Page History

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When converting to JPEG packing with the Jasper JasPer library, you get the above assertion:

Code Block
% grib_set -s packingType=grid_jpeg input.grib2 output.grib2 grib_set: jpc_enc.c:186: jpc_abstorelstepsize: Assertion `!((expn) & (~0x1f))' failed. Aborted (core dumped)

This problem can also occur if you have an existing JPEG packed field and you wish to encode it with different values e.g. scaling all values up

Code Block
% grib_set -s scaleValuesBy=150 input.grib2 output.grib2

Solution

This is a problem in the Jasper library. It seems to be related to the number of bits per value of the input field.

Panel

bgColor	#fff

Pick a decimal precision value that will avoid the assertion and preserves the required precision

grib_set -s setDecimalPrecision=4,packingType=grid_jpeg input.grib2 output.grib2
Check the statistics before and after
grib_ls -n statistics input.grib2
grib_ls -n statistics output.grib2
Compare the results

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Content by Label

showLabels	false
max	5
spaces	UDOC
showSpace	false
sort	modified
reverse	true
type	page
cql	label in ("grib","jpeg","jasper","packing") and label in ("grib","jpeg","packing") and label in ("encode","jpeg") and type = "page" and space = "UDOC"
labels	grib jpeg packing jasper

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