CBCS audio with no SAIZ, SAIO or SENC boxes

[glennguy]

Hello!

Very similar to #781 but this time there's nothing to use, even more out of spec!

I've attached the init and first segment:
broken.zip

The keyid/key is f8c80c25690f47368132430e5c6994ce:7bc99cb1dd0623cd0b5065056a57a1dd

Because it's audio the skip/crypt pattern is just 0,0 and from looking at an audio example that does work, the SENC box is very simple just containing the count of samples:

Unfortunately for me, I have tried but failed to create a simple 16 byte box in inputstream.adaptive to contain data: trun->GetEntries().ItemCount()

Is this something you can a) implement a fix in AP4_CencSampleInfoTable::Create, or b) advise the in pattern way to create a simple 16 byte SENC box like above?

Thanks heaps!