sps-stretch.py

#!/usr/bin/env python
import json, sys

prof = json.load(sys.stdin)
for thread in prof['profileJSON']['threads']:
    raw = thread['samples']
    low = [raw[i]['time'] - raw[i-1]['time'] for i in xrange(1, len(raw))]
    while True:
        oldlen = len(low)
        avg = sum(low) / oldlen
        low = [s for s in low if s < 2 * avg]
        if len(low) == oldlen:
            break
    print >>sys.stderr, "Estimated sample tick %g ms" % avg
    padded = []
    last = raw[0]['time']
    for sample in raw:
        n = int((sample['time'] - last) / avg)
        padded += [sample] * max(n, 1)
        last = sample['time']
    thread['samples'] = padded
json.dump(prof, sys.stdout, separators=(",",":"))