/*
* @(#)SEQDecoder.java 1.0 2010-12-25
*
* Copyright © 2010 Werner Randelshofer, Goldau, Switzerland.
* All rights reserved.
*
* You may not use, copy or modify this file, except in compliance with the
* license agreement you entered into with Werner Randelshofer.
* For details see accompanying license terms.
*/
package org.monte.media.seq;
import java.awt.image.ColorModel;
import java.awt.image.IndexColorModel;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteOrder;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.MemoryCacheImageInputStream;
/**
* {@code SEQDecoder}.
* <p>
* References:<br>
* <a href="http://www.fileformat.info/format/atari/egff.htm">http://www.fileformat.info/format/atari/egff.htm</a><br>
* <a href="http://www.atari-forum.com/wiki/index.php/ST_Picture_Formats">http://www.atari-forum.com/wiki/index.php/ST_Picture_Formats</a>
*
* @author Werner Randelshofer
* @version 1.0 2010-12-25 Created.
*/
public class SEQDecoder {
private ImageInputStream in;
/** Number of frames. */
private int nFrames;
/** Speed given in a timebase of 6000 nanoseconds. */
private int speed;
/** Offsets of the video frames. */
private long[] offsets;
/** The resolution. -1 if unknown. */
private int resolution = -1;
/** The number of colors. -1 if unknown. */
private int nColors = -1;
/** The movie track. */
private SEQMovieTrack track;
private boolean enforce8BitColorModel = true;
/** Creates a decoder for the specified input stream. */
public SEQDecoder(InputStream in) {
this.in = new MemoryCacheImageInputStream(in);
this.in.setByteOrder(ByteOrder.BIG_ENDIAN);
}
/** Creates a decoder for the specified image input stream. */
public SEQDecoder(ImageInputStream in) {
this.in = in;
this.in.setByteOrder(ByteOrder.BIG_ENDIAN);
}
/**
* Decodes the stream and produces animation frames into the specified
* movie track.
* <p>
* This method can only be called once.
*
* @param track The decoded data is stored in this track.
* @param loadAudio Whether to decode audio (currently unused).
*/
public void produce(SEQMovieTrack track, boolean loadAudio) throws IOException {
this.track = track;
readHeader();
readOffsets();
readFrames();
}
public void setEnforce8BitColorModel(boolean b) {
enforce8BitColorModel=b;
}
/** Reads the SEQ Header. Assumes that the input stream is positioned
* At the start of the file.
* <pre>
* // Seq Header. 128 bytes.
* typedef struct {
* ubyte[2] magicNumber; // [$FEDB or $FEDC]
* WORD version; // version number
* LONG numberOfFrames; // number of frames
* WORD speed; // maybe given in a timebase of 6000 nanoseconds
* ubyte[16] reserved[7];
* ubyte[6] reserved;
* } SeqHeader;
* </pre>
*/
private void readHeader() throws IOException {
int magic = in.readUnsignedShort();
if (magic != 0xfedb && magic != 0xfedc) {
throw new IOException("SEQ Header: Invalid magic number 0x" + Integer.toHexString(magic) + ", expected 0xfedb or 0xfedc.");
}
int version = in.readUnsignedShort();
if (version != 0) {
throw new IOException("SEQ Header: Invalid version " + version + ", expected 0.");
}
long numberOfFrames = in.readUnsignedInt();
if (numberOfFrames > Integer.MAX_VALUE) {
throw new IOException("SEQ Header: Too many frames " + numberOfFrames + ", expected 0.");
}
nFrames = (int) numberOfFrames;
speed = in.readUnsignedShort();
track.setJiffies(6000); // timebase is 6000 nanoseconds
//track.setPlayWrapupFrames(true);
int skipped = in.skipBytes(118);
if (skipped != 118) {
throw new IOException("SEQ Header: Unexpected EOF.");
}
}
/** Reads the SEQ Offsets. Assumes that the input stream is positioned
* at the beginning of the offsets and that the header has been read.
* <pre>
* typedef struct {
* ULONG offset;
* } frofOffset;
*
* typedef struct {
* frofOffset[] frame;
* } FrameOffsets;
* </pre>
*/
private void readOffsets() throws IOException {
offsets = new long[nFrames];
for (int i = 0; i < nFrames; i++) {
offsets[i] = in.readUnsignedInt();
}
}
/** Reads the video frames. Assumes that the input stream is positioned
* at the beginning of the frames and that the header and the offsets have
* been read.
*/
private void readFrames() throws IOException {
for (int i = 0; i < nFrames; i++) {
readFrame(i);
}
}
/** Reads a video frame. Assumes that the input stream is positioned
* at the beginning of the frame and that the header and the offsets have
* been read.
* <pre>
* typedef struct {
* ubyte[2] type; // (ignored?)
* WORD enum frhdResolution resolution; // [always 0]
* frhdColor[16] palette;
* CHAR[12] filename; // [usually " . "]
* ColorAnimation colorAnimation;
* WORD xOffset; // x offset for this frame [0 - 319]
* WORD yOffset; // y offset for this frame [0 - 199]
* WORD width; // width of this frame, in pixels (may be 0, see below)
* WORD height; // height of this frame, in pixels (may be 0, see below)
* UBYTE enum frhdOp operation; // operation [0 = copy, 1 = exclusive or]
* UBYTE enum frhdMthd storageMethod; // storage method [0 = uncompressed, 1 = compressed]
* ULONG lengthOfData; // length of data in bytes (if the data is compressed, this
* // will be the size of the compressed data BEFORE decompression)
* ubyte[16] reserved[3];
* ubyte[12] reserved;
* } FrameHeader; * </pre>
*/
private void readFrame(int i) throws IOException {
// Type and Resolution
// ===================
int type = in.readUnsignedShort();
if (type != 0xffff) {
throw new IOException("Frame Header "+i+": Invalid type "+type+", expected 0xffff.");
}
int res = in.readUnsignedShort();
if (res > 2) {
throw new IOException("Frame Header "+i+": Illegal resolution "+res+", expected range [0,2].");
}
if (resolution == -1) {
resolution = res;
switch (res) {
case 0:
track.setWidth(320);
track.setHeight(200);
track.setNbPlanes(4);
nColors = 16;
break;
case 1:
track.setWidth(640);
track.setHeight(200);
track.setNbPlanes(2);
nColors = 4;
break;
case 2:
track.setWidth(640);
track.setHeight(400);
track.setNbPlanes(1);
nColors = 2;
break;
}
}
if (res != resolution) {
throw new IOException("Frame Header "+i+": Illegal resolution change "+res+", expected "+resolution+".");
}
// Palette
// =============
byte[] r = new byte[nColors];
byte[] g = new byte[nColors];
byte[] b = new byte[nColors];
for (int j=0; j<nColors;j++) {
int clr = in.readUnsignedShort();
int red = (clr&0x700)>>8;
int green = (clr&0x70)>>4;
int blue = (clr&0x7);
r[j] = (byte) ((red<<5)|(red<<2)|(red>>>1));
g[j] = (byte) ((green<<5)|(green<<2)|(green>>>1));
b[j] = (byte) ((blue<<5)|(blue<<2)|(blue>>>1));
}
ColorModel cm= new IndexColorModel(enforce8BitColorModel?8:4, nColors, r, g, b);
// Filename
// =============
if (in.skipBytes(12) != 12) {
throw new IOException("Frame Header "+i+": Unexpected EOF in filename.");
}
// Color cycling
// =============
// color animation flag
if (in.skipBytes(1) != 1) {
throw new IOException("Frame Header "+i+": Unexpected EOF in color animation flag.");
}
// range start, range end
if (in.skipBytes(1) != 1) {
throw new IOException("Frame Header "+i+": Unexpected EOF in color animation range.");
}
// active
if (in.skipBytes(1) != 1) {
throw new IOException("Frame Header "+i+": Unexpected EOF in color animation activation flag.");
}
// speeddir
if (in.skipBytes(1) != 1) {
throw new IOException("Frame Header "+i+": Unexpected EOF in color animation speeddir.");
}
// steps
if (in.skipBytes(2) != 2) {
throw new IOException("Frame Header "+i+": Unexpected EOF in color animation steps.");
}
// Dimensions
// ==========
int xOffset = in.readUnsignedShort();
int yOffset = in.readUnsignedShort();
int width = in.readUnsignedShort();
int height = in.readUnsignedShort();
// Encoding
// ==============
int operation = in.readUnsignedByte();
if (operation > 1) {
throw new IOException("Frame Header "+i+": Unexpected operation "+operation+", expected range [0,1|.");
}
int storageMethod = in.readUnsignedByte();
if (storageMethod > 1) {
throw new IOException("Frame Header "+i+": Unexpected storage method "+storageMethod+", expected range [0,1|.");
}
long nData = in.readUnsignedInt();
if (nData > Integer.MAX_VALUE) {
throw new IOException("Frame Header "+i+": Too much data "+nData+", expected range [0,"+Integer.MAX_VALUE+"|.");
}
// Reserved
if (in.skipBytes(60) != 60) {
throw new IOException("Frame Header "+i+": Unexpected EOF in reserved fields.");
}
// Read image data
byte[] data = new byte[(int) nData];
in.readFully(data);
SEQDeltaFrame f = new SEQDeltaFrame();
f.setBounds(xOffset, yOffset, width, height);
f.setOperation(operation);
f.setStorageMethod(storageMethod);
f.setData(data);
f.setColorModel(cm);
f.setRelTime(speed);
f.setInterleave(1);
track.addFrame(f);
}
}