6 Bitstream

26.4043GPPEnhanced aacPlus encoder Spectral Band Replication (SBR) partEnhanced aacPlus general audio codecGeneral audio codec audio processing functionsRelease 17TS

Figure 10 below gives a brief hierarchical representation of the SBR and parametric stereo parts of the aacPlus bitstream, with references to the corresponding decoder specifications.  An overview of sbr_extension_data() is given in [1], Figure 4.19A, and subclause 4.4.2.8 of [1] defines the syntax.  Clearly, the operation of the SBR Bitstream Multiplexer in Figure 5 is defined by this syntax.  The optional CRC calculation is also defined by the decoder description [1], subclause 4.5.2.8.1.  For convenience, pointers to the relevant sections in the present document are given within paranthesises in Figure 10.

extension_payload()                 [1], Amendment Subpart 4, Table 4.51
  sbr_extension_data()              [1], Subclause 4.4.2.8, Table 4.54A
    sbr_header()                     ", ", Table 4.55A (5.3)
    sbr_data()                       ", ", Table 4.56A
      sbr_single_channel_element()   ", ", Table 4.57A
        sbr_grid()                   ", ", Table 4.61A (5.4.3)
        sbr_dtdf()                   ", ", Table 4.62A (5.8)
        sbr_invf()                   ", ", Table 4.63A (5.6.4)
        sbr_envelope()               ", ", Table 4.64A (5.5, 5.7, 5.8)
        sbr_noise()                  ", ", Table 4.65A (5.6.3, 5.7, 5.8)
        sbr_sinusoidal_coding()      ", ", Table 4.66A (5.6.5)
        sbr_extension()             [7], Subclause 8.A.2, Table 8.A.1
          ps_data()                 [7], Subclause 8.4.1, Table 8.1

Figure 10: Enhanced aacPlus with parametric stereo bitstream hierarchy

Annex A (informative):
Change history

Change history

Date

TSG SA#

TSG Doc.

CR

Rev

Subject/Comment

Old

New

2004-09

25

SP-040636

Approved at SA#25

2.0.0

6.0.0

2007-09

36

Version for Release 7

6.0.0

7.0.0

2008-12

42

Version for Release 8

7.0.0

8.0.0

2009-12

46

Version for Release 9

8.0.0

9.0.0

2011-03

51

Version for Release 10

9.0.0

10.0.0

2012-09

57

Version for Release 11

10.0.0

11.0.0

2014-09

65

Version for Release 12

11.0.0

12.0.0

2015-12

70

Version for Release 13

12.0.0

13.0.0

Change history

Date

Meeting

TDoc

CR

Rev

Cat

Subject/Comment

New version

2017-03

75

Version for Release 14

14.0.0

2018-06

80

Version for Release 15

15.0.0

2020-07

Update to Rel-16 version (MCC)

16.0.0

2022-04

Update to Rel-17 version (MCC)

17.0.0