diff --git a/test_utils/CMakeLists.txt b/test_utils/CMakeLists.txt
index 4fa4cadee..272c8fdbe 100644
--- a/test_utils/CMakeLists.txt
+++ b/test_utils/CMakeLists.txt
@@ -48,6 +48,20 @@ gu_copy_test_data(ref_grid_172.landmask.grib1)
 gu_copy_test_data(ref_grid_220.landmask.grib1)
 gu_copy_test_data(tocgrib2.nml)
 gu_copy_test_data(tocgrib2_bad.nml)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx)
+gu_copy_test_data(ref_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx)
 
 if(FTP_TEST_FILES)
   message(STATUS "Getting FTP test files...")  
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx
new file mode 100644
index 000000000..8e3284520
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx
new file mode 100644
index 000000000..d2a1d6ddd
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx
new file mode 100644
index 000000000..2d667c564
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx
new file mode 100644
index 000000000..3508621dc
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx
new file mode 100644
index 000000000..b1e6cea0d
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx
new file mode 100644
index 000000000..551f92c4c
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx
new file mode 100644
index 000000000..12250d0a7
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx
new file mode 100644
index 000000000..1392e16aa
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx
new file mode 100644
index 000000000..a22a78835
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx
new file mode 100644
index 000000000..4a17f9e21
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx
new file mode 100644
index 000000000..5e966b4e9
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx
new file mode 100644
index 000000000..238db8b99
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx
new file mode 100644
index 000000000..a00134c83
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx differ
diff --git a/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx
new file mode 100644
index 000000000..8d9baf643
Binary files /dev/null and b/test_utils/data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx differ
diff --git a/test_utils/run_cnvgrib_tests.sh b/test_utils/run_cnvgrib_tests.sh
index 61ac3779c..e70714cdc 100644
--- a/test_utils/run_cnvgrib_tests.sh
+++ b/test_utils/run_cnvgrib_tests.sh
@@ -2,39 +2,111 @@
 # This is a test script for the NCEPLIBS-grib_util project.
 #
 # Ed Hartnett, 12/25/21
+# Alyson Stahl, 1/29/25
 
 set -e
 echo ""
 echo "*** Running cnvgrib test"
 
+# Show all options
+../utils/cnvgrib -h
+
+# Run with zero arguments
+../utils/cnvgrib && exit 2
+
+# Run with incorrect number of arguments
+../utils/cnvgrib -g21 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 && exit 2
+
+# Run with no -gxx option
+../utils/cnvgrib -p0 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.grib1 && exit 2
+
+# Invalid master table version
+../utils/cnvgrib -g21 -mastertable_ver_0 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.grib1 && exit 2
+
+# Invalid input file
+../utils/cnvgrib -g21 - test_gdaswave.t00z.wcoast.0p16.f000.grib1 && exit 3
+
+# Invalid conversion option
+../utils/cnvgrib -g11 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.grib1 && exit 5
+
 # Convert test file to GRIB1.
 ../utils/cnvgrib -g21 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.grib1
 
-# Generate an inventory of the GRIB1 file.
-#../src/wgrib/wgrib test_gdaswave.t00z.wcoast.0p16.f000.grib1 &> test_gdaswave.t00z.wcoast.0p16.f000.grib1.inventory.txt
+# Convert GRIB1 output back to GRIB2, create index, and compare to expected output
+# First 120 bytes contain differences, so ignore them.
+
+# Simple packing
+../utils/cnvgrib -g12 -p0 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_simple.grib2.idx
+
+# Complex Packing
+../utils/cnvgrib -g12 -p2 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex.grib2.idx
+
+# Complex Packing w/ primary missing values
+../utils/cnvgrib -g12 -p2 -m test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m.grib2.idx
+
+# Complex Packing w/ no explicit missing values included
+../utils/cnvgrib -g12 -p2 -m0 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex_m0.grib2.idx
+
+# Complex Packing w/ 1st order diffs
+../utils/cnvgrib -g12 -p31 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex1.grib2.idx
+
+# Complex Packing w/ 2nd order diffs
+../utils/cnvgrib -g12 -p32 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_complex2.grib2.idx
+
+# PNG Packing
+../utils/cnvgrib -g12 -p41 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g12_png.grib2.idx
+
+# Convert GRIB2 to GRIB2, create index, and compare to expected output
+# First 120 bytes contain differences, so ignore them.
 
-# Check against expected output.
-#cmp test_gdaswave.t00z.wcoast.0p16.f000.grib1.inventory.txt data/ref_gdaswave_grib1_inventory.txt
+# Simple packing
+../utils/cnvgrib -g22 -p0 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_simple.grib2.idx
 
-# Convert GRIB1 output back to GRIB2.
-../utils/cnvgrib -g12 test_gdaswave.t00z.wcoast.0p16.f000.grib1 test_gdaswave.t00z.wcoast.0p16.f000.grib2
+# Complex Packing
+../utils/cnvgrib -g22 -p2 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex.grib2.idx
 
-# Create an index of a GRIB2 file.
-../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.grib2.idx
+# Complex Packing w/ primary missing values
+../utils/cnvgrib -g22 -p2 -m data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m.grib2.idx
 
-# Check against expected output. First 120 bytes contain differences,
-# so ignore them.
-cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2.idx
+# Complex Packing w/ no explicit missing values included
+../utils/cnvgrib -g22 -p2 -m0 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex_m0.grib2.idx
 
-# Convert test file to another GRIB2 file.
-../utils/cnvgrib -g22 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000_2.grib2
+# Complex Packing w/ 1st order diffs
+../utils/cnvgrib -g22 -p31 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex1.grib2.idx
 
-# Create an index of the new GRIB2 file.
-../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000_2.grib2 test_gdaswave.t00z.wcoast.0p16.f000_2.grib2.idx
+# Complex Packing w/ 2nd order diffs
+../utils/cnvgrib -g22 -p32 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_complex2.grib2.idx
 
-# Check against expected output. First 120 bytes contain differences,
-# so ignore them.
-cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000_2.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000_2.grib2.idx
+# PNG Packing
+../utils/cnvgrib -g22 -p41 data/ref_gdaswave.t00z.wcoast.0p16.f000.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2
+../utils/grb2index 1 test_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2 test_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx
+cmp -i 120 test_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx data/ref_gdaswave.t00z.wcoast.0p16.f000.g22_png.grib2.idx
 
 echo "*** SUCCESS!"
 exit 0