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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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 program 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 program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "graphics/jpeg.h"
#include "common/endian.h"
#include "common/util.h"
namespace Graphics {
// Order used to traverse the quantization tables
uint8 JPEG::_zigZagOrder[64] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63
};
JPEG::JPEG() :
_str(NULL), _w(0), _h(0), _numComp(0), _components(NULL), _numScanComp(0),
_scanComp(NULL), _currentComp(NULL) {
// Initialize the quantization tables
for (int i = 0; i < JPEG_MAX_QUANT_TABLES; i++)
_quant[i] = NULL;
// Initialize the Huffman tables
for (int i = 0; i < 2 * JPEG_MAX_HUFF_TABLES; i++) {
_huff[i].count = 0;
_huff[i].values = NULL;
_huff[i].sizes = NULL;
_huff[i].codes = NULL;
}
}
JPEG::~JPEG() {
reset();
}
void JPEG::reset() {
// Reset member variables
_str = NULL;
_w = _h = 0;
// Free the components
for (int c = 0; c < _numComp; c++)
_components[c].surface.free();
delete[] _components; _components = NULL;
_numComp = 0;
// Free the scan components
delete[] _scanComp; _scanComp = NULL;
_numScanComp = 0;
_currentComp = NULL;
// Free the quantization tables
for (int i = 0; i < JPEG_MAX_QUANT_TABLES; i++) {
delete[] _quant[i];
_quant[i] = NULL;
}
// Free the Huffman tables
for (int i = 0; i < 2 * JPEG_MAX_HUFF_TABLES; i++) {
_huff[i].count = 0;
delete[] _huff[i].values; _huff[i].values = NULL;
delete[] _huff[i].sizes; _huff[i].sizes = NULL;
delete[] _huff[i].codes; _huff[i].codes = NULL;
}
}
bool JPEG::read(Common::SeekableReadStream *str) {
// Reset member variables and tables from previous reads
reset();
// Save the input stream
_str = str;
bool ok = true;
bool done = false;
while (!_str->eos() && ok && !done) {
// Read the marker
uint16 marker = _str->readByte();
if (marker != 0xFF) {
error("JPEG: Invalid marker[0]: 0x%02X", marker);
ok = false;
break;
}
while (marker == 0xFF)
marker = _str->readByte();
// Process the marker data
switch (marker) {
case 0xC0: // Start Of Frame
ok = readSOF0();
break;
case 0xC4: // Define Huffman Tables
ok = readDHT();
break;
case 0xD8: // Start Of Image
break;
case 0xD9: // End Of Image
done = true;
break;
case 0xDA: // Start Of Scan
ok = readSOS();
break;
case 0xDB: // Define Quantization Tables
ok = readDQT();
break;
case 0xE0: // JFIF/JFXX segment
ok = readJFIF();
break;
case 0xFE: // Comment
_str->seek(_str->readUint16BE() - 2, SEEK_CUR);
break;
default: { // Unknown marker
uint16 size = _str->readUint16BE();
warning("JPEG: Unknown marker %02X, skipping %d bytes", marker, size - 2);
_str->seek(size - 2, SEEK_CUR);
}
}
}
return ok;
}
bool JPEG::readJFIF() {
/* uint16 length = */ _str->readUint16BE();
uint32 tag = _str->readUint32BE();
if (tag != MKID_BE('JFIF'))
return false;
_str->readByte(); // NULL
/* byte majorVersion = */ _str->readByte();
/* byte minorVersion = */ _str->readByte();
/* byte densityUnits = */ _str->readByte();
/* uint16 xDensity = */ _str->readUint16BE();
/* uint16 yDensity = */ _str->readUint16BE();
byte thumbW = _str->readByte();
byte thumbH = _str->readByte();
_str->seek(thumbW * thumbH * 3, SEEK_CUR); // Ignore thumbnail
return true;
}
// Marker 0xC0 (Start Of Frame, Baseline DCT)
bool JPEG::readSOF0() {
debug(5, "JPEG: readSOF0");
uint16 size = _str->readUint16BE();
// Read the sample precision
uint8 precision = _str->readByte();
if (precision != 8) {
warning("JPEG: Just 8 bit precision supported at the moment");
return false;
}
// Image size
_h = _str->readUint16BE();
_w = _str->readUint16BE();
// Number of components
_numComp = _str->readByte();
if (size != 8 + 3 * _numComp) {
warning("JPEG: Invalid number of components");
return false;
}
// Allocate the new components
delete[] _components;
_components = new Component[_numComp];
// Read the components details
for (int c = 0; c < _numComp; c++) {
_components[c].id = _str->readByte();
_components[c].factorH = _str->readByte();
_components[c].factorV = _components[c].factorH & 0xF;
_components[c].factorH >>= 4;
_components[c].quantTableSelector = _str->readByte();
}
return true;
}
// Marker 0xC4 (Define Huffman Tables)
bool JPEG::readDHT() {
debug(5, "JPEG: readDHT");
uint16 size = _str->readUint16BE() - 2;
uint32 pos = _str->pos();
while ((uint32)_str->pos() < (size + pos)) {
// Read the table type and id
uint8 tableId = _str->readByte();
uint8 tableType = tableId >> 4; // type 0: DC, 1: AC
tableId &= 0xF;
uint8 tableNum = (tableId << 1) + tableType;
// Free the Huffman table
delete[] _huff[tableNum].values; _huff[tableNum].values = NULL;
delete[] _huff[tableNum].sizes; _huff[tableNum].sizes = NULL;
delete[] _huff[tableNum].codes; _huff[tableNum].codes = NULL;
// Read the number of values for each length
uint8 numValues[16];
_huff[tableNum].count = 0;
for (int len = 0; len < 16; len++) {
numValues[len] = _str->readByte();
_huff[tableNum].count += numValues[len];
}
// Allocate memory for the current table
_huff[tableNum].values = new uint8[_huff[tableNum].count];
_huff[tableNum].sizes = new uint8[_huff[tableNum].count];
_huff[tableNum].codes = new uint16[_huff[tableNum].count];
// Read the table contents
int cur = 0;
for (int len = 0; len < 16; len++) {
for (int i = 0; i < numValues[len]; i++) {
_huff[tableNum].values[cur] = _str->readByte();
_huff[tableNum].sizes[cur] = len + 1;
cur++;
}
}
// Fill the table of Huffman codes
cur = 0;
uint16 curCode = 0;
uint8 curCodeSize = _huff[tableNum].sizes[0];
while (cur < _huff[tableNum].count) {
// Increase the code size to fit the request
while (_huff[tableNum].sizes[cur] != curCodeSize) {
curCode <<= 1;
curCodeSize++;
}
// Assign the current code
_huff[tableNum].codes[cur] = curCode;
curCode++;
cur++;
}
}
return true;
}
// Marker 0xDA (Start Of Scan)
bool JPEG::readSOS() {
debug(5, "JPEG: readSOS");
uint16 size = _str->readUint16BE();
// Number of scan components
_numScanComp = _str->readByte();
if (size != 6 + 2 * _numScanComp) {
warning("JPEG: Invalid number of components");
return false;
}
// Allocate the new scan components
delete[] _scanComp;
_scanComp = new Component *[_numScanComp];
// Reset the maximum sampling factors
_maxFactorV = 0;
_maxFactorH = 0;
// Component-specification parameters
for (int c = 0; c < _numScanComp; c++) {
// Read the desired component id
uint8 id = _str->readByte();
// Search the component with the specified id
bool found = false;
for (int i = 0; !found && i < _numComp; i++) {
if (_components[i].id == id) {
// We found the desired component
found = true;
// Assign the found component to the c'th scan component
_scanComp[c] = &_components[i];
}
}
if (!found) {
warning("JPEG: Invalid component");
return false;
}
// Read the entropy table selectors
_scanComp[c]->DCentropyTableSelector = _str->readByte();
_scanComp[c]->ACentropyTableSelector = _scanComp[c]->DCentropyTableSelector & 0xF;
_scanComp[c]->DCentropyTableSelector >>= 4;
// Calculate the maximum sampling factors
if (_scanComp[c]->factorV > _maxFactorV)
_maxFactorV = _scanComp[c]->factorV;
if (_scanComp[c]->factorH > _maxFactorH)
_maxFactorH = _scanComp[c]->factorH;
// Initialize the DC predictor
_scanComp[c]->DCpredictor = 0;
}
// Initialize the scan surfaces
for (int c = 0; c < _numScanComp; c++)
_scanComp[c]->surface.create(_w, _h, 1);
// Start of spectral selection
if (_str->readByte() != 0) {
warning("JPEG: Progressive scanning not supported");
return false;
}
// End of spectral selection
if (_str->readByte() != 63) {
warning("JPEG: Progressive scanning not supported");
return false;
}
// Successive approximation parameters
if (_str->readByte() != 0) {
warning("JPEG: Progressive scanning not supported");
return false;
}
// Entropy coded sequence starts, initialize Huffman decoder
_bitsNumber = 0;
// Read all the scan MCUs
uint16 xMCU = _w / (_maxFactorH * 8);
uint16 yMCU = _h / (_maxFactorV * 8);
bool ok = true;
for (int y = 0; ok && (y < yMCU); y++)
for (int x = 0; ok && (x < xMCU); x++)
ok = readMCU(x, y);
return ok;
}
// Marker 0xDB (Define Quantization Tables)
bool JPEG::readDQT() {
debug(5, "JPEG: readDQT");
uint16 size = _str->readUint16BE() - 2;
uint32 pos = _str->pos();
while ((uint32)_str->pos() < (pos + size)) {
// Read the table precision and id
uint8 tableId = _str->readByte();
bool highPrecision = (tableId & 0xF0) != 0;
// Validate the table id
tableId &= 0xF;
if (tableId > JPEG_MAX_QUANT_TABLES) {
warning("JPEG: Invalid number of components");
return false;
}
// Create the new table if necessary
if (!_quant[tableId])
_quant[tableId] = new uint16[64];
// Read the table (stored in Zig-Zag order)
for (int i = 0; i < 64; i++)
_quant[tableId][i] = highPrecision ? _str->readUint16BE() : _str->readByte();
}
return true;
}
bool JPEG::readMCU(uint16 xMCU, uint16 yMCU) {
bool ok = true;
for (int c = 0; ok && (c < _numComp); c++) {
// Set the current component
_currentComp = _scanComp[c];
// Read the data units of the current component
for (int y = 0; ok && (y < _scanComp[c]->factorV); y++)
for (int x = 0; ok && (x < _scanComp[c]->factorH); x++)
ok = readDataUnit(xMCU * _scanComp[c]->factorH + x, yMCU * _scanComp[c]->factorV + y);
}
return ok;
}
float JPEG::idct(int x, int y, int weight, int fx, int fy) {
float vx = cos((2 * x + 1) * fx * PI / 16);
float vy = cos((2 * y + 1) * fy * PI / 16);
float ret = (float)weight * vx * vy;
if (fx == 0)
ret /= sqrt(2.0f);
if (fy == 0)
ret /= sqrt(2.0f);
return ret;
}
bool JPEG::readDataUnit(uint16 x, uint16 y) {
// Prepare an empty data array
int16 readData[64];
for (int i = 1; i < 64; i++)
readData[i] = 0;
// Read the DC component
readData[0] = _currentComp->DCpredictor + readDC();
_currentComp->DCpredictor = readData[0];
// Read the AC components (stored in Zig-Zag)
readAC(readData);
// Calculate the DCT coefficients from the input sequence
int16 DCT[64];
for (int i = 0; i < 64; i++) {
// Dequantize
int16 val = readData[i];
int16 quant = _quant[_currentComp->quantTableSelector][i];
val *= quant;
// Store the normalized coefficients, undoing the Zig-Zag
DCT[_zigZagOrder[i]] = val;
}
// Shortcut the IDCT for DC component
float result[64];
for (int i = 0; i < 64; i++)
result[i] = DCT[0] / 2;
// Apply the IDCT (PAG31)
for (int i = 1; i < 64; i++) {
if (DCT[i])
for (int _y = 0; _y < 8; _y++)
for (int _x = 0; _x < 8; _x++)
result[_y * 8 + _x] += idct(_x, _y, DCT[i], i % 8, i / 8);
}
// Level shift to make the values unsigned
// Divide by 4 is final part of IDCT
for (int i = 0; i < 64; i++) {
result[i] = result[i] / 4 + 128;
if (result[i] < 0)
result[i] = 0;
if (result[i] > 255)
result[i] = 255;
}
// Paint the component surface
uint8 scalingV = _maxFactorV / _currentComp->factorV;
uint8 scalingH = _maxFactorH / _currentComp->factorH;
// Convert coordinates from MCU blocks to pixels
x <<= 3;
y <<= 3;
for (int j = 0; j < 8; j++) {
for (int sV = 0; sV < scalingV; sV++) {
// Get the beginning of the block line
byte *ptr = (byte *)_currentComp->surface.getBasePtr(x * scalingH, (y + j) * scalingV + sV);
for (int i = 0; i < 8; i++) {
for (uint8 sH = 0; sH < scalingH; sH++) {
*ptr = (byte)(result[j * 8 + i]);
ptr++;
}
}
}
}
return true;
}
int16 JPEG::readDC() {
// DC is type 0
uint8 tableNum = _currentComp->DCentropyTableSelector << 1;
// Get the number of bits to read
uint8 numBits = readHuff(tableNum);
// Read the requested bits
return readSignedBits(numBits);
}
void JPEG::readAC(int16 *out) {
// AC is type 1
uint8 tableNum = (_currentComp->ACentropyTableSelector << 1) + 1;
// Start reading AC element 1
uint8 cur = 1;
while (cur < 64) {
uint8 s = readHuff(tableNum);
uint8 r = s >> 4;
s &= 0xF;
if (s == 0) {
if (r == 15) {
// Skip 16 values
cur += 16;
} else {
// EOB: end of block
cur = 64;
}
} else {
// Skip r values
cur += r;
// Read the next value
out[cur] = readSignedBits(s);
cur++;
}
}
}
int16 JPEG::readSignedBits(uint8 numBits) {
uint16 ret = 0;
if (numBits > 16) error("requested %d bits", numBits); //XXX
// MSB=0 for negatives, 1 for positives
for (int i = 0; i < numBits; i++)
ret = (ret << 1) + readBit();
// Extend sign bits (PAG109)
if (!(ret >> (numBits - 1)))
{
uint16 tmp = ((uint16)-1 << numBits) + 1;
ret = ret + tmp;
}
return ret;
}
// TODO: optimize?
uint8 JPEG::readHuff(uint8 table) {
bool foundCode = false;
uint8 val = 0;
uint8 cur = 0;
uint8 codeSize = 1;
uint16 code = readBit();
while (!foundCode) {
// Prepare a code of the current size
while (codeSize < _huff[table].sizes[cur]) {
code = (code << 1) + readBit();
codeSize++;
}
// Compare the codes of the current size
while (!foundCode && (codeSize == _huff[table].sizes[cur])) {
if (code == _huff[table].codes[cur]) {
// Found the code
val = _huff[table].values[cur];
foundCode = true;
} else {
// Continue reading
cur++;
}
}
}
return val;
}
uint8 JPEG::readBit() {
// Read a whole byte if necessary
if (_bitsNumber == 0) {
_bitsData = _str->readByte();
_bitsNumber = 8;
// Detect markers
if (_bitsData == 0xFF) {
uint8 byte2 = _str->readByte();
// A stuffed 0 validates the previous byte
if (byte2 != 0) {
if (byte2 == 0xDC) {
// DNL marker: Define Number of Lines
// TODO: terminate scan
printf("DNL marker detected: terminate scan\n");
} else {
printf("Error: marker 0x%02X read in entropy data\n", byte2);
}
}
}
}
_bitsNumber--;
return (_bitsData & (1 << _bitsNumber)) ? 1 : 0;
}
Surface *JPEG::getComponent(uint c) {
for (int i = 0; i < _numComp; i++)
if (_components[i].id == c) // We found the desired component
return &_components[i].surface;
return NULL;
}
} // End of Graphics namespace
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