Merge pull request #605 from AlysonStahl-NOAA/as_aec

Adding g2c_enc_aec()/g2c_dec_aec() functions for int input/output

Author: AlysonStahl-NOAA

src/decenc_aec.c

@@ -148,3 +148,76 @@ enc_aec(unsigned char *data, g2int ctemplen, g2int nbits, g2int flags,
 
     return ret;
 }
+
+/**
+ * Decode an AEC code stream specified in the [CCSDS 121.0-B-3 Blue
+ * Book](https://public.ccsds.org/Pubs/121x0b3.pdf).
+ *
+ * @param cpack Pointer to buffer that holds the input AEC code
+ * stream.
+ * @param len Length (in bytes) of the buffer that holds the input
+ * AEC code stream.
+ * @param nbits CCSDS bits per sample.
+ * @param flags CCSDS compression options mask.
+ * @param block_size CCSDS block size.
+ * @param rsi CCSDS reference sample interval.
+ * @param cfld Pointer to output buffer from the AEC decoder.
+ * @param cfldlen length of output buffer.
+ *
+ * @return
+ * - >0 Length of data from AEC decoder
+ * - 0 Successful decode (AEC_OK)
+ * - -1 AEC_CONF_ERROR
+ * - -2 AEC_STREAM_ERROR
+ * - -3 AEC_DATA_ERROR
+ * - -4 AEC_MEM_ERROR
+ * - -5 AEC_RSI_OFFSETS_ERROR
+ *
+ * @author Alyson Stahl @date 10/2025
+ */
+int
+g2c_dec_aec(unsigned char *cpack, int len, int nbits, int flags,
+            int block_size, int rsi, unsigned char *cfld, int cfldlen)
+{
+    g2int len8 = len, nbits8 = nbits, flags8 = flags;
+    g2int block_size8 = block_size, rsi8 = rsi, cfldlen8 = cfldlen;
+
+    return dec_aec(cpack, len8, nbits8, flags8, block_size8, rsi8,
+                   cfld, cfldlen8);
+}
+
+/**
+ * Encode data into an AEC code stream specified in the
+ * [CCSDS 121.0-B-3 Blue Book](https://public.ccsds.org/Pubs/121x0b3.pdf).
+ *
+ * @param data Pointer to buffer that holds the input data.
+ * @param ctemplen Length (in bytes) of the buffer that holds
+ * the input data..
+ * @param nbits CCSDS bits per sample.
+ * @param flags CCSDS compression options mask.
+ * @param block_size CCSDS block size.
+ * @param rsi CCSDS reference sample interval.
+ * @param aecbuf Pointer to buffer holding the AEC encoded stream.
+ * @param aecbuflen Length of AEC code stream.
+ *
+ * @return
+ * - >0 Exact length of AEC encoded data.
+ * - 0 Successful decode (AEC_OK)
+ * - -1 AEC_CONF_ERROR
+ * - -2 AEC_STREAM_ERROR
+ * - -3 AEC_DATA_ERROR
+ * - -4 AEC_MEM_ERROR
+ * - -5 AEC_RSI_OFFSETS_ERROR
+ *
+ * @author Alyson Stahl @date 10/2025
+ */
+int
+g2c_enc_aec(unsigned char *data, int ctemplen, int nbits, int flags,
+            int block_size, int rsi, unsigned char *aecbuf, int *aecbuflen)
+{
+    g2int ctemplen8 = ctemplen, nbits8 = nbits, flags8 = flags;
+    g2int block_size8 = block_size, rsi8 = rsi, aecbuflen8 = *aecbuflen;
+
+    return enc_aec(data, ctemplen8, nbits8, flags8, block_size8, rsi8,
+                   aecbuf, &aecbuflen8);
+}

src/grib2.h.in

@@ -384,6 +384,10 @@ int g2c_enc_png(unsigned char *data, int width, int height, int nbits,
                 unsigned char *pngbuf);
 int g2c_dec_png(unsigned char *pngbuf, int *width, int *height,
                 unsigned char *cout);
+int g2c_enc_aec(unsigned char *data, int ctemplen, int nbits, int flags,
+                int block_size, int rsi, unsigned char *aecbuf, int *aecbuflen);
+int g2c_dec_aec(unsigned char *cpack, int len, int nbits, int flags,
+                int block_size, int rsi, unsigned char *cfld, int cfldlen);
 int g2c_aecpackf(float *fld, size_t width, size_t height, int *idrstmpl,
                  unsigned char *cpack, size_t *lcpack);
 int g2c_aecpackd(double *fld, size_t width, size_t height, int *idrstmpl,

tests/tst_aec.c

@@ -154,6 +154,44 @@ main()
         }
     }
     printf("ok!\n");
+    printf("Testing g2c_enc_aec()/g2c_dec_aec() call...");
+    {
+        unsigned char data[4] = {1, 2, 3, 4};
+        unsigned char cout[200];
+        int nbits = 32;
+        int datalen = 4;
+        int aeclen = 200;
+        int ccsds_flags;
+        int ccsds_block_size;
+        int ccsds_rsi;
+        unsigned char *databuf;
+        unsigned char *aecbuf;
+
+        int i, ret;
+
+        databuf = data;
+        aecbuf = cout;
+
+        ccsds_flags = CCSDS_FLAGS;
+        ccsds_block_size = 16;
+        ccsds_rsi = 128;
+
+        /* Encode some data. */
+        ret = g2c_enc_aec(databuf, datalen, nbits, ccsds_flags, ccsds_block_size,
+                          ccsds_rsi, aecbuf, &aeclen);
+        if (ret < 0)
+            return G2C_ERROR;
+
+        /* Now decode it. */
+        ret = g2c_dec_aec(aecbuf, aeclen, nbits, ccsds_flags, ccsds_block_size,
+                          ccsds_rsi, cout, datalen);
+        if (ret < 0)
+            return G2C_ERROR;
+
+        for (i = 0; i < datalen; i++)
+            if (cout[i] != data[i])
+                return G2C_ERROR;
+    }
     printf("SUCCESS!\n");
     return 0;
 }