Replace text line in simple Flash file (SWF) on-the-fly with Java

getAbstract summarizes business books into concise 5-page summaries. Our main delivery format is PDF. We use a Flash viewer for online viewing, for which we convert the PDF files to SWF using SWFTools pdf2swf. Now we need to find a way to "stamp" the SWF file generated with a copyright notice, before streaming it to the Flash viewer. We already do this with the actual PDF, but stamping the PDF and then convert it to SWF for each download is too slow. What we need is: A way (preferrably in Java and in-memory) to replace a line of text in the existing SWF file before streaming it to the web. We tried the Open-Source Transform SWF library, which looks promising, but we lack the deeper understanding of the Flash internals, to solve the problems that occurred. Maybe the task is just fixing a bug or two in Transform SWF. So you should be familiar with the SWF file format and Java.