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/*
* ultra.c
*
* Routines to implement ultra based encoding (minilzo).
* ultrazip supports packed rectangles if the rects are tiny...
* This improves performance as lzo has more data to work with at once
* This is 'UltraZip' and is currently not implemented.
*/
#include <rfb/rfb.h>
#include "minilzo.h"
/*
* lzoBeforeBuf contains pixel data in the client's format.
* lzoAfterBuf contains the lzo (deflated) encoding version.
* If the lzo compressed/encoded version is
* larger than the raw data or if it exceeds lzoAfterBufSize then
* raw encoding is used instead.
*/
static int lzoBeforeBufSize = 0;
static char *lzoBeforeBuf = NULL;
static int lzoAfterBufSize = 0;
static char *lzoAfterBuf = NULL;
static int lzoAfterBufLen;
/*
* rfbSendOneRectEncodingZlib - send a given rectangle using one Zlib
* rectangle encoding.
*/
#define MAX_WRKMEM ((LZO1X_1_MEM_COMPRESS) + (sizeof(lzo_align_t) - 1)) / sizeof(lzo_align_t)
static rfbBool
rfbSendOneRectEncodingUltra(rfbClientPtr cl,
int x,
int y,
int w,
int h)
{
rfbFramebufferUpdateRectHeader rect;
rfbZlibHeader hdr;
int deflateResult;
int i;
char *fbptr = (cl->scaledScreen->frameBuffer + (cl->scaledScreen->paddedWidthInBytes * y)
+ (x * (cl->scaledScreen->bitsPerPixel / 8)));
int maxRawSize;
int maxCompSize;
maxRawSize = (w * h * (cl->format.bitsPerPixel / 8));
if (lzoBeforeBufSize < maxRawSize) {
lzoBeforeBufSize = maxRawSize;
if (lzoBeforeBuf == NULL)
lzoBeforeBuf = (char *)malloc(lzoBeforeBufSize);
else
lzoBeforeBuf = (char *)realloc(lzoBeforeBuf, lzoBeforeBufSize);
}
/*
* lzo requires output buffer to be slightly larger than the input
* buffer, in the worst case.
*/
maxCompSize = (maxRawSize + maxRawSize / 16 + 64 + 3);
if (lzoAfterBufSize < maxCompSize) {
lzoAfterBufSize = maxCompSize;
if (lzoAfterBuf == NULL)
lzoAfterBuf = (char *)malloc(lzoAfterBufSize);
else
lzoAfterBuf = (char *)realloc(lzoAfterBuf, lzoAfterBufSize);
}
/*
* Convert pixel data to client format.
*/
(*cl->translateFn)(cl->translateLookupTable, &cl->screen->serverFormat,
&cl->format, fbptr, lzoBeforeBuf,
cl->scaledScreen->paddedWidthInBytes, w, h);
if ( cl->compStreamInitedLZO == FALSE ) {
cl->compStreamInitedLZO = TRUE;
/* Work-memory needed for compression. Allocate memory in units
* of `lzo_align_t' (instead of `char') to make sure it is properly aligned.
*/
cl->lzoWrkMem = malloc(sizeof(lzo_align_t) * (((LZO1X_1_MEM_COMPRESS) + (sizeof(lzo_align_t) - 1)) / sizeof(lzo_align_t)));
}
/* Perform the compression here. */
deflateResult = lzo1x_1_compress((unsigned char *)lzoBeforeBuf, (lzo_uint)(w * h * (cl->format.bitsPerPixel / 8)), (unsigned char *)lzoAfterBuf, (lzo_uint *)&maxCompSize, cl->lzoWrkMem);
/* maxCompSize now contains the compressed size */
/* Find the total size of the resulting compressed data. */
lzoAfterBufLen = maxCompSize;
if ( deflateResult != LZO_E_OK ) {
rfbErr("lzo deflation error: %d\n", deflateResult);
return FALSE;
}
/* Update statics */
cl->rectanglesSent[rfbEncodingUltra]++;
cl->bytesSent[rfbEncodingUltra] += (sz_rfbFramebufferUpdateRectHeader
+ sz_rfbZlibHeader + lzoAfterBufLen);
if (cl->ublen + sz_rfbFramebufferUpdateRectHeader + sz_rfbZlibHeader
> UPDATE_BUF_SIZE)
{
if (!rfbSendUpdateBuf(cl))
return FALSE;
}
rect.r.x = Swap16IfLE(x);
rect.r.y = Swap16IfLE(y);
rect.r.w = Swap16IfLE(w);
rect.r.h = Swap16IfLE(h);
rect.encoding = Swap32IfLE(rfbEncodingUltra);
memcpy(&cl->updateBuf[cl->ublen], (char *)&rect,
sz_rfbFramebufferUpdateRectHeader);
cl->ublen += sz_rfbFramebufferUpdateRectHeader;
hdr.nBytes = Swap32IfLE(lzoAfterBufLen);
memcpy(&cl->updateBuf[cl->ublen], (char *)&hdr, sz_rfbZlibHeader);
cl->ublen += sz_rfbZlibHeader;
for (i = 0; i < lzoAfterBufLen;) {
int bytesToCopy = UPDATE_BUF_SIZE - cl->ublen;
if (i + bytesToCopy > lzoAfterBufLen) {
bytesToCopy = lzoAfterBufLen - i;
}
memcpy(&cl->updateBuf[cl->ublen], &lzoAfterBuf[i], bytesToCopy);
cl->ublen += bytesToCopy;
i += bytesToCopy;
if (cl->ublen == UPDATE_BUF_SIZE) {
if (!rfbSendUpdateBuf(cl))
return FALSE;
}
}
return TRUE;
}
/*
* rfbSendRectEncodingUltra - send a given rectangle using one or more
* LZO encoding rectangles.
*/
rfbBool
rfbSendRectEncodingUltra(rfbClientPtr cl,
int x,
int y,
int w,
int h)
{
int maxLines;
int linesRemaining;
rfbRectangle partialRect;
partialRect.x = x;
partialRect.y = y;
partialRect.w = w;
partialRect.h = h;
/* Determine maximum pixel/scan lines allowed per rectangle. */
maxLines = ( ULTRA_MAX_SIZE(w) / w );
/* Initialize number of scan lines left to do. */
linesRemaining = h;
/* Loop until all work is done. */
while ( linesRemaining > 0 ) {
int linesToComp;
if ( maxLines < linesRemaining )
linesToComp = maxLines;
else
linesToComp = linesRemaining;
partialRect.h = linesToComp;
/* Encode (compress) and send the next rectangle. */
if ( ! rfbSendOneRectEncodingUltra( cl,
partialRect.x,
partialRect.y,
partialRect.w,
partialRect.h )) {
return FALSE;
}
/* Technically, flushing the buffer here is not extrememly
* efficient. However, this improves the overall throughput
* of the system over very slow networks. By flushing
* the buffer with every maximum size lzo rectangle, we
* improve the pipelining usage of the server CPU, network,
* and viewer CPU components. Insuring that these components
* are working in parallel actually improves the performance
* seen by the user.
* Since, lzo is most useful for slow networks, this flush
* is appropriate for the desired behavior of the lzo encoding.
*/
if (( cl->ublen > 0 ) &&
( linesToComp == maxLines )) {
if (!rfbSendUpdateBuf(cl)) {
return FALSE;
}
}
/* Update remaining and incremental rectangle location. */
linesRemaining -= linesToComp;
partialRect.y += linesToComp;
}
return TRUE;
}
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