Add operator error for 429-5 with too many PNGs.

 - ST 429-5 implicitly limits timed text resources
   to 4095.
 - add a error log and exit when exceeded

1 files changed, 22 insertions, 0 deletions

diff --git a/src/AS_DCP_TimedText.cpp b/src/AS_DCP_TimedText.cpp
index 60cb098..3bea4e3 100644
--- a/src/AS_DCP_TimedText.cpp
+++ b/src/AS_DCP_TimedText.cpp
@@ -518,6 +518,22 @@ ASDCP::TimedText::MXFWriter::h__Writer::SetSourceStream(ASDCP::TimedText::TimedT
   ResourceList_t::const_iterator ri;
   Result_t result = TimedText_TDesc_to_MD(m_TDesc);
 
+  /* st0429-5-2017 limitation:  the maximum number of sub-descriptors
+       is limited by the maximum length of the sub-descriptor array
+       contained in the timed text descriptor in the MXF header
+
+     catch it here for operator messages
+
+     max bytes 65536
+
+     8    - array len + array item size
+     16*n - 16 * number of sub-descriptors
+
+     max sub-descriptors is 4095
+      (4095*16) + 8 = 65258
+      (4096*16) + 8 = 65544
+  */
+  int resource_available = 4095;
 
   /* this method will grow the requested header buffer, m_HeaderSize,
       to accommodate the space needed for the timed text subdescriptors
@@ -529,6 +545,12 @@ ASDCP::TimedText::MXFWriter::h__Writer::SetSourceStream(ASDCP::TimedText::TimedT
   bool sd_array_init = false;
   for ( ri = m_TDesc.ResourceList.begin() ; ri != m_TDesc.ResourceList.end() && ASDCP_SUCCESS(result); ri++ )
     {
+      if (! resource_available--)
+        {
+          DefaultLogSink().Error("Exceeded allowed SMPTE ST 429-5 resources.\n");
+          return RESULT_FORMAT;
+        }
+
       TimedTextResourceSubDescriptor* resourceSubdescriptor = new TimedTextResourceSubDescriptor(m_Dict);
       GenRandomValue(resourceSubdescriptor->InstanceUID);
       resourceSubdescriptor->AncillaryResourceID.Set((*ri).ResourceID);