Based on the technical string you shared, here is what that "feature" usually means: Common Interpretations
: It often indicates a "Solid" or high-quality audio encode (like DD+ 5.1 or Lossless ), ensuring the sound isn't "hollow" or poorly compressed. hHTJfdCCggOwIGAZepedSNrlW0U0LBAh-(1)-EkMZWks1.m...
The string hHTJfdCC... appears to be a or a unique identifier used by: Based on the technical string you shared, here
Look at the and Subtitle streams to see if "Solid" refers to a specific language or audio format. hHTJfdCCggOwIGAZepedSNrlW0U0LBAh-(1)-EkMZWks1.m...