
     Reconstruction of the symbols  313  can involve multiple different units depending on the type of the coded video picture or parts thereof (such as: inter and intra picture, inter and intra block), and other factors. Which units are involved, and how, can be controlled by the subgroup control information that was parsed from the coded video sequence by the parser  304 . The flow of such subgroup control information between the parser  304  and the multiple units below is not depicted for clarity. 
     Beyond the functional blocks already mentioned, decoder  300  can be conceptually subdivided into a number of functional units as described below. In a practical implementation operating under commercial constraints, many of these units interact closely with each other and can, at least partly, be integrated into each other. However, for the purpose of describing the disclosed subject matter, the conceptual subdivision into the functional units below is appropriate. 
     A first unit is the scaler/inverse transform unit  305 . The scaler/inverse transform unit  305  receives quantized transform coefficient as well as control information, including which transform to use, block size, quantization factor, quantization scaling matrices, etc. as symbol(s)  313  from the parser  304 . It can output blocks comprising sample values, that can be input into aggregator  310 . 
     In some cases, the output samples of the scaler/inverse transform  305  can pertain to an intra coded block; that is: a block that is not using predictive information from previously reconstructed pictures, but can use predictive information from previously reconstructed parts of the current picture. Such predictive information can be provided by an intra picture prediction unit  307 . In some cases, the intra picture prediction unit  307  generates a block of the same size and shape of the block under reconstruction, using surrounding already reconstructed information fetched from the current (partly reconstructed) picture  309 . The aggregator  310 , in some cases, adds, on a per sample basis, the prediction information the intra prediction unit  307  has generated to the output sample information as provided by the scaler/inverse transform unit  305 . 
     In other cases, the output samples of the scaler/inverse transform unit  305  can pertain to an inter coded, and potentially motion compensated block. In such a case, a Motion Compensation Prediction unit  306  can access reference picture memory  308  to fetch samples used for prediction. After motion compensating the fetched samples in accordance with the symbols  313  pertaining to the block, these samples can be added by the aggregator  310  to the output of the scaler/inverse transform unit (in this case called the residual samples or residual signal) so to generate output sample information. The addresses within the reference picture memory form where the motion compensation unit fetches prediction samples can be controlled by motion vectors, available to the motion compensation unit in the form of symbols  313  that can have, for example X, Y, and reference picture components. Motion compensation also can include interpolation of sample values as fetched from the reference picture memory when sub-sample exact motion vectors are in use, motion vector prediction mechanisms, and so forth. 
     The output samples of the aggregator  310  can be subject to various loop filtering techniques in the loop filter unit  311 . Video compression technologies can include in-loop filter technologies that are controlled by parameters included in the coded video bitstream and made available to the loop filter unit  311  as symbols  313  from the parser  304 , but can also be responsive to meta-information obtained during the decoding of previous (in decoding order) parts of the coded picture or coded video sequence, as well as responsive to previously reconstructed and loop-filtered sample values. 
     The output of the loop filter unit  311  can be a sample stream that can be output to the render device  312  as well as stored in the reference picture memory  557  for use in future inter-picture prediction. 
     Certain coded pictures, once fully reconstructed, can be used as reference pictures for future prediction. Once a coded picture is fully reconstructed and the coded picture has been identified as a reference picture (by, for example, parser  304 ), the current reference picture  309  can become part of the reference picture buffer  308 , and a fresh current picture memory can be reallocated before commencing the reconstruction of the following coded picture. 
     The video decoder  300  may perform decoding operations according to a predetermined video compression technology that may be documented in a standard, such as ITU-T Rec. H.265. The coded video sequence may conform to a syntax specified by the video compression technology or standard being used, in the sense that it adheres to the syntax of the video compression technology or standard, as specified in the video compression technology document or standard and specifically in the profiles document therein. Also necessary for compliance can be that the complexity of the coded video sequence is within bounds as defined by the level of the video compression technology or standard. In some cases, levels restrict the maximum picture size, maximum frame rate, maximum reconstruction sample rate (measured in, for example megasamples per second), maximum reference picture size, and so on. Limits set by levels can, in some cases, be further restricted through Hypothetical Reference Decoder (HRD) specifications and metadata for HRD buffer management signaled in the coded video sequence. 
     In an embodiment, the receiver  302  may receive additional (redundant) data with the encoded video. The additional data may be included as part of the coded video sequence(s). The additional data may be used by the video decoder  300  to properly decode the data and/or to more accurately reconstruct the original video data. Additional data can be in the form of, for example, temporal, spatial, or signal-to-noise ratio (SNR) enhancement layers, redundant slices, redundant pictures, forward error correction codes, and so on. 
       FIG. 4  may be a functional block diagram of a video encoder  400  according to an embodiment of the present disclosure. 
     The encoder  400  may receive video samples from a video source  401  (that is not part of the encoder) that may capture video image(s) to be coded by the encoder  400 . 
     The video source  401  may provide the source video sequence to be coded by the encoder ( 303 ) in the form of a digital video sample stream that can be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, . . . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ) and any suitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). In a media serving system, the video source  401  may be a storage device storing previously prepared video. In a videoconferencing system, the video source  401  may be a camera that captures local image information as a video sequence. Video data may be provided as a plurality of individual pictures that impart motion when viewed in sequence. The pictures themselves may be organized as a spatial array of pixels, wherein each pixel can comprise one or more samples depending on the sampling structure, color space, etc. in use. A person skilled in the art can readily understand the relationship between pixels and samples. The description below focuses on samples. 
     According to an embodiment, the encoder  400  may code and compress the pictures of the source video sequence into a coded video sequence  410  in real time or under any other time constraints as required by the application. Enforcing appropriate coding speed is one function of Controller  402 . Controller controls other functional units as described below and is functionally coupled to these units. The coupling is not depicted for clarity. Parameters set by controller can include rate control related parameters (picture skip, quantizer, lambda value of rate-distortion optimization techniques, . . . ), picture size, group of pictures (GOP) layout, maximum motion vector search range, and so forth. A person skilled in the art can readily identify other functions of controller  402  as they may pertain to video encoder  400  optimized for a certain system design. 
     Some video encoders operate in what a person skilled in the art readily recognizes as a “coding loop.” As an oversimplified description, a coding loop can consist of the encoding part of an encoder  402  (“source coder” henceforth) (responsible for creating symbols based on an input picture to be coded, and a reference picture(s)), and a (local) decoder  406  embedded in the encoder  400  that reconstructs the symbols to create the sample data that a (remote) decoder also would create (as any compression between symbols and coded video bitstream is lossless in the video compression technologies considered in the disclosed subject matter). That reconstructed sample stream is input to the reference picture memory  405 . As the decoding of a symbol stream leads to bit-exact results independent of decoder location (local or remote), the reference picture buffer content is also bit exact between local encoder and remote encoder. In other words, the prediction part of an encoder “sees” as reference picture samples exactly the same sample values as a decoder would “see” when using prediction during decoding. This fundamental principle of reference picture synchronicity (and resulting drift, if synchronicity cannot be maintained, for example because of channel errors) is well known to a person skilled in the art. 
     The operation of the “local” decoder  406  can be the same as of a “remote” decoder  300 , which has already been described in detail above in conjunction with  FIG. 3 . Briefly referring also to  FIG. 4 , however, as symbols are available and en/decoding of symbols to a coded video sequence by entropy coder  408  and parser  304  can be lossless, the entropy decoding parts of decoder  300 , including channel  301 , receiver  302 , buffer  303 , and parser  304  may not be fully implemented in local decoder  406 . 
     An observation that can be made at this point is that any decoder technology except the parsing/entropy decoding that is present in a decoder also necessarily needs to be present, in substantially identical functional form, in a corresponding encoder. The description of encoder technologies can be abbreviated as they are the inverse of the comprehensively described decoder technologies. Only in certain areas a more detail description is required and provided below. 
     As part of its operation, the source coder  403  may perform motion compensated predictive coding, which codes an input frame predictively with reference to one or more previously-coded frames from the video sequence that were designated as “reference frames.” In this manner, the coding engine  407  codes differences between pixel blocks of an input frame and pixel blocks of reference frame(s) that may be selected as prediction reference(s) to the input frame. 
     The local video decoder  406  may decode coded video data of frames that may be designated as reference frames, based on symbols created by the source coder  403 . Operations of the coding engine  407  may advantageously be lossy processes. When the coded video data may be decoded at a video decoder (not shown in  FIG. 4 ), the reconstructed video sequence typically may be a replica of the source video sequence with some errors. The local video decoder  406  replicates decoding processes that may be performed by the video decoder on reference frames and may cause reconstructed reference frames to be stored in the reference picture cache  405 . In this manner, the encoder  400  may store copies of reconstructed reference frames locally that have common content as the reconstructed reference frames that will be obtained by a far-end video decoder (absent transmission errors). 
     The predictor  404  may perform prediction searches for the coding engine  407 . That is, for a new frame to be coded, the predictor  404  may search the reference picture memory  405  for sample data (as candidate reference pixel blocks) or certain metadata such as reference picture motion vectors, block shapes, and so on, that may serve as an appropriate prediction reference for the new pictures. The predictor  404  may operate on a sample block-by-pixel block basis to find appropriate prediction references. In some cases, as determined by search results obtained by the predictor  404 , an input picture may have prediction references drawn from multiple reference pictures stored in the reference picture memory  405 . 
     The controller  402  may manage coding operations of the video coder  403 , including, for example, setting of parameters and subgroup parameters used for encoding the video data. 
     Output of all aforementioned functional units may be subjected to entropy coding in the entropy coder  408 . The entropy coder translates the symbols as generated by the various functional units into a coded video sequence, by loss-less compressing the symbols according to technologies known to a person skilled in the art as, for example Huffman coding, variable length coding, arithmetic coding, and so forth. 
     The transmitter  409  may buffer the coded video sequence(s) as created by the entropy coder  408  to prepare it for transmission via a communication channel  411 , which may be a hardware/software link to a storage device which would store the encoded video data. The transmitter  409  may merge coded video data from the video coder  403  with other data to be transmitted, for example, coded audio data and/or ancillary data streams (sources not shown). 
     The controller  402  may manage operation of the encoder  400 . During coding, the controller  405  may assign to each coded picture a certain coded picture type, which may affect the coding techniques that may be applied to the respective picture. For example, pictures often may be assigned as one of the following frame types: 
     An Intra Picture (I picture) may be one that may be coded and decoded without using any other frame in the sequence as a source of prediction. Some video codecs allow for different types of Intra pictures, including, for example Independent Decoder Refresh Pictures. A person skilled in the art is aware of those variants of I pictures and their respective applications and features. 
     A Predictive picture (P picture) may be one that may be coded and decoded using intra prediction or inter prediction using at most one motion vector and reference index to predict the sample values of each block. 
     A Bi-directionally Predictive Picture (B Picture) may be one that may be coded and decoded using intra prediction or inter prediction using at most two motion vectors and reference indices to predict the sample values of each block. Similarly, multiple-predictive pictures can use more than two reference pictures and associated metadata for the reconstruction of a single block. 
     Source pictures commonly may be subdivided spatially into a plurality of sample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 samples each) and coded on a block-by-block basis. Blocks may be coded predictively with reference to other (already coded) blocks as determined by the coding assignment applied to the blocks&#39; respective pictures. For example, blocks of I pictures may be coded non-predictively or they may be coded predictively with reference to already coded blocks of the same picture (spatial prediction or intra prediction). Pixel blocks of P pictures may be coded non-predictively, via spatial prediction or via temporal prediction with reference to one previously coded reference pictures. Blocks of B pictures may be coded non-predictively, via spatial prediction or via temporal prediction with reference to one or two previously coded reference pictures. 
     The video coder  400  may perform coding operations according to a predetermined video coding technology or standard, such as ITU-T Rec. H.265. In its operation, the video coder  400  may perform various compression operations, including predictive coding operations that exploit temporal and spatial redundancies in the input video sequence. The coded video data, therefore, may conform to a syntax specified by the video coding technology or standard being used. 
     In an embodiment, the transmitter  409  may transmit additional data with the encoded video. The source coder  403  may include such data as part of the coded video sequence. Additional data may comprise temporal/spatial/SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, Supplementary Enhancement Information (SEI) messages, Visual Usability Information (VUI) parameter set fragments, and so on. 
       FIG. 5  is a schematic illustrations of a general workflow  500  including interfaces IF 1  and IF 2  between an origin server  501 , a client  502 , and an ad server  503  respectively. Such general and simplified architecture illustration corresponds to embodiments described herein including signaling configurations including an in-manifest update event overcoming the technical disadvantageous discussed above, and of course, the interfaces IF 1  and IF 2  need not be direct connections but instead may be merely simplifications of one or more networked connections between those illustrated element representations. 
       FIG. 6  is a simplified flow diagram  600  regarding various embodiments including one or more mid-roll ads with technically advantageous early termination via at least features regarding the herein disclosed in-manifest features. 
     At S 60 , it is determined to proceed to S 61  at which an origin server, such as origin server  501  in  FIG. 5 , publishes an MPD containing a program, such as a main live program which may be occurring in or near real-time for example. At S 62 , it is considered whether an ad-break occurs, and if so, when it is determined that an ad-break has occurred, via mid-roll signaling such as with MPEG-DASH for example, the origin server inserts at least an in-manifest/inband MPD validity expiration event (herein also referred to simply as an “event”) to signal a need for an MPD update at S 63 , and at S 64 , when the client receives such event, the client parses the event, and, based on timing information in that event, such as one or more timers representing an initial ad-break duration and a time or frequency at which to check for updates described further below, calculates an expiration time in a timeline on which to update or check for an update to MPD data. 
     Accordingly, additionally at S 64 , when the time or frequency or signal otherwise occurs according to the event, the client requests an MPD update, from the origin server or otherwise from a resource described below and indicated by the event, before the MPD expiration time for the overall ad-break as initially reported to the client, and in response, the client receives such update, if any, and updates the clients expected MPD information as illustrated at S 65 . Such S 63 -S 65  features may occur prior to or after at least partial playing of the ad, such as via the client switching from the origin server to the ad server, such as ad-server  503  as illustrated simply in  FIG. 5 . 
     At S 65 , the client switches to the ad-break and starts streaming from the ad-server. The new MPD herein contains an in-manifest MPD validity expiration event stream which has a remote element using xlink, and the new MPD also has one or more of a minimumUpdatePeriod value either for that event stream or as inherited from an MPD@minimumUpdatePeriod value described further herein below. At S 67 , while streaming content from the ad-server, the client request MPD validity expiration EventStream, with a frequency equal to or larger than a minimumUpdatePeriod, from at least the resource noted above and as defined, for example, by xlink. Whenever the client receives a new MPD validity expiration Event from that EventStream, such as at S 68 , the client parses that new event and processes that event according to the timing model of MPD validity expiration, and the client updates the MPD before expiration time set by the MPD validity expiration, such as the otherwise end of the ad-break (termination) previously indicated. The update may signal an end of the ad-break and a switch back, as at S 69 , to the stream (e.g., live stream) via the client switching back from the ad server to the origin server or may signal one or more new parameters of the event. That is, at S 69 , the new MPD update may be determined to include an updated ad duration instructing the client to switch back to the live server at either a new early terminating moment in the timeline or immediately as an early terminating moment with respect to such one or more mid-roll of a single or sequence of mid-roll ads. 
       FIG. 7  is a simplified flow diagram  700  regarding various embodiments including one or more pre-roll ads with technically advantageous early termination via at least features regarding the herein disclosed in-manifest features. 
     At S 71 , an origin server, such as origin server  501  in  FIG. 5 , publishes an MPD containing a pre-roll ad and a program, such as a main live program which may be occurring in or near real-time for example. At S 72 , the client starts streaming the pre-roll ad from the ad-server. According to exemplary embodiments, the MPD contains an in manifest MPD validity expiration event stream which has a remove element using xlink, such as similarly described above with respect to  FIG. 6 , and the new MPD also has one or more of a minimumUpdatePeriod value either for that event stream or as inherited from an MPD@minimumUpdatePeriod value described further herein below. At S 77 , while streaming content from the ad-server, the client request MPD validity expiration EventStream, with a frequency equal to or larger than a minimumUpdatePeriod, from at least the resource noted above and as defined, for example, by xlink. Whenever the client receives a new MPD validity expiration Event from that EventStream, such as at S 78 , the client parses that new event and processes that event according to the timing model of MPD validity expiration, and the client updates the MPD before expiration time set by the MPD validity expiration, such as the otherwise end of the ad-break (termination) previously indicated. The update may signal an end of the ad-break and a switch, as at S 79 , to the stream (e.g., live stream) via the client switching back from the ad server to the origin server or may signal one or more new parameters of the event. That is, at  79 , the new MPD update may be determined to include an updated ad duration instructing the client to switch to the live server at either a new early terminating moment in the timeline or immediately as an early terminating moment with respect to such one or more pre-roll of a single or sequence of pre-roll ads. The illustration at  FIG. 7  with respect to the end at S 79  will be understood to also link to S 60  of  FIG. 6  at which further possible content delivery with respect to also one or more mid-roll ads may proceed as described above, such as with  FIG. 6 . That is, the features of  FIG. 7 , may immediately precede those of  FIG. 7 . 
     According to exemplary embodiments, such signaling may be defined, for example with an in-manifest MPD validity expiration, as follows. There is herein defined a scheme included a specific schemeIDUri that may be defined for an in-manifest MPD validity expiration such as: “urn:mpeg::dash:manifest-event:2020”, and an EventStream element carrying such events may use such URI in their @schemeIDUri. 
     Further with respect to such signaling, as similar to Inband MPD validity expiration events, same values may be used to signal a type of MPD update event as: 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 @value 
                 Description 
               
               
                   
               
             
            
               
                 1 
                 Event@messageData contains the smallest publish time for valid MPDs. 
               
               
                   
                 Event@presentationTime defines the offset from which only MPDs with publish  
               
               
                   
                 times equal or larger than the above publish time are valid.  
               
               
                   
                 The Event@duration expresses the remaining duration of Media Presentation from  
               
               
                   
                 the event time. If the event duration is 0, Media Presentation ends at the event time.  
               
               
                   
                 If 0xFFFF, the media presentation duration may be unknown. In a case in which both  
               
               
                   
                 a presentation_time_delta and an event)duration are zero, then a Media Presentation  
               
               
                   
                 may be ended.  
               
               
                 2 
                 indicates that MPD validity expiration events as with the @value = 1 noted above. In  
               
               
                   
                 addition to such indication, the message includes an MPD Patch as defined in  
               
               
                   
                 subclause 5.10.4.3 in DASHEvent.mpd field within the message_data field.  
               
               
                 3 
                 indicates that MPD validity expiration events as @value = 1 as noted above. In  
               
               
                   
                 addition to such indication, the message includes a complete MPD Patch as defined  
               
               
                   
                 in subclause 5.10.4.4 in DASHEvent.mpd field within the message_data field. 
               
               
                   
               
            
           
         
       
     
     Further, events with same id values may be considered equivalent, and therefore, receipt of a plurality of such events may result in checking whether a value is a same and then processing only one as adequate, such as per check or per some time period predetermined with respect to the event and/or client. 
     Further, there may be use of in-manifest MPD expiration events with MPD level EventStreams, and in order to completely untie the in-manifest MPD expiration events from periods, these events can be used for EventStreams that are defined at an MPD level and are independent to one or more periods according to exemplary embodiments. 
     Accordingly, by exemplary embodiments described herein, the technical problems noted above may be advantageously improved upon by one or more of these technical solutions as This disclosure introduces, among other things, an in-manifest event, which is inserted in an MPD, equivalent of an inband MPD validity expiration event. This in-manifest event may have the same properties of an inband MPD validity expiration event, and therefore the DASH client can process the in-manifest event in a way. There is also disclosed herein how the in-manifest event can be used for early termination of any of pre-roll and mid-roll ads which has an advantageous technical effect in solution to the technical problems described above regarding technical absence of desireable early termination of such ads. 
     The techniques described above, can be implemented as computer software using computer-readable instructions and physically stored in one or more computer-readable media or by a specifically configured one or more hardware processors. For example,  FIG. 8  shows a computer system  800  suitable for implementing certain embodiments of the disclosed subject matter. 
     The computer software can be coded using any suitable machine code or computer language, that may be subject to assembly, compilation, linking, or like mechanisms to create code comprising instructions that can be executed directly, or through interpretation, micro-code execution, and the like, by computer central processing units (CPUs), Graphics Processing Units (GPUs), and the like. 
     The instructions can be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, internet of things devices, and the like. 
     The components shown in  FIG. 8  for computer system  800  are exemplary in nature and are not intended to suggest any limitation as to the scope of use or functionality of the computer software implementing embodiments of the present disclosure. Neither should the configuration of components be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary embodiment of a computer system  800 . 
     Computer system  800  may include certain human interface input devices. Such a human interface input device may be responsive to input by one or more human users through, for example, tactile input (such as: keystrokes, swipes, data glove movements), audio input (such as: voice, clapping), visual input (such as: gestures), olfactory input (not depicted). The human interface devices can also be used to capture certain media not necessarily directly related to conscious input by a human, such as audio (such as: speech, music, ambient sound), images (such as: scanned images, photographic images obtain from a still image camera), video (such as two-dimensional video, three-dimensional video including stereoscopic video). 
     Input human interface devices may include one or more of (only one of each depicted): keyboard  801 , mouse  802 , trackpad  803 , touch screen  810 , joystick  805 , microphone  806 , scanner  808 , camera  807 . 
     Computer system  800  may also include certain human interface output devices. Such human interface output devices may be stimulating the senses of one or more human users through, for example, tactile output, sound, light, and smell/taste. Such human interface output devices may include tactile output devices (for example tactile feedback by the touch-screen  810 , or joystick  805 , but there can also be tactile feedback devices that do not serve as input devices), audio output devices (such as: speakers  809 , headphones (not depicted)), visual output devices (such as screens  810  to include CRT screens, LCD screens, plasma screens, OLED screens, each with or without touch-screen input capability, each with or without tactile feedback capability—some of which may be capable to output two dimensional visual output or more than three dimensional output through means such as stereographic output; virtual-reality glasses (not depicted), holographic displays and smoke tanks (not depicted)), and printers (not depicted). 
     Computer system  800  can also include human accessible storage devices and their associated media such as optical media including CD/DVD ROM/RW  820  with CD/DVD  811  or the like media, thumb-drive  822 , removable hard drive or solid state drive  823 , legacy magnetic media such as tape and floppy disc (not depicted), specialized ROM/ASIC/PLD based devices such as security dongles (not depicted), and the like. 
     Those skilled in the art should also understand that term “computer readable media” as used in connection with the presently disclosed subject matter does not encompass transmission media, carrier waves, or other transitory signals. 
     Computer system  800  can also include interface  899  to one or more communication networks  898 . Networks  898  can for example be wireless, wireline, optical. Networks  898  can further be local, wide-area, metropolitan, vehicular and industrial, real-time, delay-tolerant, and so on. Examples of networks  898  include local area networks such as Ethernet, wireless LANs, cellular networks to include GSM, 3G, 4G, 5G, 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  898  commonly require external network interface adapters that attached to certain general-purpose data ports or peripheral buses ( 850  and  851 ) (such as, for example USB ports of the computer system  800 ; others are commonly integrated into the core of the computer system  800  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  898 , computer system  800  can communicate with other entities. Such communication can be uni-directional, receive only (for example, broadcast TV), uni-directional send-only (for example CANbusto 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. 
     Aforementioned human interface devices, human-accessible storage devices, and network interfaces can be attached to a core  840  of the computer system  800 . 
     The core  840  can include one or more Central Processing Units (CPU)  841 , Graphics Processing Units (GPU)  842 , a graphics adapter  817 , specialized programmable processing units in the form of Field Programmable Gate Areas (FPGA)  843 , hardware accelerators for certain tasks  844 , and so forth. These devices, along with Read-only memory (ROM)  845 , Random-access memory  846 , internal mass storage such as internal non-user accessible hard drives, SSDs, and the like  847 , may be connected through a system bus  848 . In some computer systems, the system bus  848  can be accessible in the form of one or more physical plugs to enable extensions by additional CPUs, GPU, and the like. The peripheral devices can be attached either directly to the core&#39;s system bus  848 , or through a peripheral bus  851 . Architectures for a peripheral bus include PCI, USB, and the like. 
     CPUs  841 , GPUs  842 , FPGAs  843 , and accelerators  844  can execute certain instructions that, in combination, can make up the aforementioned computer code. That computer code can be stored in ROM  845  or RAM  846 . Transitional data can be also be stored in RAM  846 , whereas permanent data can be stored for example, in the internal mass storage  847 . Fast storage and retrieval to any of the memory devices can be enabled through the use of cache memory, that can be closely associated with one or more CPU  841 , GPU  842 , mass storage  847 , ROM  845 , RAM  846 , and the like. 
     The computer readable media can have computer code thereon for performing various computer-implemented operations. The media and computer code can be those specially designed and constructed for the purposes of the present disclosure, or they can be of the kind well known and available to those having skill in the computer software arts. 
     As an example and not by way of limitation, the computer system having architecture  1200 , and specifically the core  840  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  840  that are of non-transitory nature, such as core-internal mass storage  847  or ROM  845 . The software implementing various embodiments of the present disclosure can be stored in such devices and executed by core  840 . A computer-readable medium can include one or more memory devices or chips, according to particular needs. The software can cause the core  840  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  846  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  844 ), 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. 
     While this disclosure has described several exemplary embodiments, there are alterations, permutations, and various substitute equivalents, which fall within the scope of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise numerous systems and methods which, although not explicitly shown or described herein, embody the principles of the disclosure and are thus within the spirit and scope thereof.