static void opj_v4dwt_decode(opj_v4dwt_t* OPJ_RESTRICT dwt)
{
OPJ_INT32 a, b;
+ /* BUG_WEIRD_TWO_INVK (look for this identifier in tcd.c) */
+ /* Historic value for 2 / opj_invK */
+ /* Normally, we should use invK, but if we do so, we have failures in the */
+ /* conformance test, due to MSE and peak errors significantly higher than */
+ /* accepted value */
+ /* Due to using two_invK instead of invK, we have to compensate in tcd.c */
+ /* the computation of the stepsize for the non LL subbands */
+ const float two_invK = 1.625732422f;
if (dwt->cas == 0) {
if (!((dwt->dn > 0) || (dwt->sn > 1))) {
return;
opj_v4dwt_decode_step1_sse(dwt->wavelet + a, dwt->win_l_x0, dwt->win_l_x1,
_mm_set1_ps(opj_K));
opj_v4dwt_decode_step1_sse(dwt->wavelet + b, dwt->win_h_x0, dwt->win_h_x1,
- _mm_set1_ps(opj_invK));
+ _mm_set1_ps(two_invK));
opj_v4dwt_decode_step2_sse(dwt->wavelet + b, dwt->wavelet + a + 1,
dwt->win_l_x0, dwt->win_l_x1,
(OPJ_UINT32)opj_int_min(dwt->sn, dwt->dn - a),
opj_v4dwt_decode_step1(dwt->wavelet + a, dwt->win_l_x0, dwt->win_l_x1,
opj_K);
opj_v4dwt_decode_step1(dwt->wavelet + b, dwt->win_h_x0, dwt->win_h_x1,
- opj_invK);
+ two_invK);
opj_v4dwt_decode_step2(dwt->wavelet + b, dwt->wavelet + a + 1,
dwt->win_l_x0, dwt->win_l_x1,
(OPJ_UINT32)opj_int_min(dwt->sn, dwt->dn - a),
{
/* Table E-1 - Sub-band gains */
- const OPJ_INT32 log2_gain = (l_band->bandno == 0) ? 0 :
+ /* BUG_WEIRD_TWO_INVK (look for this identifier in dwt.c): */
+ /* the test (!isEncoder && l_tccp->qmfbid == 0) is strongly */
+ /* linked to the use of two_invK instead of invK */
+ const OPJ_INT32 log2_gain = (!isEncoder &&
+ l_tccp->qmfbid == 0) ? 0 : (l_band->bandno == 0) ? 0 :
(l_band->bandno == 3) ? 2 : 1;
/* Nominal dynamic range. Equation E-4 */