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I've installed QGIS 3.6 for MAC, with GDAL 2.4, ECW GDAL Plugin for GDAL 2.4, and manually installed the libraries from ERDAS ECWJP2SDK 5.4.

This allows me to insert ECW files as raster layers in QGIS. I'd like to export them all as GeoTIF, so I was thinking of using GDAL Translate (convert format) in batch mode.

However, GDAL doesnt seem to recognize ECW: in QGIS messages panel I get "xyz.ecw not recognized as a supported file format.".

In QGIS preferences / GDAL I am seeing ECW with "rw+" flag and "ERDAS Compressed Wavelets (SDK 5.4)" so I think it was installed correctly (and ECW files do display, they just are not understood by GDAL).

All help deeply aprecciated.

Using macOS 10.14.3.

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    On windows I'd say it's a path problem. If it works through QGIS why not just batch translate from the toolbox; but more importantly why? You will gain nothing converting to GeoTIFF as the loss already occurred when the ECW was created and take up many times more space for the same information. – Michael Stimson Mar 13 at 0:33
  • @MichaelStimson - I was trying to get the information as less proprietary as possible to keep me from having recurrent issues with ECW files whenever I update QGIS, or GDAL. But I understand that file size will increase to keep the same quality (maybe 10 times!). And you were right, I had just found out the problem (answer is below) a few minutes before your comment. Thanks for helping. – BMM Mar 13 at 0:46
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    ECW is usually 20:1 for RGB and 10:1 for grey. The ECW format has been around for a long time and read-only drivers are generally available.. not trying to dissuade you from your endeavor but I'd still keep the ECWs in preference and only use the GeoTIFF for those very rare packages that don't support ECW at all; perhaps even convert as needed. – Michael Stimson Mar 13 at 0:54
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I got it to work. I think the instructions on the QGIS 2.6 for macOS installer's read me are not 100% correct. There we can read:

For the Value enter: /Library/Frameworks/Python.framework/Versions/3.6/bin:/Library/Frameworks/GDAL.framework/Versions/2.3/Programs:

but it turned out I had to enter 2 PATH variables and not only one. Plus, the GDAL version should be 2.4 instead of 2.3!

PATH configuration

Do it like in the image above and GDAL will recognize ECW files.

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