Organisation internationale de normalisation

Action Points

ISO/IEC DIS 23001-10 (SC 29 N 14417)

Part 10: Carriage of Timed Metadata Metrics of Media in ISO Base Media File Format

DIS (2015-01-22)

15. Green Metadata (23001-11)

    1. Topics

       1. Green Metadata

2. Contributions

Number	Session	Title	Source		Dispositions
m34840	Green	Summary of Voting on ISO/IEC DIS 23001-11	SC 29 Secretariat		Refer N14852
m34868	Green	Study of ISO/IEC DIS 23001-11	Spencer Cheng		Accepted N14853
m34977	Green	Efficient Carriage of Green Metadata in an AVC SEI Message	Felix C. Fernandes, Spencer Cheng	Accepted N14951
m34978	Green	Proposed Edits to the Green Metadata DIS Text	Felix C. Fernandes	Accepted N14853
m35009	Green	HEVC decoding with tunable image quality	E.Nogues, E.Raffin, M.Pelcat, D.Menard, X.Ducloux	Noted
m35148	Green	Best Effort Decoding for Green MPEG - An example application	Alexis Michael Tourapis, David Singer, Krasimir Kolarov, Steve Saunders	Noted
m35163	Green	Revised HEVC SEI Message for Green Metadata	Spencer Cheng, Jiangtao Wen	Accepted N14853
m35279	Green	Proposed reference bitstreams for Green MPEG Compliance	Nicolas DEROUINEAU, Nicolas TIZON, Didier NICHOLSON,	Noted

1. Summary of discussions

   1. M34868: Study of ISO/IEC DIS 23001-11

• 
  In response to feedback from the video group, updates the metrics for quality recovery after low-power encoding.
  

1. M34934: Test Vectors for Green Metadata Signalling in MPEG DASH

• 
  Three HEVC CfP sequences are concatenated to create a single 32-second sequence which is then encoded.
  
• 
  Ten video representations are created across various resolutions and bitrates.
  
• 
  Two-second segments are stored for each representation.
  
• 
  Decoder-power indication metadata is provided for all the segments.
  
• 
  The contribution will be discussed in the DASH group.
  

1. M34977: Efficient Carriage of Green Metadata in an AVC SEI Message

• 
  Worst-case analysis is provided for the four complexity metrics.
  
• 
  The worst-case, largest number of each metric is used to compute its percentage.
  
• 
  Due to a calculation error, the 4:2:2 multiplier should be changed from 192 to 256.
  
• 
  Flag indicators are replaced by type indicators, as suggested by the video.
  

1. M34978: Proposed Edits to the Green Metadata DIS Text

• 
  Discussed and accepted the edits.
  

1. M35009: HEVC Decoding with Tunable Image Quality

• 
  The decoder is modified by activating certain power-saving mechanisms on an increasing number of frames given a level from 0 to 12. Level 0 is the compliant HEVC decoder with no power savings. Levels 1 to 12 provide increasing amounts of power savings by applying the following mechanisms: turning off deblocking/SAO filters and using a low-complexity interpolation filter.
  
• 
  Tested on two platforms: ARM-based Exynos and Intel.
  
• 
  About 20% and 10% power savings were shown at Level 12 for the random-access and all-intra scenarios, respectively.
  
• 
  On both platforms, a linear trend was observed for PSNR-degradation vs. Power saving. Since power-saving is proportional to complexity reduction, this result suggests that a (psnr-degradation, complexity reduction) pair can be used as metadata.
  
• 
  Further study is encouraged to address the following:
  
  1. 
     Show linear relation between power saving and complexity reduction.
     
  2. 
     Explain the usage of the proposed metadata based on the #1.
     
  3. 
     Show power saving measured over the entire mobile device. The Monsoon power monitor (https://www.msoon.com/LabEquipment/PowerMonitor/) can be used for this purpose.
     
  4. 
     Provide video clips for subjective viewing.
     
     • 
       Check that for the same power reduction, the metadata provides better subjective quality than would be obtained by just increasing the QP.
       
     • 
       Check that, for the same bitrate, at Level 12, the metadata provides at least the same quality as AVC, but with more power-saving.
       
• 
  Discuss with video group.
  

1.