| Mp4aBox ( sample (frame encoding) description box)
At first glance appears to hold no of channels but actually always returns 2 even for mono recordings
so just need to skip over data in order to get to child atom esds
4 bytes version/flags = byte hex version + 24-bit hex flags
(current = 0)
-> 6 bytes reserved = 48-bit value set to zero
-> 2 bytes data reference index
= short unsigned index from 'dref' box
-> 2 bytes QUICKTIME audio encoding version = short hex version
- default = 0 ; audio data size before decompression = 1
-> 2 bytes QUICKTIME audio encoding revision level
= byte hex version
- default = 0 ; video can revise this value
-> 4 bytes QUICKTIME audio encoding vendor
= long ASCII text string
- default = 0
-> 2 bytes audio channels = short unsigned count
(mono = 1 ; stereo = 2)
-> 2 bytes audio sample size = short unsigned value
(8 or 16)
-> 2 bytes QUICKTIME audio compression id = short integer value
- default = 0
-> 2 bytes QUICKTIME audio packet size = short value set to zero
-> 4 bytes audio sample rate = long unsigned fixed point rate |
