Add support for cmID, purl, egid MP4 atoms (taglib#862). (taglib#863)

Author: ufleisch

taglib/mp4/mp4tag.cpp

@@ -78,7 +78,8 @@ MP4::Tag::Tag(TagLib::File *file, MP4::Atoms *atoms) :
       parseInt(atom);
     }
     else if(atom->name == "tvsn" || atom->name == "tves" || atom->name == "cnID" ||
-            atom->name == "sfID" || atom->name == "atID" || atom->name == "geID") {
+            atom->name == "sfID" || atom->name == "atID" || atom->name == "geID" ||
+            atom->name == "cmID") {
       parseUInt(atom);
     }
     else if(atom->name == "plID") {
@@ -93,6 +94,9 @@ MP4::Tag::Tag(TagLib::File *file, MP4::Atoms *atoms) :
     else if(atom->name == "covr") {
       parseCovr(atom);
     }
+    else if(atom->name == "purl" || atom->name == "egid") {
+      parseText(atom, -1);
+    }
     else {
       parseText(atom);
     }
@@ -480,7 +484,8 @@ MP4::Tag::save()
       data.append(renderInt(name.data(String::Latin1), it->second));
     }
     else if(name == "tvsn" || name == "tves" || name == "cnID" ||
-            name == "sfID" || name == "atID" || name == "geID") {
+            name == "sfID" || name == "atID" || name == "geID" ||
+            name == "cmID") {
       data.append(renderUInt(name.data(String::Latin1), it->second));
     }
     else if(name == "plID") {
@@ -492,6 +497,9 @@ MP4::Tag::save()
     else if(name == "covr") {
       data.append(renderCovr(name.data(String::Latin1), it->second));
     }
+    else if(name == "purl" || name == "egid") {
+      data.append(renderText(name.data(String::Latin1), it->second, TypeImplicit));
+    }
     else if(name.size() == 4){
       data.append(renderText(name.data(String::Latin1), it->second));
     }