==14026== Invalid read of size 4
==14026==    at 0x100073724: mov_write_moov_tag (in ./ffmpeg_g)
==14026==    by 0x7FFF5FBFCAFF: ???
==14026==    by 0x751DE8: _swrite (in /usr/lib/system/libsystem_c.dylib)
==14026==    by 0x7E657F: ??? (in /usr/lib/system/libsystem_c.dylib)
==14026==    by 0x27: ???
==14026==    by 0x1006C1367: program_name (in ./ffmpeg_g)
==14026==    by 0x3: ???
==14026==    by 0x7FFF5FBFCB4F: ???
==14026==    by 0x77ED90: __sfvwrite (in /usr/lib/system/libsystem_c.dylib)
==14026==    by 0x7FFF5FBFCB77: ???
==14026==    by 0x10104F11F: ???
==14026==    by 0x7FFF5FBFD14F: ???
==14026==  Address 0x1010a5d88 is not stack'd, malloc'd or (recently) free'd
==14026==