Enable g2int and int outputs for jpeg decoding with OpenJPEG (#591)

* create static function int_dec_jpeg2000 to decenc_openjpeg.c to handle g2int and int outputs

* typos

* format

* more format issues

* Update decenc_openjpeg.c

* address void expression warning

* enable tests for openjpeg

Author: AlysonStahl-NOAA

src/decenc_openjpeg.c

@@ -243,10 +243,14 @@ opj_stream_create_default_memory_stream(opj_memory_stream *memoryStream, OPJ_BOO
  * PROGRAM HISTORY LOG:
  * - 2002-12-02  Gilbert
  * - 2016-06-08  Jovic
+ * - 2025-03-07 Stahl | added functionality to handle g2int and int outputs
  *
  * @param injpc Input JPEG2000 code stream.
  * @param bufsize Length (in bytes) of the input JPEG2000 code stream.
- * @param outfld Output matrix of grayscale image values.
+ * @param outfld Pointer to either int or g2int array, already
+ * allocated, that gets the unpacked data.
+ * @param out_is_g2int Non-zero if the output array is of type g2int
+ * (i.e. 64-bit ints), zero if output is an int array (32-bits).
  *
  * @return
  * - 0 Successful decode
@@ -255,37 +259,10 @@ opj_stream_create_default_memory_stream(opj_memory_stream *memoryStream, OPJ_BOO
  *
  * @note Requires OpenJPEG Version 2.
  *
- * @author Alyson Stahl
+ * @author Stephen Gilbert, Jovic, Stahl
  */
-int
-g2c_dec_jpeg2000(char *injpc, size_t bufsize, int *outfld)
-{
-    return dec_jpeg2000(injpc, bufsize, (g2int *)outfld);
-}
-
-/**
- * This Function decodes a JPEG2000 code stream specified in the
- * JPEG2000 Part-1 standard (i.e., ISO/IEC 15444-1) using OpenJPEG.
- *
- * PROGRAM HISTORY LOG:
- * - 2002-12-02  Gilbert
- * - 2016-06-08  Jovic
- *
- * @param injpc Input JPEG2000 code stream.
- * @param bufsize Length (in bytes) of the input JPEG2000 code stream.
- * @param outfld Output matrix of grayscale image values.
- *
- * @return
- * - 0 Successful decode
- * - -3 Error decode jpeg2000 code stream.
- * - -5 decoded image had multiple color components. Only grayscale is expected.
- *
- * @note Requires OpenJPEG Version 2.
- *
- * @author Stephen Gilbert, Jovic
- */
-int
-dec_jpeg2000(char *injpc, g2int bufsize, g2int *outfld)
+static int
+int_dec_jpeg2000(char *injpc, g2int bufsize, void *outfld, int out_is_g2int)
 {
     int iret = 0;
     OPJ_INT32 mask;
@@ -348,8 +325,16 @@ dec_jpeg2000(char *injpc, g2int bufsize, g2int *outfld)
 
     mask = (1 << image->comps[0].prec) - 1;
 
-    for (unsigned int i = 0; i < image->comps[0].w * image->comps[0].h; i++)
-        outfld[i] = (g2int)(image->comps[0].data[i] & mask);
+    if (out_is_g2int)
+    {
+        for (unsigned int i = 0; i < image->comps[0].w * image->comps[0].h; i++)
+            ((g2int *)outfld)[i] = (g2int)(image->comps[0].data[i] & mask);
+    }
+    else
+    {
+        for (unsigned int i = 0; i < image->comps[0].w * image->comps[0].h; i++)
+            ((int *)outfld)[i] = (int)(image->comps[0].data[i] & mask);
+    }
 
     if (!opj_end_decompress(codec, stream))
     {
@@ -369,6 +354,61 @@ dec_jpeg2000(char *injpc, g2int bufsize, g2int *outfld)
     return iret;
 }
 
+/**
+ * This Function decodes a JPEG2000 code stream specified in the
+ * JPEG2000 Part-1 standard (i.e., ISO/IEC 15444-1) using OpenJPEG.
+ *
+ * PROGRAM HISTORY LOG:
+ * - 2002-12-02  Gilbert
+ * - 2016-06-08  Jovic
+ *
+ * @param injpc Input JPEG2000 code stream.
+ * @param bufsize Length (in bytes) of the input JPEG2000 code stream.
+ * @param outfld Output matrix of grayscale image values.
+ *
+ * @return
+ * - 0 Successful decode
+ * - -3 Error decode jpeg2000 code stream.
+ * - -5 decoded image had multiple color components. Only grayscale is expected.
+ *
+ * @note Requires OpenJPEG Version 2.
+ *
+ * @author Alyson Stahl
+ */
+int
+g2c_dec_jpeg2000(char *injpc, size_t bufsize, int *outfld)
+{
+    return int_dec_jpeg2000(injpc, bufsize, outfld, 0);
+}
+
+/**
+ * This Function decodes a JPEG2000 code stream specified in the
+ * JPEG2000 Part-1 standard (i.e., ISO/IEC 15444-1) using OpenJPEG.
+ *
+ * PROGRAM HISTORY LOG:
+ * - 2002-12-02  Gilbert
+ * - 2016-06-08  Jovic
+ * - 2025-03-07 Stahl | moved code to int_dec_jpeg2000() function to handle int outputs
+ *
+ * @param injpc Input JPEG2000 code stream.
+ * @param bufsize Length (in bytes) of the input JPEG2000 code stream.
+ * @param outfld Output matrix of grayscale image values.
+ *
+ * @return
+ * - 0 Successful decode
+ * - -3 Error decode jpeg2000 code stream.
+ * - -5 decoded image had multiple color components. Only grayscale is expected.
+ *
+ * @note Requires OpenJPEG Version 2.
+ *
+ * @author Stephen Gilbert, Jovic, Stahl
+ */
+int
+dec_jpeg2000(char *injpc, g2int bufsize, g2int *outfld)
+{
+    return int_dec_jpeg2000(injpc, bufsize, outfld, 1);
+}
+
 /**
  * This Function encodes a grayscale image into a JPEG2000 code stream
  * specified in the JPEG2000 Part-1 standard (i.e., ISO/IEC 15444-1)

tests/tst_jpeg.c

@@ -20,7 +20,6 @@ main()
 
     printf("Testing JPEG functions.\n");
     /* g2c_set_log_level(10); */
-#ifdef USE_JPEG2000
     printf("Testing enc_jpeg2000()/dec_jpeg2000() call...");
     {
         unsigned char data[DATA_LEN] = {1, 2, 3, 4};
@@ -72,7 +71,6 @@ main()
         }
     }
     printf("ok!\n");
-#endif
     {
         g2int height = 2, width = 2;
         g2int len = PACKED_LEN, ndpts = DATA_LEN;