Here you go:
Strict Import brl.pixmap Import brl.stream Import brl.EndianStream Function SavePixmapBMP(pixmap:TPixmap,url:Object) Local stream:TStream Local buf:Byte[] Local hsize,hoffset Local size,width,height Local planes,bits,compression,isize,xpels,ypels,cols,inuse Local w,y stream=WriteStream(url) If Not stream Return width=pixmap.width height=pixmap.height w=width*3 w=(w+3)&$fffc hsize=w*height+54 size=40 hoffset=54 planes=1 bits=24 compression=0 isize=40 xpels=2834 ypels=2834 cols=0 inuse=0 stream=LittleEndianStream(stream) WriteByte stream,Asc("B") WriteByte stream,Asc("M") WriteInt stream,hsize WriteInt stream,0 WriteInt stream,hoffset WriteInt stream,size WriteInt stream,width WriteInt stream,height WriteShort stream,planes WriteShort stream,bits WriteInt stream,compression WriteInt stream,isize WriteInt stream,xpels WriteInt stream,ypels WriteInt stream,cols WriteInt stream,inuse buf=New Byte[w] For y=height-1 To 0 Step -1 ConvertPixels(pixmap.pixelptr(0,y),pixmap.format,buf,PF_BGR888,width) stream.WriteBytes(buf,w) Next stream.close() EndFunction