OSM - OpenStreetMap XML and PBF
Driver short name
OSM
Build dependencies
libsqlite3 (and libexpat for OSM XML)
This driver reads OpenStreetMap files, in .osm (XML based) and .pbf (optimized binary) formats.
The driver is available if GDAL is built with SQLite support and, for .osm XML files, with Expat support.
The filenames must end with .osm or .pbf extension.
The driver will categorize features into 5 layers :
points : "node" features that have significant tags attached.
lines : "way" features that are recognized as non-area.
multilinestrings : "relation" features that form a multilinestring(type = 'multilinestring' or type = 'route').
multipolygons : "relation" features that form a multipolygon (type = 'multipolygon' or type = 'boundary'), and "way" features that are recognized as area.
other_relations : "relation" features that do not belong to the above 2 layers.
Driver capabilities
Supports Georeferencing
This driver supports georeferencing
Supports VirtualIO
This driver supports virtual I/O operations (/vsimem/, etc.)
Configuration
In the data folder of the GDAL distribution, you can find an
osmconf.ini
file that can be customized to fit your needs. You can also define an
alternate path with the OSM_CONFIG_FILE configuration option.
The customization is essentially which OSM attributes and keys should be translated into OGR layer fields.
Fields can be computed with SQL expressions (evaluated by SQLite engine) from other fields/tags. For example to compute the z_order attribute.
Configuration options
The following configuration options are available:
OSM_CONFIG_FILE=<filename>: Path to an OSM configuration file. See Configuration.
OSM_MAX_TMPFILE_SIZE=<MB>: Defaults to
100. Size of the internal SQLite database used to resolve geometries. If that database remains under the size specified by this option, it will reside in RAM. If it grows above, it will be written in a temporary file on disk. By default, this file will be written in the current directory, unless you define theCPL_TMPDIRconfiguration option.OSM_USE_CUSTOM_INDEXING=[YES/NO]: Defaults to
YES. For indexation of nodes, a custom mechanism not relying on SQLite is used by default (indexation of ways to solve relations is still relying on SQLite). It can speed up operations significantly. However, in some situations (non increasing node ids, or node ids not in expected range), it might not work and the driver will output an error message suggesting to relaunch by setting this configuration option to NO.OSM_COMPRESS_NODES=[YES/NO]: Defaults to
NO. When custom indexing is used (OSM_USE_CUSTOM_INDEXING=YES, default case), theOSM_COMPRESS_NODESconfiguration option can be set to YES. This option might be turned on to improve performance when I/O access is the limiting factor (typically the case of rotational disk), and will be mostly efficient for country-sized OSM extracts where compression rate can go up to a factor of 3 or 4, and help keep the node DB to a size that fit in the OS I/O caches. For whole planet file, the effect of this option will be less efficient. This option consumes additional 60 MB of RAM.OGR_INTERLEAVED_READING=value: See Interleaved reading.
Interleaved reading
Due to the nature of OSM files and how the driver works internally, the default reading mode that works per-layer might not work correctly, because too many features will accumulate in the layers before being consumed by the user application.
Starting with GDAL 2.2, applications should use the
GDALDataset::GetNextFeature() API to iterate over features in the order
they are produced.
For earlier versions, for large files, applications should set the
OGR_INTERLEAVED_READING=YES configuration option to turn on a special
reading mode where the following reading pattern must be used:
bool bHasLayersNonEmpty;
do
{
bHasLayersNonEmpty = false;
for( int iLayer = 0; iLayer < poDS->GetLayerCount(); iLayer++ )
{
OGRLayer *poLayer = poDS->GetLayer(iLayer);
OGRFeature* poFeature;
while( (poFeature = poLayer->GetNextFeature()) != NULL )
{
bHasLayersNonEmpty = true;
OGRFeature::DestroyFeature(poFeature);
}
}
}
while( bHasLayersNonEmpty );
Note : the ogr2ogr application has been modified to use that
OGR_INTERLEAVED_READING mode without any
particular user action.
Spatial filtering
Due to way .osm or .pbf files are structured and the parsing of the file is done, for efficiency reasons, a spatial filter applied on the points layer will also affect other layers. This may result in lines or polygons that have missing vertices.
To improve this, a possibility is using a larger spatial filter with some buffer for the points layer, and then post-process the output to apply the desired filter. This would not work however if a polygon has vertices very far away from the interest area. In which case full conversion of the file to another format, and filtering of the resulting lines or polygons layers would be needed.
Reading .osm.bz2 files and/or online files
.osm.bz2 are not natively recognized, however you can process them (on Unix), with the following command :
bzcat my.osm.bz2 | ogr2ogr -f SQLite my.sqlite /vsistdin/
You can convert a .osm or .pbf file without downloading it :
wget -O - http://www.example.com/some.pbf | ogr2ogr -f SQLite my.sqlite /vsistdin/
or
ogr2ogr -f SQLite my.sqlite /vsicurl_streaming/http://www.example.com/some.pbf -progress
And to combine the above steps :
wget -O - http://www.example.com/some.osm.bz2 | bzcat | ogr2ogr -f SQLite my.sqlite /vsistdin/
Open options
CONFIG_FILE=<filename>: Defaults to
{GDAL_DATA}/osmconf.ini. Configuration filename.USE_CUSTOM_INDEXING=[YES/NO]: Defaults to
YES. Whether to enable custom indexing.COMPRESS_NODES=[YES/NO]: Defaults to
NO. Whether to compress nodes in temporary DB.MAX_TMPFILE_SIZE=<MBytes>: Defaults to
100. Maximum size in MB of in-memory temporary file. If it exceeds that value, it will go to disk.INTERLEAVED_READING=[YES/NO]: Defaults to
NO. Whether to enable interleaved reading.TAGS_FORMAT=[HSTORE/JSON]: (GDAL >= 3.7) Defaults to
HSTORE. Format for all_tags/other_tags fields.