According to spec, core:sample_count for annotation is optional:
_The sample_count Field
The number of samples that this Segment applies to. If sample_count is not provided, it SHOULD be assumed that the annotation applies from sample_start through the end of the Dataset, in all other cases samplecount MUST be provided.
According to spec, core:sample_count for annotation is optional:
_The sample_count Field The number of samples that this Segment applies to. If sample_count is not provided, it SHOULD be assumed that the annotation applies from sample_start through the end of the Dataset, in all other cases samplecount MUST be provided.