Esempio n. 1
0
size_t
enet_range_coder_compress (void * context, const ENetBuffer * inBuffers, size_t inBufferCount, size_t inLimit, enet_uint8 * outData, size_t outLimit)
{
    ENetRangeCoder * rangeCoder = (ENetRangeCoder *) context;
    enet_uint8 * outStart = outData, * outEnd = & outData [outLimit];
    const enet_uint8 * inData, * inEnd;
    enet_uint32 encodeLow = 0, encodeRange = ~0;
    ENetSymbol * root;
    enet_uint16 predicted = 0;
    size_t order = 0, nextSymbol = 0;

    if (rangeCoder == NULL || inBufferCount <= 0 || inLimit <= 0)
      return 0;

    inData = (const enet_uint8 *) inBuffers -> data;
    inEnd = & inData [inBuffers -> dataLength];
    inBuffers ++;
    inBufferCount --;

    ENET_CONTEXT_CREATE (root, ENET_CONTEXT_ESCAPE_MINIMUM, ENET_CONTEXT_SYMBOL_MINIMUM);

    for (;;)
    {
        ENetSymbol * subcontext, * symbol;
#ifdef ENET_CONTEXT_EXCLUSION
        const ENetSymbol * childContext = & emptyContext;
#endif
        enet_uint8 value;
        enet_uint16 count, under, * parent = & predicted, total;
        if (inData >= inEnd)
        {
            if (inBufferCount <= 0)
              break;
            inData = (const enet_uint8 *) inBuffers -> data;
            inEnd = & inData [inBuffers -> dataLength];
            inBuffers ++;
            inBufferCount --;
        }
        value = * inData ++;

        for (subcontext = & rangeCoder -> symbols [predicted];
             subcontext != root;
#ifdef ENET_CONTEXT_EXCLUSION
             childContext = subcontext,
#endif
                subcontext = & rangeCoder -> symbols [subcontext -> parent])
        {
            ENET_CONTEXT_ENCODE (subcontext, symbol, value, under, count, ENET_SUBCONTEXT_SYMBOL_DELTA, 0);
            * parent = symbol - rangeCoder -> symbols;
            parent = & symbol -> parent;
            total = subcontext -> total;
#ifdef ENET_CONTEXT_EXCLUSION
            if (childContext -> total > ENET_SUBCONTEXT_SYMBOL_DELTA + ENET_SUBCONTEXT_ESCAPE_DELTA)
              ENET_CONTEXT_ENCODE_EXCLUDE (childContext, value, under, total, 0);
#endif
            if (count > 0)
            {
                ENET_RANGE_CODER_ENCODE (subcontext -> escapes + under, count, total);
            }
            else
            {
                if (subcontext -> escapes > 0 && subcontext -> escapes < total)
                    ENET_RANGE_CODER_ENCODE (0, subcontext -> escapes, total);
                subcontext -> escapes += ENET_SUBCONTEXT_ESCAPE_DELTA;
                subcontext -> total += ENET_SUBCONTEXT_ESCAPE_DELTA;
            }
            subcontext -> total += ENET_SUBCONTEXT_SYMBOL_DELTA;
            if (count > 0xFF - 2*ENET_SUBCONTEXT_SYMBOL_DELTA || subcontext -> total > ENET_RANGE_CODER_BOTTOM - 0x100)
              ENET_CONTEXT_RESCALE (subcontext, 0);
            if (count > 0) goto nextInput;
        }

        ENET_CONTEXT_ENCODE (root, symbol, value, under, count, ENET_CONTEXT_SYMBOL_DELTA, ENET_CONTEXT_SYMBOL_MINIMUM);
        * parent = symbol - rangeCoder -> symbols;
        parent = & symbol -> parent;
        total = root -> total;
#ifdef ENET_CONTEXT_EXCLUSION
        if (childContext -> total > ENET_SUBCONTEXT_SYMBOL_DELTA + ENET_SUBCONTEXT_ESCAPE_DELTA)
          ENET_CONTEXT_ENCODE_EXCLUDE (childContext, value, under, total, ENET_CONTEXT_SYMBOL_MINIMUM);
#endif
        ENET_RANGE_CODER_ENCODE (root -> escapes + under, count, total);
        root -> total += ENET_CONTEXT_SYMBOL_DELTA;
        if (count > 0xFF - 2*ENET_CONTEXT_SYMBOL_DELTA + ENET_CONTEXT_SYMBOL_MINIMUM || root -> total > ENET_RANGE_CODER_BOTTOM - 0x100)
          ENET_CONTEXT_RESCALE (root, ENET_CONTEXT_SYMBOL_MINIMUM);

    nextInput:
        if (order >= ENET_SUBCONTEXT_ORDER)
          predicted = rangeCoder -> symbols [predicted].parent;
        else
          order ++;
        ENET_RANGE_CODER_FREE_SYMBOLS;
    }

    ENET_RANGE_CODER_FLUSH;

    return (size_t) (outData - outStart);
}
Esempio n. 2
0
size_t
enet_range_coder_compress (void * context, const ENetBuffer * inBuffers, size_t inBufferCount, size_t inLimit, enet_uint8 * outData, size_t outLimit)
{
#ifdef _DEBUG
//Seth - just some debug stuff to see how much this compresion was really doing.. not bad!
//	char stCrap[256];
//	int inBuff = inLimit;
#endif
    
	ENetRangeCoder * rangeCoder = (ENetRangeCoder *) context;
    enet_uint8 * outStart = outData, * outEnd = & outData [outLimit];
    const enet_uint8 * inData, * inEnd;
    enet_uint32 encodeLow = 0, encodeRange = ~0;
    ENetSymbol * root;
    enet_uint16 predicted = 0;
    size_t order = 0, nextSymbol = 0;

    if (rangeCoder == NULL || inBufferCount <= 0 || inLimit <= 0)
      return 0;

    inData = (const enet_uint8 *) inBuffers -> data;
    inEnd = & inData [inBuffers -> dataLength];
    inBuffers ++;
    inBufferCount --;

    ENET_CONTEXT_CREATE (root, ENET_CONTEXT_ESCAPE_MINIMUM, ENET_CONTEXT_SYMBOL_MINIMUM);

    for (;;)
    {
        ENetSymbol * subcontext, * symbol;
#ifdef ENET_CONTEXT_EXCLUSION
        const ENetSymbol * childContext = & emptyContext;
#endif
        enet_uint8 value;
        enet_uint16 count, under, * parent = & predicted, total;
        if (inData >= inEnd)
        {
            if (inBufferCount <= 0)
              break;
            inData = (const enet_uint8 *) inBuffers -> data;
            inEnd = & inData [inBuffers -> dataLength];
            inBuffers ++;
            inBufferCount --;
        }
        value = * inData ++;
    
        for (subcontext = & rangeCoder -> symbols [predicted]; 
             subcontext != root; 
#ifdef ENET_CONTEXT_EXCLUSION
             childContext = subcontext, 
#endif
                subcontext = & rangeCoder -> symbols [subcontext -> parent])
        {
            ENET_CONTEXT_ENCODE (subcontext, symbol, value, under, count, ENET_SUBCONTEXT_SYMBOL_DELTA, 0);
            * parent = symbol - rangeCoder -> symbols;
            parent = & symbol -> parent;
            total = subcontext -> total;
#ifdef ENET_CONTEXT_EXCLUSION
            if (childContext -> total > ENET_SUBCONTEXT_SYMBOL_DELTA + ENET_SUBCONTEXT_ESCAPE_DELTA)
              ENET_CONTEXT_ENCODE_EXCLUDE (childContext, value, under, total, 0);
#endif
            if (count > 0)
            {
                ENET_RANGE_CODER_ENCODE (subcontext -> escapes + under, count, total);
            }
            else
            {
                if (subcontext -> escapes > 0 && subcontext -> escapes < total) 
                    ENET_RANGE_CODER_ENCODE (0, subcontext -> escapes, total); 
                subcontext -> escapes += ENET_SUBCONTEXT_ESCAPE_DELTA;
                subcontext -> total += ENET_SUBCONTEXT_ESCAPE_DELTA;
            }
            subcontext -> total += ENET_SUBCONTEXT_SYMBOL_DELTA;
            if (count > 0xFF - 2*ENET_SUBCONTEXT_SYMBOL_DELTA || subcontext -> total > ENET_RANGE_CODER_BOTTOM - 0x100)
              ENET_CONTEXT_RESCALE (subcontext, 0);
            if (count > 0) goto nextInput;
        }

        ENET_CONTEXT_ENCODE (root, symbol, value, under, count, ENET_CONTEXT_SYMBOL_DELTA, ENET_CONTEXT_SYMBOL_MINIMUM);
        * parent = symbol - rangeCoder -> symbols;
        parent = & symbol -> parent;
        total = root -> total;
#ifdef ENET_CONTEXT_EXCLUSION
        if (childContext -> total > ENET_SUBCONTEXT_SYMBOL_DELTA + ENET_SUBCONTEXT_ESCAPE_DELTA)
          ENET_CONTEXT_ENCODE_EXCLUDE (childContext, value, under, total, ENET_CONTEXT_SYMBOL_MINIMUM); 
#endif
        ENET_RANGE_CODER_ENCODE (root -> escapes + under, count, total);
        root -> total += ENET_CONTEXT_SYMBOL_DELTA; 
        if (count > 0xFF - 2*ENET_CONTEXT_SYMBOL_DELTA + ENET_CONTEXT_SYMBOL_MINIMUM || root -> total > ENET_RANGE_CODER_BOTTOM - 0x100)
          ENET_CONTEXT_RESCALE (root, ENET_CONTEXT_SYMBOL_MINIMUM);

    nextInput:
        if (order >= ENET_SUBCONTEXT_ORDER) 
          predicted = rangeCoder -> symbols [predicted].parent;
        else 
          order ++;
        ENET_RANGE_CODER_FREE_SYMBOLS;
    }

    ENET_RANGE_CODER_FLUSH;

#ifdef _DEBUG
//	sprintf(stCrap, "in buffer count %d, compressed to %d\r\n", inBuff, (outData - outStart));
//	OutputDebugString(stCrap);
#endif
	g_enetTotalBytesSentDecompressed += inLimit;

	g_enetTotalBytesSent += outData - outStart;


	return (size_t) (outData - outStart);
}