That's an oxy moron,
if you receive images, then they are images,
if you receive video, then it's a video, which consist of many images and an audio track.
I think you can convert images to video using ffmpeg, in which you assign the image, the video encoding, and how many seconds of video you need from it, and can actually tie together multiple groups of these into a complete video, or a video prefix or suffix to compliment a video. I think you can also watermark using an image with the alpha channel turned on.
But that's alot of work. You'll need the correct ffmpeg, a wrapper to call ffmpeg, and then will have to write a result parser, regex to analyze the result string from the command prompt.
if the images are blobs in the column, then I think ffmpeg wants to read the image file stream off the disk drive, but it may take the stream in memory. I forget, it's been a year.
I ended up writing my own wrapper, because I couldn't find anything that really worked, and for vb.
exe Wrapper for asp.net
Video for media handler