tree ae470d7d0f82cb3444094d7ab2391b4ed05a0798
parent 77a831f49b6062194bd5c40cbdb2a642bc39d988
author Vignesh Venkat <vigneshv@google.com> 1715180661 -0700
committer Vignesh Venkatasubramanian <vigneshvg@users.noreply.github.com> 1715193204 -0700

read.c: Validate trak contains exactly one tkhd

From the spec:
```
Box Type: 'tkhd'
Container: TrackBox
Mandatory: Yes
Quantity: Exactly one
```