guidance on /undefined url or decoder missing

[pvgenuchten]

hi team, i tried the explorer today and i'm a bit stuck on the interaction with our cogs.

I wonder if you have some guidance on how to debug the issue, does the explorer have some extended logging modus?

I was testing with this cog
https://dev-files.isric.org/soilgrids/latest/data_aggregated/1000m/sand/sand_30-60cm_mean_1000.tif

• i noticed the initial head and range requests are successfull, but the 4th request is:
  https://geotiffjs.github.io/cog-explorer/undefined. Something wrong with the COG? It is generated from gdal. What is the best approach to validate cogs?
• In console i got an error that decoder.worker.js is missing, i noticed a lot of discussion on this topic elsewhere, is it relevant or related to a problem in COG?

Thanks for sharing your ideas, paul.

[landryb]

Fwiw, i'm interested in this topic too. I've tried loading our gdal-generated COGs too in https://geotiffjs.github.io/cog-explorer or in a locally-deployed instance and so far nothing has been displayed in the page, even if the network console show ~180Mb downloaded in ~35 requests, and there are no other error msgs in the js console (besides the decoder.worker.js one).

i dont think the decoder.worker.js thing is important, because the two openaerial/hot-osm samples load fine..

[landryb]

adding some console.log statements here and there, i've seen an openlayers assertion about the resolutions array being in the wrong order (points at https://openlayers.org/en/v4.6.5/doc/errors/#17) but the code is supposed to reverse it already.. puzzling.

[landryb]

what is strange is that while my cog has 12 levels of overviews for each of the 3 bands, addSceneLayer in https://github.com/geotiffjs/cog-explorer/blob/master/src/components/mapview.jsx#L180 thinks i have 26 images per band ? maybe because some of those are overviews for the mask band..

Band 1 Block=512x512 Type=Byte, ColorInterp=Red
  Overviews: 485000x572500, 242500x286250, 121250x143125, 60625x71562, 30312x35781, 15156x17890, 7578x8945, 3789x4472, 1894x2236, 947x1118, 473x559, 236x279
  Mask Flags: PER_DATASET 
  Overviews of mask band: 485000x572500, 242500x286250, 121250x143125, 60625x71562, 30312x35781, 15156x17890, 7578x8945, 3789x4472, 1894x2236, 947x1118, 473x559, 236x279

i think at that point openlayers complains because the array has resolutions for both types and cant figure out how to sort them:

addSceneLayer: tiff has images: 26
addSceneLayer: resolutions 0.19999999999989954,0.19999999999989954,0.39999999999979907,0.7999999999995981,1.5999999999991963,3.1999999999983926,6.400105568748435,12.80021113749687,25.60042227499374,51.20084454998748,102.42872228083557,204.85744456167114,410.14799154313437,822.0338983046719,0.39999999999979907,0.7999999999995981,1.5999999999991963,3.1999999999983926,6.400105568748435,12.80021113749687,25.60042227499374,51.20084454998748,102.42872228083557,204.85744456167114,410.14799154313437,822.0338983046719

so something (in my case at least) must be done to ignore the mask bands.

[landryb]

after hacking a bit the js code, it seems to me that cog-explorer wasnt tested recently with cogs produced by gdal ?

after fixing the resolutions array, i'm stumbling on geokeys being null on https://github.com/geotiffjs/cog-explorer/blob/master/src/components/mapview.jsx#L196