<put algortithm description here>
Input layer
[raster]Nodata value, leave as none to take the nodata value from input
[string]<put parameter description here>
Default: none
Clipping extent
[extent]<put parameter description here>
Default: 0,1,0,1
Additional creation parameters
[string]Optional.
<put parameter description here>
Default: (not set)
Output layer
[raster]processing.runalg('gdalogr:cliprasterbyextent', input, no_data, projwin, extra, output)