Extract section from Premiere without re-compression
I know this is an old question abandoned by the asker, but I use ffmpeg to stream copy (re-mux) sections.

Example 1: Single output

Skip first 14 minutes and make a 30 second output:

ffmpeg -ss 00:14:00 -i input -t 30 -c copy -map 0 output



This will not re-encode, so the process is quick and preserves the quality.
Depending on your input format the output may not be exactly from the desired time, but usually it's close enough. See the -ss option in the FFmpeg documentation for more info.


Example 2: One segment of every n seconds

Use the segment muxer:

ffmpeg -i input -c copy -map 0 -segment_time 30 -f segment output%03d.foo



This will not re-encode, so the process is quick and preserves the quality.
Note that splitting may not be accurate, unless you force the reference stream key-frames at the given time. See the segment muxer documentation for more info.