From 3d35d0f3af46ee206a3ea147298aad3d83a7775c Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Mon, 18 May 2020 20:17:07 +0200 Subject: [PATCH] tcd.c: add comment --- src/lib/openjp2/tcd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/lib/openjp2/tcd.c b/src/lib/openjp2/tcd.c index 503dc472..e41e7772 100644 --- a/src/lib/openjp2/tcd.c +++ b/src/lib/openjp2/tcd.c @@ -1009,6 +1009,9 @@ static INLINE OPJ_BOOL opj_tcd_init_tile(opj_tcd_t *p_tcd, OPJ_UINT32 p_tile_no, /** avoid an if with storing function pointer */ l_gain = (*l_gain_ptr)(l_band->bandno); numbps = (OPJ_INT32)(l_image_comp->prec + l_gain); + + /* Delta_b value of Equation E-3 in "E.1 Inverse quantization + * procedure" of the standard */ l_band->stepsize = (OPJ_FLOAT32)(((1.0 + l_step_size->mant / 2048.0) * pow(2.0, (OPJ_INT32)(numbps - l_step_size->expn)))) * fraction; /* Mb value of Equation E-2 in "E.1 Inverse quantization