Merge pull request #62 from bbc/philipn-data-essence-keys

Reader tolerates number != 01 in Timed Text essence key
bbc · Mar 28, 2024 · 0c72b44 · 0c72b44
2 parents 0a6a015 + cdb3c75
commit 0c72b44
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Showing 4 changed files with 14 additions and 2 deletions.
diff --git a/deps/libMXF/mxf/mxf_labels_and_keys.c b/deps/libMXF/mxf/mxf_labels_and_keys.c
@@ -247,6 +247,13 @@ void mxf_complete_essence_element_key(mxfKey *key, uint8_t count, uint8_t type,
     key->octet15 = num;
 }
 
+void mxf_complete_essence_element_key_from_track_num(mxfKey *key, uint32_t track_num)
+{
+    key->octet13 = (uint8_t)((track_num >> 16) & 0xff);
+    key->octet14 = (uint8_t)((track_num >> 8) & 0xff);
+    key->octet15 = (uint8_t)(track_num & 0xff);
+}
+
 void mxf_complete_essence_element_track_num(uint32_t *trackNum, uint8_t count, uint8_t type, uint8_t num)
 {
     *trackNum &= 0xFF000000;

diff --git a/deps/libMXF/mxf/mxf_labels_and_keys.h b/deps/libMXF/mxf/mxf_labels_and_keys.h
@@ -777,6 +777,7 @@ static const mxfUL ADM_ITU2076_PROFILES_LEVELS =
 
 
 void mxf_complete_essence_element_key(mxfKey *key, uint8_t count, uint8_t type, uint8_t num);
+void mxf_complete_essence_element_key_from_track_num(mxfKey *key, uint32_t track_num);
 void mxf_complete_essence_element_track_num(uint32_t *trackNum, uint8_t count, uint8_t type, uint8_t num);
 
 

diff --git a/include/bmx/mxf_reader/MXFTimedTextTrackReader.h b/include/bmx/mxf_reader/MXFTimedTextTrackReader.h
@@ -74,6 +74,7 @@ class MXFTimedTextTrackReader : public MXFFileTrackReader
 
 private:
     uint32_t mBodySID;
+    mxfKey mEssenceElementKey;
 };
 
 

diff --git a/src/mxf_reader/MXFTimedTextTrackReader.cpp b/src/mxf_reader/MXFTimedTextTrackReader.cpp
@@ -54,6 +54,9 @@ MXFTimedTextTrackReader::MXFTimedTextTrackReader(MXFFileReader *file_reader, siz
 {
     BMX_ASSERT(track_info->essence_type == TIMED_TEXT);
     mBodySID = 0;
+
+    mEssenceElementKey = MXF_EE_K(TimedText);
+    mxf_complete_essence_element_key_from_track_num(&mEssenceElementKey, track_info->file_track_number);
 }
 
 MXFTimedTextTrackReader::~MXFTimedTextTrackReader()
@@ -110,7 +113,7 @@ void MXFTimedTextTrackReader::ReadTimedText(FILE *file_out, unsigned char **data
 {
     BMX_ASSERT(mBodySID != 0);
 
-    ReadStream(mBodySID, &MXF_EE_K(TimedText), file_out, data_out, size_out, 0);
+    ReadStream(mBodySID, &mEssenceElementKey, file_out, data_out, size_out, 0);
 }
 
 void MXFTimedTextTrackReader::ReadAncillaryResourceById(mxfUUID resource_id, FILE *file_out,
@@ -147,7 +150,7 @@ TimedTextMXFResourceProvider* MXFTimedTextTrackReader::CreateResourceProvider()
         provider = new TimedTextMXFResourceProvider(file);
 
         vector<pair<int64_t, int64_t> > ranges;
-        ReadStream(mBodySID, &MXF_EE_K(TimedText), 0, 0, 0, &ranges);
+        ReadStream(mBodySID, &mEssenceElementKey, 0, 0, 0, &ranges);
         provider->AddTimedTextResource(ranges);
 
         vector<TimedTextAncillaryResource> &anc_resources = GetManifest()->GetAncillaryResources();