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[Complexity] Complexity overhead for MDCT Stereo Decoding

Basic info

  • Float reference:
  • Fixed point:
    • Encoder (fixed): n/a
    • Decoder (fixed): 76bdb538

Bug description

There is approx. 50% complexity overhead for the 64 kbit/s stereo decoder:

Float:

 --- Complexity analysis [WMOPS] ---  

                                                  |------  SELF  ------|   |---  CUMULATIVE  ---|
                               routine    calls     min     max     avg      min     max     avg 
                       ---------------   ------   ------  ------  ------   ------  ------  ------
                       ivas_jbm_dec_tc     1.00    1.276   1.277   1.276   25.914  43.248  34.989
                          ivas_cpe_dec     1.00    1.268  10.331   4.106   24.638  41.972  33.713
                         ivas_core_dec     1.00    1.272   1.297   1.295   23.369  35.845  29.607
                  stereo_mdct_core_dec     1.00   15.509  27.577  21.537   22.074  34.549  28.312
                        mdct_core_invQ     1.00    5.235   9.534   6.724    5.235   9.534   6.724
    ivas_jbm_dec_feed_tc_to_rendererer     1.00    0.014   0.014   0.014    0.014   0.014   0.014
                       ivas_dec_render     1.00    2.481   2.487   2.482    2.481   2.487   2.482
                            ApplyFdCng     0.05    1.379   2.471   1.963    1.379   2.471   1.963
                       ---------------   ------   ------  ------  ------
                                 total  1050.00   28.442  45.775  37.521

BASOP

--- Complexity analysis [WMOPS] ---  

                                                  |------  SELF  ------|   |---  CUMULATIVE  ---|
                               routine    calls     min     max     avg      min     max     avg 
                       ---------------   ------   ------  ------  ------   ------  ------  ------
                       ivas_jbm_dec_tc     1.00    6.279   6.601   6.354   47.571  67.351  57.101
                          ivas_cpe_dec     1.00    2.492  13.559   5.225   41.207  60.997  50.746
                         ivas_core_dec     1.00    4.568   4.970   4.948   38.715  50.626  45.521
                  stereo_mdct_core_dec     1.00   27.459  38.893  34.131   33.763  45.674  40.573
                        mdct_core_invQ     1.00    4.763   8.330   6.442    4.763   8.330   6.442
    ivas_jbm_dec_feed_tc_to_rendererer     1.00    0.010   0.010   0.010    0.010   0.010   0.010
                       ivas_dec_render     1.00    1.887   1.893   1.888    1.887   1.893   1.888
                       ---------------   ------   ------  ------  ------
                                 total  1050.00   49.469  69.248  58.998

Ways to reproduce

  • ./IVAS_dec stereo 48 ../stvST48c_64kbps.192 out.wav

Bitstream: stvST48c_64kbps.192