Internal libtiff: fix writing a Predictor=3 file with non-native endi…

…anness
OSGeo · Dec 18, 2024 · 42e8bb7 · 42e8bb7
1 parent 50194b6
commit 42e8bb7
Show file tree

Hide file tree

Showing 4 changed files with 31 additions and 5 deletions.
diff --git a/autotest/gcore/data/gtiff/float32_lzw_predictor_3_big_endian.tif b/autotest/gcore/data/gtiff/float32_lzw_predictor_3_big_endian.tif
diff --git a/autotest/gcore/tiff_read.py b/autotest/gcore/tiff_read.py
@@ -73,6 +73,7 @@
     ("empty1bit.tif", 1, 0),
     ("gtiff/int64_full_range.tif", 1, 65535),
     ("gtiff/uint64_full_range.tif", 1, 1),
+    ("gtiff/float32_lzw_predictor_3_big_endian.tif", 1, 4672),
 ]
 
 

diff --git a/autotest/gcore/tiff_write.py b/autotest/gcore/tiff_write.py
@@ -11868,3 +11868,23 @@ def test_tiff_write_band_IMAGERY(tmp_vsimem):
         )
     with gdal.Open(filename2) as ds:
         assert ds.GetRasterBand(1).GetMetadata_Dict("IMAGERY") == {"foo": "bar"}
+
+
+###############################################################################
+#
+
+
+@pytest.mark.skipif(
+    not check_libtiff_internal_or_at_least(4, 7, 1),
+    reason="libtiff internal or >= 4.7.1 needed",
+)
+def test_tiff_write_float32_predictor_3_endianness(tmp_path):
+
+    out_filename = str(tmp_path / "out.tif")
+    gdal.GetDriverByName("GTiff").CreateCopy(
+        out_filename,
+        gdal.Open("data/float32.tif"),
+        options=["COMPRESS=LZW", "ENDIANNESS=INVERTED", "PREDICTOR=3"],
+    )
+    with gdal.Open(out_filename) as ds:
+        assert ds.GetRasterBand(1).Checksum() == 4672
diff --git a/frmts/gtiff/libtiff/tif_predict.c b/frmts/gtiff/libtiff/tif_predict.c
@@ -208,16 +208,12 @@ static int PredictorSetupDecode(TIFF *tif)
         /*
          * The data should not be swapped outside of the floating
          * point predictor, the accumulation routine should return
-         * byres in the native order.
+         * bytes in the native order.
          */
         if (tif->tif_flags & TIFF_SWAB)
         {
             tif->tif_postdecode = _TIFFNoPostDecode;
         }
-        /*
-         * Allocate buffer to keep the decoded bytes before
-         * rearranging in the right order
-         */
     }
 
     return 1;
@@ -305,6 +301,15 @@ static int PredictorSetupEncode(TIFF *tif)
             sp->encodetile = tif->tif_encodetile;
             tif->tif_encodetile = PredictorEncodeTile;
         }
+        /*
+         * The data should not be swapped outside of the floating
+         * point predictor, the differentiation routine should return
+         * bytes in the native order.
+         */
+        if (tif->tif_flags & TIFF_SWAB)
+        {
+            tif->tif_postdecode = _TIFFNoPostDecode;
+        }
     }
 
     return 1;