Do you access Prime content via the primevideo.com domain? if you mean the length of the ASIN, It's no different if you go to prime content from amazon.com.
I have another update regarding Amazon Video titles: It seems that what I assumed was a fluke or a drm error is not so. for some weird reason, I am able to download my purchased amazon titles in unencrypted .mp4 format. the dl speed is horrible (around 100 to 200 KB\s) but at least I don't have to encode raw video.
I think it's got something to do with the way I access Amazon content. I use a paid DNS service because I'm outside the US. Maybe the routing does something to circumvent the drm and lets me download unencrypted (but very slowly)...
Edit to say: Hulu works flawlessly! I was able to download a 720p tv episode as unencrypted .mp4. Too bad the audio on Hulu is low bitrate though (only 64kbps aac) but other than that it works very nicely even though it's a bit of a menial work to download a single file (takes around 2-3 minutes of setup for each video).
The tool is
not for sale (unless someone will make me an offer I can't refuse

).
If you up for some work in order to archive your precious streaming content I recommend this tool (even though I'm not selling

)!
Go to "Tools" --> "Options" and try changing the "segment buffers" to see if it helps speed up download