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Content for  TS 26.118  Word version:  18.0.0

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5.2 Video Media Profiles  5.2.1 Introduction and Overview  5.2.2 Basic Video Media Profile  5.2.2.1 Overview  5.2.2.2 File Format Signaling and Encapsulation  5.2.2.3 DASH Integration  5.2.2.3.1 Definition  5.2.2.3.2 Additional Restrictions for DASH Representations  5.2.2.3.3 DASH Adaptation Set Constraints  5.2.3 Main Video Media Profile  5.2.3.1 Overview  5.2.3.2 File Format Signaling and Encapsulation  5.2.3.3 DASH Integration  5.2.3.3.1 Definition  5.2.3.3.2 Additional Restrictions for DASH Representations  5.2.3.3.3 DASH Adaptation Set Constraints  5.2.3.3.4 Adaptation Set Ensembles for Viewport-Optimized offering  5.2.3.3.4.1 Introduction   5.2.3.3.4.2 Definition and Adaptation Set Signalling   5.2.3.3.4.3 Representation Constraints in an Ensemble   5.2.3.3.4.4 Adaptation Set Constraints in an Ensemble   5.2.4 Advanced Video Media Profile  5.2.4.1 Overview  5.2.4.2 File Format Signaling and Encapsulation  5.2.4.3 DASH Integration  5.2.4.3.1 Definition  5.2.4.3.2 Additional Restrictions for DASH Representations  5.2.4.3.3 DASH Adaptation Set Constraints  5.2.4.3.4 Adaptation Set Constraints for Viewport Selection 
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5.2  Video Media Profiles  p. 40

5.2.1  Introduction and Overview  p. 40

This clause defines the media profiles for video. Media profiles include specification on the following:
  • Elementary stream constraints based on the video operation points defined in clause 5.1.
  • File format encapsulation constraints and signalling including capability signalling. The defines to a 3GPP VR Track as defined above.
  • DASH Adaptation Set constraints and signalling including capability signalling. This defines a DASH content format profile.
Table 5.2-1 provides an overview of the Media Profiles defined in the remainder of clause 5.2.
Media Profile Operation Point Sample Entry DASH Integration
Basic VideoBasic H.264/AVCresv
avc1		Single Adaptation Set
Single Representation streaming
Main VideoMain H.265/HEVC or Main 8K H.265/HEVCresv
hvc1		Single or Multiple independent Adaptation Sets offered
Single Representation streaming
Advanced VideoFlexible H.265/HEVCresv
hvc1, hvc2		Single or Multiple dependent Adaptation Sets offered Single or Multiple representation streaming
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5.2.2  Basic Video Media Profile  p. 41

5.2.2.1  Overview  p. 41

The Basic Video Media Profile permits to download and stream elementary streams for VR content generated according to the H.264/AVC Basic Operation Point as defined in clause 5.1.4. This enables reuse of the avc1 sample entry as for example also used in the TV Video Profiles in TS 26.116. It also permits to reuse streaming the VR video content in an adaptive manner by offering multiple switchable Representations in a single Adaptation Set in a DASH MPD.
For content generation guidelines for this media profile refer to Annex A.2.3.
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5.2.2.2  File Format Signaling and Encapsulation  p. 41

3GP VR Tracks conforming to this media profile used in the context of the specification shall conform to ISO BMFF [17] with the following further requirements:
  • The bitstream included on the track shall comply to the Bitstream requirements and recommendations for the Basic H.264/AVC Operation Point as defined in clause 5.1.4.
  • The sample entry type of each sample entry of the track shall be equal to 'resv'.
  • The scheme_type value of SchemeTypeBox in the RestrictedSchemeInfoBox shall be 'podv', and all instances of Compatible­Scheme­TypeBox defined in ISO/IEC 23090-2 [13] in the same Restricted­Scheme­Info­Box shall include at least the scheme_type value 'erpv'.
  • The untransformed sample entry type shall be equal to 'avc1' as defined in ISO/IEC 14496-15 [9].
  • The Track Header Box ('tkhd') shall obey the following constraints:
  • The width and height fields for a visual track shall specify the track's visual presentation size as fixed-point 16.16 values expressed in on a uniformly sampled grid (commonly called square pixels) (of the decoded texture signal)
  • The Video Media Header ('vmhd') shall obey the following constraints:
    • The value of the version field shall be set to '0'.
    • The value of the graphicsmode field shall be set to '0'.
    • The value of the opcolor field shall be set to {'0', '0', '0'}.
  • The Sample Description Box ('stsd') obeys the following constraints:
    • A visual sample entry shall be used.
    • The box shall include a NAL Structured Video Parameter Set.
    • width and height field shall correspond to the cropped horizontal and vertical sample counts provided in the Sequence Parameter Set of the track.
    • It shall contain a Decoder Configuration Record which signals the Profile, Level, and other parameters of the video track.
    • It shall contain AVCConfigurationBox as defined in ISO/IEC 14496-15 [9] which signals the Profile, Level, Bit depth, and other parameters conforming to the bitstream constraints specified in clause 5.1.4.
  • The Colour Information Box ('colr') should be present. If present, it shall signal the colour_primaries, transfer_characteristics and matrix_coeffs applicable to all the bitstreams associated with this sample entry.
  • The ProjectionFormatBox with projection_type equal to 0 as defined in ISO/IEC 23090-2 [13] should be present in the sample entry applying to the sample containing the picture.
  • It shall not contain the RegionWisePackingBox as defined in ISO/IEC 23090-2 [13] and StereoVideoBox.
  • If the content contained in the Bitstream in the track does not cover the entire sphere, the CoverageInformationBox as defined in ISO/IEC 23090-2 [13] should be present. If present, only a single region may be signaled and the following restrictions apply:
    • The coverage_shape_type shall be set to 1.
    • The num_regions value shall be set to 1.
    • The view_idc_presence_flag shall be set to 0.
    • The default_view_idc shall be set to 0.
If 3GP VR Tracks conforming to the constraints of this media profile, the '3vrb' ISO brand should be set as a compatible_brand in the File Type Box ('ftyp').
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5.2.2.3  DASH Integration  p. 42

5.2.2.3.1  Definition  p. 42
If all Representations in an Adaptation Set conform to the requirements in clause 5.2.2.3.2 and the Adaptation Set conforms to the requirements in clause 5.2.2.3.3, then the @profiles parameter in the Adaptation Set may signal conformance to this Operation Point by using "urn:3GPP:vrstream:mp:video:basic".
5.2.2.3.2  Additional Restrictions for DASH Representations  p. 42
If a VR Track conforming to this media profile is included in a DASH Representation, the Representation use movie fragments and therefore, the following additional requirements apply:
  • The Media Header Box ('mdhd') shall obey the following constraints:
    • The value of the duration field shall be set to '0'.
    • The value of the duration field in the Movie Header Box ('mvhd') shall be set to a value of '0'.
  • The Sample Table Box ('stbl') shall obey the following constraints:
    • The entry_count field of the Sample-to-Chunk Box ('stsc') shall be set to '0'.
    • Both the sample_size and sample_count fields of the Sample Size Box ('stsz') box shall be set to zero ('0'). The sample_count field of the Sample Size Box ('stz2') box shall be set to zero ('0'). The actual sample size information can be found in the Track Fragment Run Box ('trun') for the track.
    • The entry_count field of the Chunk Offset Box ('stco') shall be set to '0'.
  • The Track Header Box ('tkhd') shall obey the following constraints:
    • The value of the duration field shall be set to '0'.
  • Movie Fragment Header Boxes ('mfhd') shall contain sequence_number values that are sequentially numbered starting with the number 1 and incrementing by +1, sequenced by movie fragment storage and presentation order.
  • Any Segment Index Box ('sidx'), if present, shall obey the additional constraints:
    • The timescale field shall have the same value as the timescale field in the Media Header Box ('mdhd') within the same track; and
    • The reference_ID field shall be set to the track_ID of the ISO Media track as defined in the Track Header Box ('tkhd').
    • The Segment Index shall describe the entire file and only a single Segment Index Box shall be present.
For all Representation in an Adaptation Set, the following shall apply:
  • The identical coverage information shall be present on all Representations in one Adaptation Set.
  • The frame rates of all Representations in one Adaptation Set shall be identical.
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5.2.2.3.3  DASH Adaptation Set Constraints  p. 43
For a video Adaptation Set, the following constraints apply:
  • The @codecs parameter shall be present on Adaptation Set level and shall signal the maximum required capability to decode any Representation in the Adaptation Set. The @codecs parameter should be signalled on the Representation level if different from the one on Adaptation Set level.
  • The attributes @maxWidth and @maxHeight shall be present. They are expected be used to signal the original projected source content format. This means that they may exceed the actual largest size of any coded Representation in one Adaptation Set.
  • The @width and @height shall be signalled for each Representation (possibly defaulted on Adaptation Set level) and shall match the values of the maximum width and height in the Sample Description box of the contained Representation.
  • The Chroma Format may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:MatrixCoefficients as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
    • The signalling shall be on Adaptation Set level.
  • The Colour Primaries and Transfer Function may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:ColourPrimaries and urn:mpeg:mpegB:cicp:TransferCharacteristics as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • The @frameRate should be signalled on Adaptation Set level.
  • Random Access Points shall be signalled by @startsWithSAP set to 1 or 2.
  • a Supplemental Descriptor should be used to signal the projection by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:pf as defined ISO/IEC 23090-2 [13] and the omaf:@projection_type attribute set to 0.
  • If the CoverageInformationBox is present, a Supplemental Descriptor should be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:cc as defined ISO/IEC 23090-2 [13] and shall match the information provided in the CoverageInformationBox. Specifically,
    • the cc@shape_type shall be present and be set to 1.
    • the cc@view_idc_presence_flag shall not be present.
    • exactly one cc.CoverageInfo element shall be present.
      • any cc.CoverageInfo attribute that is not centre_azimuth, centre_elevation,
        azimuth_range and elevation_range, shall not be present.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • The FramePacking element shall not be present.
  • The @profiles parameters may be present to signal the constraints for the Adaptation Set.
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5.2.3  Main Video Media Profile  p. 44

5.2.3.1  Overview  p. 44

The Main Video Media Profile permits to download and stream elementary streams for VR content generated according to the H.265/HEVC Main Operation Point as defined in clause 5.1.5 or H.265/HEVC Main 8K Operation Point as defined in clause 5.1.7. This enables reuse of the hvc1 sample entry as for example also used in the TV Video Profiles in TS 26.116. It also permits to reuse streaming the VR video content in an adaptive manner by offering multiple switchable Representations in a single Adaptation Set in a DASH MPD. Furthermore, this profile enables that multiple Video Adaptation Sets are offered for the same content, each encoded for a preferred viewport. Multiple Viewpoints may be signaled, for example expressing different type of content or different camera positions.
For content generation guidelines for this media profile refer to Annex A.2.3.2.
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5.2.3.2  File Format Signaling and Encapsulation  p. 44

3GP VR Tracks conforming to this media profile used in the context of the specification shall conform to ISO BMFF [17] with the following further requirements:
  • The included in the video track shall comply to the Bitstream requirements and recommendations for the Main.H.265/HEVC Operation Point as defined in clause 5.1.5 or Main.8K H.265/HEVC Operation Point as defined in clause 5.1.7 with the additional constraints
    • the region-wise packing SEI message (payloadType equal to 155). if present in any H.265/HEVC RAP, shall be present in any H.265/HEVC RAP and shall be identical for all H.265/HEVC RAP.
  • The sample entry type of each sample entry of the track shall be equal to 'resv'.
  • The scheme_type value of SchemeTypeBox in the RestrictedSchemeInfoBox shall be 'podv', and all instances of CompatibleSchemeTypeBox defined in ISO/IEC 23090-2 [13] in the same RestrictedSchemeInfoBox shall include at least one of the scheme_type values 'erpv' and 'ercm'.
  • The untransformed sample entry type shall be equal to 'hvc1' as defined in ISO/IEC 14496-15 [9].
  • The Track Header Box ('tkhd') shall obey the following constraints:
    • The width and height fields for a visual track shall specify the track's visual presentation size as fixed-point 16.16 values expressed in on a uniformly sampled grid (commonly called square pixels) (of the decoded texture signal)
  • The Video Media Header ('vmhd') shall obey the following constraints:
    • The value of the version field shall be set to '0'.
    • The value of the graphicsmode field shall be set to '0'.
    • The value of the opcolor field shall be set to {'0', '0', '0'}.
  • The Sample Description Box ('stsd') obeys the following constraints:
    • A visual sample entry shall be used.
    • The box shall include at least one Sequence Parameter Set NAL unit.
    • width and height field shall correspond to the cropped horizontal and vertical sample counts provided in the Sequence Parameter Set of the track.
    • It shall contain a Decoder Configuration Record which signals the Profile, Level, and other parameters of the video track.
  • The Colour Information Box ('colr') should be present. If present, it shall signal the colour_primaries, transfer_characteristics and matrix_coeffs applicable to all the bitstreams associated with this sample entry.
  • The ProjectionFormatBox with projection_type equal to 0 as defined in ISO/IEC 23090-2 [13] shall be present in the sample entry applying to the sample containing the picture.
  • If the content contained in the Bitstream in the track does not cover the entire sphere, the CoverageInformationBox as defined in ISO/IEC 23090-2 [17] should be present. If present, only a single region may be signaled and the following restrictions apply:
    • The coverage_shape_type shall be set to 1, i.e. the sphere region is specified by two azimuth circles and two elevation circles.
    • The num_regions value shall be set to 1.
    • The view_idc_presence_flag shall be set to 0.
    • The default_view_idc shall be set to 0 or 3.
  • If the content contained in the Bitstream in the track includes the region-wise packing SEI message (payloadType equal to 155), then the RegionWisePackingBox as defined in ISO/IEC 23090-2 [17] shall be present. It shall signal the same information that is included in the region-wise packing SEI message(s) in the elementary stream.
  • If the content contained in the Bitstream in the track does includes the frame packing arrangement SEI message (payloadType equal to 45) in the video stream, the StereoVideoBox shall be present in the sample entry applying to the sample containing the picture. When StereoVideoBox is present, it shall signal the frame packing format that is included in the frame packing arrangement SEI message(s) in the elementary stream.
If 3GP VR Tracks conforming to the constraints of this media profile, the '3vrm' ISO brand should be set as a compatible_brand in the File Type Box ('ftyp').
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5.2.3.3  DASH Integration  p. 46

5.2.3.3.1  Definition  p. 46
If all Representations in an Adaptation Set conform to the requirements in clause 5.2.3.3.2 and the Adaptation Set conforms to the requirements in clause 5.2.3.3.3, then the @profiles parameter in the Adaptation Set may signal conformance to this Operation Point by using "urn:3GPP:vrstream:mp:video:main".
Clause 5.2.3.3.4 defines Adaptation Set Ensembles for viewport-optimized offering.
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5.2.3.3.2  Additional Restrictions for DASH Representations  p. 46
If a VR Track conforming to this media profile is included in a DASH Representation, the Representation use movie fragments and therefore, the following additional requirements apply:
  • The Media Header Box ('mdhd') shall obey the following constraints:
    • The value of the duration field shall be set to '0'.
    • The value of the duration field in the Movie Header Box ('mvhd') shall be set to a value of '0'
  • The Sample Table Box ('stbl') shall obey the following constraints:
    • The entry_count field of the Sample-to-Chunk Box ('stsc') shall be set to '0'.
    • Both the sample_size and sample_count fields of the Sample Size Box ('stsz') box shall be set to zero ('0'). The sample_count field of the Sample Size Box ('stz2') box shall be set to zero ('0'). The actual sample size information can be found in the Track Fragment Run Box ('trun') for the track.
    • The entry_count field of the Chunk Offset Box ('stco') shall be set to '0'.
  • The Track Header Box ('tkhd') shall obey the following constraints:
    • The value of the duration field shall be set to '0'.
  • Movie Fragment Header Boxes ('mfhd') shall contain sequence_number values that are sequentially numbered starting with the number 1 and incrementing by +1, sequenced by movie fragment storage and presentation order.
  • Any Segment Index Box ('sidx'), if present, shall obey the additional constraints:
    • The timescale field shall have the same value as the timescale field in the Media Header Box ('mdhd') within the same track; and
    • The reference_ID field shall be set to the track_ID of the ISO Media track as defined in the Track Header Box ('tkhd').
    • The Segment Index shall describe the entire file and only a single Segment Index Box shall be present.
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5.2.3.3.3  DASH Adaptation Set Constraints  p. 46
For all Representation in an Adaptation Set, the following shall apply:
  • The identical coverage information shall be present on all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
  • The frame rates of all Representations in one Adaptation Set shall be identical.
  • The identical region-wise packing information shall be present all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
  • The identical stereoscopic information shall be present all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
For an Adaptation Set, the following constraints apply:
  • The @codecs parameter shall be present on Adaptation Set level and shall signal the maximum required capability to decode any Representation in the Adaptation Set. The @codecs parameter should be signalled on the Representation level if different from the one on Adaptation Set level.
  • The attributes @maxWidth and @maxHeight shall be present. They are expected be used to signal the used format prior to encoding. This means that they may exceed the actual largest size of any coded Representation in one Adaptation Set.
  • The @width and @height shall be signalled for each Representation (possibly defaulted on Adaptation Set level) and shall match the values of the maximum width and height in the Sample Description box of the contained Representation.
  • The Chroma Format may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:MatrixCoefficients as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
    • The signalling shall be on Adaptation Set level.
  • The Colour Primaries and Transfer Function may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:ColourPrimaries and urn:mpeg:mpegB:cicp:TransferCharacteristics as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • The @frameRate shall be signalled on Adaptation Set level.
  • Random Access Points shall be signalled by @startsWithSAP set to 1 or 2.
  • A Supplemental Descriptor should be used to signal the projection by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:pf as defined ISO/IEC 23090-2 [13] and the omaf:@projection_type attribute set to 0.
  • If the CoverageInformationBox is present then the Coverage information should be signaled on Adaptation Set. If signalled
    • a Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:cc as defined ISO/IEC 23090-2 [13] and shall match the information provided in the CoverageInformationBox. Specifically:
      • The cc@shape_type shall be present and be set to 1.
      • The cc@view_idc_presence_flag shall not be present.
      • Exactly one cc.CoverageInfo element shall be present.
      • Any cc.CoverageInfo attribute that is not centre_azimuth, centre_elevation,
        azimuth_range and elevation_range, shall not be present.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • If the StereoVideoBox is present then the stereo information should be signaled on Adaptation Set. If signalled
    • A FramePacking descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:VideoFramePackingType as defined ISO/IEC 23008-1 [10] and the @value attribute shall be set to 4.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
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5.2.3.3.4  Adaptation Set Ensembles for Viewport-Optimized offering  p. 48
5.2.3.3.4.1  Introduction   p. 48
If multiple Adaptation Sets are offered for the same content in order to permit seamless switching across Representations for a different Viewports, each offered in a different Adaptation Set, then this forms an Ensemble of Adaptation Sets. Note that switching across viewports is not a DASH client functionality, but it is enabled by possible access to the pose and/or viewport information by the DASH client using the 3GPP VR API as shown in Figure 4.6.
5.2.3.3.4.2  Definition and Adaptation Set Signalling   p. 48
An Ensemble is defined as by Adaptation Sets with a Viewpoint Descriptor for which the value of the @schemeIdURI is prefixed as urn:3GPP:vrstream:ve and the actual value is urn:3GPP:vrstream:ve:<id> with <id> an unsigned integer that is identical for all Adaptation Sets in one Ensemble. By using different ids, multiple ensembles may be defined, each defining a different content (for example different camera angles). The value of @value of the descriptor, if present, is either
  • a single unsigned integer value that is different for each Adaptation Set in the Ensemble. If this is present, then the spherical region-wise quality ranking (SRQR) descriptor as defined in ISO/IEC 23090-2 [13] for which the value of the @schemeIdURI is prefixed as urn:mpeg:mpegI:omaf:2017:srqr shall be present in the each Adaptation Set, or
  • a tuple of integer values, separated by a white-spaces. The semantics and order are as follows:
    • centre_azimuth: Specifies the azimuth of the centre point of the sphere region in units of 2−16 degrees relative to the 3GPP coordinate system for which this Ensemble has been optimized.
    • centre_elevation: Specifies the elevation of the centre point of the sphere region in units of 2−16 degrees relative to the 3GPP coordinate system for which this Ensemble has been optimized.
    the spherical region-wise quality ranking (SRQR) descriptor as defined in ISO/IEC 23090-2 [13] for which the value of the @schemeIdURI is prefixed as urn:mpeg:mpegI:omaf:2017:srqr may additionally be present for additional information.
If the @value attribute is not present, then this Adaptation Set is not optimized for any Viewport. At most one adaptation set without the @value not present shall be present.
One Adaptation Set of one Ensemble shall be signalled as the main content. Signaling as main content shall be done by using the Role descriptor with @schemeIdUri="urn:mpeg:dash:role:2011" and @value="main". If for the main Ensemble an Adaptation Set is present for which the @value of the Viewpoint descriptor is not present, then this should be signalled as the main Adaptation Set.
The content should be offered such that within an Ensemble, if multiple Adaptation Sets with different centre points are signalled, the one is preferred which has the minimum square distance to actual Viewport center.
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5.2.3.3.4.3  Representation Constraints in an Ensemble   p. 49
For all Representations in an Ensemble, the following shall apply:
  • The identical coverage information shall be present on all Representations in one Ensemble, both on ISO BMFF and elementary stream level.
  • The frame rates of all Representations in one Ensemble shall be identical.
  • The identical stereoscopic information shall be present all Representations in one Ensemble, both on ISO BMFF and elementary stream level.
5.2.3.3.4.4  Adaptation Set Constraints in an Ensemble   p. 49
For all Adaptation Sets in an Ensemble, the following shall apply:
  • The @codecs parameter shall be identical for all Adaptation Sets in one Ensemble.
  • The Chroma Format shall be identical for all Adaptation Sets in one Ensemble.
  • The Color Primaries and Transfer Function shall be identical for all Adaptation Sets in one Ensemble.
  • The @frameRate shall be identical for all Adaptation Sets in one Ensemble.
  • Segments and subsegments shall be aligned, i.e. @segmentAlignment or @subSegmentAlignment shall be present and shall signal the same unsigned integer value for all Adaptation Sets in an Ensemble.
  • Coverage information shall be identical for all Adaptation Sets in one Ensemble.
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5.2.4  Advanced Video Media Profile  p. 49

5.2.4.1  Overview  p. 49

This Profile permits to download and stream elementary streams for VR content generated according to the Flexible H.265/HEVC operation point as defined in clause 5.1.6. It also allows unconstrained use of rectangular region-wise packing and monoscopic and stereoscopic spherical video up to 360 degrees are supported. With the presence of region-wise packing, the resolution or quality of the omnidirectional video could be emphasized in certain regions, e.g., according to the user's viewing orientation. In addition, the untransformed sample entry type 'hvc2' is allowed, making it possible to use extractors and get a conforming HEVC bitstream when tile-based streaming is used.
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5.2.4.2  File Format Signaling and Encapsulation  p. 49

3GP VR Tracks conforming to this media profile used in the context of the specification shall conform to ISO BMFF [17] with the following further requirements.
When a track is the only track in a file, compatible_brands containing a brand equal to '3vra' in FileTypeBox indicates that the track conforms to this media profile. When a file contains multiple tracks, compatible_brands containing a brand equal to '3vra' in FileTypeBox indicates that at least one of the tracks conforms to this media profile.
  • The video track shall be indicated to conform to this media profile through one or both of FileTypeBox and TrackTypeBox.
  • At least one sample entry type of each sample entry of the track shall be equal to 'resv'.
  • The scheme_type value of SchemeTypeBox in the RestrictedSchemeInfoBox shall be 'podv', and of all instances of CompatibleSchemeTypeBox defined in ISO/IEC 23090-2 [13] in the same RestrictedSchemeInfoBox shall include at least one of the scheme_type values 'erpv' and 'ercm'.
  • The untransformed sample entry type shall be equal to 'hvc1' or 'hvc2' as defined in ISO/IEC 14496-15 [9].
  • When the untransformed sample entry type is 'hvc2', the track shall include one or more 'scal' track references.
  • LHEVCConfigurationBox as defined in ISO/IEC 14496-15 [9] shall not be present in VisualSampleEntry.
  • HEVCConfigurationBox as defined in ISO/IEC 14496-15 [9] in VisualSampleEntry shall be added such that it does not contradict to the Bitstream requirements of the Flexible H.265/HEVC operation point in clause 5.1.6.
  • The track_not_intended_for_presentation_alone flag of the TrackHeaderBox may be used to indicate that a track is not intended to be presented alone.
  • The Track Header Box ('tkhd') shall obey the following constraints:
    • The width and height fields for a visual track shall specify the track's visual presentation size as fixed-point 16.16 values expressed in on a uniformly sampled grid (commonly called square pixels) (of the decoded texture signal)
  • The Video Media Header ('vmhd') shall obey the following constraints:
    • The value of the version field shall be set to '0'.
    • The value of the graphicsmode field shall be set to '0'.
    • The value of the opcolor field shall be set to {'0', '0', '0'}.
  • The Sample Description Box ('stsd') obeys the following constraints:
    • A visual sample entry shall be used.
    • The box shall include a NAL Structured Video Parameter Set.
    • width and height field shall correspond to the cropped horizontal and vertical sample counts provided in the Sequence Parameter Set of the track.
    • It shall contain a Decoder Configuration Record which signals the Profile, Level, and other parameters of the video track.
  • The Colour Information Box ('colr') should be present. If present, it shall signal the colour_primaries, transfer_characteristics and matrix_coeffs applicable to all the bitstreams associated with this sample entry.
  • A ProjectionFormatBox as defined in ISO/IEC 23090-2 [13] shall be present in the sample entry with projection_type equal to 0 or 1.
  • If the content contained in the Bitstream in the track does not cover the entire sphere, the CoverageInformationBox as defined in ISO/IEC 23090-2 [13] should be present.
  • If the video content contained in the Bitstream in the track is a subset of the entire video content carried in the file and the CoverageInformationBox as defined in ISO/IEC 23090-2 [13] is present, the following restrictions apply:
    • If the equirectangular projection is used then,
    • The coverage_shape_type shall be set to 1, i.e. the sphere region is specified by two azimuth circles and two elevation circles.
    • The num_regions value shall be set to 1.
    • If the cubemap projection is used, then one of the two following options applies:
      1. The coverage_shape_type shall be set to 1, i.e. the sphere region is specified by two azimuth circles and two elevation circles and the num_regions value shall be set to 1, or
      2. The coverage_shape_type shall be set to 0, i.e. the sphere region is specified by four great circles.
    • The view_idc_presence_flag shall be set to 0.
    • The default_view_idc shall be set to 0 or 3.
  • If the content contained in the Bitstream in the track includes the region-wise packing SEI message (payloadType equal to 155), then the RegionWisePackingBox as defined in ISO/IEC 23090-2 [13] shall be present. It shall signal the same information that is included in the region-wise packing SEI message(s) in the elementary stream.
  • If the content contained in the Bitstream in the track includes the frame packing arrangement SEI message (payloadType equal to 45) in the video stream, the StereoVideoBox shall be present in the sample entry applying to the sample containing the picture. When StereoVideoBox is present, it shall signal the frame packing format that is included in the frame packing arrangement SEI message(s) in the elementary stream.
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5.2.4.3  DASH Integration  p. 51

5.2.4.3.1  Definition  p. 51
If all Representations in an Adaptation Set conform to the requirements in clause 5.2.4.3.2 and the Adaptation Set conforms to the requirements in clause 5.2.4.3.3, then the @profiles parameter in the Adaptation Set may signal conformance to this Operation Point by using "urn:3GPP:vrstream:mp:video:advanced".
5.2.4.3.2  Additional Restrictions for DASH Representations  p. 51
If a VR Track conforming to this media profile is included in a DASH Representation, the Representation use movie fragments and therefore, the following additional requirements apply:
  • The value of the duration field in the Media Header Box ('mdhd') shall be set to a value of '0'.
  • The value of the duration field in the Movie Header Box ('mvhd') shall be set to a value of '0'.
  • The value of the duration field in the Track Header Box ('tkhd') shall be set to a value of '0'.
  • Movie Fragment Header Boxes ('mfhd') may contain sequence_number values that are not sequentially numbered.
  • Any Segment Index Box ('sidx'), if present, shall obey the additional constraints:
    • the timescale field shall have the same value as the timescale field in the Media Header Box ('mdhd') within the same track;
    • the reference_ID field shall be set to the track_ID of the ISO Media track as defined in the Track Header Box ('tkhd').
  • The Sample Table Box ('stbl') shall obey the following constraints:
    • The entry_count field of the Sample-to-Chunk Box ('stsc') shall be set to '0'.
    • Both the sample_size and sample_count fields of the Sample Size Box ('stsz') box shall be set to zero ('0'). The sample_count field of the Sample Size Box ('stz2') box shall be set to zero ('0'). The actual sample size information can be found in the Track Fragment Run Box ('trun') for the track.
  • The entry_count field of the Chunk Offset Box ('stco') shall be set to '0'.
  • The same projection format shall be used on all Representations in one Adaptation Set.
  • The same frame packing format shall be used on all Representations in one Adaptation Set.
  • The same coverage information shall be used on all Representations in one Adaptation Set.
  • The same spatial resolution shall be used on all Representations in one Adaptation Set.
  • When @dependencyId is used, the values of profiles of the respective dependent and complementary Representations shall be the same.
When the MPD contains a Representation with a track for which the untransformed sample entry type is equal to 'hvc2', the following applies:
  • Either the Representations carrying a track conforming to the media profile track constraints with the untransformed sample entry type equal to 'hvc2' shall contain @dependencyId listing all dependent Representations that carry a track conforming to the media profile track constraints with the untransformed sample entry type equal to 'hvc1' or a Preselection property descriptor shall be present and constrained as follows:
    • The Main Adaptation Set shall contain a Representation carrying a track conforming to the media profile track constraints with the untransformed sample entry type equal to 'hvc2'.
    • The Partial Adaptation Sets shall contain Representations each carrying a track conforming to the media profile track constraints with the untransformed sample entry type equal to 'hvc1'.
  • The Initialization Segment of the Representation that contains @dependencyId or belongs to the Main Adaptation Set is constrained as follows:
    • Tracks conform to the media profile track constraints.
    • The track corresponding to the untransformed sample entry type equal to 'hvc2' refers to the tracks indicated in the TrackReferenceBox of the Initialization Segment.
When switching or accessing Representations at each segment or subsegment is relevant, the following DASH profiles include sufficient constraints:
  • ISO Base Media File Format Live profile: urn:mpeg:dash:profile:isoff-live:2011
  • ISO Base Media File Format Main profile: urn:mpeg:dash:profile:isoff-main:2011
When low latency considerations are relevant, the following DASH profiles provide tools to support efficient low latency services:
  • ISO Base Media File Format On Demand profile: urn:mpeg:dash:profile:isoff-on-demand:2011
  • ISO Base Media File Format Broadcast TV profile: urn:mpeg:dash:profile:isoff-broadcast:2015
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5.2.4.3.3  DASH Adaptation Set Constraints  p. 52
For all Representation in an Adaptation Set, the following shall apply:
  • The identical coverage information shall be present on all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
  • The frame rates of all Representations in one Adaptation Set shall be identical.
  • The identical region-wise packing information shall be present all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
  • The identical stereoscopic information shall be present all Representations in one Adaptation Set, both on ISO BMFF and elementary stream level.
For an Adaptation Set, the following constraints apply:
  • The @codecs parameter shall be present on Adaptation Set level and shall signal the maximum required capability to decode any Representation in the Adaptation Set. The @codecs parameter should be signalled on the Representation level if different from the one on Adaptation Set level.
  • The attributes @maxWidth and @maxHeight shall be present. They are expected be used to signal the decoded texture format of the original signal. This means that they may exceed the actual largest size of any coded Representation in one Adaptation Set.
  • The @width and @height shall be signalled for each Representation (possibly defaulted on Adaptation Set level) and shall match the values of the maximum width and height in the Sample Description box of the contained Representation.
  • The Chroma Format may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:MatrixCoefficients as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
    • The signalling shall be on Adaptation Set level.
  • The Colour Primaries and Transfer Function may be signalled. If signalled:
    • An Essential or Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:ColourPrimaries and urn:mpeg:mpegB:cicp:TransferCharacteristics as defined ISO/IEC 23001-8 [10] and the @value attribute according to Table 4 of ISO/IEC 23001-8 [10]. The values shall match the values set in the VUI.
      The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • The @frameRate shall be signalled on Adaptation Set level.
  • Random Access Points shall be signalled by @startsWithSAP set to 1 or 2.
  • An Essential Descriptor shall be used to signal the projection by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:pf as defined ISO/IEC 23090-2 [13] and the omaf:@projection_type attribute set to 0 or 1.
  • If the CoverageInformationBox is present, then the Coverage information should be signaled on Adaptation Set. If signalled:
    • A Supplemental Descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegI:omaf:2017:cc as defined ISO/IEC 23090-2 [13] and shall match the information provided in the CoverageInformationBox. Specifically,
      • the cc@shape_type shall be present and be set to 0 or 1.
      • the cc@view_idc_presence_flag shall not be present.
      • exactly one cc.CoverageInfo element shall be present.
      • any cc.CoverageInfo attribute that is not centre_azimuth, centre_elevation, azimuth_range and elevation_range, shall not be present.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • If the StereoVideoBox is present, then the stereo information should be signaled on Adaptation Set. If signalled:
    • a FramePacking descriptor shall be used to signal the value by setting the @schemeIdURI attribute to urn:mpeg:mpegB:cicp:VideoFramePackingType as defined ISO/IEC 23008-1 [10] and the @value attribute shall be set to 4.
    • The signalling shall be on Adaptation Set level only, i.e. the value shall not be different for different Representations in one Adaptation Set.
  • The following applies for the use of @mimeType:
    • @mimeType of the Main Adaptation Set shall include the profiles parameter '3vra'.
    • When Preselection is used, the value of profiles of the main Adaptation Set shall be the same as the value of profiles of its partial Adaptation Sets.
  • When Preselection is used, the following applies:
    • The value of @subsegmentAlignment in the Main Adaptation Set shall be an unsigned integer and equal to the value of @subsegmentAlignment of the each associated Partial Adaptation Set.
    • The value of @segmentAlignment in the Main Adaptation Set shall be an unsigned integer and equal to the value of @segmentAlignment of the each associated Partial Adaptation Set.
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5.2.4.3.4  Adaptation Set Constraints for Viewport Selection  p. 54
If multiple Adaptation Sets are offered for the same content which have emphasized quality regions for different viewports, in order to provide signaling information for switching across Viewports, the spherical region-wise quality ranking (SRQR) descriptor as defined in ISO/IEC 23090-2 [13] for which the value of the @schemeIdURI is prefixed as urn:mpeg:mpegI:omaf:2017:srqr shall be present in the each Adaptation Set with following restrictions:
  • The sphRegionQuality@view_idc_presence_flag shall be set to 0.
  • The sphRegionQuality@default_view_idc shall be set to 0 or 3.
  • The value of sphRegionQualityll.qualityInfo@quality_ranking shall be greater than 0.
For all Representations in multiple Adaptation Sets for switching accross Viewports, the following shall apply:
  • The identical coverage information shall be present on all Representations, both on ISO BMFF and elementary stream level.
  • The frame rates of all Representations in Adaptation Sets shall be identical.
  • The identical stereoscopic information shall be present all Representations, both on ISO BMFF and elementary stream level.
For all Adaptation Sets with SRQR descriptors for switching across Viewports, the following shall apply:
  • The @codecs parameter shall be identical for all Adaptation Sets.
  • The Chroma Format shall be identical for all Adaptation Sets.
  • The Colour Primaries and Transfer Function shall be identical for all Adaptation Sets.
  • The @frameRate shall be identical for all Adaptation Sets.
  • Segments and subsegments shall be aligned, i.e. @segmentAlignment or @subSegmentAlignment shall be present and shall signal the same unsigned integer value for all Adaptation Sets.
  • Coverage information shall be identical for all Adaptation Sets.
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