International organisation for standardisation organisation internationale de normalisation

4.1.2Audio/Systems Interaction: Super-I-Frame and DASH (Tue 10:30 – 11:00)

Schuyler Quackenbush, ARL, presented

m23576

Super-I-Frame and Audio/Systems Interaction

S. R. Quackenbush

The contribution described the behaviour of audio codecs in the DASH framework. DASH experts indicated that the “Program Change” scenario was not of the greatest interest. Rather, the “Bitrate Change” scenario was the most important. There was considerable discussion on what occurs when e.g. DASH switches from 5.1 channel AAC at 320 kb/s in segment N to 5.1 channel HE-AAC V2 at 128 kb/s. There appeared to no solution that avoids a zero-interval plus fade-in as the HE-AAC decoder starts up from instantiation.

It was decided that Audio would draft text describing audio codec behaviour in DASH:

• 
  Recommended restrictions on audio encoders
  
• 
  Resulting audio codec behavior
  

This information may be incorporated into DASH part 3 (Technical Report on recommended practices).

It a related issue, it was decided that Audio would draft text describing audio codec behaviour in MPEG-2 Systems:

• 
  Recommended restrictions on audio encoders
  
• 
  Resulting audio codec behavior
  

This information may be incorporated into an amendment to MPEG-2 Systems.