Hi, I need to write a program which can perform jitter correction on amateur digital video, for university. I wanted to get it working for AVI files, which would have been easy enough, as I could have just used the VFW code I wrote to process AVI's for the game I'm making. However, I've been told I need to work with MPEG's, which complicates matters significantly. I've been doing a lot of reading lately about MPEG, DirectShow, DMO's, filter graphs, etc... and I'm still not sure what exactly I should use for this project. Basically, I need to be able to access several frames of video simultaneously, so that I can predict and compensate the motion. Now, from what I understand, MPEG (2?) uses fields, not frames, which is just one of the complications. The deadline on this project is drawing closer, and I don't really want to waste my time implementing a number of DirectShow filters if I'm not going to be able to use them. So, what I want to know is : Can DirectShow help me? The actual jitter correction algorithm I'll work on myself once I have access to the frames of video, but I need some advice over what route to take to get those frames. I've thought of three (seemingly) different options: 1) Should I use a filter graph in a DirectShow application? I might need to create a kind of "feedback loop" where the output of a series of filters is hooked back up as one of the inputs. Can I do this? 2) Alternatively, are there free DMO's available that will allow me to do everything from opening, decoding and then reencoding the file once I've adjusted it? DMO's can apparently be used without needing to be tied to DirectShow graphs. Would this be a better solution? 3) Should I perhaps use a filter graph, and then just write a DMO for the jitter correction step, and insert it into the graph? Also, I'm *fairly* proficient in C++, but I've never used COM before, and the one project I've done with C# was very pleasant (Web-server -> Database interface). So, if possible, I'd like to write this project in C#. However, the DirectX C++ documentation I have mentions nothing about C#, and says only that Visual Basic exposes a limited subset of DirectShow features. What is the status with regards to C#? There is, of course, another option, which is to find a free MPEG encoder/decoder, and forget about DirectX completely, but I haven't had much luck with that so far. Any suggestions to any (or all) of my questions is greatly appreciated. Thank you $£¥

Thank's for replying. I have a few more questions tho...

I'm still not sure whether to use DirectShow filters or a set of DirectX Media Objects (DMO's, which the documentation encourages me to write instead of a filter) or to use a mixture of the two.

Will a filter allow me more complicated processing than simply blending two images, if I should need it? Do I need to worry about deadlocks and taking up too much processor time? If I want to re-encode the video once I've adjusted it, will it be easy to do that (considering I'm doubling the number of frames, will I be able to double the frame-rate as well?)

COM scares me a little :) I'm a final year Electrical Engineering and Computer Science student, and other than this project I don't have that much going on at the moment (Power Systems 4 and Computer Science 3, so I have plently of time to work on this tho, so I think I can at least get up and running with the COM part.

It's just that I need to show some preliminary work to my project leader ASAP, so I'm getting a little anxious now about getting started, and wasting time.

And if anyone can enlighten me as to if this is possible in C# I'd be most appreciative. Considering there doesn't seem to be much (any?) documentation for C# DirectShow, I probably won't go down this route, but I need to know if I have the option.

Thanks again for taking the time to read my long posts.

$£¥