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How is content stored in recording?

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ramks
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Joined: 2010-06-17

Is there any differences in the way in which an clear content, encrypted for subscription content and ppv content are recorded?

Thanks
Ram

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cpratt
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Joined: 2008-12-18

Are you asking if these types are handled differently by the stack or are you asking if there are differences in how the bits are actually recorded on disk?

Currently, the RI stack doesn't differentiate between the recording of these content types. It will attempt to call the platform to record all types - regardless of CA or CCI. More fine-grained control is going to be added in a future release.

On cable networks, recording encrypted content is significantly different than clear-content recording since the decrypt/trans-crypt involves the use of CableCard resources - potentially involving user interaction (e.g. MMI) and backchannel communication. And a typical platform implementation for recording encrypted content involves a trans-crypt: converting from the on-the-wire encryption to on-disk (or full-disk) encryption.

ramks
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Joined: 2010-06-17

Thanks for the reply.

Are you asking if these types are handled differently by the stack or are you asking if there are differences in how the bits are actually recorded on disk?
[Ram] I was asking both.

Currently, the RI stack doesn't differentiate between the recording of these content types. It will attempt to call the platform to record all types - regardless of CA or CCI. More fine-grained control is going to be added in a future release.
[Ram] So, from both OCAP app and middleware perspective there should n't be any difference between a clear and encrypted recording. (I am assuming that Card has the key to decrypt)

On cable networks, recording encrypted content is significantly different than clear-content recording since the decrypt/trans-crypt involves the use of CableCard resources - potentially involving user interaction (e.g. MMI) and backchannel communication. And a typical platform implementation for recording encrypted content involves a trans-crypt: converting from the on-the-wire encryption to on-disk (or full-disk) encryption.
[Ram] Can I say that the difference ends once the decryption is done?
I indirectly mean transcryption is not an atomic process.
step1: decrypt the content using Card resources.
step2: encrypt the content and write to the disk.
For clear content, it is just step2.

cpratt
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Joined: 2008-12-18

The app can determine if the content is encrypted (via ServiceDetails/CAIdentification.isFree()) - but it isn't required to be aware of the fact when it schedules a RecordingRequest or buffers via a ServiceContext.

Regarding transcryption: I believe the CC has the ability to transcrypt internally. Have a look at the OC-SP-CCCP2.0 specification (http://www.cablelabs.com/specifications/OC-SP-CCCP2.0-I10-090904.pdf).

Regarding host requirements for recording storage, please refer to the OpenCable Host 2.0 DVR Extension (http://www.cablelabs.com/specifications/OC-SP-HOST2-DVREXT-I01-050502.pdf).

hth,

cp