Signed-off-by: Martin Storsjö <martin@martin.st>

It will overflow if somebody keeps streaming for a time long enough.

start_time is in stream timebase units while end_time is
in AV_TIME_BASE ones.

recording_time is in AV_TIME_BASE units.

Consider the corner case with a list size larger than the wrap
number.

Avoid calling av_get_frame_filename twice, once to generate the
segment filename and once to generate the playlist.

The segment path is desumed from the playlist path, recording a
relative path in the playlist while serving the file could lead
to misleading results.

Signed-off-by: Martin Storsjö <martin@martin.st>

If s->filename doesn't contain any period/filename extension to strip
away, the buffer will be too small to fit both strings. This isn't
any buffer overflow since the concatenation uses av_strlcat with
the right buffer size.
Signed-off-by: Martin Storsjö <martin@martin.st>

Simplifies usage but has higher latency.