What's wrong with my use of timestamps/timebases for frame seeking/reading using libav (ffmpeg)?

Question

So I want to grab a frame from a video at a specific time using libav for the use as a thumbnail.

What I\'m using is t

Answer 1

I replaced

av_seek_frame(format_context, stream_index, request_timestamp, 0);

with

avformat_seek_file(format_context, stream_index, INT64_MIN, request_timestamp, INT64_MAX, 0);

and suddenly I get reasonable output. Great.
And it only took a day in almost complete documentation darkness. :/