[prev in list] [next in list] [prev in thread] [next in thread] 

List:       helix-datatype-dev
Subject:    [datatype-dev] RE: Small packets in ASF file format
From:       <ext-liz.fu () nokia ! com>
Date:       2010-02-18 22:45:57
Message-ID: 218D7B58E1EF544A8DF24C14758BE77028BA5D6A57 () NOK-EUMSG-02 ! mgdnok ! nokia ! com
[Download RAW message or body]

Hi Jyotsana,

Thanks for replying me. You are right, there are some objects at the very end are \
less than 15 bytes. But I don't understand why most of the video objects we got are \
different as those in "Window Media ASF Viewer". I searched the raw data (clip file), \
cannot find those 5 bytes payload data in the file.  

With our exist WMDRM module, these small payload objects are fine because there is a \
'InitDecrypt()' function call which takes the last 15 bytes of payload data before \
decrypt the data. In new WMDRM module, this InitDerypt() function is no longer there \
and all those payloads smaller than 15 bytes failed to get decrypted. This happens to \
all the video clips, so I think we should probably not to get those small payloads at \
the first place. 

Thanks,
Liz 
 

-----Original Message-----
From: ext Jyotsana Rathore [mailto:jrathore@real.com] 
Sent: Tuesday, February 16, 2010 8:32 PM
To: Fu Liz (EXT-DextraTech/Dallas); datatype-dev@helixcommunity.org
Cc: nokia-private-dev@helixcommunity.org; Ward Shy (Nokia-D/Dallas); Eric Hyche
Subject: RE: Small packets in ASF file format

Hi Liz,

Sorry to have missed your earlier email.
I tried to debug this issue (on Windows platform) on my end, however since the file \
is DRM protected, InitHelixDRM() returned an error for me. On Symbian, \
datatype\wm\wmdrm\platform\symbian\symbian_wmdrmplugin.cpp must be handling the \
decrypted packets.  Are none of the drm protected files working on Symbian or is this \
the only case? If none, then maybe the payload size/data/key parsed is incorrect. \
When I looked at the "Window Media ASF Viewer" there were are few packets in stream 2 \
object 59 onwards that were less than 15 bytes.  I am adding few more folks to this \
thread who might know more about the WMDRM plugin.

Thanks,
Jyotsana
________________________________________
From: nokia-private-dev-bounces@helixcommunity.org \
[nokia-private-dev-bounces@helixcommunity.org] On Behalf Of ext-liz.fu@nokia.com \
                [ext-liz.fu@nokia.com]
Sent: Tuesday, February 16, 2010 1:29 PM
To: ext-liz.fu@nokia.com; datatype-dev@helixcommunity.org
Cc: nokia-private-dev@helixcommunity.org
Subject: [Nokia-private-dev] RE: Small packets in ASF file format

Any response?

Thanks,
Liz

_____________________________________________
From:    Fu Liz (EXT-DextraTech/Dallas)
Sent:   Thursday, February 11, 2010 1:38 PM
To:     'datatype-dev@helixcommunity.org'
Cc:     'nokia-private-dev@helixcommunity.org'
Subject:        Small packets in ASF file format

Hi,

I am looking into the problem that failed to decrypt WMDRM protected files on \
Symbian. I noticed that all the failures happened at those packets with less than 15 \
bytes payload data in video stream. But by viewing the clip payload data using \
"Window Media ASF Viewer", I don't see any those small packets (see screenshot \
below). These small packets happened in both 210-Cayennes branch and 420-Brizo \
branch. In several follow up emails, I'll attach payload dumps and helix log files \
obtained in both 210 and 420 branches. The log files contain payload size info. The \
clip used for this testing is \
http://wmtap.smdisp.net/janus/download.asp?CaseID=CTC4&Content=CTC4_423kbps_350kbpsVideo_64kbpsAudio_30fps.wmv


It will be very appreciated if someone could take a look at this issue and explain to \
me why we get these small packets. Thanks,
Liz
<< OLE Object: PBrush >>  << OLE Object: Picture (Metafile) >>


_______________________________________________
Datatype-dev mailing list
Datatype-dev@helixcommunity.org
http://lists.helixcommunity.org/mailman/listinfo/datatype-dev


[prev in list] [next in list] [prev in thread] [next in thread]