Why splitted in short sequences?


During my last trip by bike in town, I did a capture with the APP on my smartphone and as result I have the following directories :
2019_03_31_14_18_41_440_+0200 594 photos
2019_03_31_14_39_53_216_+0200 601 photos
2019_03_31_14_55_21_220_+0200 590 photos
2019_03_31_15_14_01_405_+0200 601 photos
2019_03_31_15_31_09_367_+0200 600 photos
2019_03_31_15_47_09_248_+0200 599 photos
2019_03_31_16_05_22_209_+0200 87 photos
2019_03_31_17_05_17_623_+0200 601 photos
2019_03_31_17_19_55_390_+0200 9 photos

Parameters are default one (a capture each 5 meters). I wonder why, once uploaded (by desktop app), trip is splited into so much small different sequences (90,14,20 photos…). In my understanding, a new sequence is started if there is a long time and/or a long space between 2 photos but perhap’s I’m wrong.
It seems to have no relation between directories and sequences ? Is it due to upload problems or interruptions ?
(does not really matters, just to understand…)
Btw, I also have a warning on each photo regarding data type for two EXIF fields, width and length:
Warning, tag ImageWidth ignored. The tag type is 3 which is not according to its standard type 4
Warning, tag ImageLength ignored. The tag type is 3 which is not according to its standard type 4
If needed, I have log.log file and mapillary_trace.

My phone is :
*********** Phone Info ***********
Mapillary versionName : 3.147
Mapillary versionCode : 447
Android name : REL
Android version : 27
Android device : HWEML
Android device model : EML-L29
Android device manufacturer : HUAWEI


I don’t know the exact parameters but the automatic splitting is a bit more complex than just distance.

Here are some related conversations:



Yes, that is the process I mentioned earlier - but apparently, this needs to take not only the times, but also the compass angle into account. Will improve that script so we can make the below case working. [http://mapillary.trydiscourse.com/t/why-is-mapillary-breaking-everything/2142/3]

I seem to have a similar issue. Uploaded a batch of ~700 images/1sec split/no compass angle with the desktop uploader, no issues during upload, sequencing is totally broken, in particular I have heaps of sequences with just 1 image which are not connected to anything before or after. Also, the rendering on the map is kind of strange along those 1 image stretches - see screenshot