static void CreateCodeArray( HUFF_ENTRY * HuffRoot,
ogg_uint32_t *HuffCodeArray,
unsigned char *HuffCodeLengthArray,
ogg_uint32_t CodeValue,
unsigned char CodeLength ) {
/* If we are at a leaf then fill in a code array entry. */
if ( ( HuffRoot->ZeroChild == NULL ) && ( HuffRoot->OneChild == NULL ) ){
HuffCodeArray[HuffRoot->Value] = CodeValue;
HuffCodeLengthArray[HuffRoot->Value] = CodeLength;
}else{
/* Recursive calls to scan down the tree. */
CodeLength++;
CreateCodeArray(HuffRoot->ZeroChild, HuffCodeArray, HuffCodeLengthArray,
((CodeValue << 1) + 0), CodeLength);
CreateCodeArray(HuffRoot->OneChild, HuffCodeArray, HuffCodeLengthArray,
((CodeValue << 1) + 1), CodeLength);
}
}
/****************************************************************************
*
* ROUTINE : CreateCodeArray
*
* INPUTS : The tree root
* A HuffCodeArray
* A HuffCodeLengthArray
* The code value of the root.
* The length of the code in bits.
*
* OUTPUTS :
*
* RETURNS :
*
* FUNCTION : This funtion creates the code array from the huffman tree
* that is used to code tokens.
*
* SPECIAL NOTES : None.
*
*
* ERRORS : None.
*
****************************************************************************/
void CreateCodeArray( HUFF_ENTRY * HuffRoot,
UINT32 * HuffCodeArray,
UINT8 * HuffCodeLengthArray,
UINT32 CodeValue, UINT8 CodeLength )
{
/* If we are at a leaf then fill in a code array entry. */
if ( ( HuffRoot->ZeroChild == NULL ) && ( HuffRoot->OneChild == NULL ) )
{
HuffCodeArray[HuffRoot->Value] = CodeValue;
HuffCodeLengthArray[HuffRoot->Value] = CodeLength;
}
else
{
/* Recursive calls to scan down the tree. */
CreateCodeArray( (HUFF_ENTRY *)(HuffRoot->ZeroChild), HuffCodeArray, HuffCodeLengthArray, ((CodeValue << 1) + 0), (UINT8)(CodeLength + 1) );
CreateCodeArray( (HUFF_ENTRY *)(HuffRoot->OneChild), HuffCodeArray, HuffCodeLengthArray, ((CodeValue << 1) + 1), (UINT8)(CodeLength + 1) );
}
}
static void BuildHuffmanTree( HUFF_ENTRY **HuffRoot,
ogg_uint32_t *HuffCodeArray,
unsigned char *HuffCodeLengthArray,
ogg_uint32_t HIndex,
const ogg_uint32_t *FreqList ){
HUFF_ENTRY *entry_ptr;
HUFF_ENTRY *search_ptr;
/* First create a sorted linked list representing the frequencies of
each token. */
CreateHuffmanList( HuffRoot, HIndex, FreqList );
/* Now build the tree from the list. */
/* While there are at least two items left in the list. */
while ( HuffRoot[HIndex]->Next != NULL ){
/* Create the new node as the parent of the first two in the list. */
entry_ptr = (HUFF_ENTRY *)_ogg_calloc(1,sizeof(*entry_ptr));
entry_ptr->Value = -1;
entry_ptr->Frequency = HuffRoot[HIndex]->Frequency +
HuffRoot[HIndex]->Next->Frequency ;
entry_ptr->ZeroChild = HuffRoot[HIndex];
entry_ptr->OneChild = HuffRoot[HIndex]->Next;
/* If there are still more items in the list then insert the new
node into the list. */
if (entry_ptr->OneChild->Next != NULL ){
/* Set up the provisional 'new root' */
HuffRoot[HIndex] = entry_ptr->OneChild->Next;
HuffRoot[HIndex]->Previous = NULL;
/* Now scan through the remaining list to insert the new entry
at the appropriate point. */
if ( entry_ptr->Frequency <= HuffRoot[HIndex]->Frequency ){
entry_ptr->Next = HuffRoot[HIndex];
HuffRoot[HIndex]->Previous = entry_ptr;
entry_ptr->Previous = NULL;
HuffRoot[HIndex] = entry_ptr;
}else{
search_ptr = HuffRoot[HIndex];
while ( (search_ptr->Next != NULL) &&
(search_ptr->Frequency < entry_ptr->Frequency) ){
search_ptr = search_ptr->Next;
}
if ( search_ptr->Frequency < entry_ptr->Frequency ){
entry_ptr->Next = NULL;
entry_ptr->Previous = search_ptr;
search_ptr->Next = entry_ptr;
}else{
entry_ptr->Next = search_ptr;
entry_ptr->Previous = search_ptr->Previous;
search_ptr->Previous->Next = entry_ptr;
search_ptr->Previous = entry_ptr;
}
}
}else{
/* Build has finished. */
entry_ptr->Next = NULL;
entry_ptr->Previous = NULL;
HuffRoot[HIndex] = entry_ptr;
}
/* Delete the Next/Previous properties of the children (PROB NOT NEC). */
entry_ptr->ZeroChild->Next = NULL;
entry_ptr->ZeroChild->Previous = NULL;
entry_ptr->OneChild->Next = NULL;
entry_ptr->OneChild->Previous = NULL;
}
/* Now build a code array from the tree. */
CreateCodeArray( HuffRoot[HIndex], HuffCodeArray,
HuffCodeLengthArray, 0, 0);
}
void BuildHuffmanTree( UINT32 RootIndex, UINT32 HIndex, UINT32 * FreqList )
{
HUFF_ENTRY * entry_ptr;
HUFF_ENTRY * search_ptr;
HUFF_ENTRY ** HuffRoot;
// Select the Huffmant tree root.
if ( RootIndex < 2 )
HuffRoot = HuffRoot_VP31;
else
HuffRoot = HuffRoot_VP33;
/* First create a sorted linked list representing the frequencies of each token. */
CreateHuffmanList( HuffRoot, HIndex, FreqList );
/* Now build the tree from the list. */
/* While there are at least two items left in the list. */
while ( HuffRoot[HIndex]->Next != NULL )
{
/* Create the new node as the parent of the first two in the list. */
//entry_ptr = GlobalAlloc( GPTR, sizeof(HUFF_ENTRY) );
entry_ptr = (HUFF_ENTRY *)SytemGlobalAlloc( sizeof(HUFF_ENTRY) );
if ( entry_ptr == NULL )
IssueWarning( "Allocation Error in BuildHuffman" );
entry_ptr->Value = -1;
entry_ptr->Frequency = HuffRoot[HIndex]->Frequency + ( ((HUFF_ENTRY *)HuffRoot[HIndex]->Next)->Frequency );
entry_ptr->ZeroChild = (char *)HuffRoot[HIndex];
entry_ptr->OneChild = (char *)(HuffRoot[HIndex]->Next);
/* If there are still more items in the list then insert the new node into the list. */
if ( ((HUFF_ENTRY *)entry_ptr->OneChild)->Next != NULL )
{
/* Set up the provisional 'new root' */
HuffRoot[HIndex] = (HUFF_ENTRY *)( ((HUFF_ENTRY *)entry_ptr->OneChild)->Next );
HuffRoot[HIndex]->Previous = NULL;
/* Now scan through the remaining list to insert the new entry at the appropriate point. */
if ( entry_ptr->Frequency <= HuffRoot[HIndex]->Frequency )
{
entry_ptr->Next = (char * )HuffRoot[HIndex];
HuffRoot[HIndex]->Previous = (char * )entry_ptr;
entry_ptr->Previous = (char * )NULL;
HuffRoot[HIndex] = entry_ptr;
}
else
{
search_ptr = HuffRoot[HIndex];
while ( (search_ptr->Next != NULL) &&
(search_ptr->Frequency < entry_ptr->Frequency) )
{
search_ptr = (HUFF_ENTRY *)search_ptr->Next;
}
if ( search_ptr->Frequency < entry_ptr->Frequency )
{
entry_ptr->Next = (char * )NULL;
entry_ptr->Previous = (char * )search_ptr;
search_ptr->Next = (char * )entry_ptr;
}
else
{
entry_ptr->Next = (char * )search_ptr;
entry_ptr->Previous = search_ptr->Previous;
((HUFF_ENTRY *)(search_ptr->Previous))->Next = (char * )entry_ptr;
search_ptr->Previous = (char * )entry_ptr;
}
}
}
else
{
/* Build has finished. */
entry_ptr->Next = NULL;
entry_ptr->Previous = NULL;
HuffRoot[HIndex] = entry_ptr;
}
/* Delete the Next/Previous properties of the children (PROB NOT NEC). */
((HUFF_ENTRY *)entry_ptr->ZeroChild)->Next = NULL;
((HUFF_ENTRY *)entry_ptr->ZeroChild)->Previous = NULL;
((HUFF_ENTRY *)entry_ptr->OneChild)->Next = NULL;
((HUFF_ENTRY *)entry_ptr->OneChild)->Previous = NULL;
}
/* Now build a code array from the tree. */
if ( RootIndex < 2 )
CreateCodeArray( HuffRoot[HIndex], HuffCodeArray_VP31[HIndex], HuffCodeLengthArray_VP31[HIndex], 0, 0);
else
CreateCodeArray( HuffRoot[HIndex], HuffCodeArray_VP33[HIndex], HuffCodeLengthArray_VP33[HIndex], 0, 0);
}
