Hi everyone, I'm in the process of developing Slingbox support for
XBMC (which uses ffmpeg, hence the reason for me asking here too) and
unfortunately I've hit a snag I would love to fix, but I think I need
help to do that.

The problem I've encountered is that whenever resolutions higher than
320x240 are enabled on a Slingbox, it "encrypts" the stream. It seems
like some sort of very low quality encryption since the stream is
still somewhat watchable. I wouldn't be surprised if all they do is
add or change a few bytes in the stream just to screw up normal
decoding of it.

Here is a link to a copy of the stream when it's encoded:
http://trac.xbmc.org/raw-attachment/ticket/10464/Encrypted%20Slingbox%20Stream.wmv
Here is a link to a copy of the stream when it's not encoded:
http://trac.xbmc.org/raw-attachment/ticket/10464/Unencrypted%20Slingbox%20Stream.wmv

The stream is of the channel guide channel so the data is fairly
constant and predictable. Both streams have identical properties
(resolutions, bit rate, etc.).

When playing the stream XBMC complains primarily about the following
(in case this give anyone some clues as to what's going on):

12:51:46 T:3228 M:1988558848   ERROR: ffmpeg[C9C]: [wmav2] overflow in
spectral RLE, ignoring
12:51:46 T:3228 M:1988558848   ERROR: Previous line repeats 2 times.
12:51:46 T:3228 M:1988558848   ERROR: ffmpeg[C9C]: [wmav2] frame_len overflow
12:51:46 T:3228 M:1988558848   ERROR: CDVDPlayerAudio::DecodeFrame -
Decode Error. Skipping audio packet
12:51:46 T:3228 M:1988558848   DEBUG: CDVDPlayerAudio::Process - Decode Error

A full debug log snippet is located here with more messages (including
many from ffmpeg): http://pastebin.ca/1967124

I'm looking for any help to try to figure out what they have done to
the stream and a way to reverse it. Any and all help anyone can offer
is very highly appreciated not only by me, but also by everyone who
will get to use their Slingbox with XBMC.

Thanks,
Harry
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