Zotty
5th December 2007, 22:47
I'm walking through an EVO stream of a HD DVD, looking for VC-1 videostream packets. All goes well until I run into a packet which apparently has the wrong size.
The good packets start with 00 00 01 FD xx xx, where xx xx is the packet size if I'm not mistaken. Usually the size is 0x7EC which fits perfectly.
Then all of a sudden a packet with size 0x01C9 pops up (00 00 01 FD 01 C9....) and things go all screwy. When I look at the location this leads up to nothing noteworthy seems to be there, just (encrypted) video data.
Any suggestions at what might going on here? I'm at a loss...
edit:
nm, mystery solved. After looking at the decrypted data there was valid data the location pointed to (start of padding stream). I just assumed all VC-1 packets were the same size. Hadn't thought of padding... doh
The good packets start with 00 00 01 FD xx xx, where xx xx is the packet size if I'm not mistaken. Usually the size is 0x7EC which fits perfectly.
Then all of a sudden a packet with size 0x01C9 pops up (00 00 01 FD 01 C9....) and things go all screwy. When I look at the location this leads up to nothing noteworthy seems to be there, just (encrypted) video data.
Any suggestions at what might going on here? I'm at a loss...
edit:
nm, mystery solved. After looking at the decrypted data there was valid data the location pointed to (start of padding stream). I just assumed all VC-1 packets were the same size. Hadn't thought of padding... doh