[PC] DeSTRoi - PVR Content Decrypting (only for C/D series)

[merilix]

Okay, here is a first 1 MB of both encrypted and unencrypted recording. Let's see what is confusing the decoding routine.
I don't see anything suspicious, just a valid DVB-C streams with several audio tracks and EIT...

like Sisternicky already supposed, your video is neither scrampled with odd key, nor with even key. Its scrampled with "reserved for future use" key

just to explain:
there are two bits within TS frame header named Scrambling control with this meaning:
'00' = Not scrambled.
'01' = Reserved for future use,
'10' = Scrambled with even key,
'11' = Scrambled with odd key (on samsung tv recordings, the same key is used for all encrypted frames)

Previous versions of DRMDecrypt had decrypted frames flagged with '10' or '11' only.
Ive modified DRMDecrypt so it will also decrypt frames flagged with '01' and it looks good with your small example.
Hope this will not cause issues with other recordings.

are you sure regarding samba? maybe just a config problem

[Sisternicky]

Ok

after some work, I've got a new version of the GUI that hopefully fixes a bunch of problems:

-- New FTP Library: hopefully no NULL Downloads any more
-- New INF File Library: No hyroglyphics in movie titles any more and a bunch of new infos
-- "Reserved for future use" streams can now be decrypted
-- Massive performance improvements in FTP and Decrypting
and last but not lease:
-- Improved error reporting
-- Added FTP fallback again for movie listing

have fun with the new version

see viewtopic.php?f=22&t=2820&p=29743#p29743

[Spoza]

Sisternicky, the new version doesn't work at all for me, since after clicking the Download button in toolbar it's trying to connect to TV via telnet, not via FTP.
And since D series does not have telnet, it can't work.

merilix, I am as sure about the samba server as are the SamyGO developers - see http://wiki.samygo.tv/index.php5/Root_a ... _for_Mstar
Regarding the new DRMDecrypt version - it prints zillion of "Invalid data @ XXXXXXXX" messages and although the resulting stream SEEMS to be correct (e.g. PAT/PMT is now detected in TSReader; or I can see the EIT data in the TS file), the TS still can't be played in MPC-HC or loaded in VideoReDo.

[merilix]

seems to be an issue with adoption field.

Code: Select all

if(data[3]&0x20)
		offset += (data[4] +1);      // skip adaption field
	outdata[3]&=0x3f;                 // remove scrambling bits
	if(offset > TS_FRAME_SIZE)//application will crash withotu this check when file is corrupted
	{
		printf ("\nInvalid data @ %13I64u\n", dec_count);
		offset = TS_FRAME_SIZE;
	}

seems like adoption field is also encrypted by your tv but im not sure if this is always the case on each samsung tv.
Thats very strange because ts packet standard clearly says, adoption field is not encrypted.
Ive never seen such exotic steams before

pls try attached test Version to check if its working for you.

[Spoza]

merilix, this one works like a charm! thanks!
The scrambled adaptation field is probably another Samsung's weirdness :-\ (I assume it can't be caused by the DVB-C provider, right?)

[merilix]

I am glad I could help
presence of adoption fields may be caused by the broadcaster but It looks like samsung simplified his encryption procedure to always encrypt the whole 184 byte packet instead of payload only (as the standard says).
On the other hand, there is no need for samsung to follow any standard if recordings should be viewed on the recording tv only :-\

[Sisternicky]

Sisternicky, the new version doesn't work at all for me, since after clicking the Download button in toolbar it's trying to connect to TV via telnet, not via FTP.
And since D series does not have telnet, it can't work.

merilix, I am as sure about the samba server as are the SamyGO developers - see http://wiki.samygo.tv/index.php5/Root_a ... _for_Mstar
Regarding the new DRMDecrypt version - it prints zillion of "Invalid data @ XXXXXXXX" messages and although the resulting stream SEEMS to be correct (e.g. PAT/PMT is now detected in TSReader; or I can see the EIT data in the TS file), the TS still can't be played in MPC-HC or loaded in VideoReDo.

Thanks for the Info. I uploaded a new version with FTP Fallback for movielisting. So it should work again for D Series
(See: viewtopic.php?f=22&t=2820&p=29707#p29664)

[Spoza]

Thanks for the Info. I uploaded a new version with FTP Fallback for movielisting. So it should work again for D Series

Just a partial success here...
Movielisting now works fine (more or less... I see one strange character in one of the titles, but I don't have any details yet to report), but clicking Download button in the movielist window has still the same effect - "preparing download" window opens with the "...please wait..." message apeearing for a second or two and then both windows close and I'm back in the main window.
Trying to process a file manually downloaded to a local folder freezes the application during the decryption process and at the end it crashes. Did you incorporate the "adaptation field workaround" we discussed with merilix earlier today?

One more tip for improvement - setup should detect the existing installation and offer to install to the existing location instead of the default one as it does now.
Plus, the product name is misspelled in the setup - it says "Recordungs" instead of "Recordings"
Actually - is it really necessary to INSTALL?! Isn't it enough just to copy a bunch of files to a directory and run the EXE?

[Sisternicky]

Ok,

hopefully, it is now fixed...

I implemented the Adaption Field Fix as well as some bugfixing in the FTP Download function. (and corrected the spelling error).
I also uploaded a binary 7z archive for those who do not want to use the installer.
Again, sorry guys that I have to use you as guinea pigs...

See: viewtopic.php?f=22&t=2820&p=29972#p29972

[Spoza]

Sorry, still the same - preparing download, please wait... and bang, back to main window...
Then I captured the communication with Wireshark and after downloading the movielist it doesn't touch the FTP anymore - what is the "preparing to download" supposed to do? It does not even try to download...