I am wanting a directshow transform filter that can accept two DV input streams and output a single DV stream that is a composition of the two inputs. The filter should provide an interface to select the portion of each source that appears in the output sample. For example from source 1 I may want rect 0,180,540,576 to appear at rect 0,0,360,576 of the output and from source 2 I may want rect 0,180,540,576 to appear at rect 360,0,720,576 of the output. There would therefore only be a vertical or horizontal orientation of the sources in the output. The selections from the source will NEVER require any stretching onto the output because this filter MUST preserve the interlacing of sources onto the output. Their should be the option to flip the orientation of the source onto the output eg flip the image either horizontally or vertically. This filter must be able to complete this tranformation without causing the graph to drop frames. This is a realtime composition. The sources will always use DV streams, generally coming directly from a DV camera. The output from the graph will be written to disk in the first instance. If it is possible to preview the graph without causing an impact on performance then I'd like this option. I will also require a small test application that includes the creation of the graph, running it and having the output written to disk. If there are specific hardware requirements for this setup then please advise.