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Task group activities Joint Meetings
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- Bu səhifədəki naviqasiya:
- File format issues (Tue 1700-1800)
- MPEG Assets: Conformance (Wed 1130-1200)
- Augmented Reality (Wed 1200-1300)
- Task Group discussions
Task group activities
Max Neuendorf, FhG-IIS, gave a presentation on the proposed 3D Audio “Immediate Play-out Frame” (IPF). The key attributes of the IPF are:
Thomas Stockhammer, noted that this can be a general mechanism for Random Access and Splicing. Ingo Hofmann, FhG-IIS, noted that DASH client may fetch segments well in advance of when they are needed, so that a bitrate peak at the SAP is not an issue. Masayuki Nishiguchi, Sony, gave an application scenario on 2-screen presentation.
Or perhaps
Fingerprint is audio business and information for out-of-scope implementation SMPTE also has this effort
The Audio Chair presented the EBU “Audio Model” document. Audio will generate Liaison statement to say “MPEG is happy to support EBU in mapping the EBU Audio Model to the MPEG-4 File Format” David Singer, Apple, presented WD on Improved audio support in the ISO Base Media File Format, which will be a WG11 document from this meeting. Audio subgroup agreed to study this WD as part of the DRC workplan and propose answers to the “questions” explicitly posed in the WD text (Section 2.5). For example, File Format boxes may be expressed in an equivalent but more compact form for use in Audio elementary streams.
Put all MPEG Audio conformance data on FTP account at: wg11.sc29.org This will be done by the Audio Chair (see Christian Tulvan email of April 26, 2013). This includes
This conformance information can be viewed and downloaded at this URL http://wg11.sc29.org/conformance
The 3DG Chair reviewed the conclusions of the joint meeting at the previous MPEG meeting. He gave an overview of MPEG-4 Advanced Audio BIFS nodes that might be used in Augmented Reality. Experts noted that estimates of the real-world acoustic environment could be done by:
The 3DG Chair noted that Augmented Reality could enhance or process aspects of real-world audio. The location of (possibly many) microphones could be used to perform generalized beamforming as a means to genaralized audio scene analysis.
Monday - 3D Audio Information The Chair presented
Nils Peters, Qualcomm, presented
Binauralization formats Werner Oomen, Philips, presented
The contributions points out that different use cases (e.g. battery powered vs. line powered) motivate different binauralization computational complexity (e.g. parametric vs. FIR). Hence, there is a need for different file-based representations of a BRIR. Thomas Sporer, FhG-IDMT, Clemens Par, Suissaudec, reported on the status of X212 standardization at the 135th AES meeting. There will be a draft in December 2013, after which there is a ballot. Any AES member can comment during the ballot period. Marc Emerit, Orange, presented
The contribution poses the question: should MPEG-H 3D Audio be required to read the AES X212 SOFA file format. There could be another interface to the 3D Audio decoder which could read:
Clemens Par, Suisaudec, noted that SOFA (which is the X212 format) can have additional restrictions imposed by MPEG 3D Audio so that the file format is more “light weight.” Marc Emerit, Orange, proposes the flowing:
Audio Subgroup Experts will work to harmonize the Orange 3D Audio interface and the Philips 3D Audio interface and report back later in the week. Jan P, FhG-IIS, notes that we should pick a normative binauralization technology and support that low-level parameterization. Werner Oomen, Philips, supports the idea of supporting additional, generic, parametric representations.
Johannes Hilpert, FhG-IIS, presented
The contributions give an overview of the 3D Audio encoder and decoder as WD text and RM software. WD Text Decoder can do
USAC-3D has new tools (with respect to USAC)
Object metadata
SAOC object coding
Mix objects onto channels to get combined loudspeaker signals Renderer
Software
Johannes Hilpert, FhG-IIS, presented
The contribution describes the changes to USAC to create USAC-3D and the changes to SAOC-DE to create SAOC-3D. Changes are described above. There was some discussion on whether to create a MPEG-D USAC “v2” that would be USAC-3D. USAC-3D will persist and can perform the role of “MPEG-D USAC v2.” One could move this to MPEG-D. Alternatively, if USAC does not have significant market penetration, MPEG could amend MPEG-D to incorporate MPEG-3D such that today’s MPEG-D no longer exists and there is only one USAC coder that has all features of MPEG-3D. Johannes Hilpert, FhG-IIS, presented
The contribution reports on bugs found in the RM0 software. The presenter felt that the bug fixes do not have a significant perceptible impact on the decoded output. Fixed code with a quality assurance test could be available at the next meeting. Assuming this is true, then CEs could proceed with RM0 bitstreams and decoded waveforms. It was the consensus of the Audio subgroup to incorporate all the bugfixes into the reference software. The Audio subgroup anticipates that FhG-IIS will do a quality check on the bugfixes during the AhG period and bring to the next MPEG meeting
A second point in the contribution was that RM0 uses the LD-SAOC filterbank for the format converter. At the e.g. 512 kb/s rate, the core coder (USAC-3D) uses “classic” QMF and was interfaced to the render via time domain signals. Evidence was presented (as listening test data) that using “classic” QMF in the render at this bit rate does not harm the performance. Draft workplan for listening test to explore if LD-SAOC provides an advantage vs. classic QMF. HOA Oliver Wuebbolt, Technicolor, presented
HOA 3D Audio decoder consists of
Binauralization can use as input either loudspeaker feeds or HOA coefficient channels (e.g. if they have fewer channels than loudspeaker feeds). Binauralization is via the Orange algorithm. Predominant sounds are identified using a possible 900 points on the sphere. Johannes Boehm, Technicolor, presented
The zip archive contains two software archives: RM0 decoder and informative encoder. Additional Functionalities for Version 1 Max Neuendorf, FhG-IIS, presented
The contribution proposes several new functionalities for MPEG-H 3D Audio in response to m14855, “Timeline and Requirements for MPEG-H 3D Audio Version 1,” from the 105th meeting. Proposed are architectures and/or coding schemes for:
Experts should draft a workplan to
Masayuki Nishiguchi, Sony, presented
The contribution desires to not change anything in a legacy “main screen” broadcast system. It is not possible to have timestamps in the legacy system. However, it is also desired to have a second, e.g. Tablet, presentation that can be synchronized with the main screen legacy broadcast. It identifies the following requirements:
Evidence was presented indicating that proposed technology will work in as low as -18 dB SNR acoustic environment (i.e. SNR at tablet microphone). This discussion will be continued in the Audio, Systems joint meeting. New CE Werner Oomen, Philips, presented
The contribution announces the intent for a CE on rendering. Specifically, it proposes a CE that tests rendering for the case of very different loudspeaker positions, e.g. a front loudspeaker sound bar plus 2 surround speakers. The envisioned subjective test requires
Proposes that there should be a rendering algorithm choice based on loudspeaker position and/or geometry. This assumes that the decoder can be informed of the target loudspeaker geometry. The CE would use a MUSHRA test in which
Philips would make available to a cross-check site the target loudspeaker device. Richard Furse, Muse440, asked whether such an alternative rendering would be normative. The presenter stated that MPEG could choose to standardize additional renderers or to just support proprietary renders via some normative interface. The Chair noted that this CE is a vehicle to clarify
The Audio subgroup looks forward to more information at the next meeting. 3D Audio Information The Chair presented
HOA CE/Merge Nils Peters, Qualcomm, presented information on the following contributions
The contribution reports on a CE in which the Technicolor “Predominant Sounds” module is replaced by the Qualcomm “Significant Sounds” module. The results of a MUSHRA listening test with 24 listeners. When differential scores are analysed, it shows that:
These items tended to be “dense” sound fields. In additions, the CE technology decoder as compared to the RM0 decoder had
Thomas Sporer, FhG-IDMT asked whether the presenter checked whether the listening test sites could be pooled, based on statistical principles. The presenter noted that he checked and can confirm that an ANOVA does not show the test sites as a significant factor. Max Neuendorf, FhG-IIS, asked for raw listener data. Chair said that it would be made available. The Chair noted that there appears to be support for:
A final decision will be made after experts have the opportunity to review the data. Continued Discussion Werner Oomen, Philips, stated there were significant differences between listening test sites. Bernhard Grill, FhG-IIS, reminded that the goal is to build the best standard, and suggested to draft a workplan to further investigate, e.g. the performance of the integrated system. Deep Sen, Qualcomm, noted that Qualcomm has an algorithm that selects between the Technicolor and the Qualcomm tools in a signal-responsive manner. The Chair suggested that on Friday morning Qualcomm present information on what the discriminator tool would do in terms of deciding which tool to use (Qualcomm or Technicolor) in intervals of some TBD length for each CfP test item. It that information permits Audio experts to infer the quality rating of the integrated system including the discriminator tool, then a decision could be made. Otherwise, Qualcomm should conduct a listening test to determine the performance of the integrated system including the discriminator tool and report this at the next meeting. General Discussion Max Neuendork, FhG-IIS, made a presentation on the Contributions to V1 document It was the consensus of the Audio subgroup to
Joe H made a presentation on testing the significance of the LD-SAOC update issues It was the consensus of the Audio subgroup to conduct the test as indicated and to document the test process in the Workplan on 3D Audio. A/V Synchronization Masayuki Nishiguchi, Sony, presented the Workplan on Audio Synchronization. Oliver Webeult, Technicolor, noted that there are two classes of technology that are applicable:
He further noted that the test conditions for the evaluation should be defined. The workplan will be edited and reviewed again on Friday. The Chair encourages Audio experts to bring contributions to the next MPEG meeting on the topic of 3D Audio Renderer API. Workplan on DRC Fabian Kuech, FhG-IIS, presented a draft workplan which was reviewed. Binauralization CE Jan Plogsties, FhG-IIS, make a presentation that made the following points
Needs to be API for alternative Binauralization algorithms, including
FhG-IIS can make “Mozart” BRIR available as part of 3D Audio Reference Software Check some or all Binauralization CE technology with other BRIRs Define API (or APIs) so that use of alternate BRIR with normative 3D Audio Binauralization is possible Define API so that alternate binauralizations are possible The Chair summed up the consensus points in the group. Audio experts agree that:
3D Audio should support a normative interface to decoded channel/object/HOA signals and metadata. The Audio subgroup looks forward to contributions on these topics at the next meeting. 3D Audio should support a normative interface to BRIR. There was discussion on “AES X212” or “parametric” interfaces, and this needs more discussion. The Audio subgroup looks forward to contributions on this topic at the next meeting. Audio experts agree that there should be a path so that users have access to a potentially large market of BRIR. Selection of Binauralization Technology Gregory Pallone, Orange, gave a presentation. He proposed revised FFT and QMF complexity. He noted that a way forward could be to select a time-domain and a QMF domain binauralization, with selection based on whether data from decoded channel/object/HOA signals is time-domain or QMF domain. He further noted that the marketplace BRIRs could be time-domain BRIR, QMF domain representations or other parameterized representations. One algorithm for converting time-domain BRIR to 3D Audio parameterized representations should be normative. Alternate parameterizations would be available via normative parameter interfaces. Jeongil Seo, ETRI, stated a different view: that time-domain BRIR in the marketplace is enough, and that a further parameterization block will deliver the necessary parameters to the 3D Audio binauralization. Taegyu Lee, Yonsei and Henney Oh, Wilus, gave a presentation on complexity of the various binauralization algorithms. Jan Plogsties, FhG-IIS, stated that computational complexity in the MPEG Audio subgroup is traditionally paper-in-pencil analysis. He further proposed that Audio either
Werner proposes to select one now and analyize it for BRIR. Chair proposes that we
Harald Fuchs, FhG-IIS, presented information on the following contributions
The presenter proposes
It was the consensus of the Audio Subgroup to incorporate all recommened changes in the presentation into the SAOC-DE PDAM text. The Chair noted that the DoC on ISO/IEC 23003-2:2010/PDAM 3, Dialog Enhancement must still be reviewed by the group. Leon Terentiv, FhG-IIS, presented
The contribution proposes several corrections to MPEG SAOC text, most are aligning text to reference software, but some are editorial. It was the consensus of the Audio Subgroup to issue these corrections as a Defect Report on MPEG SAOC text. The Chair noted that there must be an NB ballot comment that asks to “fix all known errors” in order to incorporate the Defect Report corrections into ISO/IEC 23003-2:2010/COR 2, SAOC that is expected to issue at the next meeting. The Chair also noted that the editor should remember to correct the reference software error in some future DCOR.
The Chair presented
The contribution reports on the final step in the JAME project, revising the stereo coding modules. A subjective listening test information is given that, in summary, shows that JAME is 30 MUSHRA points better than the MPEG USAC reference encoder, and that the USAC Reference Quality Encoder (i.e. the USAC RM11 bitsteams) is 10 MUSHRA points better than JAME. The contribution notes that JAME1.13.5 (Committed on September 26, 2013) is available on the MPEG SVN server. The Chair noted that the JAME code base can be used by MPEG-H 3D Audio CE proponents to develop and verify a desired API in the context of JAME and use the modified JAME code base to communicate the desired API the 3D Audio RM proponent so that the proponent can modify the Reference Quality codec to support the desired API. Daniel Fischer, FhG-IIS, presented
The contribution documents:
It was the consensus of the Audio subgroup to issue this information as a Defect Report on USAC Conformance and Reference Software.
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