Add ECW to GDAL

[deregnab]

Hello,

I would like to add ecw lib to gdal inside the docker container. I managed to add ecw by recompiling gdal inside the docker.

I'm compiling gdal with this tutorial (with different paths and versions + I installed the required packages + I don't remove libgdal20): https://gist.github.com/1papaya/568c4580b1909071696c1cb119101823

When I try to access an ecw file stored on the server I get a request timeout error

Do I need to restart the server once gdal is recompiled?

[dmarteau]

Hi,

It seems that gdal load all loaders at startup then yes, you surely need to restart the server if you want your changes to be taken into account.

Anyway, a timeout error means than your requests probably failed because of a worker crash: you should have a look to the container logs for debug infos.

[deregnab]

Hello @dmarteau,

I'm not used to python webserver especially with the tornado framework, so I don't really know how to restart the server once the docker is started. How am I suppose to restart it while keeping the docker running? Or do I have to restart the docker once I added the ECW library?

Thank you in advance

[dmarteau]

Hi,

The container is a single application container, that is, restarting the service is the same as restarting the container, i.e:

docker restart <container_name> 

[dmarteau]

@deregnab In all case if you remove the container you will have to install your loaders again: the best option is to build a derived image that install your gdal loaders.

[deregnab]

Thanks a lot for your quick answer.

[deregnab]

Hello,

I think I managed to build my own image that added ecw to gdal.

I use your qgis-platform in its 3.6, I installed the packages needed for the install and I build my image.

I created a project (1 tif and 1 ecw) which is working properly in local :

The container's build seems successful and the docker run is working but when I tried to read a project with an ecw file, I have the following message in the logs:

Warning 1: TIFFReadDirectory:Sum of Photometric type-related color channels and ExtraSamples doesn't match SamplesPerPixel. Defining non-color channels as ExtraSamples.
ERROR 4: `/projects/ecwFile.ecw' not recognized as a supported file format.
2019-05-13 13:53:08,125 WARNING [53]    Qgis: : 1 unavailable layers found:
2019-05-13 13:53:08,125 WARNING [53]    Qgis: :  * ./ecwFile.ecw
2019-05-13 13:53:08,126 INFO    [53]    Cache 'project.qgs' updated with path: /projects/project.qgs
2019-05-13 13:53:08,126 DEBUG   [53]    Cleaning config cache entry /projects/prkject.qgs
2019-05-13 13:53:08,126 INFO    [53]    Qgis: Server: MAP: map.qgs
2019-05-13 13:53:08,126 INFO    [53]    Qgis: Server: REQUEST:GetCapabilities
2019-05-13 13:53:08,126 INFO    [53]    Qgis: Server: SERVICE:WMS
2019-05-13 13:53:08,126 INFO    [53]    Qgis: Server: VERSION:1.3.0
2019-05-13 13:53:08,127 WARNING [53]    Qgis: : WMS capabilities document not found in cache
2019-05-13 13:53:08,131 WARNING [53]    Qgis: : Set WMS capabilities document in cache
2019-05-13 13:53:08,132 DEBUG   [53]    b'D;\x07\xf0u\x82\x11\xe9\x8e-\x02B\xac\x11\x00\x07': Flushing response data: (5908 bytes)
2019-05-13 13:53:08,132 INFO    [53]    Qgis: Server: Request finished in 6 ms
2019-05-13 13:53:08,132 DEBUG   [36]    SND worker: b'D;\x07\xf0u\x82\x11\xe9\x8e-\x02B\xac\x11\x00\x07' -> client: b'OWS-SERVER-1' : b"pB+@u\x86\x11\xe9\x8f'\x02B\xac\x11\x00\x07"
2019-05-13 13:53:08,133 DEBUG   [36]    READY b'D;\x07\xf0u\x82\x11\xe9\x8e-\x02B\xac\x11\x00\x07'
2019-05-13 13:53:08,133 RREQ    [1]     200 GET ?MAP=+map.qgs&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetCapabilities 37  5908    
2019-05-13 13:53:08,133 REQ [1] Myip    200 GET /ows/?MAP=%20map.qgs&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetCapabilities  37  5908    Mozilla/5.0 QGIS/3.6.2-Noosa    

I can't use either tif or ecw file but if I remove the ecw from the project, I can access the tif file

Thanks in advance

[dmarteau]

Warning 1: TIFFReadDirectory:Sum of Photometric type-related color channels and ExtraSamples doesn't match SamplesPerPixel. Defining non-color channels as ExtraSamples. ERROR 4: `/projects/ecwFile.ecw' not recognized as a supported file format.

These are Gdal errors, AMHA there is maybe a problem with your gdal installation in the container. Try to use gdal tools (gdalinfo etc...) to check your data in a running container.

[deregnab]

Hello,

You were right the issue lies in ecw installation for gdal, I made a mistake while choosing ecw's license option and didn't take the server one.

So it's no wonder that the server wasn't working properly.

Thanks for your time

[deregnab]

Hello,

I think I managed to install gdal with ecw properly on the container, however, ecw is skipped when used with qgis-server.

I know there is a GDAL_SKIP variable that I tried to modify in order to avoid the skip but it didn't work at all and I don't know how to resolve it or if it's even possible.

I also tried with qgis' older versions and with an old version(SDK3.3 instead of SDK5.4) of ecw too and I got 2 behaviors :

• qgis <= 3.4 read the project but do not detect ecw files. The other files are loaded properly
• qgis >= 3.6 try to read the ecw file and I can't load any file in the project

Thanks in advance

[dmarteau]

@deregnab This appears to be a very Qgis specific issue that is going beyond my knowlegde, I think that you should address the issue to Qgis mailing list: https://lists.osgeo.org/mailman/listinfo/qgis-developer.