this is very cool, but...where does one get the data to visualize? Is there a standard for flamegraph data structures?

There appears to be zero documentation on what it needs as input.

> Stack samples can be captured using Linux perf_events, FreeBSD pmcstat (hwpmc), DTrace, SystemTap, and many other profilers. See the stackcollapse-* converters

https://github.com/brendangregg/FlameGraph