I wanted to capture a braking drive (11 L298N direction signals, with speed 0), with readable measure tape.
First run had some frame corruptions I have not seen before.
After rebooting I captured again (./braking_eol 150 170 80).
What is really cool is that that run had 0 frame skips.
But that run was captured with 102fps only, no idea why not 204fps.
Good news is that all frame deltas are in 9775µs..9784µs range.
Stored frame.pts allows to build "tape measure location/time" pairs for every 1/100th second of video, giving clear speedup and braking speeds for every of the 256 frames!
I created 25fps video from the 256 frames and uploaded to youtube (allows to stop video and single frame step forwards/backwards with "."/"," keys).
https://www.youtube.com/watch?v=QVlSSb4 ... e=youtu.be For completeness, this is complete frame.pts:
Code: Select all
# timecode format v2
0.000
9.779
19.558
29.337
39.117
48.896
58.675
68.454
78.234
88.013
97.792
107.571
117.350
127.130
136.909
146.688
156.468
166.247
176.026
185.805
195.584
205.364
215.143
224.922
234.701
244.483
254.260
264.041
273.818
283.598
293.377
303.156
312.935
322.714
332.494
342.273
352.052
361.831
371.610
381.390
391.169
400.948
410.727
420.507
430.286
440.065
449.844
459.623
469.403
479.182
488.961
498.740
508.520
518.299
528.078
537.857
547.637
557.416
567.195
576.974
586.753
596.533
606.312
616.091
625.870
635.651
645.429
655.208
664.987
674.766
684.546
694.325
704.104
713.884
723.663
733.442
743.221
753.000
762.780
772.559
782.338
792.117
801.896
811.676
821.455
831.234
841.013
850.793
860.572
870.351
880.130
889.910
899.689
909.468
919.247
929.026
938.806
948.585
958.364
968.143
977.923
987.702
997.481
1007.261
1017.040
1026.819
1036.598
1046.377
1056.156
1065.936
1075.715
1085.494
1095.273
1105.053
1114.832
1124.611
1134.390
1144.170
1153.949
1163.728
1173.508
1183.287
1193.066
1202.845
1212.624
1222.403
1232.183
1241.962
1251.741
1261.521
1271.299
1281.079
1290.858
1300.637
1310.416
1320.196
1329.975
1339.754
1349.533
1359.312
1369.092
1378.871
1388.650
1398.429
1408.209
1417.988
1427.767
1437.546
1447.326
1457.105
1466.884
1476.663
1486.442
1496.222
1506.001
1515.780
1525.560
1535.339
1545.118
1554.897
1564.677
1574.456
1584.235
1594.014
1603.794
1613.573
1623.352
1633.131
1642.910
1652.689
1662.469
1672.248
1682.027
1691.806
1701.585
1711.365
1721.144
1730.923
1740.702
1750.482
1760.261
1770.041
1779.819
1789.599
1799.378
1809.157
1818.936
1828.716
1838.495
1848.274
1858.053
1867.833
1877.612
1887.391
1897.170
1906.949
1916.729
1926.508
1936.287
1946.066
1955.850
1965.625
1975.405
1985.183
1994.962
2004.742
2014.521
2024.300
2034.080
2043.859
2053.638
2063.417
2073.197
2082.975
2092.755
2102.534
2112.313
2122.093
2131.872
2141.651
2151.430
2161.209
2170.989
2180.768
2190.547
2200.326
2210.105
2219.885
2229.664
2239.443
2249.222
2259.002
2268.781
2278.560
2288.339
2298.118
2307.898
2317.677
2327.456
2337.235
2347.016
2356.794
2366.573
2376.353
2386.131
2395.911
2405.690
2415.469
2425.248
2435.028
2444.807
2454.586
2464.365
2474.145
2483.924
2493.703
And this is analysis:
Code: Select all
$ ~/ptsanalyze frame.pts 0
creating tstamps.csv
256 frames were captured at 102fps
frame delta time[us] distribution
1 9775
2 9777
7 9778
179 9779
59 9780
3 9781
1 9782
1 9784
after skip frame indices (middle column)
0 frame skips (0%)
$