Subject: [rohc] ROHC-FN RTP Prolog code

From: julije ozegovic <[email-masked]>
Date: Tue, 08 Jul 2003 17:32:36 +0200

Dear colleagues,

enclosed please find a zipped Prolog file version 3.1

       FN31-TCP-RTP.PL

which includes RTP profile in ROHC-FN.

RTP profile presented is adapted to the possibilities of current Prolog
test program by ROKE MANOR:

       - UDP length is not inferred
       - NBO is not implemented
       - CRC is not implemented, zero bits are inserted
       - scale uses explicit scale factor (160)
       - list is shortened for 8 CSRCs, to avoid 64 bit order field

However, it can be of benefit to review the capabilities of ROHC-FN.

Best regards,
Julije Ozegovic

---

From: "Price, Richard" <[email-masked]>
Date: Wed, 9 Jul 2003 13:15:02 +0100

> which includes RTP profile in ROHC-FN.

Hi Julije,

I'm impressed you managed to get an RTP profile working using a ROHC-FN
compiler designed for ROHC-TCP ;-)

This work could be very useful when we're considering the extensibility
of ROHC-FN itself. It's interesting to know how much effort is needed to
define new profiles using ROHC-FN, whether the existing library of
encoding methods is sufficient, and so forth.

>        - CRC is not implemented, zero bits are inserted

The above three encoding methods can be defined using ROHC-FN, so it
shouldn't be a problem to introduce them if needed.

>        - scale uses explicit scale factor (160)

The choice of scale factor for encoding the RTP Timestamp is left up to
the implementer. Setting the scale factor to a fixed value of 160 is a
valid implementation choice (although not necessarily the optimal choice)...

>        - list is shortened for 8 CSRCs, to avoid 64 bit order field

This is a limitation of the current Prolog implementation. Since we're
storing field values using floating-point numbers, the maximum field
size that the Prolog implementation can currently handle is 53 bits.
At some stage I intend to update the implementation to store fields
"properly" as bit strings, removing the restriction on field sizes.

Regards,

Richard

> However, it can be of benefit to review the capabilities of ROHC-FN.

_______________________________________________
Rohc mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/rohc