Crash bug in e572las on e57 file with timestamps

[Andrew Johnson]

Hello,

e572las appears to have a crash bug with certain e57 files that includes timestamps (acquisitionStart and acquisitionEnd). I've attached a file that exhibits the issue. To reproduce the issue, run:

e572las64 -o output.las onlyTimestamp7K.e57

Thanks, Andrew

[LAStools - efficient tools for LiDAR processing]

Hi Andrew,
thanks for the sample file. What is the according open specification where the timestamp fields are defined so we can have a look at this.

Thanks,

Jochen @rapidlasso

[Andrew Johnson]

Hello,

Thanks. It's possible that adding support for the fields will be more laborious, so maybe these fields can just be ignored rather than causing e572las to crash?

Just for reference, the e57 file is saved from Agisoft Metashape (https://www.agisoft.com/) with the [x] Timestamps checkbox enabled in the export options.

Regarding your question, the e57 file format specification is not open - it requires payment ($99) - https://store.astm.org/e2807-11r19e01.html

So I can't reference that. The next best thing is the source code of libe57 which is the reference implementation of the E57 spec. Here are some places in the code where acquisitionStart / acquisitionEnd is referenced:

https://github.com/hlrs-vis/libe57/blob/f870df483f022a5a32f02ea9c895deb218c37c05/src/tools/e57_v0_6.rnc#L57

https://github.com/hlrs-vis/libe57/blob/f870df483f022a5a32f02ea9c895deb218c37c05/src/tools/e57unpack.cpp#L351

https://github.com/hlrs-vis/libe57/blob/f870df483f022a5a32f02ea9c895deb218c37c05/src/tools/las2e57.cpp#L1086

Thanks, Andrew

[LAStools - efficient tools for LiDAR processing]

Hi Andrew,

it is unbelievable that there are still file formats around which are not complete open to the public.
Right now you have 2 good workarounds:

(a) do not use E57

(b) do not use the timestamp checkbox

We will put this issue on the todo list, if there are another huge requests on E57 we probably touch this thing again.

As long as the spec is not open it is a not-much-fun thing to fix just one field.

Either we cover the E57 format in full (which is hard to estimate right now) or we just leave it as it is.

Otherwise we have to patch the reader every 2 weeks for another field, tag, version,...

Sorry for let you waiting in this issue a bit.

Cheers,

Jochen @rapidlasso