KasmVNC/common/rfb/TightEncoder.cxx
2020-09-20 12:16:44 +00:00

284 lines
6.8 KiB
C++

/* Copyright (C) 2000-2003 Constantin Kaplinsky. All Rights Reserved.
* Copyright (C) 2011 D. R. Commander. All Rights Reserved.
* Copyright 2014 Pierre Ossman for Cendio AB
*
* 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 <assert.h>
#include <rdr/OutStream.h>
#include <rfb/PixelBuffer.h>
#include <rfb/Palette.h>
#include <rfb/encodings.h>
#include <rfb/ConnParams.h>
#include <rfb/SConnection.h>
#include <rfb/TightEncoder.h>
#include <rfb/TightConstants.h>
using namespace rfb;
struct TightConf {
int idxZlibLevel, monoZlibLevel, rawZlibLevel;
};
//
// Compression level stuff. The following array contains zlib
// settings for each of 10 compression levels (0..9).
//
// NOTE: The parameters used in this encoder are the result of painstaking
// research by The VirtualGL Project using RFB session captures from a variety
// of both 2D and 3D applications. See http://www.VirtualGL.org for the full
// reports.
static const TightConf conf[10] = {
{ 0, 0, 0 }, // 0
{ 1, 1, 1 }, // 1
{ 3, 3, 2 }, // 2
{ 5, 5, 2 }, // 3
{ 6, 7, 3 }, // 4
{ 7, 8, 4 }, // 5
{ 7, 8, 5 }, // 6
{ 8, 9, 6 }, // 7
{ 9, 9, 7 }, // 8
{ 9, 9, 9 } // 9
};
TightEncoder::TightEncoder(SConnection* conn) :
Encoder(conn, encodingTight, EncoderPlain, 256)
{
setCompressLevel(-1);
}
TightEncoder::~TightEncoder()
{
}
bool TightEncoder::isSupported()
{
return conn->cp.supportsEncoding(encodingTight);
}
void TightEncoder::setCompressLevel(int level)
{
if (level < 0 || level > 9)
level = 2;
idxZlibLevel = conf[level].idxZlibLevel;
monoZlibLevel = conf[level].monoZlibLevel;
rawZlibLevel = conf[level].rawZlibLevel;
}
void TightEncoder::writeRect(const PixelBuffer* pb, const Palette& palette)
{
switch (palette.size()) {
case 0:
writeFullColourRect(pb, palette);
break;
case 1:
Encoder::writeSolidRect(pb, palette);
break;
case 2:
writeMonoRect(pb, palette);
break;
default:
writeIndexedRect(pb, palette);
}
}
void TightEncoder::writeSolidRect(int width, int height,
const PixelFormat& pf,
const rdr::U8* colour)
{
rdr::OutStream* os;
os = conn->getOutStream();
os->writeU8(tightFill << 4);
writePixels(colour, pf, 1, os);
}
void TightEncoder::writeMonoRect(const PixelBuffer* pb, const Palette& palette)
{
const rdr::U8* buffer;
int stride;
buffer = pb->getBuffer(pb->getRect(), &stride);
switch (pb->getPF().bpp) {
case 32:
writeMonoRect(pb->width(), pb->height(), (rdr::U32*)buffer, stride,
pb->getPF(), palette);
break;
case 16:
writeMonoRect(pb->width(), pb->height(), (rdr::U16*)buffer, stride,
pb->getPF(), palette);
break;
default:
writeMonoRect(pb->width(), pb->height(), (rdr::U8*)buffer, stride,
pb->getPF(), palette);
}
}
void TightEncoder::writeIndexedRect(const PixelBuffer* pb, const Palette& palette)
{
const rdr::U8* buffer;
int stride;
buffer = pb->getBuffer(pb->getRect(), &stride);
switch (pb->getPF().bpp) {
case 32:
writeIndexedRect(pb->width(), pb->height(), (rdr::U32*)buffer, stride,
pb->getPF(), palette);
break;
case 16:
writeIndexedRect(pb->width(), pb->height(), (rdr::U16*)buffer, stride,
pb->getPF(), palette);
break;
default:
// It's more efficient to just do raw pixels
writeFullColourRect(pb, palette);
}
}
void TightEncoder::writeFullColourRect(const PixelBuffer* pb, const Palette& palette)
{
const int streamId = 0;
rdr::OutStream* os;
rdr::OutStream* zos;
int length;
const rdr::U8* buffer;
int stride, h;
os = conn->getOutStream();
os->writeU8(streamId << 4);
// Set up compression
if ((pb->getPF().bpp != 32) || !pb->getPF().is888())
length = pb->getRect().area() * pb->getPF().bpp/8;
else
length = pb->getRect().area() * 3;
zos = getZlibOutStream(streamId, rawZlibLevel, length);
// And then just dump all the raw pixels
buffer = pb->getBuffer(pb->getRect(), &stride);
h = pb->height();
while (h--) {
writePixels(buffer, pb->getPF(), pb->width(), zos);
buffer += stride * pb->getPF().bpp/8;
}
// Finish the zlib stream
flushZlibOutStream(zos);
}
void TightEncoder::writePixels(const rdr::U8* buffer, const PixelFormat& pf,
unsigned int count, rdr::OutStream* os)
{
rdr::U8 rgb[2048];
if ((pf.bpp != 32) || !pf.is888()) {
os->writeBytes(buffer, count * pf.bpp/8);
return;
}
while (count) {
unsigned int iter_count;
iter_count = sizeof(rgb)/3;
if (iter_count > count)
iter_count = count;
pf.rgbFromBuffer(rgb, buffer, iter_count);
os->writeBytes(rgb, iter_count * 3);
buffer += iter_count * pf.bpp/8;
count -= iter_count;
}
}
void TightEncoder::writeCompact(rdr::OutStream* os, rdr::U32 value)
{
rdr::U8 b;
b = value & 0x7F;
if (value <= 0x7F) {
os->writeU8(b);
} else {
os->writeU8(b | 0x80);
b = value >> 7 & 0x7F;
if (value <= 0x3FFF) {
os->writeU8(b);
} else {
os->writeU8(b | 0x80);
os->writeU8(value >> 14 & 0xFF);
}
}
}
rdr::OutStream* TightEncoder::getZlibOutStream(int streamId, int level, size_t length)
{
// Minimum amount of data to be compressed. This value should not be
// changed, doing so will break compatibility with existing clients.
if (length < 12)
return conn->getOutStream();
assert(streamId >= 0);
assert(streamId < 4);
zlibStreams[streamId].setUnderlying(&memStream);
zlibStreams[streamId].setCompressionLevel(level);
return &zlibStreams[streamId];
}
void TightEncoder::flushZlibOutStream(rdr::OutStream* os_)
{
rdr::OutStream* os;
rdr::ZlibOutStream* zos;
zos = dynamic_cast<rdr::ZlibOutStream*>(os_);
if (zos == NULL)
return;
zos->flush();
zos->setUnderlying(NULL);
os = conn->getOutStream();
writeCompact(os, memStream.length());
os->writeBytes(memStream.data(), memStream.length());
memStream.clear();
}
//
// Including BPP-dependent implementation of the encoder.
//
#define BPP 8
#include <rfb/TightEncoderBPP.cxx>
#undef BPP
#define BPP 16
#include <rfb/TightEncoderBPP.cxx>
#undef BPP
#define BPP 32
#include <rfb/TightEncoderBPP.cxx>
#undef BPP