View Single Post
Old 12-19-2020, 07:10 PM  
Human being with feelings
planetnine's Avatar
Join Date: Oct 2007
Location: Lincoln, UK
Posts: 7,981

Just a quick technical question about reading metadata from the bext chunk of BWF files before I erroneously submit a bug report. I have some production recordings with large time offsets that the new version item ruler won’t allow me to check the “include BWF offset” box on. Turns out REAPER thinks these have a negative value of source offset (in source properties).

How do you read the bytes for “Time Offset Lo” and “Time Offset Hi” in the bext chunk? The EBU spec seems to say two dwords, but are these as two unsigned 32-bit integers, two signed integers, or one 64-bit signed or unsigned integer?

The offset is large enough that the msb of the first dword is a “1” while the “Hi” dword is still zero. Are you reading this Lo dword as a signed integer? The maths checks out with the negative value of offset returned. If so, is the metadata written incorrectly? The bytes are Lo 01 bc 0e ad (and Hi 00 00 00 00) which gives 16:48:08:00 at 48k if read unsigned. Is this a REAPER bug or a recorder one?

Nathan, Lincoln, UK. | Item Marker Tool. (happily retired) | Source Time Position Tool. | CD Track Marker Tool. | Timer Recording Tool. | dB marks on MCP faders FR.
planetnine is offline   Reply With Quote