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Merged
palemieux merged 1 commit into from
Oct 31, 2026
Merged

java: Improve consistency of MXF reading across classes #39

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2 changes: 1 addition & 1 deletion java-common/src/main/java/com/sandflow/smpte/mxf/FillItem.java
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Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ public static FillItem fromTriplet(Triplet triplet) throws KLVException {

FillItem fi = new FillItem();

if (!getKey().equalsIgnoreVersion(triplet.getKey())) {
if (!isInstance(triplet.getKey())) {
return null;
}

Expand Down
61 changes: 56 additions & 5 deletions java-common/src/main/java/com/sandflow/smpte/mxf/MXFFiles.java
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Expand Up @@ -30,13 +30,15 @@

package com.sandflow.smpte.mxf;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.SeekableByteChannel;

import com.sandflow.smpte.klv.KLVDataInput;
import com.sandflow.smpte.klv.LocalTagRegister;
import com.sandflow.smpte.klv.MemoryTriplet;
import com.sandflow.smpte.klv.Triplet;
import com.sandflow.smpte.klv.exceptions.KLVException;
Expand Down Expand Up @@ -180,6 +182,53 @@ public static EssenceElementInfo nextElement(InputStream is) throws IOException,
return new EssenceElementInfo(elementKey, elementLength, sid);
}

/**
* Skips triplets until a Partition Pack is found, and reads it
*
* @param kis KLV input
* @return First Partition Pack read, or null if the end of the input is
* reached before one is found
* @throws IOException
* @throws KLVException
*/
public static PartitionPack skipToPartitionPack(KLVDataInput kis) throws IOException, KLVException {
try {
while (true) {
PartitionPack pp = PartitionPack.fromTriplet(kis.readTriplet());

if (pp != null) {
return pp;
}
}
} catch (EOFException e) {
return null;
}
}

/**
* Skips any Fill Items that follow a Partition Pack, and reads the Primer Pack.
*
* @param kis Input positioned after a Partition Pack
* @return Local Tag Register, or null if the first non-Fill Item is not a
* Primer Pack or the end of the input is reached
* @throws IOException
* @throws KLVException
*/
public static LocalTagRegister skipToPrimerPack(KLVDataInput kis) throws IOException, KLVException {
try {
while (true) {
kis.resetCount();
Triplet t = kis.readTriplet();

if (!FillItem.isInstance(t.getKey())) {
return PrimerPack.createLocalTagRegister(t);
}
}
} catch (EOFException e) {
return null;
}
}

/**
* Seeks to the footer partition, assuming the current position of the
* channel is within the run-in (SMPTE ST 377-1 Section 6.5), the footer
Expand All @@ -197,9 +246,11 @@ public static long seekFooterPartition(SeekableByteChannel mxffile) throws IOExc

KLVDataInput kis = new KLVDataInput(Channels.newInputStream(mxffile));

Triplet t = kis.readTriplet();
Triplet t;

if (t == null) {
try {
t = kis.readTriplet();
} catch (EOFException e) {
return -1;
}

Expand Down Expand Up @@ -232,9 +283,9 @@ public static long seekFooterPartition(SeekableByteChannel mxffile) throws IOExc

kis = new KLVDataInput(Channels.newInputStream(mxffile));

t = kis.readTriplet();

if (t == null) {
try {
t = kis.readTriplet();
} catch (EOFException e) {
return -1;
}

Expand Down
62 changes: 14 additions & 48 deletions java-common/src/main/java/com/sandflow/smpte/regxml/MXFFragmentBuilder.java
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Original file line number Diff line number Diff line change
Expand Up @@ -36,11 +36,12 @@
import com.sandflow.smpte.klv.Triplet;
import com.sandflow.smpte.klv.exceptions.KLVException;
import com.sandflow.smpte.mxf.FillItem;
import com.sandflow.smpte.mxf.HeaderMetadataSet;
import com.sandflow.smpte.mxf.MXFDataInput;
import com.sandflow.smpte.mxf.MXFEvent;
import com.sandflow.smpte.mxf.MXFException;
import com.sandflow.smpte.mxf.MXFFiles;
import com.sandflow.smpte.mxf.PartitionPack;
import com.sandflow.smpte.mxf.PrimerPack;
import com.sandflow.smpte.regxml.dict.DefinitionResolver;
import com.sandflow.smpte.regxml.dict.definitions.ClassDefinition;
import com.sandflow.smpte.regxml.dict.definitions.Definition;
Expand All @@ -65,21 +66,6 @@ public class MXFFragmentBuilder {

private static final UL PREFACE_KEY = UL.fromURN("urn:smpte:ul:060e2b34.027f0101.0d010101.01012f00");

private static final UL INSTANCE_UID_ITEM_UL = UL.fromURN("urn:smpte:ul:060e2b34.01010101.01011502.00000000");

/**
* Returns the Instance ID (InstanceUID property) of a Group, or null if the
* Group does not carry one.
*/
private static UUID getInstanceID(Group group) {
for (Triplet t : group.getItems()) {
if (INSTANCE_UID_ITEM_UL.equalsIgnoreVersion(t.getKey())) {
return new UUID(t.getValue());
}
}
return null;
}

/**
* Returns a DOM Document Fragment containing a RegXML Fragment rooted at
* the first Header Metadata object with a class that descends from the
Expand Down Expand Up @@ -115,14 +101,7 @@ public static DocumentFragment fromInputStream(
/* look for the partition pack */
MXFDataInput kis = new MXFDataInput(mxfpartition);

PartitionPack pp = null;

for (Triplet t; (t = kis.readTriplet()) != null;) {

if ((pp = PartitionPack.fromTriplet(t)) != null) {
break;
}
}
PartitionPack pp = MXFFiles.skipToPartitionPack(kis);

if (pp == null) {

Expand All @@ -132,21 +111,8 @@ public static DocumentFragment fromInputStream(

}

/* start counting header metadata bytes */
kis.resetCount();

/* look for the primer pack */
LocalTagRegister localreg = null;

for (Triplet t; (t = kis.readTriplet()) != null; kis.resetCount()) {

/* skip fill items, if any */
if (!FillItem.getKey().equalsIgnoreVersion(t.getKey())) {
localreg = PrimerPack.createLocalTagRegister(t);
break;
}

}
/* look for the primer pack and start counting header metadata bytes */
LocalTagRegister localreg = MXFFiles.skipToPrimerPack(kis);

if (localreg == null) {

Expand All @@ -159,9 +125,9 @@ public static DocumentFragment fromInputStream(
ArrayList<Group> gs = new ArrayList<>();
HashMap<UUID, Group> setresolver = new HashMap<>();

for (Triplet t;
kis.getReadCount() < pp.getHeaderByteCount()
&& (t = kis.readTriplet()) != null;) {
while (kis.getReadCount() < pp.getHeaderByteCount()) {

Triplet t = kis.readTriplet();

if (INDEX_TABLE_SEGMENT_UL.equalsIgnoreVersion(t.getKey())) {

Expand All @@ -174,23 +140,23 @@ public static DocumentFragment fromInputStream(

break;

} else if (FillItem.getKey().equalsIgnoreVersion(t.getKey())) {
} else if (FillItem.isInstance(t.getKey())) {

/* skip fill items */
continue;
}

try {
Group g = Set.fromLocalSet(t, localreg);
Set s = Set.fromLocalSet(t, localreg);

if (g != null) {
if (s != null) {

gs.add(g);
gs.add(s);

UUID instanceID = getInstanceID(g);
UUID instanceID = HeaderMetadataSet.getInstanceID(s);

if (instanceID != null) {
setresolver.put(instanceID, g);
setresolver.put(instanceID, s);
}

} else {
Expand Down
17 changes: 10 additions & 7 deletions java-library/src/main/java/com/sandflow/smpte/mxf/RandomAccessFileInfo.java
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@

package com.sandflow.smpte.mxf;

import java.io.EOFException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
Expand Down Expand Up @@ -178,9 +179,10 @@ public RandomAccessFileInfo(RandomAccessInputSource raip, EventHandler evthandle
raip.position(raip.size() - ripSize);

RandomIndexPack rip = null;
Triplet t = mis.readTriplet();
if (t != null) {
rip = RandomIndexPack.fromTriplet(t);
try {
rip = RandomIndexPack.fromTriplet(mis.readTriplet());
} catch (EOFException e) {
/* reported below */
}
if (rip == null) {
/* no RIP where it should be */
Expand All @@ -203,9 +205,10 @@ public RandomAccessFileInfo(RandomAccessInputSource raip, EventHandler evthandle
/* seek to and read partition */
raip.position(rip.getOffsets().get(i).getOffset());
PartitionPack pp = null;
t = mis.readTriplet();
if (t != null) {
pp = PartitionPack.fromTriplet(t);
try {
pp = PartitionPack.fromTriplet(mis.readTriplet());
} catch (EOFException e) {
/* reported below */
}
if (pp == null) {
/* no partition pack where expected */
Expand Down Expand Up @@ -301,7 +304,7 @@ public RandomAccessFileInfo(RandomAccessInputSource raip, EventHandler evthandle
Triplet it = mis.readTriplet();

/* skip fill items that pad the index byte count to the KAG */
if (FillItem.getKey().equalsIgnoreVersion(it.getKey())) {
if (FillItem.isInstance(it.getKey())) {
continue;
}

Expand Down
19 changes: 3 additions & 16 deletions java-library/src/main/java/com/sandflow/smpte/mxf/StreamingFileInfo.java
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Expand Up @@ -54,16 +54,8 @@ private static Preface readHeaderMetadataFrom(InputStream is, long headerByteCou
throws IOException, KLVException, MXFException {
MXFDataInput mis = new MXFDataInput(is);

/* look for the primer pack */
LocalTagRegister localreg = null;
for (Triplet t; (t = mis.readTriplet()) != null; mis.resetCount()) {

/* skip fill items, if any */
if (!FillItem.getKey().equalsIgnoreVersion(t.getKey())) {
localreg = PrimerPack.createLocalTagRegister(t);
break;
}
}
/* look for the primer pack and start counting header metadata bytes */
LocalTagRegister localreg = MXFFiles.skipToPrimerPack(mis);

if (localreg == null) {
MXFException.handle(evthandler, new MXFEvent(
Expand Down Expand Up @@ -154,12 +146,7 @@ public StreamingFileInfo(InputStream is, EventHandler evthandler)
MXFDataInput mis = new MXFDataInput(is);

/* look for the header partition pack */
PartitionPack pp = null;
for (Triplet t; (t = mis.readTriplet()) != null;) {
if ((pp = PartitionPack.fromTriplet(t)) != null) {
break;
}
}
PartitionPack pp = MXFFiles.skipToPartitionPack(mis);

if (pp == null) {
MXFException.handle(evthandler,
Expand Down
16 changes: 4 additions & 12 deletions java-library/src/main/java/com/sandflow/smpte/tools/RegMXFDump.java
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Original file line number Diff line number Diff line change
Expand Up @@ -47,8 +47,8 @@
import com.sandflow.smpte.mxf.MXFInputContext;
import com.sandflow.smpte.mxf.MXFDataInput;
import com.sandflow.smpte.mxf.MXFException;
import com.sandflow.smpte.mxf.MXFFiles;
import com.sandflow.smpte.mxf.PartitionPack;
import com.sandflow.smpte.mxf.PrimerPack;
import com.sandflow.smpte.mxf.RandomIndexPack;
import com.sandflow.smpte.mxf.StaticLocalTags;
import com.sandflow.smpte.mxf.types.IndexTableSegment;
Expand Down Expand Up @@ -155,16 +155,8 @@ public boolean handle(Event evt) {
/* read header metadata */
if (pp.getHeaderByteCount() > 0) {

/* look for the primer pack */
LocalTagRegister localreg = null;
for (Triplet t; (t = mis.readTriplet()) != null; mis.resetCount()) {

/* skip fill items, if any */
if (!FillItem.getKey().equalsIgnoreVersion(t.getKey())) {
localreg = PrimerPack.createLocalTagRegister(t);
break;
}
}
/* look for the primer pack and start counting header metadata bytes */
LocalTagRegister localreg = MXFFiles.skipToPrimerPack(mis);

/*
* capture all local sets within the header metadata
Expand Down Expand Up @@ -219,7 +211,7 @@ public void handleEvent(Event evt) throws MXFException {
while (mis.getReadCount() < pp.getIndexByteCount()) {
Triplet t = mis.readTriplet();

if (FillItem.getKey().equalsIgnoreVersion(t.getKey())) {
if (FillItem.isInstance(t.getKey())) {
continue;
}

Expand Down
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