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////////////////////////////////////////////////////////////////////////////////
//
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////////
package
{
import flash.display.BitmapData;
import flash.utils.ByteArray;
public final class JPEGEncoder
{
// Static table initialization
private const ZigZag:Vector.<int> = Vector.<int>([
0, 1, 5, 6,14,15,27,28,
2, 4, 7,13,16,26,29,42,
3, 8,12,17,25,30,41,43,
9,11,18,24,31,40,44,53,
10,19,23,32,39,45,52,54,
20,22,33,38,46,51,55,60,
21,34,37,47,50,56,59,61,
35,36,48,49,57,58,62,63
]);
private var a:Vector.<String> = new Vector.<String>();
private var YTable:Vector.<int> = new Vector.<int>(64, true);
private var UVTable:Vector.<int> = new Vector.<int>(64, true);
private var outputfDCTQuant:Vector.<int> = new Vector.<int>(64, true);
private var fdtbl_Y:Vector.<Number> = new Vector.<Number>(64, true);
private var fdtbl_UV:Vector.<Number> = new Vector.<Number>(64, true);
private var sf:int;
private const aasf:Vector.<Number> = Vector.<Number>([
1.0, 1.387039845, 1.306562965, 1.175875602,
1.0, 0.785694958, 0.541196100, 0.275899379
]);
private var YQT:Vector.<int> = Vector.<int>([
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68,109,103, 77,
24, 35, 55, 64, 81,104,113, 92,
49, 64, 78, 87,103,121,120,101,
72, 92, 95, 98,112,100,103, 99
]);
private const UVQT:Vector.<int> = Vector.<int>([
17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
]);
private function initQuantTables(sf:int):void
{
var a:Vector.<String> = new Vector.<String>();
var i:int;
const I64:int = 64;
const I8:int = 8;
for (i = 0; i < I64; ++i)
{
var t:int = int((YQT[i]*sf+50)*0.01);
if (t < 1) {
t = 1;
} else if (t > 255) {
t = 255;
}
YTable[ZigZag[i]] = t;
}
for (i = 0; i < I64; i++)
{
var u:int = int((UVQT[i]*sf+50)*0.01);
if (u < 1) {
u = 1;
} else if (u > 255) {
u = 255;
}
UVTable[ZigZag[i]] = u;
}
i = 0;
for (var row:int = 0; row < I8; ++row)
{
for (var col:int = 0; col < I8; ++col)
{
fdtbl_Y[i] = (1 / (YTable [ZigZag[i]] * aasf[row] * aasf[col] * I8));
fdtbl_UV[i] = (1 / (UVTable[ZigZag[i]] * aasf[row] * aasf[col] * I8));
i++;
}
}
}
private var YDC_HT:Vector.<BitString>;
private var UVDC_HT:Vector.<BitString>;
private var YAC_HT:Vector.<BitString>;
private var UVAC_HT:Vector.<BitString>;
private function computeHuffmanTbl(nrcodes:Vector.<int>, std_table:Vector.<int>):Vector.<BitString>
{
var codevalue:int = 0;
var pos_in_table:int = 0;
var HT:Vector.<BitString> = new Vector.<BitString>(251, true);
var bitString:BitString;
for (var k:int=1; k<=16; ++k)
{
for (var j:int=1; j<=nrcodes[k]; ++j)
{
HT[std_table[pos_in_table]] = bitString = new BitString();
bitString.val = codevalue;
bitString.len = k;
pos_in_table++;
codevalue++;
}
codevalue<<=1;
}
return HT;
}
private var std_dc_luminance_nrcodes:Vector.<int> = Vector.<int>([0,0,1,5,1,1,1,1,1,1,0,0,0,0,0,0,0]);
private var std_dc_luminance_values:Vector.<int> = Vector.<int>([0,1,2,3,4,5,6,7,8,9,10,11]);
private var std_ac_luminance_nrcodes:Vector.<int> = Vector.<int>([0,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0x7d]);
private var std_ac_luminance_values:Vector.<int> = Vector.<int>([0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,
0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,
0x22,0x71,0x14,0x32,0x81,0x91,0xa1,0x08,
0x23,0x42,0xb1,0xc1,0x15,0x52,0xd1,0xf0,
0x24,0x33,0x62,0x72,0x82,0x09,0x0a,0x16,
0x17,0x18,0x19,0x1a,0x25,0x26,0x27,0x28,
0x29,0x2a,0x34,0x35,0x36,0x37,0x38,0x39,
0x3a,0x43,0x44,0x45,0x46,0x47,0x48,0x49,
0x4a,0x53,0x54,0x55,0x56,0x57,0x58,0x59,
0x5a,0x63,0x64,0x65,0x66,0x67,0x68,0x69,
0x6a,0x73,0x74,0x75,0x76,0x77,0x78,0x79,
0x7a,0x83,0x84,0x85,0x86,0x87,0x88,0x89,
0x8a,0x92,0x93,0x94,0x95,0x96,0x97,0x98,
0x99,0x9a,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,
0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,0xb5,0xb6,
0xb7,0xb8,0xb9,0xba,0xc2,0xc3,0xc4,0xc5,
0xc6,0xc7,0xc8,0xc9,0xca,0xd2,0xd3,0xd4,
0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xe1,0xe2,
0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,
0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,
0xf9,0xfa]);
private var std_dc_chrominance_nrcodes:Vector.<int> = Vector.<int>([0,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0]);
private var std_dc_chrominance_values:Vector.<int> = Vector.<int>([0,1,2,3,4,5,6,7,8,9,10,11]);
private var std_ac_chrominance_nrcodes:Vector.<int> = Vector.<int>([0,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0x77]);
private var std_ac_chrominance_values:Vector.<int> = Vector.<int>([0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,
0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71,
0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,
0xa1,0xb1,0xc1,0x09,0x23,0x33,0x52,0xf0,
0x15,0x62,0x72,0xd1,0x0a,0x16,0x24,0x34,
0xe1,0x25,0xf1,0x17,0x18,0x19,0x1a,0x26,
0x27,0x28,0x29,0x2a,0x35,0x36,0x37,0x38,
0x39,0x3a,0x43,0x44,0x45,0x46,0x47,0x48,
0x49,0x4a,0x53,0x54,0x55,0x56,0x57,0x58,
0x59,0x5a,0x63,0x64,0x65,0x66,0x67,0x68,
0x69,0x6a,0x73,0x74,0x75,0x76,0x77,0x78,
0x79,0x7a,0x82,0x83,0x84,0x85,0x86,0x87,
0x88,0x89,0x8a,0x92,0x93,0x94,0x95,0x96,
0x97,0x98,0x99,0x9a,0xa2,0xa3,0xa4,0xa5,
0xa6,0xa7,0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,
0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xc2,0xc3,
0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xd2,
0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,
0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,
0xea,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,
0xf9,0xfa
]);
private function initHuffmanTbl():void
{
YDC_HT = computeHuffmanTbl(std_dc_luminance_nrcodes,std_dc_luminance_values);
UVDC_HT = computeHuffmanTbl(std_dc_chrominance_nrcodes,std_dc_chrominance_values);
YAC_HT = computeHuffmanTbl(std_ac_luminance_nrcodes,std_ac_luminance_values);
UVAC_HT = computeHuffmanTbl(std_ac_chrominance_nrcodes,std_ac_chrominance_values);
}
private var bitcode:Vector.<BitString> = new Vector.<BitString>(65535, true);
private var category:Vector.<int> = new Vector.<int>(65535, true);
private function initCategoryNumber():void
{
var nrlower:int = 1;
var nrupper:int = 2;
var bitString:BitString;
const I15:int = 15;
var pos:int;
for (var cat:int=1; cat<=I15; ++cat)
{
//Positive numbers
for (var nr:int=nrlower; nr<nrupper; ++nr)
{
pos = int(32767+nr);
category[pos] = cat;
bitcode[pos] = bitString = new BitString();
bitString.len = cat;
bitString.val = nr;
}
//Negative numbers
for (var nrneg:int=-(nrupper-1); nrneg<=-nrlower; ++nrneg)
{
pos = int(32767+nrneg);
category[pos] = cat;
bitcode[pos] = bitString = new BitString();
bitString.len = cat;
bitString.val = nrupper-1+nrneg;
}
nrlower <<= 1;
nrupper <<= 1;
}
}
// IO functions
private var byteout:ByteArray;
private var bytenew:int = 0;
private var bytepos:int = 7;
private function writeBits(bs:BitString):void
{
var value:int = bs.val;
var posval:int = bs.len-1;
while ( posval >= 0 )
{
if (value & uint(1 << posval) )
bytenew |= uint(1 << bytepos);
posval--;
bytepos--;
if (bytepos < 0)
{
if (bytenew == 0xFF)
{
byteout.writeByte(0xFF);
byteout.writeByte(0);
}
else byteout.writeByte(bytenew);
bytepos=7;
bytenew=0;
}
}
}
// DCT & quantization core
private function fDCTQuant(data:Vector.<Number>, fdtbl:Vector.<Number>):Vector.<int>
{
/* Pass 1: process rows. */
var dataOff:int=0;
var d0:Number, d1:Number, d2:Number, d3:Number, d4:Number, d5:Number, d6:Number, d7:Number;
var i:int;
const I8:int = 8;
const I64:int = 64;
for (i=0; i<I8; ++i)
{
d0 = data[int(dataOff)];
d1 = data[int(dataOff+1)];
d2 = data[int(dataOff+2)];
d3 = data[int(dataOff+3)];
d4 = data[int(dataOff+4)];
d5 = data[int(dataOff+5)];
d6 = data[int(dataOff+6)];
d7 = data[int(dataOff+7)];
var tmp0:Number = d0 + d7;
var tmp7:Number = d0 - d7;
var tmp1:Number = d1 + d6;
var tmp6:Number = d1 - d6;
var tmp2:Number = d2 + d5;
var tmp5:Number = d2 - d5;
var tmp3:Number = d3 + d4;
var tmp4:Number = d3 - d4;
/* Even part */
var tmp10:Number = tmp0 + tmp3; /* phase 2 */
var tmp13:Number = tmp0 - tmp3;
var tmp11:Number = tmp1 + tmp2;
var tmp12:Number = tmp1 - tmp2;
data[int(dataOff)] = tmp10 + tmp11; /* phase 3 */
data[int(dataOff+4)] = tmp10 - tmp11;
var z1:Number = (tmp12 + tmp13) * 0.707106781; /* c4 */
data[int(dataOff+2)] = tmp13 + z1; /* phase 5 */
data[int(dataOff+6)] = tmp13 - z1;
/* Odd part */
tmp10 = tmp4 + tmp5; /* phase 2 */
tmp11 = tmp5 + tmp6;
tmp12 = tmp6 + tmp7;
/* The rotator is modified from fig 4-8 to avoid extra negations. */
var z5:Number = (tmp10 - tmp12) * 0.382683433; /* c6 */
var z2:Number = 0.541196100 * tmp10 + z5; /* c2-c6 */
var z4:Number = 1.306562965 * tmp12 + z5; /* c2+c6 */
var z3:Number = tmp11 * 0.707106781; /* c4 */
var z11:Number = tmp7 + z3; /* phase 5 */
var z13:Number = tmp7 - z3;
data[int(dataOff+5)] = z13 + z2; /* phase 6 */
data[int(dataOff+3)] = z13 - z2;
data[int(dataOff+1)] = z11 + z4;
data[int(dataOff+7)] = z11 - z4;
dataOff += 8; /* advance pointer to next row */
}
/* Pass 2: process columns. */
dataOff = 0;
for (i=0; i<I8; ++i)
{
d0 = data[int(dataOff)];
d1 = data[int(dataOff + 8)];
d2 = data[int(dataOff + 16)];
d3 = data[int(dataOff + 24)];
d4 = data[int(dataOff + 32)];
d5 = data[int(dataOff + 40)];
d6 = data[int(dataOff + 48)];
d7 = data[int(dataOff + 56)];
var tmp0p2:Number = d0 + d7;
var tmp7p2:Number = d0 - d7;
var tmp1p2:Number = d1 + d6;
var tmp6p2:Number = d1 - d6;
var tmp2p2:Number = d2 + d5;
var tmp5p2:Number = d2 - d5;
var tmp3p2:Number = d3 + d4;
var tmp4p2:Number = d3 - d4;
/* Even part */
var tmp10p2:Number = tmp0p2 + tmp3p2; /* phase 2 */
var tmp13p2:Number = tmp0p2 - tmp3p2;
var tmp11p2:Number = tmp1p2 + tmp2p2;
var tmp12p2:Number = tmp1p2 - tmp2p2;
data[int(dataOff)] = tmp10p2 + tmp11p2; /* phase 3 */
data[int(dataOff+32)] = tmp10p2 - tmp11p2;
var z1p2:Number = (tmp12p2 + tmp13p2) * 0.707106781; /* c4 */
data[int(dataOff+16)] = tmp13p2 + z1p2; /* phase 5 */
data[int(dataOff+48)] = tmp13p2 - z1p2;
/* Odd part */
tmp10p2 = tmp4p2 + tmp5p2; /* phase 2 */
tmp11p2 = tmp5p2 + tmp6p2;
tmp12p2 = tmp6p2 + tmp7p2;
/* The rotator is modified from fig 4-8 to avoid extra negations. */
var z5p2:Number = (tmp10p2 - tmp12p2) * 0.382683433; /* c6 */
var z2p2:Number = 0.541196100 * tmp10p2 + z5p2; /* c2-c6 */
var z4p2:Number = 1.306562965 * tmp12p2 + z5p2; /* c2+c6 */
var z3p2:Number= tmp11p2 * 0.707106781; /* c4 */
var z11p2:Number = tmp7p2 + z3p2; /* phase 5 */
var z13p2:Number = tmp7p2 - z3p2;
data[int(dataOff+40)] = z13p2 + z2p2; /* phase 6 */
data[int(dataOff+24)] = z13p2 - z2p2;
data[int(dataOff+ 8)] = z11p2 + z4p2;
data[int(dataOff+56)] = z11p2 - z4p2;
dataOff++; /* advance pointer to next column */
}
// Quantize/descale the coefficients
var fDCTQuant:Number;
for (i=0; i<I64; ++i)
{
// Apply the quantization and scaling factor & Round to nearest integer
fDCTQuant = data[int(i)]*fdtbl[int(i)];
outputfDCTQuant[int(i)] = (fDCTQuant > 0.0) ? int(fDCTQuant + 0.5) : int(fDCTQuant - 0.5);
}
return outputfDCTQuant;
}
// Chunk writing
private function writeAPP0():void
{
byteout.writeShort(0xFFE0); // marker
byteout.writeShort(16); // length
byteout.writeByte(0x4A); // J
byteout.writeByte(0x46); // F
byteout.writeByte(0x49); // I
byteout.writeByte(0x46); // F
byteout.writeByte(0); // = "JFIF",'\0'
byteout.writeByte(1); // versionhi
byteout.writeByte(1); // versionlo
byteout.writeByte(0); // xyunits
byteout.writeShort(1); // xdensity
byteout.writeShort(1); // ydensity
byteout.writeByte(0); // thumbnwidth
byteout.writeByte(0); // thumbnheight
}
private function writeSOF0(width:int, height:int):void
{
byteout.writeShort(0xFFC0); // marker
byteout.writeShort(17); // length, truecolor YUV JPG
byteout.writeByte(8); // precision
byteout.writeShort(height);
byteout.writeShort(width);
byteout.writeByte(3); // nrofcomponents
byteout.writeByte(1); // IdY
byteout.writeByte(0x11); // HVY
byteout.writeByte(0); // QTY
byteout.writeByte(2); // IdU
byteout.writeByte(0x11); // HVU
byteout.writeByte(1); // QTU
byteout.writeByte(3); // IdV
byteout.writeByte(0x11); // HVV
byteout.writeByte(1); // QTV
}
private function writeDQT():void
{
byteout.writeShort(0xFFDB); // marker
byteout.writeShort(132); // length
byteout.writeByte(0);
var i:int;
const I64:int = 64;
for (i=0; i<I64; ++i)
byteout.writeByte(YTable[i]);
byteout.writeByte(1);
for (i=0; i<I64; ++i)
byteout.writeByte(UVTable[i]);
}
private function writeDHT():void
{
byteout.writeShort(0xFFC4); // marker
byteout.writeShort(0x01A2); // length
byteout.writeByte(0); // HTYDCinfo
var i:int;
const I11:int = 11;
const I16:int = 16;
const I161:int = 161;
for (i=0; i<I16; ++i)
byteout.writeByte(std_dc_luminance_nrcodes[int(i+1)]);
for (i=0; i<=I11; ++i)
byteout.writeByte(std_dc_luminance_values[int(i)]);
byteout.writeByte(0x10); // HTYACinfo
for (i=0; i<I16; ++i)
byteout.writeByte(std_ac_luminance_nrcodes[int(i+1)]);
for (i=0; i<=I161; ++i)
byteout.writeByte(std_ac_luminance_values[int(i)]);
byteout.writeByte(1); // HTUDCinfo
for (i=0; i<I16; ++i)
byteout.writeByte(std_dc_chrominance_nrcodes[int(i+1)]);
for (i=0; i<=I11; ++i)
byteout.writeByte(std_dc_chrominance_values[int(i)]);
byteout.writeByte(0x11); // HTUACinfo
for (i=0; i<I16; ++i)
byteout.writeByte(std_ac_chrominance_nrcodes[int(i+1)]);
for (i=0; i<=I161; ++i)
byteout.writeByte(std_ac_chrominance_values[int(i)]);
}
private function writeSOS():void
{
byteout.writeShort(0xFFDA); // marker
byteout.writeShort(12); // length
byteout.writeByte(3); // nrofcomponents
byteout.writeByte(1); // IdY
byteout.writeByte(0); // HTY
byteout.writeByte(2); // IdU
byteout.writeByte(0x11); // HTU
byteout.writeByte(3); // IdV
byteout.writeByte(0x11); // HTV
byteout.writeByte(0); // Ss
byteout.writeByte(0x3f); // Se
byteout.writeByte(0); // Bf
}
// Core processing
internal var DU:Vector.<int> = new Vector.<int>(64, true);
private function processDU(CDU:Vector.<Number>, fdtbl:Vector.<Number>, DC:Number, HTDC:Vector.<BitString>, HTAC:Vector.<BitString>):Number
{
var EOB:BitString = HTAC[0x00];
var M16zeroes:BitString = HTAC[0xF0];
var pos:int;
const I16:int = 16;
const I63:int = 63;
const I64:int = 64;
var DU_DCT:Vector.<int> = fDCTQuant(CDU, fdtbl);
//ZigZag reorder
for (var j:int=0;j<I64;++j) {
DU[ZigZag[j]]=DU_DCT[j];
}
var Diff:int = DU[0] - DC; DC = DU[0];
//Encode DC
if (Diff==0) {
writeBits(HTDC[0]); // Diff might be 0
} else {
pos = int(32767+Diff);
writeBits(HTDC[category[pos]]);
writeBits(bitcode[pos]);
}
//Encode ACs
const end0pos:int = 63;
for (; (end0pos>0)&&(DU[end0pos]==0); end0pos--) {};
//end0pos = first element in reverse order !=0
if ( end0pos == 0) {
writeBits(EOB);
return DC;
}
var i:int = 1;
var lng:int;
while ( i <= end0pos ) {
var startpos:int = i;
for (; (DU[i]==0) && (i<=end0pos); ++i) {}
var nrzeroes:int = i-startpos;
if ( nrzeroes >= I16 ) {
lng = nrzeroes>>4;
for (var nrmarker:int=1; nrmarker <= lng; ++nrmarker)
writeBits(M16zeroes);
nrzeroes = int(nrzeroes&0xF);
}
pos = int(32767+DU[i]);
writeBits(HTAC[int((nrzeroes<<4)+category[pos])]);
writeBits(bitcode[pos]);
i++;
}
if ( end0pos != I63 ) {
writeBits(EOB);
}
return DC;
}
private var YDU:Vector.<Number> = new Vector.<Number>(64, true);
private var UDU:Vector.<Number> = new Vector.<Number>(64, true);
private var VDU:Vector.<Number> = new Vector.<Number>(64, true);
private function RGB2YUV(img:BitmapData, xpos:int, ypos:int):void
{
var pos:int=0;
const I8:int = 8;
for (var y:int=0; y<I8; ++y) {
for (var x:int=0; x<I8; ++x) {
var P:uint = img.getPixel32(xpos+x,ypos+y);
var R:int = (P>>16)&0xFF;
var G:int = (P>> 8)&0xFF;
var B:int = (P )&0xFF;
YDU[int(pos)]=((( 0.29900)*R+( 0.58700)*G+( 0.11400)*B))-0x80;
UDU[int(pos)]=(((-0.16874)*R+(-0.33126)*G+( 0.50000)*B));
VDU[int(pos)]=((( 0.50000)*R+(-0.41869)*G+(-0.08131)*B));
++pos;
}
}
}
public function JPEGEncoder(quality:int=50)
{
if (quality <= 0)
quality = 1;
if (quality > 100)
quality = 100;
sf = quality < 50 ? int(5000 / quality) : int(200 - (quality<<1));
init();
}
private function init():void
{
ZigZag.fixed = true;
aasf.fixed = true;
YQT.fixed = true;
UVQT.fixed = true;
std_ac_chrominance_nrcodes.fixed = true;
std_ac_chrominance_values.fixed = true;
std_ac_luminance_nrcodes.fixed = true;
std_ac_luminance_values.fixed = true;
std_dc_chrominance_nrcodes.fixed = true;
std_dc_chrominance_values.fixed = true;
std_dc_luminance_nrcodes.fixed = true;
std_dc_luminance_values.fixed = true;
// Create tables
initHuffmanTbl();
initCategoryNumber();
initQuantTables(sf);
}
public function encode(image:BitmapData):ByteArray
{
// Initialize bit writer
byteout = new ByteArray();
bytenew=0;
bytepos=7;
// Add JPEG headers
byteout.writeShort(0xFFD8); // SOI
writeAPP0();
writeDQT();
writeSOF0(image.width,image.height);
writeDHT();
writeSOS();
// Encode 8x8 macroblocks
var DCY:Number=0;
var DCU:Number=0;
var DCV:Number=0;
bytenew=0;
bytepos=7;
var width:int = image.width;
var height:int = image.height;
for (var ypos:int=0; ypos<height; ypos+=8)
{
for (var xpos:int=0; xpos<width; xpos+=8)
{
RGB2YUV(image, xpos, ypos);
DCY = processDU(YDU, fdtbl_Y, DCY, YDC_HT, YAC_HT);
DCU = processDU(UDU, fdtbl_UV, DCU, UVDC_HT, UVAC_HT);
DCV = processDU(VDU, fdtbl_UV, DCV, UVDC_HT, UVAC_HT);
}
}
// Do the bit alignment of the EOI marker
if ( bytepos >= 0 )
{
var fillbits:BitString = new BitString();
fillbits.len = bytepos+1;
fillbits.val = (1<<(bytepos+1))-1;
writeBits(fillbits);
}
byteout.writeShort(0xFFD9); //EOI
return byteout;
}
}
}
final class BitString
{
public var len:int = 0;
public var val:int = 0;
}