var OsmPbf = require( 'osm-pbf-stream' )

var pbfStream = fs.createReadStream( 'berlin-latest.osm.pbf' )
  .pipe( new OsmPbf.BlobParser() )
  .on( 'header', ... )
  .on( 'blob', ... )

// Now you can process the Protocol Buffer stream
// with a streaming Protobuf parser, like `pbs`
var pbs = require( 'pbs' )
var osmSchema = fs.readFileSync( 'osmformat.proto', 'utf8' )
var messages = pbs( osmSchema )

var decoder = messages.PrimitiveBlock.decode()

decoder.primitivegroup( function( group, next ) {
  console.log( 'PrimitiveGroup.nodes', group.dense || group.nodes )
  next()
})

decoder.once( 'finish', function() {
  console.log( 'EOD' )
})

// Pipe the PBF stream to the decoder
pbfStream.pipe( decoder )