[Live-devel] Trick play with scrambled content

[Ross Finlayson]

>The file is parsable for I frames and actually the indexing works. 
>The index file (.tsx) is approximately the same size as the clear 
>.tsx file and the stream captured during trick play testing seems to 
>be about the right size but looks like it does not have the 
>transport stream scramble codes set (all have been reset) and does 
>not contain any ECMs (packets required for decryption at the 
>client). Is it possible to deliver the I frames from the main asset 
>exactly as is i.e. the original TS packets from "within" the I frame 
>including ECMs and with original scramble codes?

No, because our code has no idea what any of this other stuff is.  We 
generate a 'trick play' stream by extracting the I-frame data (only; 
i.e., with no audio or anything else), and then repackaging this 
I-frame data into a new Transport Stream.

It seems to me that if you want to use our indexing/trick-play code 
'as is' you will need to recode your data so that the decryption 
information is somehow hidden inside the I-frame data (so that, to 
our MPEG parsing code, it looks just like normal I-frame data), and 
then have a separate filter - at the receiving end - that transforms 
the bogus I-frame data into real I-frame+decryption information data.

The alternative would be to modify our indexing/trick-play code to 
(somehow) index/extract your decryption information in addition to 
the I-frame data.  In that case though, you would be totally on your 
own...
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/