  A sample of more than one million Ke4 decay candidates with less than one
percent background contamination has been collected by the NA48/2 experiment at
the CERN SPS in 2003-2004, allowing a detailed study of the decay properties.
The branching ratio, inclusive of radiative Ke4gamma decays, is measured to be
BR(Ke4) = (4.257 +/- 0.016_exp +/- 0.031_ext) x 10-5 with a total relative
error of 0.8%. This measurement complements the study of S- and P-wave hadronic
form factors by assigning absolute values to the relative hadronic form factors
obtained earlier in a simultaneous analysis of the pion-pion scattering lengths
conducted on the same data sample. The overall form factor normalization f_s =
5.705 +/- 0.017_exp +/- 0.031_ext is obtained with a total relative precision
of 0.6%.
