Add support for VLR forwarding.

doc/stages/writers.las.rst

@@ -50,10 +50,21 @@ forward
   which is equivalent to specifying all the values EXCEPT the scale and
   offset values.  Scale and offset values can be forwarded as a group by
   using the special values 'scale' and 'offset' respectively.  The special
-  value 'all' is equivalent to specifying 'header', 'scale' and 'offset'.
-  If an option is specified explicitly, it will override any forwarded value.
-  If a LAS file is the result of multiple LAS input files, the values to be
-  forwarded must match or they will be ignored.
+  value 'all' is equivalent to specifying 'header', 'scale', 'offset' and
+  'vlr' (see below).
+  If a header option is specified explicitly, it will override any forwarded
+  header value.
+  If a LAS file is the result of multiple LAS input files, the header values
+  to be forwarded must match or they will be ignored and a default will
+  be used instead.
+
+  VLRs can be forwarded by using the special value 'vlr'.  VLRs containing
+  the following User IDs are NOT forwarded: 'LASF_Projection', 'LASF_Spec',
+  'liblas', 'laszip encoded'.  These VLRs are known to contain information
+  regarding the formatting of the data and will be rebuilt properly in the
+  output file as necessary.  Unlike header values, VLRs from multiple input
+  files are accumulated and each is written to the output file.  Forwarded
+  VLRs may contain duplicate User ID/Record ID pairs.
 
 minor_version
   All LAS files are version 1, but the minor version (0 - 4) can be specified

include/pdal/Metadata.hpp

@@ -558,6 +558,21 @@ class PDAL_DLL MetadataNode
         return MetadataNode();
     }
 
+    template <typename PREDICATE>
+    MetadataNodeList findChildren(PREDICATE p)
+    {
+        MetadataNodeList matches;
+
+        auto nodes = children();
+        for (auto ai = nodes.begin(); ai != nodes.end(); ++ai)
+        {
+            MetadataNode& n = *ai;
+            if (p(n))
+                matches.push_back(n);
+        }
+        return matches;
+    }
+
     template <typename PREDICATE>
     MetadataNode findChild(PREDICATE p) const
     {

io/las/LasReader.cpp

@@ -159,6 +159,7 @@ void LasReader::ready(PointTableRef table, MetadataNode& m)
     setSrsFromVlrs(m);
     MetadataNode forward = table.privateMetadata("lasforward");
     extractHeaderMetadata(forward, m);
+    extractVlrMetadata(forward, m);
 
     if (m_lasHeader.compressed())
     {
@@ -209,13 +210,13 @@ template <typename T>
 void addForwardMetadata(MetadataNode& forward, MetadataNode& m,
     const std::string& name, T val, const std::string description = "")
 {
-    m.add(name, val, description);
+    MetadataNode n = m.add(name, val, description);
 
     // If the entry doesn't already exist, just add it.
     MetadataNode f = forward.findChild(name);
     if (!f.valid())
     {
-        forward.add(name, val);
+        forward.add(n);
         return;
     }
 
@@ -484,7 +485,7 @@ SpatialReference LasReader::getSrsFromGeotiffVlr()
 }
 
 
-void LasReader::extractVlrMetadata(MetadataNode& m)
+void LasReader::extractVlrMetadata(MetadataNode& forward, MetadataNode& m)
 {
     static const size_t DATA_LEN_MAX = 1000000;
 
@@ -506,6 +507,12 @@ void LasReader::extractVlrMetadata(MetadataNode& m)
         vlrNode.add("record_id", vlr.recordId(),
             "Record ID specified by the user.");
         vlrNode.add("description", vlr.description());
+
+        if ((vlr.userId() != TRANSFORM_USER_ID) &&
+            (vlr.userId() != SPEC_USER_ID) &&
+            (vlr.userId() != LASZIP_USER_ID) &&
+            (vlr.userId() != LIBLAS_USER_ID))
+            forward.add(vlrNode);
     }
 }
 

io/las/LasReader.hpp

@@ -57,7 +57,8 @@ class PDAL_DLL LasReader : public pdal::Reader
 {
     friend class NitfReader;
 public:
-    LasReader() : pdal::Reader(), m_index(0), m_istream(NULL), m_initialized(false)
+    LasReader() : pdal::Reader(), m_index(0), m_istream(NULL),
+        m_initialized(false)
         {}
 
     virtual ~LasReader()
@@ -66,7 +67,6 @@ class PDAL_DLL LasReader : public pdal::Reader
     static void * create();
     static int32_t destroy(void *);
     std::string getName() const;
-
     Options getDefaultOptions();
 
     const LasHeader& header() const
@@ -88,14 +88,15 @@ class PDAL_DLL LasReader : public pdal::Reader
         return m_istream;
     }
     virtual void destroyStream()
+    {
+        if (m_istream && m_initialized)
         {
-            if (m_istream && m_initialized)
-            {
-                FileUtils::closeFile(m_istream);
-                m_istream = NULL;
-                m_initialized = false;
-            }
+            FileUtils::closeFile(m_istream);
+            m_istream = NULL;
+            m_initialized = false;
         }
+    }
+
 private:
     LasError m_error;
     LasHeader m_lasHeader;
@@ -117,7 +118,7 @@ class PDAL_DLL LasReader : public pdal::Reader
     SpatialReference getSrsFromWktVlr();
     SpatialReference getSrsFromGeotiffVlr();
     void extractHeaderMetadata(MetadataNode& forward, MetadataNode& m);
-    void extractVlrMetadata(MetadataNode& m);
+    void extractVlrMetadata(MetadataNode& forward, MetadataNode& m);
     virtual QuickInfo inspect();
     virtual void ready(PointTableRef table)
         { ready(table, m_metadata); }

io/las/LasWriter.cpp

@@ -197,7 +197,10 @@ void LasWriter::fillForwardList(const Options &options)
     for (auto& name : forwards)
     {
         if (name == "all")
+        {
             m_forwards.insert(all.begin(), all.end());
+            m_forwardVlrs = true;
+        }
         else if (name == "header")
             m_forwards.insert(header.begin(), header.end());
         else if (name == "scale")
@@ -290,11 +293,11 @@ void LasWriter::readyTable(PointTableRef table)
     m_srs = getSpatialReference().empty() ?
         table.spatialRef() : getSpatialReference();
 
-    setVlrsFromMetadata();
     setVlrsFromSpatialRef();
     setExtraBytesVlr();
     MetadataNode forward = table.privateMetadata("lasforward");
     fillHeader(forward);
+    setVlrsFromMetadata(forward);
 }
 
 
@@ -379,26 +382,27 @@ MetadataNode LasWriter::findVlrMetadata(MetadataNode node,
 
 /// Set VLRs from metadata for forwarded info, or from option-provided data
 /// otherwise.
-void LasWriter::setVlrsFromMetadata()
+void LasWriter::setVlrsFromMetadata(MetadataNode& forward)
 {
     std::vector<uint8_t> data;
 
-    for (auto oi = m_optionInfos.begin(); oi != m_optionInfos.end(); ++oi)
-    {
-        VlrOptionInfo& vlrInfo = *oi;
+    if (!m_forwardVlrs)
+        return;
+
+    auto pred = [](MetadataNode n)
+        { return Utils::startsWith(n.name(), "vlr_"); };
 
-        if (vlrInfo.m_name == "FORWARD")
+    MetadataNodeList nodes = forward.findChildren(pred);
+    for (auto& n : nodes)
+    {
+        const MetadataNode& userIdNode = n.findChild("user_id");
+        const MetadataNode& recordIdNode = n.findChild("record_id");
+        if (recordIdNode.valid() && userIdNode.valid())
         {
-            MetadataNode m = findVlrMetadata(m_metadata, vlrInfo.m_recordId,
-                vlrInfo.m_userId);
-            if (m.empty())
-                continue;
-            data = Utils::base64_decode(m.value());
+            data = Utils::base64_decode(n.value());
+            uint16_t recordId = (uint16_t)std::stoi(recordIdNode.value());
+            addVlr(userIdNode.value(), recordId, n.description(), data);
         }
-        else
-            data = Utils::base64_decode(vlrInfo.m_value);
-        addVlr(vlrInfo.m_userId, vlrInfo.m_recordId, vlrInfo.m_description,
-            data);
     }
 }
 

io/las/LasWriter.hpp

@@ -135,7 +135,7 @@ class PDAL_DLL LasWriter : public FlexWriter
     void fillHeader(MetadataNode& forward);
     point_count_t fillWriteBuf(const PointView& view, PointId startId,
         std::vector<char>& buf);
-    void setVlrsFromMetadata();
+    void setVlrsFromMetadata(MetadataNode& forward);
     MetadataNode findVlrMetadata(MetadataNode node, uint16_t recordId,
         const std::string& userId);
     void setExtraBytesVlr();

test/unit/io/las/LasWriterTest.cpp

@@ -300,6 +300,50 @@ TEST(LasWriterTest, forward)
     EXPECT_EQ(n1.findChild("creation_year").value<uint16_t>(), 2014);
 }
 
+TEST(LasWriterTest, forwardvlr)
+{
+    Options readerOps1;
+
+    readerOps1.add("filename", Support::datapath("las/lots_of_vlr.las"));
+    LasReader r1;
+    r1.addOptions(readerOps1);
+
+    std::string testfile = Support::temppath("tmp.las");
+    FileUtils::deleteFile(testfile);
+
+    Options writerOps;
+    writerOps.add("forward", "vlr");
+    writerOps.add("filename", testfile);
+
+    LasWriter w;
+    w.setInput(r1);
+    w.addOptions(writerOps);
+
+    PointTable t;
+
+    w.prepare(t);
+    w.execute(t);
+
+    Options readerOps;
+    readerOps.add("filename", testfile);
+
+    LasReader r;
+
+    r.setOptions(readerOps);
+
+    PointTable t2;
+
+    r.prepare(t2);
+    r.execute(t2);
+
+    MetadataNode forward = t2.privateMetadata("lasforward");
+
+    auto pred = [](MetadataNode temp)
+        { return Utils::startsWith(temp.name(), "vlr_"); };
+    MetadataNodeList nodes = forward.findChildren(pred);
+    EXPECT_EQ(nodes.size(), 388UL);
+}
+
 // Test that data from three input views gets written to separate output files.
 TEST(LasWriterTest, flex)
 {