Commit 8a69cf17 authored by vaillancour's avatar vaillancour
Browse files

more comments to limiter functions

parent 67a77ab8

lib_enc/ivas_stereo_td_analysis.c

+29 −1
Original line number Diff line number Diff line
@@ -1030,7 +1030,25 @@ static int16_t limit_idx_Dwnmix( 


    idx = idx_in;

    idx = check_bounds_s( idx, 1, 29 );



   /*-------------------------------------------------------------------*

    * The ratio index is limited between [1. 29]

    * in case of uncorrelated content 

    * (not interfering talker, but really uncorrelated left and right channel) 

    * after the transition period, some more checks are done to choose the 

    * dominant channel 

    * if the ratio index is below or equal to mid-range (15) 

    *   and the instantaneous ratio index is below 17

    *   then the right channel will be considered as dominant (0 or 1)

    * else if the ratio index is above or equal to mid-range (15) 

    *   and the instantaneous ratio index is above 14

    *   then the left channel will be considered as dominant (29 or 30)

    * else if the instantaneous ratio index is below 11

    *   then the right channel will be considered as dominant (0 or 1)

    * else if the instantaneous ratio index is above 19

    *   then the left channel will be considered as dominant (29 or 30)

    * else the previous ratio index will be used

    * 

    *-------------------------------------------------------------------*/

    if ( unclr_decision == 1 && tdm_last_LRTD_frame_cnt > 1 )

    {

        if ( tdm_last_LRTD_PriCh_cnt > 0 )
@@ -1080,6 +1098,16 @@ static int16_t limit_idx_NoDwnmix( 
    int16_t idx;



    idx = idx_in;

   /*-------------------------------------------------------------------*

    * if the energy ratio index is close to the mid range ]10,20[, 

    * but changing primary to secondary channel is not recommended the output 

    * index is forced to 30 (dominant left channel) unless the raw 

    * correlation difference in negative (pointing to dominant right channel ) 

    * else, 

    *   the output index is force to 0 (dominant right channel) 

    *   if the index is below or equal to mid-range 

    *   else it is force to 30 (dominant left channel)

    *-------------------------------------------------------------------*/

    if ( side_can_change == 0 && idx_in > 10 && idx_in < 20 )

    {

        idx = 30;