[gdal-dev] nodata in .bil format

[Joaquim Luis]

> I don't understand this. The .hdr file is only created/recognized for EHdr
> datasets. AAIGrid datasets have both their header and samples in the .asc file
> and the .hdr file isn't used in that case.
Grrrr. I know that too but 'head didn't think' and I just took it to be 
common to both formats (I generated the .asc after finding the issue 
with the .bil)
the .bil format does not recognize the
>> nodata value.
>> Is this a knwon issue?    (GDAL trunk on Windows)
> No, I just managed to do :
>
> gdal_translate byte.tif byte.bil -of ehdr -a_nodata 1
>
> I then deleted the byte.bil.aux.xml file just to be sure it doesn't interfere
> Band 1 Block=20x1 Type=Byte, ColorInterp=Undefined
>    NoData Value=1

>> gdalinfo lixo.bil
>> ERROR 6: lixo.bil, band 1: SetNoDataValue() not supported for this dataset.
> This message is displayed if GDALRasterBand::SetNoDataValue() is called. But in
> normal situations, it should not, unless PAM is disabled. Are you disabling PAM
> by chance ?

Yes I have (sometimes I has problems in classroom computers that didn't 
have writing privileges in the program's install dir and disable it).

So apparently the situation is, with PAM disabled once can convert from 
.bil to .asc and that caries the nodata info but accessing the .bil 
with, for example gdalinfo (and my gdalread mex) does not read the 
nodata field. Right?