[Mp4-tech] How to do bit exact test for a conformance bitstream which has missing frames?

[K.]

Hi Experts,
I have been trying to understand how JM reference decoder handles conformance bitstreams such as MR3_TANDBERG_B.264 with reference to the H.264 standard. I would really appreciate it if any one can give me some opinions about this. What I manage to understand so far is that JM reference decoder generates some "non-existing" frames through "alloc_storable_picture(...)" and then sets some parameters to ensure conformance, but I couldn't see how the sample values are created, did JM just use some existing frames in the decoded picture buffer? 
>From subclause 8.2.5.2, it says that "the sample values of the generated frames may be set to any value." But if the sample values can be set to any value, then HOW could we test for BIT EXACTNESS? since our decoder and JM decoder may not use the same sample values to generate the non-existing frames for a conformance bitstream such as MR3_TANDBERG_B.264. 
 
I'd be grateful if you could give me some help here.
Thank you in advance,
Kathy
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