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Re: SKYPE ON C650

Posted: Sat Jan 01, 2011 10:02 pm
by sbav1
Interesting subject :)

Skype back-end process ("skyhost") is execv'ed from /mtd_moip/moip/skyhost file; any chance someone can post this file for further analysis ?
Entire Skype app front-end (user interface, settings management etc.) & camera hardware drivers seem to be integrated in exeDSP binary (so Skype "widget" is not an widget per se); IPC communication beetween "skyhost" and exeDSP are being carried through sockets in /dtv (/dtv/video_out, /dtv/video_in, /dtv/pcm_out, /dtv/pcm_in, /dtv/control_sock).

BTW, this Skype-Samsung USB cam (http://shop.skype.com/webcams/tvwebcams/iss-talk-7180/) is an interesting piece of hardware by itself (OmniVision OV2640 sensor + Wolfston WM8750 audio codec + Maxim/Mobilygen MG3500 HD H.264 SoC video codec - quite powerfull !). But, sadly, it's "a little" overpriced (150$ !!!), and there are no drivers for PC availlable :cry:

Re: SKYPE ON C650

Posted: Sat Jan 01, 2011 11:20 pm
by antlane
Here's the skyhost file.
http://rapidshare.com/files/440310939/skyhost

My TV is a UE46C7000.

Re: SKYPE ON C650

Posted: Sat Jan 01, 2011 11:40 pm
by timoo
some skype related files ,you ca try dovnload skyhost.img an decrypt :) >> http://www.ulozto.cz/7202339/moipupdate-zip

Re: SKYPE ON C650

Posted: Sun Jan 02, 2011 1:30 am
by sbav1
Hmm, <http://eu.otn.firmware.s3.amazonaws.com ... kyhost.img> is downloadable, but signed and encrypted..

/mtd_moip/moip/skyhost binary is (technically speaking) not encrypted (valid ARM ELF executable); unfortunately it's packed, intentionally scrambled & obfuscated beyond recognition.. looks like Skype is _really_ serious about keeping their secrets well hidden.

Doesn't look good at all :( Too bad, reverse-engineering of the Skype communication protocol was never expected to be easy :)

Re: SKYPE ON C650

Posted: Sun Jan 02, 2011 2:23 am
by erdem_ua
I know those WebCams. Since USB 2.0 doesn't have good bandwidth for HD webcams, companies put h264 encoder to webcam and it's quite good indeed where USB 3.0 is not an option.
So if you thinking about to make same thing as we do with Non-Samsung branded WiFi dongles, it doesn't work. Because HW is different from our cheap webcams.

If you have will, you can place a wrapper code to convert standard web cam to skypecam, which generates h264 stream, but TV has not enough cpu power to do that. Might be your PC processor could be used via network. We could compress video stream at PC on the fly than feeding it to TV back but that will generate enormous delays(?) also require your PC open...

So, we might allow skype on C650 with little hacks but only with skypecam hw.
At this point, I am starting to think about price. Whopping $150 price of web cam is too pricey for a web cam. Instead you could buy second hand netbook with that money and connect it to your TV via hdmi.
It will be better solution.

This came to my mind suddenly. Nowadays, every phone framework started to support face-to-face talking via theirs phone. This phones started to support powerful GPUs in it. If we modify a phone to produce h264 video stream, we could use it as a skypecam with a wrapper code. I think It's far more easier than trying to reverse engineer skype protocol.

Re: SKYPE ON C650

Posted: Sun Jan 02, 2011 1:08 pm
by sbav1
erdem_ua wrote:So, we might allow skype on C650 with little hacks but only with skypecam hw.
Exactly :(. Maybe some other cams with H.264 hardware codec can be made to work (not so cheap, either, quite limited choice), but that's a big "maybe" - it will require a lot of work, as hardware support in exeDSP is strictly limited to just one model, i.e. samsung-skype 150$ cam.
With cheap webcams, due to hardware limitation, it will be Skype without video (at best).
Dysplaying incoming video feed may be possible, but there will be no live video from TV side of the connection.

OTOH, I think Samsung Skype Cam compatibility restriction (C7000 & C8000 models only - ? ) is purely artificial..
First thing to check & fix will be /mtd_moip/ directory in C650 root file system (it's probably a dedicated flash partition in C7000/C8000, or maybe just a symlink ?); I guess this directory is missing in C650, right ?