I have a PlayReady protected Smooth Stream, which I encrypt manually (by adding the Protection element to the client manifest, adding a Sample Encryption Box inside each fragment's traf box and encrypting the actual mdat payload).
I am trying to implement a new feature - send several non encrypted fragments (e.g., ads or first N fragments of the stream) within that stream.
After reading the PIFF standard by Microsoft, I attempted to send non encrypted data by setting the flags field to 0x00001, and the algorithm_id, sample_count and key_id fields in the Sample Encryption Box to zeros (As mentioned in section 5.3.2.2 of the PIFF standard).
While trying to play that stream, the sample players I tested (http://playready.directtaps.net/pr/doc/slee/ and player.smooth.vertigo.com/) played the content, but skipped the non encrypted fragments and started directly from the encrypted ones.
Is this feature even possible to implement? Am I doing anything wrong?
P.S., I tried to omit the Sample Encryption Box altogether, but that resulted in the players refusing to play the stream entirely.
Any help will be greatly appreciated.