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-rw-r--r--krfb/libvncserver/rre.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/krfb/libvncserver/rre.c b/krfb/libvncserver/rre.c
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+++ b/krfb/libvncserver/rre.c
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+/*
+ * rre.c
+ *
+ * Routines to implement Rise-and-Run-length Encoding (RRE). This
+ * code is based on krw's original javatel rfbserver.
+ */
+
+/*
+ * OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
+ * Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.
+ * All Rights Reserved.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <stdio.h>
+#include "rfb.h"
+
+/*
+ * rreBeforeBuf contains pixel data in the client's format.
+ * rreAfterBuf contains the RRE encoded version. If the RRE encoded version is
+ * larger than the raw data or if it exceeds rreAfterBufSize then
+ * raw encoding is used instead.
+ */
+
+static int rreBeforeBufSize = 0;
+static char *rreBeforeBuf = NULL;
+
+static int rreAfterBufSize = 0;
+static char *rreAfterBuf = NULL;
+static int rreAfterBufLen;
+
+static int subrectEncode8(CARD8 *data, int w, int h);
+static int subrectEncode16(CARD16 *data, int w, int h);
+static int subrectEncode32(CARD32 *data, int w, int h);
+static CARD32 getBgColour(char *data, int size, int bpp);
+
+
+/*
+ * rfbSendRectEncodingRRE - send a given rectangle using RRE encoding.
+ */
+
+Bool
+rfbSendRectEncodingRRE(cl, x, y, w, h)
+ rfbClientPtr cl;
+ int x, y, w, h;
+{
+ rfbFramebufferUpdateRectHeader rect;
+ rfbRREHeader hdr;
+ int nSubrects;
+ int i;
+ char *fbptr = (cl->screen->frameBuffer + (cl->screen->paddedWidthInBytes * y)
+ + (x * (cl->screen->bitsPerPixel / 8)));
+
+ int maxRawSize = (cl->screen->width * cl->screen->height
+ * (cl->format.bitsPerPixel / 8));
+
+ if (rreBeforeBufSize < maxRawSize) {
+ rreBeforeBufSize = maxRawSize;
+ if (rreBeforeBuf == NULL)
+ rreBeforeBuf = (char *)malloc(rreBeforeBufSize);
+ else
+ rreBeforeBuf = (char *)realloc(rreBeforeBuf, rreBeforeBufSize);
+ }
+
+ if (rreAfterBufSize < maxRawSize) {
+ rreAfterBufSize = maxRawSize;
+ if (rreAfterBuf == NULL)
+ rreAfterBuf = (char *)malloc(rreAfterBufSize);
+ else
+ rreAfterBuf = (char *)realloc(rreAfterBuf, rreAfterBufSize);
+ }
+
+ (*cl->translateFn)(cl->translateLookupTable,
+ &(cl->screen->rfbServerFormat),
+ &cl->format, fbptr, rreBeforeBuf,
+ cl->screen->paddedWidthInBytes, w, h);
+
+ switch (cl->format.bitsPerPixel) {
+ case 8:
+ nSubrects = subrectEncode8((CARD8 *)rreBeforeBuf, w, h);
+ break;
+ case 16:
+ nSubrects = subrectEncode16((CARD16 *)rreBeforeBuf, w, h);
+ break;
+ case 32:
+ nSubrects = subrectEncode32((CARD32 *)rreBeforeBuf, w, h);
+ break;
+ default:
+ rfbLog("getBgColour: bpp %d?\n",cl->format.bitsPerPixel);
+ exit(1);
+ }
+
+ if (nSubrects < 0) {
+
+ /* RRE encoding was too large, use raw */
+
+ return rfbSendRectEncodingRaw(cl, x, y, w, h);
+ }
+
+ cl->rfbRectanglesSent[rfbEncodingRRE]++;
+ cl->rfbBytesSent[rfbEncodingRRE] += (sz_rfbFramebufferUpdateRectHeader
+ + sz_rfbRREHeader + rreAfterBufLen);
+
+ if (cl->ublen + sz_rfbFramebufferUpdateRectHeader + sz_rfbRREHeader
+ > 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(rfbEncodingRRE);
+
+ memcpy(&cl->updateBuf[cl->ublen], (char *)&rect,
+ sz_rfbFramebufferUpdateRectHeader);
+ cl->ublen += sz_rfbFramebufferUpdateRectHeader;
+
+ hdr.nSubrects = Swap32IfLE(nSubrects);
+
+ memcpy(&cl->updateBuf[cl->ublen], (char *)&hdr, sz_rfbRREHeader);
+ cl->ublen += sz_rfbRREHeader;
+
+ for (i = 0; i < rreAfterBufLen;) {
+
+ int bytesToCopy = UPDATE_BUF_SIZE - cl->ublen;
+
+ if (i + bytesToCopy > rreAfterBufLen) {
+ bytesToCopy = rreAfterBufLen - i;
+ }
+
+ memcpy(&cl->updateBuf[cl->ublen], &rreAfterBuf[i], bytesToCopy);
+
+ cl->ublen += bytesToCopy;
+ i += bytesToCopy;
+
+ if (cl->ublen == UPDATE_BUF_SIZE) {
+ if (!rfbSendUpdateBuf(cl))
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+
+
+/*
+ * subrectEncode() encodes the given multicoloured rectangle as a background
+ * colour overwritten by single-coloured rectangles. It returns the number
+ * of subrectangles in the encoded buffer, or -1 if subrect encoding won't
+ * fit in the buffer. It puts the encoded rectangles in rreAfterBuf. The
+ * single-colour rectangle partition is not optimal, but does find the biggest
+ * horizontal or vertical rectangle top-left anchored to each consecutive
+ * coordinate position.
+ *
+ * The coding scheme is simply [<bgcolour><subrect><subrect>...] where each
+ * <subrect> is [<colour><x><y><w><h>].
+ */
+
+#define DEFINE_SUBRECT_ENCODE(bpp) \
+static int \
+subrectEncode##bpp(data,w,h) \
+ CARD##bpp *data; \
+ int w; \
+ int h; \
+{ \
+ CARD##bpp cl; \
+ rfbRectangle subrect; \
+ int x,y; \
+ int i,j; \
+ int hx=0,hy,vx=0,vy; \
+ int hyflag; \
+ CARD##bpp *seg; \
+ CARD##bpp *line; \
+ int hw,hh,vw,vh; \
+ int thex,they,thew,theh; \
+ int numsubs = 0; \
+ int newLen; \
+ CARD##bpp bg = (CARD##bpp)getBgColour((char*)data,w*h,bpp); \
+ \
+ *((CARD##bpp*)rreAfterBuf) = bg; \
+ \
+ rreAfterBufLen = (bpp/8); \
+ \
+ for (y=0; y<h; y++) { \
+ line = data+(y*w); \
+ for (x=0; x<w; x++) { \
+ if (line[x] != bg) { \
+ cl = line[x]; \
+ hy = y-1; \
+ hyflag = 1; \
+ for (j=y; j<h; j++) { \
+ seg = data+(j*w); \
+ if (seg[x] != cl) {break;} \
+ i = x; \
+ while ((seg[i] == cl) && (i < w)) i += 1; \
+ i -= 1; \
+ if (j == y) vx = hx = i; \
+ if (i < vx) vx = i; \
+ if ((hyflag > 0) && (i >= hx)) {hy += 1;} else {hyflag = 0;} \
+ } \
+ vy = j-1; \
+ \
+ /* We now have two possible subrects: (x,y,hx,hy) and (x,y,vx,vy) \
+ * We'll choose the bigger of the two. \
+ */ \
+ hw = hx-x+1; \
+ hh = hy-y+1; \
+ vw = vx-x+1; \
+ vh = vy-y+1; \
+ \
+ thex = x; \
+ they = y; \
+ \
+ if ((hw*hh) > (vw*vh)) { \
+ thew = hw; \
+ theh = hh; \
+ } else { \
+ thew = vw; \
+ theh = vh; \
+ } \
+ \
+ subrect.x = Swap16IfLE(thex); \
+ subrect.y = Swap16IfLE(they); \
+ subrect.w = Swap16IfLE(thew); \
+ subrect.h = Swap16IfLE(theh); \
+ \
+ newLen = rreAfterBufLen + (bpp/8) + sz_rfbRectangle; \
+ if ((newLen > (w * h * (bpp/8))) || (newLen > rreAfterBufSize)) \
+ return -1; \
+ \
+ numsubs += 1; \
+ *((CARD##bpp*)(rreAfterBuf + rreAfterBufLen)) = cl; \
+ rreAfterBufLen += (bpp/8); \
+ memcpy(&rreAfterBuf[rreAfterBufLen],&subrect,sz_rfbRectangle); \
+ rreAfterBufLen += sz_rfbRectangle; \
+ \
+ /* \
+ * Now mark the subrect as done. \
+ */ \
+ for (j=they; j < (they+theh); j++) { \
+ for (i=thex; i < (thex+thew); i++) { \
+ data[j*w+i] = bg; \
+ } \
+ } \
+ } \
+ } \
+ } \
+ \
+ return numsubs; \
+}
+
+DEFINE_SUBRECT_ENCODE(8)
+DEFINE_SUBRECT_ENCODE(16)
+DEFINE_SUBRECT_ENCODE(32)
+
+
+/*
+ * getBgColour() gets the most prevalent colour in a byte array.
+ */
+static CARD32
+getBgColour(data,size,bpp)
+ char *data;
+ int size;
+ int bpp;
+{
+
+#define NUMCLRS 256
+
+ static int counts[NUMCLRS];
+ int i,j,k;
+
+ int maxcount = 0;
+ CARD8 maxclr = 0;
+
+ if (bpp != 8) {
+ if (bpp == 16) {
+ return ((CARD16 *)data)[0];
+ } else if (bpp == 32) {
+ return ((CARD32 *)data)[0];
+ } else {
+ rfbLog("getBgColour: bpp %d?\n",bpp);
+ exit(1);
+ }
+ }
+
+ for (i=0; i<NUMCLRS; i++) {
+ counts[i] = 0;
+ }
+
+ for (j=0; j<size; j++) {
+ k = (int)(((CARD8 *)data)[j]);
+ if (k >= NUMCLRS) {
+ rfbLog("getBgColour: unusual colour = %d\n", k);
+ exit(1);
+ }
+ counts[k] += 1;
+ if (counts[k] > maxcount) {
+ maxcount = counts[k];
+ maxclr = ((CARD8 *)data)[j];
+ }
+ }
+
+ return maxclr;
+}
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