CHANGE REQUEST. Status: Draft Internal Review X Community Review Agreed

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1 CHANGE REQUEST DASH-IF IOP CR 0007 rev - Current versin: 4.0 Status: Draft Internal Review X Cmmunity Review Agreed Title: Surce: Anntatin and Client Mdel fr Cntent Selectin DASH-IF IOP Supprting Cmpanies: Qualcmm Incrprated Categry: A Date: Use ne f the fllwing categries: C (crrectin) A (additin f feature) B (editrial mdificatin) Reasn fr change: Summary f change: Cnsequences if nt apprved: DASH supprts many different aspects t add Anntatin fr Adaptatin Sets. The reasn fr this is that different use cases have been defined that may be specific fr specific ecsystems. Hwever, fr cnsistent interperability, DASH-IF IOP misses clear guidelines fr the cntent generatin as well as fr the client implementatin t select audi and vide tracks at startup and peratins. Therefre, a cnsistent signalling framewrk is necessary. Prvide a list f permitted Adaptatin Set anntatins in DASH-IF IOP Prvide requirements and recmmendatins fr cntent authring Prvide a client reference implementatin that makes use f the anntatin Nt applicable. Sectins affected: Other cmments: 3.2.4, 3.9 (new) Disclaimer: This dcument is nt yet final. It is prvided fr public review until the deadline mentined belw. If yu have cmments n the dcument, please submit cmments by ne f the fllwing means: - at the github repsitry (public at r - dashif+ip@grupspaces.cm Please add a detailed descriptin f the prblem and the cmment. Cmmenting Deadline: April 30 th, 2017 Expected Publicatin: June 30 th, 2017 Based n the received cmments a final dcument will be published latest by the expected publicatin date belw, integrated in a new versin f DASH-IF IOP if the fllwing additinal criteria are fulfilled: - All cmments frm cmmunity review are addressed - The relevant aspects fr the Cnfrmance Sftware are dcumented - IOP test cases are prvided

2 FIRST CHANGE: Presence f Attributes and Elements Elements and attributes are expected t be present fr certain Adaptatin Sets and Representatins t enable suitable initial selectin and switching. Simple rules are prvided in this sectin. A detailed descriptin f multi-track cntent ffering is prvided in clause 3.9. Specifically the fllwing applies: Fr any Vide Adaptatin Sets as defined in Errr! Reference surce nt fund. the fllwing attributes shall be if all Representatins have the same if all Representatins have the same if all Representatins have the same frame Nte: The shuld be used such that they describe the target display size. This means that they may exceed the actual largest size f any cded Representatin in ne Adaptatin Set. Fr any Representatin within an Vide Adaptatin Sets as defined in Errr! Reference surce nt fund. the fllwing attributes shall be if nt present in AdaptatinSet if nt present in AdaptatinSet if nt present in AdaptatinSet Nte: attributes shuld indicate the vertical and hrizntal sample cunt f encded and crpped vide samples, nt the intended display size in pixels. Fr Adaptatin Set r fr any Representatin within an Vide Adaptatin Sets as defined in Errr! Reference surce nt fund. the shall either nt be present r shall be set t "prgressive". Fr any Audi Adaptatin Sets as defined in Errr! Reference surce nt fund. the fllwing attributes shall be Fr any Representatin within an Audi Adaptatin Sets as defined in Errr! Reference surce nt fund. the fllwing elements and attributes shall be if nt present in AdaptatinSet element AudiChannelCnfiguratin, if nt present in AdaptatinSet element

3 SECOND CHANGE: 3.10 Anntatin and Client Mdel fr Cntent Selectin Intrductin Beynd the ability t prvide multiple Representatins f the same media cmpnent in ne Adaptatin Set, DASH MPDs als prvide the functinality t anntate Adaptatin Sets, such that clients can typically select at mst ne Adaptatin Set fr each media type, based n the encding and descriptin prvided in the MPD. The selectin is based n client capabilities, client preferences, user preferences and pssibly als interactive signalling with the user. Typically, the signalling and selectin is independent f the cdec in use. This clause prvides requirements and recmmendatins fr labelling Adaptatin Sets, if multiple tracks are ffered. Nte that there may be cases that multiple Representatins frm different Adaptatin Sets per media type are chsen fr playback, fr example if there is a dependency acrss Representatins. In ther cases, a DASH client may be asked t select mre than ne Adaptatin Set per media type based n applicatin decisins. Multiple Adaptatin Sets may be ffered t prvide the same cntent in different encdings, fr example different cdecs; r different surce frmats, fr example ne Adaptatin Set encded frm a standard dynamic range master and anther encded frm a high dynamic range vide master. Alternatively, Adaptatin Sets may describe different cntent, fr example different languages, r different camera views f the same event that are prvided in a synchrnized presentatin in ne MPD. Prper labelling f Adaptatin Sets in MPDs cnfrming t DASH-IF IOPs is essential in rder t enable cnsistent client implementatins. In additin, als a mdel is needed n hw the client makes use f the anntatin fr a cntent authrs t understand the expected effect f the labelling n playback Adaptatin Set Labeling Optins fr Selectin DASH in ISO/IEC [1] prvides many ptins fr labelling Adaptatin Sets. In rder t prvide mre cnsistency in the cntext f DASH-IF, Table 1 prvides a restricted subset f labels fr which DASH-IF IOPS prvide interperability, i.e. n hw they are expected t be used by the cntent authrs and hw they are expected t be used by clients. The table prvides infrmatin specific fr each media type. It is expected that DASH clients fllwing the DASH IOPs recgnize the descriptrs, elements, and attributes as dcumented in Table 1. Other rganizatins may define additinal descriptrs r elements, as well as prcessing mdels fr clients. Table 1 Adaptatin Set Attributes and Elements and Usage in DASH-IF IOPs (see ISO/IEC [1]) Attribute r Element Use fr media type Detailed Usage in DASH-IF IOPs General Attributes and Elements fr any media O See ISO/IEC [1], clause Table 9. If nt present, it is inherited frm the MPD r Perid. This may be used fr example t signal extensins fr new media prfiles in the MPD. At least ne f the values defined in Table 1 and Table 2 f this dcument shall be present, r inferred frm MPD r Perid O See ISO/IEC [1], clause Table 5. The attribute may be used and shall be different at least fr different media type. If present, the value shall be greater than 0. Fr all Adaptatin Sets in

4 the same grup, the Grup shall be the same. Only ne Representatin in a Grup is intended t be presented at a time. Hwever, tw r multiple grups f the same media type may exist, if the cntent authr expects simultaneus presentatin f tw r mre Representatin f the same media OD default =1 See ISO/IEC [1], clause Table 9. This attribute shuld be used t dis-ambiguate Adaptatin Sets within ne grup fr selectin and expresses the preference f the MPD authr n selecting Adaptatin Sets fr which the DASH client des make a decisin therwise. Examples include tw vide cdecs prviding the same cntent, but ne f the tw prvides higher cmpressin efficiency and is therefre preferred by the MPD authr. CntentPrtectin 0 N See ISO/IEC [1], clause Table 9. If this element is present, then the cntent is prtected. If nt present, n cntent prtectin is applied. Fr details and usage please refer t clause 7.

5 Label 0 N See ISO/IEC [1], clause Table 9. This element enables t prvide a textual descriptin f the cntent. This element shuld be used if cntent authr expects that clients supprts UI fr selectin. Hwever, this element must nt be used as the sle differentiating element as at start-up n user interactin is available. EssentialPrperty 0 N See ISO/IEC [1], clause Table 9 specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr fr prcessing the cntaining element. The fllwing schemes are expected t be recgnized by a DASH-IF client independent f the media type: (see clause 3.2.9) SupplementalPrperty See ISO/IEC [1], clause Table 9 specifies infrmatin abut the cntaining element that is cnsidered supplemental by the Media Presentatin authr fr prcessing the cntaining element. In n case this infrmatin is used fr differentiatin, the infrmatin may used by a DASH client fr imprved peratin. The fllwing schemes are expected t be recgnized by a DASH-IF client independent f the media type: - urn:mpeg:dash:adaptatin-setswitching:2016 (see clause 3.8) - (see clause 3.2.9) - urn:mpeg:dash:perid-cntinuity:2015 (see clause ) - urn:mpeg:dash:perid-cnnectivity:2015 (see clause ) Viewpint 0 N Prvides the ability t indicate that media differentiates by a different ViewPint. Attributes and Elements fr media type Vide If nt present, n view pint is assigned and n differentiatin is taken. Fr detailed usage f this descriptr, see M See ISO/IEC [1], clause Table 9. Shall be set t M See ISO/IEC [1], clause Table 9. This prvides the cdec that is used fr the Adaptatin Set. It expresses the cdec that is necessary t playback all Representatins in ne Adaptin Set. The fllwing cdecs are expected t be recgnized by a DASH-IF client: Cdecs in Table 16

6 Cdecs in Table O See ISO/IEC [1], clause Table 5. shall be present, if the picture aspect rati is a differentiating parameter in the O See ISO/IEC [1], clause Table 5. This values shuld be present t express the maximum width in samples after decder sample crpping f any Representatin cntained in the Adaptatin Set. The value shuld be the maximum hrizntal sample cunt f any SPS in the cntained O See ISO/IEC [1], clause Table 5. This values shuld be present t express the maximum height in pixel f any Representatin cntained in the Adaptatin Set. The value shuld be the maximum hrizntal sample cunt f any SPS in the cntained O See ISO/IEC [1], clause Table 5. This values shuld be present t express the maximum frame rate, i.e. the maximum value f any entry in the Decder cnfiguratin recrd f the signaled frame rate, if cnstant frame rate is prvided. cntained in the Adaptatin OD Default: prgres sive See ISO/IEC [1], clause Table 5. This value is expected t be nt present. If present, it is expected t be set t "prgressive". EssentialPrperty 0 N See ISO/IEC [1], clause Table 9. specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr fr prcessing the cntaining element. The fllwing schemes are expected t be recgnized by a DASH-IF client fr vide: urn:mpeg:mpegb:cicp:<parameter> as defined in ISO/IEC Errr! Reference surce nt fund. and <Parameter> ne f the fllwing: ClurPrimaries, TransferCharacteristics, r MatrixCefficients Accessibility 0 N See ISO/IEC [1], clause Table 9. In DASH-IF IOPs tw schemes fr accessibility are defined. - the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type vide tgether with the Accessibility descriptr:

7 sign captins - the scheme when CEA-608 is used as defined in clause , set t "urn:scte:dash:cc:cea-608:2015" Rle 0 N See ISO/IEC [1], clause Table 5. In DASH-IF IOPs nly the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type vide tgether with the Rle descriptr: - captin - subtitle - main - alternate - supplementary - sign - emergency If nt present, the rle is assumed t be alternate Rating 0 N See ISO/IEC [1], clause Table 5. Attributes and Elements fr media type Audi DASH-IF IOPs d nt define a Rating scheme. If present, Adaptatin Sets using this descriptr may be ignred by the DASH-IF IOP M See ISO/IEC [1], clause Table 9. Shall set t M See ISO/IEC [1], clause Table 9. This prvides the cdec that is used fr the Adaptatin Set. It expresses the cdec that is necessary t playback all Representatins in ne Adaptin Set. The fllwing cdecs are expected t be recgnized by a DASH-IF client: Cdecs in Table 19 Cdecs in Table 22 Cdecs in Table 23 Cdecs in Table 24 Cdecs in Table 25 Cdecs in Table 26

8 Nte: additinal values need t be added with new cdecs being O See ISO/IEC [1], clause Table 5. The language shuld be present. If nt present, the language is unknwn r n language O See ISO/IEC [1], clause Table 9. This attribute may be present t supprt utput devices that may nly be able t render specific values. AudiChannelCnfiguratin 0 N See ISO/IEC [1], clause Table 9. specifies infrmatin abut the Audi channel cnfiguratin.the fllwing schemes are expected t be recgnized by a DASH-IF client fr audi: urn:mpeg:dash:23003:3:audi_channel_cnfig uratin:2011 as defined in ISO/IEC [1], urn:mpeg:mpegb:cicp:<parameter> as defined in ISO/IEC Errr! Reference surce nt fund. and <Parameter> ne f the fllwing: OutputChannelPsitin r ChannelCnfiguratin tag:dlby.cm,2014:dash:audi_channel_cnf iguratin:2011 as defined at Nte: Anntatin may be different fr ther cdecs and may be updated EssentialPrperty 0 N See ISO/IEC [1], clause Table 9. specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr fr prcessing the cntaining element. The fllwing schemes are expected t be recgnized by a DASH-IF client fr audi: urn:mpeg:dash:audi-receiver-mix:2014 as defined in ISO/IEC , clause Accessibility 0 N See ISO/IEC [1], clause Table 5. In DASH-IF IOPs nly the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type audi tgether with the Accessibility descriptr: descriptin enhanced-audi-intelligibility Rle 0 N See ISO/IEC [1], clause Table 5. In DASH-IF IOPs nly the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , ,

9 urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type audi tgether with the Accessibility descriptr: - main - alternate - supplementary - cmmentary - dub - emergency If nt present, the rle is assumed t be alternate Rating 0 N See ISO/IEC [1], clause Table 5. Attributes and Elements fr media type Subtitle DASH-IF IOPs d nt define a Rating scheme. If present, Adaptatin Sets using this descriptr may be ignred by the DASH-IF IOP M See ISO/IEC [1], clause Table 9. Shall set t "applicatin/mp4" r O See ISO/IEC [1], clause Table 9. This prvides the cdec that is used fr the Adaptatin Set. It expresses the cdec that is necessary t playback all Representatins in ne Adaptin Set. The fllwing cdecs are expected t be recgnized by a DASH-IF client: Cdecs in Table 20 Nte: mre need t be added with new cdecs being O See ISO/IEC [1], clause Table 5. The language shuld be present. If nt present, the language is unknwn r n language applies. Accessibility 0 N See ISO/IEC [1], clause Table 5. In DASH-IF IOPs nly the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type subtitle tgether with the Accessibility descriptr: - captin - sign

10 Rle 0 N See ISO/IEC [1], clause Table 5. In DASH-IF IOPs nly the Rle scheme as defined by MPEG-DASH shuld be used as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 The DASH rle scheme and with the fllwing values is expected t be recgnized by a DASH-IF client fr media type subtitle tgether with the Accessibility descriptr: - main - alternate - supplementary - cmmentary - dub - descriptin - emergency If nt present, the rle is assumed t be alternate Cntent Mdel In rder t supprt the cntent authr in prviding cntent in a cnsistent manner, Figure 1 prvides a cnceptual cntent mdel fr DASH cntent in ne Perid f an MPD. The cntent may be described by an Asset Identifier as a whle and may cntain different media types, vide, audi, subtitle and applicatin types. Signalling f media types is ut f scpe fr this sectin, fr details refer t sectin Figure 1 Cntent Mdel fr DASH Multitrack Within each media type, the cntent authr may want t ffer different cntent alternatives that are time-aligned, but each alternative represents different cntent. Autmatic selectin f the cntent alternative is nt expected t be dne by the DASH client as the client wuld nt have sufficient infrmatin t make such decisins. Hwever, the selectin is

11 expected t be dne by cmmunicatin with an applicatin r the user, typically using a user interface apprpriate fr selectin. Hwever, in the absence f this external cmmunicatin, r at startup, the DASH client still needs t playback cntent and therefre benefits frm infrmatin f what is the default cntent. Such signalling shuld be prvided by the cntent authr. Such default cntent is referred t as main cntent, whereas any cntent that is nt main is referred t as alternative. There may be multiple alternatives which may need t be distinguished. We define main and alternative cntent. Examples fr such are synchrnized camera views f ne master cntent. The main camera view is prvided as main cntent, all ther views as alternative cntent. Furthermre, it may be that cntent f different media type is linked by the cntent authr, t express that tw cntent f different media type are preferably played tgether. We define assciated cntent fr this purpse. As an example, there may be a main cmmentatr assciated with the main camera view, but fr a different camera view, a different assciated cmmentary is prvided. In additin t semantical cntent level differentiatin, each cntent alternative may be prepared with different target versins, based n cntent preparatin prperties (dwnmix, subsampling, translatin, suitable fr trick mde, etc.), client preferences (decding r rendering preferences, e.g. cdec), client capabilities (DASH prfile supprt, decding capabilities, rendering capabilities) r user preferences (accessibility, language, etc.). In simple AV playut and in the absence f guidance frm an applicatin, a cntent authr expects that the DASH client selects at mstne target versin fr each Grup taking int accunt its capabilities and preferences and the capabilities and preferences f the media subsystem. Hwever, an applicatin may bviusly select multiple Grups and playut different vide Adaptatin Sets t supprt fr example picture-in-picture, multi-angle and s n. In additin, the cntent authr may als prvide pririties fr target versins, if the receivers supprts multiple f thse. Typical examples are that the cntent is prepared fr H.264/AVC and H.265/HEVC capable receivers, and the cntent authr prefers the selectin f the H.265/HEVC versin as its distributin is mre efficient. A device supprting bth decders may then chse the ne with higher pririty signalled by the cntent authr. In a similar versin, the same cntent may be prvided in different languages. In this case it can still be expected that the language can be autmatically selected by the client, s it is assigned t a target versin. Again a cntent authr may express pririties n languages, fr example preferring the native language ver a dubbed ne. Languages may be cnsidered as alternative cntent as well, but as lng as autmatic selectin can be prvided, it may be cnsidered as different target versins. Hence fr each cntent f ne media type, different target versins may exist and the anntatin f the cntent expressed that it is expected that autmated selectin can be dne. Each target versin is preferably accumulated in ne Adaptatin Set, with exceptins such as scalable cdecs. Finally, in the cntent mdel, each f the target versin typically has multiple Representatins that are prepared t enable dynamic switching. This aspect is utside the scpe f this sectin as switching by the client is expected t be dne independent f the media type as well as the target versin, primarily using the bandwidth and pssibly abstract quality infrmatin. Hwever, the signalling n the target versins may prvide infrmatin n hw t distribute the available bitrate acrss different media types. Based n this cntent mdel and the available elements, attributes and descriptrs frm Table 1, requirements and recmmendatins are prvided fr Adaptatin Set Signalling t address main and alternative cntent, assciated cntent as well as different target versins. Based n the signalling, a client decisin mdel is develped that may serve a cntent prvider as a reference client t test if the anntatin prvided in the MPD prvides the prper results Signalling Requirements and Recmmendatins General Assuming the cntent authr can map its cntent t the abve cntent mdel, this sectin prvides signalling requirements and recmmendatins fr such cntent, such that the cntent authr can expect prper playback f its cntent fr DASH-IF IOP clients In general, if multiple Adaptatin Sets fr ne media types are prvided, sufficient infrmatin shuld be prvided such that a DASH client make prper selectins, either autmatically cmmunicating with it s platfrm r in cmmunicatin with the applicatin/user.

12 Alternative Cntent Signalling If a Perid cntains alternative cntent fr ne media type, then the alternatives shuld be differentiated. In additin, ne f the alternatives shuld be prvided as main cntent. The main cntent is intended t be selected by the client in the absence f any ther infrmatin, e.g. at startup r if the anntatin f the cntent cannt be used. Main cntent is signaled by using the Rle descriptr with Rle scheme as defined by MPEG-DASH in ISO/IEC , , urn:mpeg:dash:rle:2011 with value set t main. Alternative cntent is signaled by using the Rle descriptr with Rle scheme as defined by MPEG-DASH in ISO/IEC , , urn:mpeg:dash:rle:2011 with value set t alternative. If an Adaptatin Set des nt include either f the tw signals, it is assumed t be main cntent. The alternative cntent may be selected by the client, if the client des have the capability t select alternatives, typically by either cmmunicating with the applicatin r with the user. If main and alternative cntent is prvided in the Media Presentatin, then cntent alternatives shall be signaled by at least ne f the tw: - a ViewPint descriptr. If ViewPint is used fr differentiatin, then at least each alternative Adaptatin Set f the same media type shall include a ViewPint with the same value The cntent is differentiated by different values fr attribute in the descriptr fr different cntent. - a Label element. If Label is used fr differentiatin, then at least each alternative Adaptatin Set shall include a Label with the same value The cntent is differentiated by different values fr the Label element. A ViewPint descriptr is typically used if a target applicatin (identified by the the value is expected that can make use f the values in the ViewPint descriptr. A Label element is typically used if the DASH client can prvide a user interactin Assciated Cntent Signalling Fr assciated cntent f different media types, the ViewPint descriptr is used. If different media types all belng t ne cntent alternative, they share the same View Pint descriptr, i.e. the same value and Nte als that even if the DASH client des nt understand the value it wuld stll bey the rules fr assciated selectin. The DASH client may fr example use the labels f different vide alternatives fr selectin, and play the audi accrding t ViewPint assciatin Media-type Independent Target Versin Anntatin Adaptatin Sets within ne media type and cntent alternative shall differ by at least by ne f the fllwing anntatin labels - CntentPrtectin (need t prvide sme details n what the ptins are: present, nt-present, different schemes) wrk with cntent prtectin task frce - EssentialPrperty (nt-present, trickmde, a media type specific value, unknwn value, which may be extended) - Any f thse dcumented in sectin fr media type vide, sectin fr media type audi and fr media type subtitle. Adaptatin Sets with elements EssentialPrperty nt using any f the permitted values in this dcument shuld nt be present. In additin, Adaptatin Sets within ne media type and cntent alternative shuld differ by different values If nt present r nn-differentiating values are prvided, then the cntent authr shuld expect a randm selectin f Adaptatin Sets in case it is able t handle multiple Adaptatin Sets within ne media type and cntent alternative.

13 Vide Target Versin Anntatin Vide Adaptatin Sets f ne cntent alternative shall differ by at least by ne f the fllwing anntatin specifies the cdecs present within the Representatin. The cdecs parameters shall als include the prfile and level infrmatin where specifies the hrizntal and vertical visual presentatin size f the vide media specifies the maximum frame rate f the vide media type EssentialPrperty: specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr selecting this cmpnent. The fllwing different ptins exist: nt-present; generic parameters frm abve; list in Table 1; unknwn value, which may be extended Accessibility descriptr with Rle scheme as defined by MPEG-DASH in ISO/IEC , , urn:mpeg:dash:rle:2011 with value set t sign, captin r subtitle. The presence f captin r subtitle signals pen ( burned in ) captins r subtitles. the scheme when CEA-608 is used as defined in clause , set t "urn:scte:dash:cc:cea-608:2015" indicating the use f CEA-608 captins carried in SEI messages. Adaptatin Sets with elements Rating and FramePacking as well nt set t prgressive shuld nt be present. The cntent authr shuld use attribute in rder t express preference fr vide selectin. If captins are burned in with vide Adaptatin Set, and ther vide Adaptatin Sets are available as well, the cntent authr shuld use t indicate the selectin pririty f this Adaptatin Set cmpared t thers withut burned in captins Audi Target Versin Anntatin Audi Adaptatin Sets f ne cntent alternative shall differ by at least by ne f the fllwing anntatin specifies the cdecs present within the Representatin. The cdecs parameters shall als include the prfile and level infrmatin where specifies the dminant language f the audi If nt present, the language is unknwn r n language specifies the maximum sampling rate f the cntent If nt present, the audi sampling rate is unknwn The AudiChannelCnfiguratin specifies supprt fr utput devices that may nly be able t render specific values. This element shuld be present. If n AudiChannelCnfiguratin is present, then this value is unknwn. If the cdec is anyne in Table 19, Table 24, Table 25 r Table 26, then any f the fllwing may be used urn:mpeg:dash:23003:3:audi_channel_cnfiguratin:2011 as defined in ISO/IEC [1],

14 urn:mpeg:mpegb:cicp:<parameter> as defined in ISO/IEC Errr! Reference surce nt fund. and <Parameter> ne f the fllwing: OutputChannelPsitin r ChannelCnfiguratin If the cdec is ec-3 r ac-4 accrding t Table 22, then the fllwing shall be used tag:dlby.cm,2014:dash:audi_channel_cnfiguratin:2011" as defined at (see sectin ) If the cdec is anyne in Table 23, then refer t DTS specificatin 9302K62400 Errr! Reference surce nt fund. EssentialPrperty: specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr selecting this cmpnent. The fllwing different ptins exist: nt-present; generic parameters frm abve; unknwn value, which may be extended Accessibility descriptr with Rle scheme as defined by MPEG-DASH in ISO/IEC , , urn:mpeg:dash:rle:2011 with value set t descriptin r enhanced-audiintelligibility. Adaptatin Sets with element Rating shuld nt be present Subtitle Target Versin Anntatin Subtitle Adaptatin Sets f ne cntent alternative shall differ by at least by ne f the fllwing anntatin specifies the cdecs present within the Representatin. The cdecs parameters shall als include the prfile and level infrmatin where specifies the language f the subtitle If nt present, the language is unknwn r n language applies EssentialPrperty: specifies infrmatin abut the cntaining element that is cnsidered essential by the Media Presentatin authr selecting this cmpnent. The fllwing different ptins exist: nt-present; generic parameters frm abve; unknwn value, which may be extended Accessibility descriptr with Rle scheme as defined by MPEG-DASH in ISO/IEC , , urn:mpeg:dash:rle:2011 with value set t descriptin r captin. Adaptatin Sets with element Rating shuld nt be present Other Anntatin, Auxiliary Data In additin t selectin relevant data, the Adaptatin Set may als signal additinal auxiliary infrmatin. Auxiliary infrmatin is expressed by - The Rle descriptr with the Rle scheme as defined by MPEG-DASH as defined in ISO/IEC , , urn:mpeg:dash:rle:2011 with the fllwing values: captin subtitle main alternate supplementary sign

15 emergency dub - The Supplemental descriptr with pairs: set t " and the value attribute f the Adaptatin Set t which these trick mde Representatins belng. Perid-cntinuus Adaptatin Sets by using set t "urn:mpeg:dash:perid-cntinuity:2015" with f the descriptr matching the value f f a Adaptatin Set that is cntained in the MPD, Perid-cnnected Adaptatin Sets by using set t "urn:mpeg:dash:perid-cnnectivity:2015" with f the descriptr matching the value f f a Adaptatin Set that is cntained in the MPD, Switching acrss Adaptatin set t urn:mpeg:dash:adaptatinset-switching:2016 and is a cmma-separated list f Adaptatin Set IDs that may be seamlessly switched t frm this Adaptatin Set Client Prcessing Reference Mdel Intrductin The fllwing client mdel serves tw purpses: - In the absence f ther infrmatin, the fllwing client mdel may be implemented in a DASH client fr the purpse f selectin f Adaptatin Set fr playut - A cntent authr may use the mdel t verify that the anntatin is prperly dne in rder t get the desired client behaviur. In the mdel it is assumed that the client can get sufficient infrmatin n at least the fllwing prperties: - Fr each cdec in string, the DASH client can get infrmatin if the media playback platfrm can decde the cdec as described in the string. The answer shuld be yes r n. - Fr each DRM system in the XXX string, the DASH client can get infrmatin if the media playback platfrm can handle this DRM as described in the string. The answer shuld be yes r n. - the DASH client can get infrmatin n the media playback platfrm and rendering capabilities in terms f the maximum spatial reslutin fr vide that can be handled the maximum frame rate fr vide that can be handled the audi channel cnfiguratin f the audi system the audi sampling rate f the audi system - the preferred language f the system - Accessibility settings fr captins, subtitles, audi descriptin, enhanced audi intelligibility, - Ptentially preferences n media playback and rendering f the platfrm Nte f any f these functinalities are nt fulfilled, then it may still be functinal, but it may nt result in the full experience as prvided by the cntent authr. As an example, if the DASH client cannt determine the preferred language, it may just use the selectin pririty fr language selectin.

16 Generic Prcessing Mdel The DASH client uses the MPD and finds the Perid that it likes t jin, typically the first ne fr On-Demand cntent and the ne at the live edge fr live cntent. In rder t select the media t be played, the DASH client assumes that the cntent is ffered accrding t the cntent mdel abve. 1. The DASH client lks fr main cntent, i.e. any Adaptatin Set with anntatin Rle@schemeIdURI="urn:mpeg:dash:rle:2011" and Rle@value="alternative" is excluded initially fr selectin. Nte that in this mdel it is assumed that immediate startup is desired. If the DASH client wants t g ver the alternatives upfrnt befre starting the service, then the sequence is slightly different, but still fllws the remaining principles. 2. DASH Client checks each Adaptatin Set fr the supprted capabilities f the platfrm Cdec supprt DRM supprt Rendering capabilities If any f the capabilities are nt supprted, then the Adaptatin Set is excluded frm the selectin prcess. 3. The DASH client checks if it supprts fr CEA-608 rendering as defined in If nt supprted, any accessibility descriptr with remved. Nte that the Adaptatin Set is maintained as it may used fr regular vide decding. 4. DASH Client checks is there are any specific settings fr accessibility in the user preferences If captins are requested by the system, the DASH client extracts all vide Adaptatin Sets that have an Accessibility descriptr assigned with either urn:mpeg:dash:rle:2011 urn:scte:dash:cc:cea-608:2015" (burned-in captins and SEI-based), as well as all subtitle Adaptatin Sets that have an Accessibility descriptr assigned with either urn:mpeg:dash:rle:2011 and makes thse available fr Adaptatin Sets that can be selected by the DASH client fr captin supprt. If multiple captin Adaptatin Sets remain, the DASH client remves all Adaptatin Sets frm the selectin that are nt in the preferred language, if language settings are prvided in the system. If n language settings in the system are prvided, r nne f the Adaptatin Sets meets the preferred languages, nne f the Adaptatin Sets are remved frm the selectin. Any Adaptatin Sets that d nt cntain language anntatin are remved, if any f the remaining Adaptatin Sets prvides prper language settings. If still multiple captin Adaptatin Sets remain, then the nes with the highest value is chsen. If still multiple captin Adaptatin Sets remain, then the DASH client makes a randm chice n which captin t enable. else if n captins are requested the Accessibility element signaling captins may be remved frm the Adaptatin Set befre cntinuing the selectin. If sign language is requested all vide Adaptatin Sets that have an Accessibility descriptr assigned are made available fr sign language supprt.

17 else if n sign language is requested the Adaptatin Set signaling sign language with the Accessibility element may be remved frm the Adaptatin Set befre cntinuing the selectin. If audi descriptins are requested all vide Adaptatin Sets that have an Accessibility descriptr assigned are made available fr audi descriptin supprt. else if n audi descriptins are requested the Adaptatin Set signaling audi descriptins with the Accessibility element may be remved frm the Adaptatin Set befre cntinuing the selectin. If enhanced audi intelligibility is requested all audi Adaptatin Sets that have an Accessibility descriptr assigned are made available fr enhanced audi intelligibility supprt. else if enhanced audi intelligibility are requested the Accessibility element may be remved frm the Adaptatin Set befre cntinuing the selectin. 5. If vide rendering is enabled, based n the remaining vide Adaptatin Sets the client selects ne as fllws: Any Adaptatin Set fr which an Essential Descriptr is present fr which the scheme r value is nt understd by the DASH client, is excluded frm the selectin Any Adaptatin Set fr which an Essential Descriptr is present fr which the scheme is is excluded frm the initial selectin If still multiple vide Adaptatin Sets remain, then the nes with the highest value is chsen. If still multiple vide Adaptatin Sets remain, then the DASH client makes a chice fr itself, pssibly n a randm basis. Nte that an Adaptatin Set selectin may include multiple Adaptatin Sets, if Adaptatin Set Switching is signaled. Hwever, the selectin is dne fr nly ne Adaptatin Set. 6. If audi rendering is enabled, based n the remaining audi Adaptatin Sets the client selects ne as fllws: Any Adaptatin Set fr which an Essential Descriptr is present fr which the scheme r value is nt understd by the DASH client, is excluded frm the selectin If multiple audi Adaptatin Sets remain, the DASH client remves all Adaptatin Sets frm the selectin that are nt in the preferred language, if language settings are prvided in the system. If n language settings in the system are prvided, r nne f the Adaptatin Sets meets the preferred languages, nne f the Adaptatin Sets are remved frm the selectin. Any Adaptatin Set that des nt cntain language anntatin are remved, if any f the remaining Adaptatin Sets prvides prper language settings. If still multiple audi Adaptatin Sets remain, then the nes with the highest value is chsen. If still multiple audi Adaptatin Sets remain, then the DASH client makes a chice fr itself, pssibly n a randm basis. Nte that an Adaptatin Set may include multiple Adaptatin Sets, if Adaptatin Set Switching r receiver mix is signaled. Hwever, the selectin is dne fr nly ne Adaptatin Set.

18 7. If subtitle rendering is enabled, based n the subtitle Adaptatin Sets the client selects ne as fllws: Any Adaptatin Set fr which an Essential Descriptr is present fr which the scheme r value is nt understd by the DASH client, is excluded frm the selectin If multiple subtitle Adaptatin Sets remain, the DASH client remves all Adaptatin Sets frm the selectin that are nt in the preferred language, if language settings are prvided in the system. If n language settings in the system are prvided, r nne f the Adaptatin Sets meets the preferred languages, nne f the Adaptatin Sets are remved frm the selectin. Any Adaptatin Set that des nt cntain language anntatin are remved, if any f the remaining Adaptatin Sets prvides prper language settings. If still multiple subtitle Adaptatin Sets remain, then the nes with the highest value is chsen. If still multiple subtitle Adaptatin Sets remain, then the DASH client makes a chice fr itself, pssibly n a randm basis. 8. If the DASH client has the ability t pssibly switch t alternative cntent, then alternative cntent may be selected either thrugh the Label functin r the ViewPint functinality. This selectin may be dne dynamically during playut and the DASH client is expected t switch t the alternative cntent. Once all alternative cntent is selected, the prcedures fllwing frm step 2 nwards apply. 9. At Perid bundary a DASH client initially lks fr a Perid cntinuity r cnnectivity, i.e. des the Perid include an Adaptatin Set that is a cntinuatin f the existing ne. If nt present it will g back t step 1 and execute the decisin lgic.