diff options
| author | Sven Gothel <sgothel@jausoft.com> | 2012-12-31 16:39:15 +0100 |
|---|---|---|
| committer | Sven Gothel <sgothel@jausoft.com> | 2012-12-31 16:39:15 +0100 |
| commit | 921b33825340d27deec2883ded21cb7434decc94 (patch) | |
| tree | 164ce843d4939144f63fd7d7db24124c86a332d4 /src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java | |
| parent | 96f8f55a8db5f430fc17ce9ea1bf45e4728ab6ac (diff) | |
Update PNGJ 0.85 -> 1.12 (w/ interlace read support) ; Added PNG Interlace read tests (TestPNGTextureFromFileNEWT)
Diffstat (limited to 'src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java')
| -rw-r--r-- | src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java | 959 |
1 files changed, 742 insertions, 217 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java b/src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java index 7343893b6..8cb4295a5 100644 --- a/src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java +++ b/src/jogl/classes/jogamp/opengl/util/pngj/PngReader.java @@ -1,42 +1,66 @@ package jogamp.opengl.util.pngj;
+import java.io.IOException;
import java.io.InputStream;
-import java.util.ArrayList;
import java.util.Arrays;
-import java.util.List;
+import java.util.HashSet;
+import java.util.zip.CRC32;
import java.util.zip.InflaterInputStream;
-import jogamp.opengl.util.pngj.PngIDatChunkInputStream.IdatChunkInfo;
+import jogamp.opengl.util.pngj.ImageInfo;
+import jogamp.opengl.util.pngj.ImageLine.SampleType;
import jogamp.opengl.util.pngj.chunks.ChunkHelper;
-import jogamp.opengl.util.pngj.chunks.ChunkList;
import jogamp.opengl.util.pngj.chunks.ChunkLoadBehaviour;
import jogamp.opengl.util.pngj.chunks.ChunkRaw;
+import jogamp.opengl.util.pngj.chunks.ChunksList;
import jogamp.opengl.util.pngj.chunks.PngChunk;
+import jogamp.opengl.util.pngj.chunks.PngChunkIDAT;
import jogamp.opengl.util.pngj.chunks.PngChunkIHDR;
+import jogamp.opengl.util.pngj.chunks.PngChunkSkipped;
import jogamp.opengl.util.pngj.chunks.PngMetadata;
-
/**
- * Reads a PNG image, line by line
+ * Reads a PNG image, line by line.
+ * <p>
+ * The reading sequence is as follows: <br>
+ * 1. At construction time, the header and IHDR chunk are read (basic image info) <br>
+ * 2. Afterwards you can set some additional global options. Eg. {@link #setUnpackedMode(boolean)},
+ * {@link #setCrcCheckDisabled()}.<br>
+ * 3. Optional: If you call getMetadata() or getChunksLisk() before start reading the rows, all the chunks before IDAT
+ * are automatically loaded and available <br>
+ * 4a. The rows are read onen by one of the <tt>readRowXXX</tt> methods: {@link #readRowInt(int)},
+ * {@link PngReader#readRowByte(int)}, etc, in order, from 0 to nrows-1 (you can skip or repeat rows, but not go
+ * backwards)<br>
+ * 4b. Alternatively, you can read all rows, or a subset, in a single call: {@link #readRowsInt()},
+ * {@link #readRowsByte()} ,etc. In general this consumes more memory, but for interlaced images this is equally
+ * efficient, and more so if reading a small subset of rows.<br>
+ * 5. Read of the last row auyomatically loads the trailing chunks, and ends the reader.<br>
+ * 6. end() forcibly finishes/aborts the reading and closes the stream
*/
public class PngReader {
/**
* Basic image info - final and inmutable.
*/
public final ImageInfo imgInfo;
- protected final String filename; // not necesarily a file, can be a description - merely informative
- private static int MAX_BYTES_CHUNKS_TO_LOAD = 640000;
- private ChunkLoadBehaviour chunkLoadBehaviour = ChunkLoadBehaviour.LOAD_CHUNK_ALWAYS;
+ /**
+ * not necesarily a filename, can be a description - merely informative
+ */
+ protected final String filename;
+
+ private ChunkLoadBehaviour chunkLoadBehaviour = ChunkLoadBehaviour.LOAD_CHUNK_ALWAYS; // see setter/getter
- private final InputStream is;
- private InflaterInputStream idatIstream;
- private PngIDatChunkInputStream iIdatCstream;
+ private boolean shouldCloseStream = true; // true: closes stream after ending - see setter/getter
- protected int currentChunkGroup = -1;
- protected int rowNum = -1; // current row number
- private int offset = 0;
- private int bytesChunksLoaded; // bytes loaded from anciallary chunks
+ // some performance/defensive limits
+ private long maxTotalBytesRead = 200 * 1024 * 1024; // 200MB
+ private int maxBytesMetadata = 5 * 1024 * 1024; // for ancillary chunks - see setter/getter
+ private int skipChunkMaxSize = 2 * 1024 * 1024; // chunks exceeding this size will be skipped (nor even CRC checked)
+ private String[] skipChunkIds = { "fdAT" }; // chunks with these ids will be skipped (nor even CRC checked)
+ private HashSet<String> skipChunkIdsSet; // lazily created from skipChunksById
+
+ protected final PngMetadata metadata; // this a wrapper over chunks
+ protected final ChunksList chunksList;
protected ImageLine imgLine;
@@ -45,12 +69,30 @@ public class PngReader { protected byte[] rowbprev = null; // rowb previous
protected byte[] rowbfilter = null; // current line 'filtered': exactly as in uncompressed stream
+ // only set for interlaced PNG
+ private final boolean interlaced;
+ private final PngDeinterlacer deinterlacer;
+
+ private boolean crcEnabled = true;
+
+ // this only influences the 1-2-4 bitdepth format
+ private boolean unpackedMode = false;
/**
- * All chunks loaded. Criticals are included, except that all IDAT chunks appearance are replaced by a single
- * dummy-marker IDAT chunk. These might be copied to the PngWriter
+ * Current chunk group, (0-6) already read or reading
+ * <p>
+ * see {@link ChunksList}
*/
- private final ChunkList chunksList;
- private final PngMetadata metadata; // this a wrapper over chunks
+ protected int currentChunkGroup = -1;
+
+ protected int rowNum = -1; // last read row number, starting from 0
+ private long offset = 0; // offset in InputStream = bytes read
+ private int bytesChunksLoaded; // bytes loaded from anciallary chunks
+
+ protected final InputStream inputStream;
+ protected InflaterInputStream idatIstream;
+ protected PngIDatChunkInputStream iIdatCstream;
+
+ protected CRC32 crctest; // If set to non null, it gets a CRC of the unfiltered bytes, to check for images equality
/**
* Constructs a PngReader from an InputStream.
@@ -65,175 +107,234 @@ public class PngReader { */
public PngReader(InputStream inputStream, String filenameOrDescription) {
this.filename = filenameOrDescription == null ? "" : filenameOrDescription;
- this.is = inputStream;
- this.chunksList = new ChunkList(null);
- this.metadata = new PngMetadata(chunksList, true);
- // reads header (magic bytes)
- byte[] pngid = new byte[PngHelper.pngIdBytes.length];
- PngHelper.readBytes(is, pngid, 0, pngid.length);
+ this.inputStream = inputStream;
+ this.chunksList = new ChunksList(null);
+ this.metadata = new PngMetadata(chunksList);
+ // starts reading: signature
+ byte[] pngid = new byte[8];
+ PngHelperInternal.readBytes(inputStream, pngid, 0, pngid.length);
offset += pngid.length;
- if (!Arrays.equals(pngid, PngHelper.pngIdBytes))
+ if (!Arrays.equals(pngid, PngHelperInternal.getPngIdSignature()))
throw new PngjInputException("Bad PNG signature");
// reads first chunk
- currentChunkGroup = ChunkList.CHUNK_GROUP_0_IDHR;
- int clen = PngHelper.readInt4(is);
+ currentChunkGroup = ChunksList.CHUNK_GROUP_0_IDHR;
+ int clen = PngHelperInternal.readInt4(inputStream);
offset += 4;
if (clen != 13)
- throw new RuntimeException("IDHR chunk len != 13 ?? " + clen);
+ throw new PngjInputException("IDHR chunk len != 13 ?? " + clen);
byte[] chunkid = new byte[4];
- PngHelper.readBytes(is, chunkid, 0, 4);
+ PngHelperInternal.readBytes(inputStream, chunkid, 0, 4);
if (!Arrays.equals(chunkid, ChunkHelper.b_IHDR))
throw new PngjInputException("IHDR not found as first chunk??? [" + ChunkHelper.toString(chunkid) + "]");
offset += 4;
- ChunkRaw chunk = new ChunkRaw(clen, chunkid, true);
- String chunkids = ChunkHelper.toString(chunkid);
- offset += chunk.readChunkData(is);
- PngChunkIHDR ihdr = (PngChunkIHDR) addChunkToList(chunk);
+ PngChunkIHDR ihdr = (PngChunkIHDR) readChunk(chunkid, clen, false);
boolean alpha = (ihdr.getColormodel() & 0x04) != 0;
boolean palette = (ihdr.getColormodel() & 0x01) != 0;
boolean grayscale = (ihdr.getColormodel() == 0 || ihdr.getColormodel() == 4);
+ // creates ImgInfo and imgLine, and allocates buffers
imgInfo = new ImageInfo(ihdr.getCols(), ihdr.getRows(), ihdr.getBitspc(), alpha, grayscale, palette);
- imgLine = new ImageLine(imgInfo);
- if (ihdr.getInterlaced() != 0)
- throw new PngjUnsupportedException("PNG interlaced not supported by this library");
- if (ihdr.getFilmeth() != 0 || ihdr.getCompmeth() != 0)
- throw new PngjInputException("compmethod o filtermethod unrecognized");
+ // allocation: one extra byte for filter type one pixel
+ rowbfilter = new byte[imgInfo.bytesPerRow + 1];
+ rowb = new byte[imgInfo.bytesPerRow + 1];
+ rowbprev = new byte[rowb.length];
+ interlaced = ihdr.getInterlaced() == 1;
+ deinterlacer = interlaced ? new PngDeinterlacer(imgInfo) : null;
+ // some checks
+ if (ihdr.getFilmeth() != 0 || ihdr.getCompmeth() != 0 || (ihdr.getInterlaced() & 0xFFFE) != 0)
+ throw new PngjInputException("compression method o filter method or interlaced unrecognized ");
if (ihdr.getColormodel() < 0 || ihdr.getColormodel() > 6 || ihdr.getColormodel() == 1
|| ihdr.getColormodel() == 5)
throw new PngjInputException("Invalid colormodel " + ihdr.getColormodel());
if (ihdr.getBitspc() != 1 && ihdr.getBitspc() != 2 && ihdr.getBitspc() != 4 && ihdr.getBitspc() != 8
&& ihdr.getBitspc() != 16)
throw new PngjInputException("Invalid bit depth " + ihdr.getBitspc());
- // allocation: one extra byte for filter type one pixel
- rowbfilter = new byte[imgInfo.bytesPerRow + 1];
- rowb = new byte[imgInfo.bytesPerRow + 1];
- rowbprev = new byte[rowb.length];
}
- private static class FoundChunkInfo {
- public final String id;
- public final int len;
- public final int offset;
- public final boolean loaded;
+ private boolean firstChunksNotYetRead() {
+ return currentChunkGroup < ChunksList.CHUNK_GROUP_1_AFTERIDHR;
+ }
+
+ /**
+ * Reads last Internally called after having read the last line. It reads extra chunks after IDAT, if present.
+ */
+ private void readLastAndClose() {
+ // offset = iIdatCstream.getOffset();
+ if (currentChunkGroup < ChunksList.CHUNK_GROUP_5_AFTERIDAT) {
+ try {
+ idatIstream.close();
+ } catch (Exception e) {
+ }
+ readLastChunks();
+ }
+ close();
+ }
+
+ private void close() {
+ if (currentChunkGroup < ChunksList.CHUNK_GROUP_6_END) { // this could only happen if forced close
+ try {
+ idatIstream.close();
+ } catch (Exception e) {
+ }
+ currentChunkGroup = ChunksList.CHUNK_GROUP_6_END;
+ }
+ if (shouldCloseStream) {
+ try {
+ inputStream.close();
+ } catch (Exception e) {
+ throw new PngjInputException("error closing input stream!", e);
+ }
+ }
+ }
+
+ // nbytes: NOT including the filter byte. leaves result in rowb
+ private void unfilterRow(int nbytes) {
+ int ftn = rowbfilter[0];
+ FilterType ft = FilterType.getByVal(ftn);
+ if (ft == null)
+ throw new PngjInputException("Filter type " + ftn + " invalid");
+ switch (ft) {
+ case FILTER_NONE:
+ unfilterRowNone(nbytes);
+ break;
+ case FILTER_SUB:
+ unfilterRowSub(nbytes);
+ break;
+ case FILTER_UP:
+ unfilterRowUp(nbytes);
+ break;
+ case FILTER_AVERAGE:
+ unfilterRowAverage(nbytes);
+ break;
+ case FILTER_PAETH:
+ unfilterRowPaeth(nbytes);
+ break;
+ default:
+ throw new PngjInputException("Filter type " + ftn + " not implemented");
+ }
+ if (crctest != null)
+ crctest.update(rowb, 1, rowb.length - 1);
+ }
+
+ private void unfilterRowAverage(final int nbytes) {
+ int i, j, x;
+ for (j = 1 - imgInfo.bytesPixel, i = 1; i <= nbytes; i++, j++) {
+ x = j > 0 ? (rowb[j] & 0xff) : 0;
+ rowb[i] = (byte) (rowbfilter[i] + (x + (rowbprev[i] & 0xFF)) / 2);
+ }
+ }
- private FoundChunkInfo(String id, int len, int offset, boolean loaded) {
- this.id = id;
- this.len = len;
- this.offset = offset;
- this.loaded = loaded;
+ private void unfilterRowNone(final int nbytes) {
+ for (int i = 1; i <= nbytes; i++) {
+ rowb[i] = (byte) (rowbfilter[i]);
}
+ }
- public String toString() {
- return "chunk " + id + " len=" + len + " offset=" + offset + (this.loaded ? " " : " X ");
+ private void unfilterRowPaeth(final int nbytes) {
+ int i, j, x, y;
+ for (j = 1 - imgInfo.bytesPixel, i = 1; i <= nbytes; i++, j++) {
+ x = j > 0 ? (rowb[j] & 0xFF) : 0;
+ y = j > 0 ? (rowbprev[j] & 0xFF) : 0;
+ rowb[i] = (byte) (rowbfilter[i] + PngHelperInternal.filterPaethPredictor(x, rowbprev[i] & 0xFF, y));
}
}
- private PngChunk addChunkToList(ChunkRaw chunk) {
- // this requires that the currentChunkGroup is ok
- PngChunk chunkType = PngChunk.factory(chunk, imgInfo);
- if (!chunkType.crit) {
- bytesChunksLoaded += chunk.len;
+ private void unfilterRowSub(final int nbytes) {
+ int i, j;
+ for (i = 1; i <= imgInfo.bytesPixel; i++) {
+ rowb[i] = (byte) (rowbfilter[i]);
+ }
+ for (j = 1, i = imgInfo.bytesPixel + 1; i <= nbytes; i++, j++) {
+ rowb[i] = (byte) (rowbfilter[i] + rowb[j]);
}
- if (bytesChunksLoaded > MAX_BYTES_CHUNKS_TO_LOAD) {
- throw new PngjInputException("Chunk exceeded available space (" + MAX_BYTES_CHUNKS_TO_LOAD + ") chunk: "
- + chunk + " See PngReader.MAX_BYTES_CHUNKS_TO_LOAD\n");
+ }
+
+ private void unfilterRowUp(final int nbytes) {
+ for (int i = 1; i <= nbytes; i++) {
+ rowb[i] = (byte) (rowbfilter[i] + rowbprev[i]);
}
- chunksList.appendReadChunk(chunkType, currentChunkGroup);
- return chunkType;
}
/**
- * Reads chunks before first IDAT. Position before: after IDHR (crc included) Position after: just after the first
- * IDAT chunk id
- *
+ * Reads chunks before first IDAT. Normally this is called automatically
+ * <p>
+ * Position before: after IDHR (crc included) Position after: just after the first IDAT chunk id
+ * <P>
* This can be called several times (tentatively), it does nothing if already run
- *
+ * <p>
* (Note: when should this be called? in the constructor? hardly, because we loose the opportunity to call
* setChunkLoadBehaviour() and perhaps other settings before reading the first row? but sometimes we want to access
* some metadata (plte, phys) before. Because of this, this method can be called explicitly but is also called
- * implicititly in some methods (getMetatada(), getChunks())
- *
- **/
- public void readFirstChunks() {
+ * implicititly in some methods (getMetatada(), getChunksList())
+ */
+ private final void readFirstChunks() {
if (!firstChunksNotYetRead())
return;
int clen = 0;
boolean found = false;
byte[] chunkid = new byte[4]; // it's important to reallocate in each iteration
- currentChunkGroup = ChunkList.CHUNK_GROUP_1_AFTERIDHR;
+ currentChunkGroup = ChunksList.CHUNK_GROUP_1_AFTERIDHR;
while (!found) {
- clen = PngHelper.readInt4(is);
+ clen = PngHelperInternal.readInt4(inputStream);
offset += 4;
if (clen < 0)
break;
- PngHelper.readBytes(is, chunkid, 0, 4);
+ PngHelperInternal.readBytes(inputStream, chunkid, 0, 4);
offset += 4;
if (Arrays.equals(chunkid, ChunkHelper.b_IDAT)) {
found = true;
- currentChunkGroup = ChunkList.CHUNK_GROUP_4_IDAT;
+ currentChunkGroup = ChunksList.CHUNK_GROUP_4_IDAT;
// add dummy idat chunk to list
- ChunkRaw chunk = new ChunkRaw(0, chunkid, false);
- addChunkToList(chunk);
+ chunksList.appendReadChunk(new PngChunkIDAT(imgInfo, clen, offset - 8), currentChunkGroup);
break;
} else if (Arrays.equals(chunkid, ChunkHelper.b_IEND)) {
throw new PngjInputException("END chunk found before image data (IDAT) at offset=" + offset);
}
- ChunkRaw chunk = new ChunkRaw(clen, chunkid, true);
- String chunkids = ChunkHelper.toString(chunkid);
- boolean loadchunk = ChunkHelper.shouldLoad(chunkids, chunkLoadBehaviour);
- offset += chunk.readChunkData(is);
- if (chunkids.equals(ChunkHelper.PLTE))
- currentChunkGroup = ChunkList.CHUNK_GROUP_2_PLTE;
- if (loadchunk)
- addChunkToList(chunk);
- if (chunkids.equals(ChunkHelper.PLTE))
- currentChunkGroup = ChunkList.CHUNK_GROUP_3_AFTERPLTE;
+ if (Arrays.equals(chunkid, ChunkHelper.b_PLTE))
+ currentChunkGroup = ChunksList.CHUNK_GROUP_2_PLTE;
+ readChunk(chunkid, clen, false);
+ if (Arrays.equals(chunkid, ChunkHelper.b_PLTE))
+ currentChunkGroup = ChunksList.CHUNK_GROUP_3_AFTERPLTE;
}
int idatLen = found ? clen : -1;
if (idatLen < 0)
throw new PngjInputException("first idat chunk not found!");
- iIdatCstream = new PngIDatChunkInputStream(is, idatLen, offset);
+ iIdatCstream = new PngIDatChunkInputStream(inputStream, idatLen, offset);
idatIstream = new InflaterInputStream(iIdatCstream);
+ if (!crcEnabled)
+ iIdatCstream.disableCrcCheck();
}
/**
* Reads (and processes) chunks after last IDAT.
**/
- private void readLastChunks() {
+ void readLastChunks() {
// PngHelper.logdebug("idat ended? " + iIdatCstream.isEnded());
- currentChunkGroup = ChunkList.CHUNK_GROUP_5_AFTERIDAT;
+ currentChunkGroup = ChunksList.CHUNK_GROUP_5_AFTERIDAT;
if (!iIdatCstream.isEnded())
iIdatCstream.forceChunkEnd();
int clen = iIdatCstream.getLenLastChunk();
byte[] chunkid = iIdatCstream.getIdLastChunk();
boolean endfound = false;
boolean first = true;
- boolean ignore = false;
+ boolean skip = false;
while (!endfound) {
- ignore = false;
+ skip = false;
if (!first) {
- clen = PngHelper.readInt4(is);
+ clen = PngHelperInternal.readInt4(inputStream);
offset += 4;
if (clen < 0)
- throw new PngjInputException("bad len " + clen);
- PngHelper.readBytes(is, chunkid, 0, 4);
+ throw new PngjInputException("bad chuck len " + clen);
+ PngHelperInternal.readBytes(inputStream, chunkid, 0, 4);
offset += 4;
}
first = false;
if (Arrays.equals(chunkid, ChunkHelper.b_IDAT)) {
- // PngHelper.logdebug("extra IDAT chunk len - ignoring : ");
- ignore = true;
+ skip = true; // extra dummy (empty?) idat chunk, it can happen, ignore it
} else if (Arrays.equals(chunkid, ChunkHelper.b_IEND)) {
- currentChunkGroup = ChunkList.CHUNK_GROUP_6_END;
+ currentChunkGroup = ChunksList.CHUNK_GROUP_6_END;
endfound = true;
}
- ChunkRaw chunk = new ChunkRaw(clen, chunkid, true);
- String chunkids = ChunkHelper.toString(chunkid);
- boolean loadchunk = ChunkHelper.shouldLoad(chunkids, chunkLoadBehaviour);
- offset += chunk.readChunkData(is);
- if (loadchunk && !ignore) {
- addChunkToList(chunk);
- }
+ readChunk(chunkid, clen, skip);
}
if (!endfound)
throw new PngjInputException("end chunk not found - offset=" + offset);
@@ -241,173 +342,597 @@ public class PngReader { }
/**
- * Calls <code>readRow(int[] buffer, int nrow)</code> using internal ImageLine as buffer. This doesn't allocate or
- * copy anything.
+ * Reads chunkd from input stream, adds to ChunksList, and returns it. If it's skipped, a PngChunkSkipped object is
+ * created
+ */
+ private PngChunk readChunk(byte[] chunkid, int clen, boolean skipforced) {
+ if (clen < 0)
+ throw new PngjInputException("invalid chunk lenght: " + clen);
+ // skipChunksByIdSet is created lazyly, if fist IHDR has already been read
+ if (skipChunkIdsSet == null && currentChunkGroup > ChunksList.CHUNK_GROUP_0_IDHR)
+ skipChunkIdsSet = new HashSet<String>(Arrays.asList(skipChunkIds));
+ String chunkidstr = ChunkHelper.toString(chunkid);
+ boolean critical = ChunkHelper.isCritical(chunkidstr);
+ PngChunk pngChunk = null;
+ boolean skip = skipforced;
+ if (maxTotalBytesRead > 0 && clen + offset > maxTotalBytesRead)
+ throw new PngjInputException("Maximum total bytes to read exceeeded: " + maxTotalBytesRead + " offset:"
+ + offset + " clen=" + clen);
+ // an ancillary chunks can be skipped because of several reasons:
+ if (currentChunkGroup > ChunksList.CHUNK_GROUP_0_IDHR && !critical)
+ skip = skip || (skipChunkMaxSize > 0 && clen >= skipChunkMaxSize) || skipChunkIdsSet.contains(chunkidstr)
+ || (maxBytesMetadata > 0 && clen > maxBytesMetadata - bytesChunksLoaded)
+ || !ChunkHelper.shouldLoad(chunkidstr, chunkLoadBehaviour);
+ if (skip) {
+ PngHelperInternal.skipBytes(inputStream, clen);
+ PngHelperInternal.readInt4(inputStream); // skip - we dont call PngHelperInternal.skipBytes(inputStream,
+ // clen + 4) for risk of overflow
+ pngChunk = new PngChunkSkipped(chunkidstr, imgInfo, clen);
+ } else {
+ ChunkRaw chunk = new ChunkRaw(clen, chunkid, true);
+ chunk.readChunkData(inputStream, crcEnabled || critical);
+ pngChunk = PngChunk.factory(chunk, imgInfo);
+ if (!pngChunk.crit)
+ bytesChunksLoaded += chunk.len;
+ }
+ pngChunk.setOffset(offset - 8L);
+ chunksList.appendReadChunk(pngChunk, currentChunkGroup);
+ offset += clen + 4L;
+ return pngChunk;
+ }
+
+ /**
+ * Logs/prints a warning.
+ * <p>
+ * The default behaviour is print to stderr, but it can be overriden.
+ * <p>
+ * This happens rarely - most errors are fatal.
+ */
+ protected void logWarn(String warn) {
+ System.err.println(warn);
+ }
+
+ /**
+ * @see #setChunkLoadBehaviour(ChunkLoadBehaviour)
+ */
+ public ChunkLoadBehaviour getChunkLoadBehaviour() {
+ return chunkLoadBehaviour;
+ }
+
+ /**
+ * Determines which ancillary chunks (metada) are to be loaded
+ *
+ * @param chunkLoadBehaviour
+ * {@link ChunkLoadBehaviour}
+ */
+ public void setChunkLoadBehaviour(ChunkLoadBehaviour chunkLoadBehaviour) {
+ this.chunkLoadBehaviour = chunkLoadBehaviour;
+ }
+
+ /**
+ * All loaded chunks (metada). If we have not yet end reading the image, this will include only the chunks before
+ * the pixels data (IDAT)
+ * <p>
+ * Critical chunks are included, except that all IDAT chunks appearance are replaced by a single dummy-marker IDAT
+ * chunk. These might be copied to the PngWriter
+ * <p>
+ *
+ * @see #getMetadata()
+ */
+ public ChunksList getChunksList() {
+ if (firstChunksNotYetRead())
+ readFirstChunks();
+ return chunksList;
+ }
+
+ int getCurrentChunkGroup() {
+ return currentChunkGroup;
+ }
+
+ /**
+ * High level wrapper over chunksList
*
- * @return The ImageLine that also is available inside this object.
+ * @see #getChunksList()
+ */
+ public PngMetadata getMetadata() {
+ if (firstChunksNotYetRead())
+ readFirstChunks();
+ return metadata;
+ }
+
+ /**
+ * If called for first time, calls readRowInt. Elsewhere, it calls the appropiate readRowInt/readRowByte
+ * <p>
+ * In general, specifying the concrete readRowInt/readRowByte is preferrable
+ *
+ * @see #readRowInt(int) {@link #readRowByte(int)}
*/
public ImageLine readRow(int nrow) {
- readRow(imgLine.scanline, nrow);
- imgLine.filterUsed = FilterType.getByVal(rowbfilter[0]);
+ if (imgLine == null)
+ imgLine = new ImageLine(imgInfo, SampleType.INT, unpackedMode);
+ return imgLine.sampleType != SampleType.BYTE ? readRowInt(nrow) : readRowByte(nrow);
+ }
+
+ /**
+ * Reads the row as INT, storing it in the {@link #imgLine} property and returning it.
+ *
+ * The row must be greater or equal than the last read row.
+ *
+ * @param nrow
+ * Row number, from 0 to rows-1. Increasing order.
+ * @return ImageLine object, also available as field. Data is in {@link ImageLine#scanline} (int) field.
+ */
+ public ImageLine readRowInt(int nrow) {
+ if (imgLine == null)
+ imgLine = new ImageLine(imgInfo, SampleType.INT, unpackedMode);
+ if (imgLine.getRown() == nrow) // already read
+ return imgLine;
+ readRowInt(imgLine.scanline, nrow);
+ imgLine.setFilterUsed(FilterType.getByVal(rowbfilter[0]));
+ imgLine.setRown(nrow);
+ return imgLine;
+ }
+
+ /**
+ * Reads the row as BYTES, storing it in the {@link #imgLine} property and returning it.
+ *
+ * The row must be greater or equal than the last read row. This method allows to pass the same row that was last
+ * read.
+ *
+ * @param nrow
+ * Row number, from 0 to rows-1. Increasing order.
+ * @return ImageLine object, also available as field. Data is in {@link ImageLine#scanlineb} (byte) field.
+ */
+ public ImageLine readRowByte(int nrow) {
+ if (imgLine == null)
+ imgLine = new ImageLine(imgInfo, SampleType.BYTE, unpackedMode);
+ if (imgLine.getRown() == nrow) // already read
+ return imgLine;
+ readRowByte(imgLine.scanlineb, nrow);
+ imgLine.setFilterUsed(FilterType.getByVal(rowbfilter[0]));
imgLine.setRown(nrow);
return imgLine;
}
/**
+ * @see #readRowInt(int[], int)
+ */
+ public final int[] readRow(int[] buffer, final int nrow) {
+ return readRowInt(buffer, nrow);
+ }
+
+ /**
* Reads a line and returns it as a int[] array.
+ * <p>
+ * You can pass (optionally) a prealocatted buffer.
+ * <p>
+ * If the bitdepth is less than 8, the bytes are packed - unless {@link #unpackedMode} is true.
+ *
+ * @param buffer
+ * Prealocated buffer, or null.
+ * @param nrow
+ * Row number (0 is top). Most be strictly greater than the last read row.
*
+ * @return The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise
+ */
+ public final int[] readRowInt(int[] buffer, final int nrow) {
+ if (buffer == null)
+ buffer = new int[unpackedMode ? imgInfo.samplesPerRow : imgInfo.samplesPerRowPacked];
+ if (!interlaced) {
+ if (nrow <= rowNum)
+ throw new PngjInputException("rows must be read in increasing order: " + nrow);
+ int bytesread = 0;
+ while (rowNum < nrow)
+ bytesread = readRowRaw(rowNum + 1); // read rows, perhaps skipping if necessary
+ decodeLastReadRowToInt(buffer, bytesread);
+ } else { // interlaced
+ if (deinterlacer.getImageInt() == null)
+ deinterlacer.setImageInt(readRowsInt().scanlines); // read all image and store it in deinterlacer
+ System.arraycopy(deinterlacer.getImageInt()[nrow], 0, buffer, 0, unpackedMode ? imgInfo.samplesPerRow
+ : imgInfo.samplesPerRowPacked);
+ }
+ return buffer;
+ }
+
+ /**
+ * Reads a line and returns it as a byte[] array.
+ * <p>
* You can pass (optionally) a prealocatted buffer.
+ * <p>
+ * If the bitdepth is less than 8, the bytes are packed - unless {@link #unpackedMode} is true. <br>
+ * If the bitdepth is 16, the least significant byte is lost.
+ * <p>
*
* @param buffer
* Prealocated buffer, or null.
* @param nrow
- * Row number (0 is top). This is mostly for checking, because this library reads rows in sequence.
+ * Row number (0 is top). Most be strictly greater than the last read row.
*
* @return The scanline in the same passwd buffer if it was allocated, a newly allocated one otherwise
*/
- public int[] readRow(int[] buffer, int nrow) {
- if (nrow < 0 || nrow >= imgInfo.rows)
- throw new PngjInputException("invalid line");
- if (nrow != rowNum + 1)
- throw new PngjInputException("invalid line (expected: " + (rowNum + 1));
+ public final byte[] readRowByte(byte[] buffer, final int nrow) {
+ if (buffer == null)
+ buffer = new byte[unpackedMode ? imgInfo.samplesPerRow : imgInfo.samplesPerRowPacked];
+ if (!interlaced) {
+ if (nrow <= rowNum)
+ throw new PngjInputException("rows must be read in increasing order: " + nrow);
+ int bytesread = 0;
+ while (rowNum < nrow)
+ bytesread = readRowRaw(rowNum + 1); // read rows, perhaps skipping if necessary
+ decodeLastReadRowToByte(buffer, bytesread);
+ } else { // interlaced
+ if (deinterlacer.getImageByte() == null)
+ deinterlacer.setImageByte(readRowsByte().scanlinesb); // read all image and store it in deinterlacer
+ System.arraycopy(deinterlacer.getImageByte()[nrow], 0, buffer, 0, unpackedMode ? imgInfo.samplesPerRow
+ : imgInfo.samplesPerRowPacked);
+ }
+ return buffer;
+ }
+
+ /**
+ * @param nrow
+ * @deprecated Now {@link #readRow(int)} implements the same funcion. This method will be removed in future releases
+ */
+ public ImageLine getRow(int nrow) {
+ return readRow(nrow);
+ }
+
+ private void decodeLastReadRowToInt(int[] buffer, int bytesRead) {
+ if (imgInfo.bitDepth <= 8)
+ for (int i = 0, j = 1; i < bytesRead; i++)
+ buffer[i] = (rowb[j++] & 0xFF); // http://www.libpng.org/pub/png/spec/1.2/PNG-DataRep.html
+ else
+ for (int i = 0, j = 1; j <= bytesRead; i++)
+ buffer[i] = ((rowb[j++] & 0xFF) << 8) + (rowb[j++] & 0xFF); // 16 bitspc
+ if (imgInfo.packed && unpackedMode)
+ ImageLine.unpackInplaceInt(imgInfo, buffer, buffer, false);
+ }
+
+ private void decodeLastReadRowToByte(byte[] buffer, int bytesRead) {
+ if (imgInfo.bitDepth <= 8)
+ System.arraycopy(rowb, 1, buffer, 0, bytesRead);
+ else
+ for (int i = 0, j = 1; j < bytesRead; i++, j += 2)
+ buffer[i] = rowb[j];// 16 bits in 1 byte: this discards the LSB!!!
+ if (imgInfo.packed && unpackedMode)
+ ImageLine.unpackInplaceByte(imgInfo, buffer, buffer, false);
+ }
+
+ /**
+ * Reads a set of lines and returns it as a ImageLines object, which wraps matrix. Internally it reads all lines,
+ * but decodes and stores only the wanted ones. This starts and ends the reading, and cannot be combined with other
+ * reading methods.
+ * <p>
+ * This it's more efficient (speed an memory) that doing calling readRowInt() for each desired line only if the
+ * image is interlaced.
+ * <p>
+ * Notice that the columns in the matrix is not the pixel width of the image, but rather pixels x channels
+ *
+ * @see #readRowInt(int) to read about the format of each row
+ *
+ * @param rowOffset
+ * Number of rows to be skipped
+ * @param nRows
+ * Total number of rows to be read. -1: read all available
+ * @param rowStep
+ * Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc
+ * @return Set of lines as a ImageLines, which wraps a matrix
+ */
+ public ImageLines readRowsInt(int rowOffset, int nRows, int rowStep) {
+ if (nRows < 0)
+ nRows = (imgInfo.rows - rowOffset) / rowStep;
+ if (rowStep < 1 || rowOffset < 0 || nRows * rowStep + rowOffset > imgInfo.rows)
+ throw new PngjInputException("bad args");
+ ImageLines imlines = new ImageLines(imgInfo, SampleType.INT, unpackedMode, rowOffset, nRows, rowStep);
+ if (!interlaced) {
+ for (int j = 0; j < imgInfo.rows; j++) {
+ int bytesread = readRowRaw(j); // read and perhaps discards
+ int mrow = imlines.imageRowToMatrixRowStrict(j);
+ if (mrow >= 0)
+ decodeLastReadRowToInt(imlines.scanlines[mrow], bytesread);
+ }
+ } else { // and now, for something completely different (interlaced)
+ int[] buf = new int[unpackedMode ? imgInfo.samplesPerRow : imgInfo.samplesPerRowPacked];
+ for (int p = 1; p <= 7; p++) {
+ deinterlacer.setPass(p);
+ for (int i = 0; i < deinterlacer.getRows(); i++) {
+ int bytesread = readRowRaw(i);
+ int j = deinterlacer.getCurrRowReal();
+ int mrow = imlines.imageRowToMatrixRowStrict(j);
+ if (mrow >= 0) {
+ decodeLastReadRowToInt(buf, bytesread);
+ deinterlacer.deinterlaceInt(buf, imlines.scanlines[mrow], !unpackedMode);
+ }
+ }
+ }
+ }
+ end();
+ return imlines;
+ }
+
+ /**
+ * Same as readRowsInt(0, imgInfo.rows, 1)
+ *
+ * @see #readRowsInt(int, int, int)
+ */
+ public ImageLines readRowsInt() {
+ return readRowsInt(0, imgInfo.rows, 1);
+ }
+
+ /**
+ * Reads a set of lines and returns it as a ImageLines object, which wrapas a byte[][] matrix. Internally it reads
+ * all lines, but decodes and stores only the wanted ones. This starts and ends the reading, and cannot be combined
+ * with other reading methods.
+ * <p>
+ * This it's more efficient (speed an memory) that doing calling readRowByte() for each desired line only if the
+ * image is interlaced.
+ * <p>
+ * Notice that the columns in the matrix is not the pixel width of the image, but rather pixels x channels
+ *
+ * @see #readRowByte(int) to read about the format of each row. Notice that if the bitdepth is 16 this will lose
+ * information
+ *
+ * @param rowOffset
+ * Number of rows to be skipped
+ * @param nRows
+ * Total number of rows to be read. -1: read all available
+ * @param rowStep
+ * Row increment. If 1, we read consecutive lines; if 2, we read even/odd lines, etc
+ * @return Set of lines as a matrix
+ */
+ public ImageLines readRowsByte(int rowOffset, int nRows, int rowStep) {
+ if (nRows < 0)
+ nRows = (imgInfo.rows - rowOffset) / rowStep;
+ if (rowStep < 1 || rowOffset < 0 || nRows * rowStep + rowOffset > imgInfo.rows)
+ throw new PngjInputException("bad args");
+ ImageLines imlines = new ImageLines(imgInfo, SampleType.BYTE, unpackedMode, rowOffset, nRows, rowStep);
+ if (!interlaced) {
+ for (int j = 0; j < imgInfo.rows; j++) {
+ int bytesread = readRowRaw(j); // read and perhaps discards
+ int mrow = imlines.imageRowToMatrixRowStrict(j);
+ if (mrow >= 0)
+ decodeLastReadRowToByte(imlines.scanlinesb[mrow], bytesread);
+ }
+ } else { // and now, for something completely different (interlaced)
+ byte[] buf = new byte[unpackedMode ? imgInfo.samplesPerRow : imgInfo.samplesPerRowPacked];
+ for (int p = 1; p <= 7; p++) {
+ deinterlacer.setPass(p);
+ for (int i = 0; i < deinterlacer.getRows(); i++) {
+ int bytesread = readRowRaw(i);
+ int j = deinterlacer.getCurrRowReal();
+ int mrow = imlines.imageRowToMatrixRowStrict(j);
+ if (mrow >= 0) {
+ decodeLastReadRowToByte(buf, bytesread);
+ deinterlacer.deinterlaceByte(buf, imlines.scanlinesb[mrow], !unpackedMode);
+ }
+ }
+ }
+ }
+ end();
+ return imlines;
+ }
+
+ /**
+ * Same as readRowsByte(0, imgInfo.rows, 1)
+ *
+ * @see #readRowsByte(int, int, int)
+ */
+ public ImageLines readRowsByte() {
+ return readRowsByte(0, imgInfo.rows, 1);
+ }
+
+ /*
+ * For the interlaced case, nrow indicates the subsampled image - the pass must be set already.
+ *
+ * This must be called in strict order, both for interlaced or no interlaced.
+ *
+ * Updates rowNum.
+ *
+ * Leaves raw result in rowb
+ *
+ * Returns bytes actually read (not including the filter byte)
+ */
+ private int readRowRaw(final int nrow) {
+ //
if (nrow == 0 && firstChunksNotYetRead())
readFirstChunks();
- rowNum++;
- if (buffer == null || buffer.length < imgInfo.samplesPerRowP)
- buffer = new int[imgInfo.samplesPerRowP];
- // swap
+ if (nrow == 0 && interlaced)
+ Arrays.fill(rowb, (byte) 0); // new subimage: reset filters: this is enough, see the swap that happens lines
+ // below
+ int bytesRead = imgInfo.bytesPerRow; // NOT including the filter byte
+ if (interlaced) {
+ if (nrow < 0 || nrow > deinterlacer.getRows() || (nrow != 0 && nrow != deinterlacer.getCurrRowSubimg() + 1))
+ throw new PngjInputException("invalid row in interlaced mode: " + nrow);
+ deinterlacer.setRow(nrow);
+ bytesRead = (imgInfo.bitspPixel * deinterlacer.getPixelsToRead() + 7) / 8;
+ if (bytesRead < 1)
+ throw new PngjExceptionInternal("wtf??");
+ } else { // check for non interlaced
+ if (nrow < 0 || nrow >= imgInfo.rows || nrow != rowNum + 1)
+ throw new PngjInputException("invalid row: " + nrow);
+ }
+ rowNum = nrow;
+ // swap buffers
byte[] tmp = rowb;
rowb = rowbprev;
rowbprev = tmp;
// loads in rowbfilter "raw" bytes, with filter
- PngHelper.readBytes(idatIstream, rowbfilter, 0, rowbfilter.length);
+ PngHelperInternal.readBytes(idatIstream, rowbfilter, 0, bytesRead + 1);
+ offset = iIdatCstream.getOffset();
+ if (offset < 0)
+ throw new PngjExceptionInternal("bad offset ??" + offset);
+ if (maxTotalBytesRead > 0 && offset >= maxTotalBytesRead)
+ throw new PngjInputException("Reading IDAT: Maximum total bytes to read exceeeded: " + maxTotalBytesRead
+ + " offset:" + offset);
rowb[0] = 0;
- unfilterRow();
+ unfilterRow(bytesRead);
rowb[0] = rowbfilter[0];
- convertRowFromBytes(buffer);
- return buffer;
+ if ((rowNum == imgInfo.rows - 1 && !interlaced) || (interlaced && deinterlacer.isAtLastRow()))
+ readLastAndClose();
+ return bytesRead;
}
/**
- * This should be called after having read the last line. It reads extra chunks after IDAT, if present.
+ * Reads all the (remaining) file, skipping the pixels data. This is much more efficient that calling readRow(),
+ * specially for big files (about 10 times faster!), because it doesn't even decompress the IDAT stream and disables
+ * CRC check Use this if you are not interested in reading pixels,only metadata.
*/
- public void end() {
- offset = (int) iIdatCstream.getOffset();
- try {
- idatIstream.close();
- } catch (Exception e) {
- }
- readLastChunks();
+ public void readSkippingAllRows() {
+ if (firstChunksNotYetRead())
+ readFirstChunks();
+ // we read directly from the compressed stream, we dont decompress nor chec CRC
+ iIdatCstream.disableCrcCheck();
try {
- is.close();
- } catch (Exception e) {
- throw new PngjInputException("error closing input stream!", e);
+ int r;
+ do {
+ r = iIdatCstream.read(rowbfilter, 0, rowbfilter.length);
+ } while (r >= 0);
+ } catch (IOException e) {
+ throw new PngjInputException("error in raw read of IDAT", e);
}
+ offset = iIdatCstream.getOffset();
+ if (offset < 0)
+ throw new PngjExceptionInternal("bad offset ??" + offset);
+ if (maxTotalBytesRead > 0 && offset >= maxTotalBytesRead)
+ throw new PngjInputException("Reading IDAT: Maximum total bytes to read exceeeded: " + maxTotalBytesRead
+ + " offset:" + offset);
+ readLastAndClose();
}
- private void convertRowFromBytes(int[] buffer) {
- // http://www.libpng.org/pub/png/spec/1.2/PNG-DataRep.html
- int i, j;
- if (imgInfo.bitDepth <= 8) {
- for (i = 0, j = 1; i < imgInfo.samplesPerRowP; i++) {
- buffer[i] = (rowb[j++] & 0xFF);
- }
- } else { // 16 bitspc
- for (i = 0, j = 1; i < imgInfo.samplesPerRowP; i++) {
- buffer[i] = ((rowb[j++] & 0xFF) << 8) + (rowb[j++] & 0xFF);
- }
- }
+ /**
+ * Set total maximum bytes to read (0: unlimited; default: 200MB). <br>
+ * These are the bytes read (not loaded) in the input stream. If exceeded, an exception will be thrown.
+ */
+ public void setMaxTotalBytesRead(long maxTotalBytesToRead) {
+ this.maxTotalBytesRead = maxTotalBytesToRead;
}
- private void unfilterRow() {
- int ftn = rowbfilter[0];
- FilterType ft = FilterType.getByVal(ftn);
- if (ft == null)
- throw new PngjInputException("Filter type " + ftn + " invalid");
- switch (ft) {
- case FILTER_NONE:
- unfilterRowNone();
- break;
- case FILTER_SUB:
- unfilterRowSub();
- break;
- case FILTER_UP:
- unfilterRowUp();
- break;
- case FILTER_AVERAGE:
- unfilterRowAverage();
- break;
- case FILTER_PAETH:
- unfilterRowPaeth();
- break;
- default:
- throw new PngjInputException("Filter type " + ftn + " not implemented");
- }
+ /**
+ * @return Total maximum bytes to read.
+ */
+ public long getMaxTotalBytesRead() {
+ return maxTotalBytesRead;
}
- private void unfilterRowNone() {
- for (int i = 1; i <= imgInfo.bytesPerRow; i++) {
- rowb[i] = (byte) (rowbfilter[i]);
- }
+ /**
+ * Set total maximum bytes to load from ancillary chunks (0: unlimited; default: 5Mb).<br>
+ * If exceeded, some chunks will be skipped
+ */
+ public void setMaxBytesMetadata(int maxBytesChunksToLoad) {
+ this.maxBytesMetadata = maxBytesChunksToLoad;
}
- private void unfilterRowSub() {
- int i, j;
- for (i = 1; i <= imgInfo.bytesPixel; i++) {
- rowb[i] = (byte) (rowbfilter[i]);
- }
- for (j = 1, i = imgInfo.bytesPixel + 1; i <= imgInfo.bytesPerRow; i++, j++) {
- rowb[i] = (byte) (rowbfilter[i] + rowb[j]);
- }
+ /**
+ * @return Total maximum bytes to load from ancillary ckunks.
+ */
+ public int getMaxBytesMetadata() {
+ return maxBytesMetadata;
}
- private void unfilterRowUp() {
- for (int i = 1; i <= imgInfo.bytesPerRow; i++) {
- rowb[i] = (byte) (rowbfilter[i] + rowbprev[i]);
- }
+ /**
+ * Set maximum size in bytes for individual ancillary chunks (0: unlimited; default: 2MB). <br>
+ * Chunks exceeding this length will be skipped (the CRC will not be checked) and the chunk will be saved as a
+ * PngChunkSkipped object. See also setSkipChunkIds
+ */
+ public void setSkipChunkMaxSize(int skipChunksBySize) {
+ this.skipChunkMaxSize = skipChunksBySize;
}
- private void unfilterRowAverage() {
- int i, j, x;
- for (j = 1 - imgInfo.bytesPixel, i = 1; i <= imgInfo.bytesPerRow; i++, j++) {
- x = j > 0 ? (rowb[j] & 0xff) : 0;
- rowb[i] = (byte) (rowbfilter[i] + (x + (rowbprev[i] & 0xFF)) / 2);
- }
+ /**
+ * @return maximum size in bytes for individual ancillary chunks.
+ */
+ public int getSkipChunkMaxSize() {
+ return skipChunkMaxSize;
}
- private void unfilterRowPaeth() {
- int i, j, x, y;
- for (j = 1 - imgInfo.bytesPixel, i = 1; i <= imgInfo.bytesPerRow; i++, j++) {
- x = j > 0 ? (rowb[j] & 0xFF) : 0;
- y = j > 0 ? (rowbprev[j] & 0xFF) : 0;
- rowb[i] = (byte) (rowbfilter[i] + FilterType.filterPaethPredictor(x, rowbprev[i] & 0xFF, y));
- }
+ /**
+ * Chunks ids to be skipped. <br>
+ * These chunks will be skipped (the CRC will not be checked) and the chunk will be saved as a PngChunkSkipped
+ * object. See also setSkipChunkMaxSize
+ */
+ public void setSkipChunkIds(String[] skipChunksById) {
+ this.skipChunkIds = skipChunksById == null ? new String[] {} : skipChunksById;
}
- public ChunkLoadBehaviour getChunkLoadBehaviour() {
- return chunkLoadBehaviour;
+ /**
+ * @return Chunk-IDs to be skipped.
+ */
+ public String[] getSkipChunkIds() {
+ return skipChunkIds;
}
- public void setChunkLoadBehaviour(ChunkLoadBehaviour chunkLoadBehaviour) {
- this.chunkLoadBehaviour = chunkLoadBehaviour;
+ /**
+ * if true, input stream will be closed after ending read
+ * <p>
+ * default=true
+ */
+ public void setShouldCloseStream(boolean shouldCloseStream) {
+ this.shouldCloseStream = shouldCloseStream;
}
- private boolean firstChunksNotYetRead() {
- return currentChunkGroup < ChunkList.CHUNK_GROUP_1_AFTERIDHR;
+ /**
+ * Normally this does nothing, but it can be used to force a premature closing. Its recommended practice to call it
+ * after reading the image pixels.
+ */
+ public void end() {
+ if (currentChunkGroup < ChunksList.CHUNK_GROUP_6_END)
+ close();
}
- public ChunkList getChunksList() {
- if (firstChunksNotYetRead())
- readFirstChunks();
- return chunksList;
+ /**
+ * Interlaced PNG is accepted -though not welcomed- now...
+ */
+ public boolean isInterlaced() {
+ return interlaced;
}
- public PngMetadata getMetadata() {
- if (firstChunksNotYetRead())
- readFirstChunks();
- return metadata;
+ /**
+ * set/unset "unpackedMode"<br>
+ * If false (default) packed types (bitdepth=1,2 or 4) will keep several samples packed in one element (byte or int) <br>
+ * If true, samples will be unpacked on reading, and each element in the scanline will be sample. This implies more
+ * processing and memory, but it's the most efficient option if you intend to read individual pixels. <br>
+ * This option should only be set before start reading.
+ *
+ * @param unPackedMode
+ */
+ public void setUnpackedMode(boolean unPackedMode) {
+ this.unpackedMode = unPackedMode;
+ }
+
+ /**
+ * @see PngReader#setUnpackedMode(boolean)
+ */
+ public boolean isUnpackedMode() {
+ return unpackedMode;
+ }
+
+ /**
+ * Disables the CRC integrity check in IDAT chunks and ancillary chunks, this gives a slight increase in reading
+ * speed for big files
+ */
+ public void setCrcCheckDisabled() {
+ crcEnabled = false;
+ }
+
+ /**
+ * Just for testing. TO be called after ending reading, only if initCrctest() was called before start
+ *
+ * @return CRC of the raw pixels values
+ */
+ long getCrctestVal() {
+ return crctest.getValue();
+ }
+
+ /**
+ * Inits CRC object and enables CRC calculation
+ */
+ void initCrctest() {
+ this.crctest = new CRC32();
}
+ /**
+ * Basic info, for debugging.
+ */
public String toString() { // basic info
return "filename=" + filename + " " + imgInfo.toString();
}
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