diff options
Diffstat (limited to 'libvncserver/ultra.c')
| -rw-r--r-- | libvncserver/ultra.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libvncserver/ultra.c b/libvncserver/ultra.c new file mode 100644 index 0000000..5825d5b --- /dev/null +++ b/libvncserver/ultra.c @@ -0,0 +1,229 @@ +/* + * 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->screen->frameBuffer + (cl->screen->paddedWidthInBytes * y) + + (x * (cl->screen->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->screen->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; + +} |