International organisation for standardisation organisation internationale de normalisation

16.3Summary of discussions

16.3.1M 33437 from ATSC related to DTS alignment for MVC transport.

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  This indicated possible implementation issues related to maintaining exact values of DTS for each view mandated in the transport of MVC.
  
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  The group decided to send a liaison response requesting additional information noting that the standard was approved few years ago and no issues have been reported todate in deployments such as BluRay DVD, DVB broadcasting and US trials.
  

16.3.2M 33226 – Carriage of Green Metadata in MPEG-2 systems. This proposed use of PES encapsulation and a descriptor.

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  There was a suggestion to constrain this to transport streams only and preclude program stream usage.
  
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  There was no issue related to static data carriage (for an entire program or event) using a descriptor. However, carriage of dynamic data may need a review of both PES and section based encapsulation mechanisms for efficiency and implementation ease.
  
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  A WD will be produced at this meeting with a resolution requesting NB’s for comment on the 2 options.
  

16.3.3M 33201 – Signaling of additional MPEG-4 audio profiles for AAC and USAC.

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  This will be constrained to LATM/LAOS only with new profiles/levels signaled in existing descriptor. Some compatibility issues related to deployed decoder behaviour was brought up and this may need further discussions. Use of new stream_type for these profiles/levels was also suggested.
  
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  The group could not agree on whether we should combine this with m 33187 and produce a WD for amendment at this meeting or produce a PDAM for carriage of MPEG-4 audio extensions at this meeting and WD for carriage of MPEG-H audio. In mid-week plenary there was agreement to create separate amendments. A WD for carriage of MPEG-4 audio will be output at this meeting.
  

16.3.4M 33187 – Carriage of MPEG-H 3D audio in MPEG-2 systems.

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  Carriage of MPEG-H audio may need additional information on buffer size and bit rates for the various configurations. These will be provided by next meeting before a PDAM can be produced. A WD will be output at this meeting.
  
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  No changes to definition of access unit, random access point and others in current MPEG-2 standard.
  

16.3.5M 33116

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  – ZTE. This proposed use of new descriptor value for HEVC_extension instead of embedding the HEVC_extension inside existing HEVC video descriptor. This was accepted and is reflected in the PDAM 7.
  

16.3.6M 33174

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  – Fraunhofer – Suggests keeping HEVC operation point descriptor at program level, keeping heirarchy_descriptor, removal of extension of HEVC video descriptor and changes to HRD descriptor. Contribution m 33439 provided comparative data rate overhead between the options for operation point signaling at program versus ES level.
  

16.3.7 M 33301

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  – Qualcomm – Suggests keeping heirarchy extension descriptor, keeping the HEVC extension in a separate descriptor instead of HEVC video descriptor (to signal operation points at ES level) and deleting HEVC operation point descriptor.
  
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  The group agreed to changes to HRD descriptor, removal of HEVC extension from HEVC video descriptor and create a new descriptor called HEVC extension descriptor for use at ES level. However, there was no agreement between the 2 methods to signal operation points (at program or ES level) and we will request NB comments during the PDAM ballot. Request for PDAM 7 and text of PDAM 7 will be output at this meeting with 3 week editing period.
  

16.4Action Points / Ballots

17.MPEG-4 ISO Base File Format (14496-12)

17.1Topics

17.1.1ISO/IEC 14496-12:201X/AMD 3: Font streams and other improvements to file format

This amendment modifies the description and format of some existing fields of the decoderSpecificInfo and also provides a definition of font data box for ISO Base Media File Format

17.1.2ISO/IEC 14496-12:201X/AMD 4: Enhanced audio support

This amendment enhances the codec-independent support for audio in the file format, adding the ability to declare downmixing and dynamic range control of audio, and describe the loudness of the program, before or after downmix or dynamic range control. It also supports the codec-independent declaration of channel layout, and identifying the carriage of DRC coefficients both in the audio stream, and in a separate track.

17.2Contributions

Number	Session	Title	Source	Dispositions
m32745	File Format	Summary of Voting on ISO/IEC 14496-12:2012/DCOR 2 and ISO/IEC 15444-12:2012/DCOR 2	SC 29 Secretariat	No
m33084	File Format	Comment on 14496-12 4th Edition	Mitsuhiro Hirabayashi Takehiko Nakano	Accepted w14439
m33217	File Format	Relaxing Movie Fragment Sequence Number	[e-mail], Cyril Concolato [e-mail], Jean Le Feuvre	noted
m33219	File Format	Codec parameters for metadata and subtitle tracks	[e-mail], Cyril Concolato [e-mail], Jean Le Feuvre	noted
m33256	File Format	WD Text of 14496-12 Amd 4	David Singer Frank Baumgarte	Accepted w14325
m33081	File Format	Study of ISOBMFF Sample Variants	Michael Dolan	noted
m33188	File Format	MPEG-H 3D Audio in the ISO base media file format	[e-mail], Bernd Czelhan [e-mail], Ingo Hofmann [e-mail], Stefan Doehla	Accepted
m33220	File Format	Considerations for TEMI in ISOBMFF	[e-mail], Cyril Concolato [e-mail], Jean Le Feuvre	Noted
m32944	File Format	Conformance bitstreams for MPEG-4 File Format	[e-mail],Richard Mitic	Accepted w14326
m33297	File Format	Partial ISO BMFF Structures	[e-mail],Thomas Stockhammer	Noted