Further Discussion
It was the consensus of the Audio subgroup to incorporate the capability to carry DRC information in uniDrc() format as a USAC3D extension element.
Figure 7: Integration of Dynamic Range Control, Loudness Normalization and Peak Limiting into the MPEG-H decoder
Recommendations and review of AhG Report
The AhG report was reviewed and was approved by the AhG members present.
Task group activities Joint Meetings Audio and Systems: File Format and CICP (Wed 1130-1230)
David Singer, Apple, presented
m32272
|
Improved audio support in the ISO base media file format (14496-12)
|
David Singer, Frank Baumgarte,
|
|
The contribution points out that DRC as used in 3D Audio requires quite a rich set of metadata. Furthermore, that metadata could be in the MP4-FF boxes or in the audio Track (i.e. Elementary Stream or ES). The presenter stated that, in principle, the DRC metada should not be stored twice in the MP4-FF (i.e. in the FF boxes and the Elementary Stream).
The contribution is a proposed amendment to 14496-12, with boxed defined to support DRC. There are a number of issues:
-
Define how to carry DRC in FF boxes (which is done)
-
Define how to carry DRC in ES (which will be done by Audio)
-
If DRC is in ES, define what might need to be duplicated in FF.
-
Consider how to use a FF Hint Track to dynamically move DRC in FF to DRC in ES.
Agreed action items:
-
Jointly approve new WD of this document
-
Workplan from Audio which contains “study points” for audio experts.
-
Investigate tracked-changes comment in WD document
-
Address minimum “redundant metadata” that is to be both FF and ES.
-
Consider software that could use hint track to automatically take FF level information into ES.
Max Neuendorf, FhG-IIS, presented
m32183
|
Update to Audio part of ISO/IEC 23001-8 (CICP)
|
Max Neuendorf, Ingo Hofmann, Nikolaus Rettelbach, Christian Ertel
|
|
The contribution presents proposed changes to the audio portion of the CICP standard. Proposed changes are:
-
Clarify the terms “channel”, “channel configuration”, “loudspeaker”, “ loudspeaker layout”, etc.
-
It proposed to add a “Definition of Terms” section to the audio part.
-
Add a loudspeaker location table.
If a current term in CICP is “replaced” as proposed in the contribution, the “legacy” term MUST be retained at least in in the definition of terms section.
Dostları ilə paylaş: |