How do I pre-allocate an output buffer for the encoder?

To pre-allocate your own output buffer, you have to first declare an OssBuf type variable. Next, you have to use a memory allocating function (such as malloc() or calloc()) to allocate the needed memory buffer and set the value field of the OssBuf structure to point to the beginning of this buffer. Finally, you have to set the length field of the OssBuf structure to the length in bytes of the allocated buffer. Then, you can call the encoder and it will use your allocated buffer to store its output.

This procedure is illustrated as follows:

OssBuf encodedData;    
. . . .    
encodedData.value = (char )malloc(1024 * sizeof(char));    
encodedData.length = 1024;    
rc = ossEncode(world, myPduNum, &myData, &encodedData);    

To determine the length of the buffer without calling ossEncode(), call ossDetermineEncodingLength().

The samples included with some of the Knowledge Center answers are meant for your general understanding of the OSS products. Different versions of the products might produce slightly different outputs. Consult the products documentation and samples for the most up-to-date products information and code examples.