VAR_GAMMA_R       133 libavfilter/vf_eq.c     eq->var_values[VAR_GAMMA_R]      =  av_clipf(av_expr_eval(eq->gamma_r_pexpr,      eq->var_values, eq),  0.1, 10.0);
VAR_GAMMA_R       140 libavfilter/vf_eq.c     eq->param[2].gamma = sqrt(eq->var_values[VAR_GAMMA_R] / eq->var_values[VAR_GAMMA_G]);