I have been working on a pre-processor for Prince that I am using to convert my self-hosted Wordpress blog (massive, up to a thousand posts a year going back 12 years, with tons of images, links, and embedded flash videos). I know there are a few services that do this, but none of them were able were robust enough to do a satisfactory job on a blog as big as mine, so I wrote my own.
For flash videos what I've been doing is replacing them with the video's thumbnail and the caption being the title followed by the proper URL of the video. Right now I'm just processing vimeo and youtube since that's all my blog tends to use. I'd love to see this built in to Prince. Here's how to do it (feel free to borrow and expand upon this):
For youtube videos:
(1) get the Video ID from either the iframe or object/embed/param html code
(2) the URL of the video is
http://www.youtube.com/watch?v=**Video-ID**(3) the title of the video can be retrieved by going to that URL and grabbing what's inside the <title> tag.
(4) the (full-sized) thumbnail of the video is
http://img.youtube.com/vi/**Video-ID**/0.jpgFor vimeo videos:
(1) get the Video ID from either the iframe or object/embed/param html code
(2) the URL of the video is
http://vimeo.com/**Video-ID**(3) retrieve the XML info file about the video from
http://vimeo.com/api/v2/video/**Video-ID**.xml(4) the title of the video is contained inside the XML file in the <title> tag
(5) the (full-sized) thumbnail of the video is contained inside the XML file in the <thumbnail_large> tag
Hope this is helpful to someone. Thrilled if it's helpful to the developers.