Boy... I feel like I'm getting in deep here... :)

The MPEG that the card spits out appears to be quite a jumbled mess of packets. Replex-0.1.3 didn't want to enable analyze, so I had to hack it cosmeticallya slight bit. This is what a raw capture looked like (for video, anyway, and I hope linewrapping doesn't uglify it):

VU: Seq hdr GOP hdr (I) length 49480  PTS  0:00:00.066   DTS  26:30:43.684
VU: (P) length  5464  PTS  0:00:00.000   diff:-0:00:00.066   DTS  0:00:00.000   
diff: 0:00:00.033
VU: (P) length 16304  PTS  0:00:00.033   DTS  0:00:00.033
VU: (B) length 20312  PTS  0:00:00.166   diff: 0:00:00.133   DTS  0:00:00.066   
diff: 0:00:00.033
VU: (P) length 10272  PTS  0:00:00.100   diff:-0:00:00.066   DTS  0:00:00.100   
diff: 0:00:00.033
VU: (P) length 13044  PTS  0:00:00.133   diff: 0:00:00.033   DTS  0:00:00.133   
diff: 0:00:00.033
VU: (B) length 22796  PTS  0:00:00.266   diff: 0:00:00.133   DTS  0:00:00.166   
diff: 0:00:00.033
VU: (P) length 10292  PTS  0:00:00.200   diff:-0:00:00.066   DTS  0:00:00.200   
diff: 0:00:00.033
VU: (P) length 12288  PTS  0:00:00.233   diff: 0:00:00.033   DTS  0:00:00.233   
diff: 0:00:00.033
VU: (B) length 22548  PTS  0:00:00.367   diff: 0:00:00.133   DTS  0:00:00.266   
diff: 0:00:00.033
VU: (P) length 10328  PTS  0:00:00.633   diff: 0:00:00.266   DTS  0:00:00.000   
diff:-0:00:00.266
VU: (P) length 12140  PTS  0:00:00.667   diff: 0:00:00.033   DTS  0:00:00.000
VU: (B) length 20376  PTS  0:00:00.800   diff: 0:00:00.133   DTS  0:00:00.700
VU: (P) length 10488  PTS  0:00:00.734   diff:-0:00:00.066   DTS  0:00:00.000   
diff:-0:00:00.700
VU: (P) length 11476  PTS  0:00:00.767   diff: 0:00:00.033   DTS  0:00:00.000
VU: Seq hdr GOP hdr (I) length 39680  PTS  0:00:00.900   diff: 0:00:00.133   
DTS  0:00:00.800
VU: (P) length  8964  PTS  0:00:00.834   diff:-0:00:00.066   DTS  0:00:00.000   
diff:-0:00:00.800
VU: (P) length 10284  PTS  0:00:00.867   diff: 0:00:00.033   DTS  0:00:00.000
VU: (B) length 19116  PTS  0:00:01.001   diff: 0:00:00.133   DTS  0:00:00.900
VU: (P) length  9500  PTS  0:00:00.934   diff:-0:00:00.066   DTS  0:00:00.000   
diff:-0:00:00.900
VU: (P) length 10100  PTS  0:00:00.967   diff: 0:00:00.033   DTS  0:00:00.000
VU: (B) length 18996  PTS  0:00:01.101   diff: 0:00:00.133   DTS  0:00:01.001


after running through replex, I see this:

VU: Seq hdr GOP hdr (I) length 48590  PTS  0:00:00.066   DTS  26:30:43.684
VU: (P) length  6075  PTS  0:00:00.000   diff:-0:00:00.066   DTS  0:00:00.000   
diff: 0:00:00.033
VU: (P) length 16200  PTS  0:00:00.033   DTS  0:00:00.033
VU: (B) length 20250  PTS  0:00:00.166   diff: 0:00:00.133   DTS  0:00:00.066   
diff: 0:00:00.033
VU: (P) length 10125  PTS  0:00:00.100   diff:-0:00:00.066   DTS  0:00:00.100   
diff: 0:00:00.033
VU: (P) length 12150  PTS  0:00:00.133   diff: 0:00:00.033   DTS  0:00:00.133   
diff: 0:00:00.033
VU: (B) length 22275  PTS  0:00:00.266   diff: 0:00:00.133   DTS  0:00:00.166   
diff: 0:00:00.033
VU: (P) length 12150  PTS  0:00:00.200   diff:-0:00:00.066   DTS  0:00:00.200   
diff: 0:00:00.033
VU: (P) length 12150  PTS  0:00:00.233   diff: 0:00:00.033   DTS  0:00:00.233   
diff: 0:00:00.033
VU: (B) length 22275  PTS  0:00:00.367   diff: 0:00:00.133   DTS  0:00:00.266   
diff: 0:00:00.033
VU: (P) length 10125  PTS  0:00:00.000   diff:-0:00:00.367   DTS  0:00:00.000   
diff:-0:00:00.266
VU: (P) length 12150  PTS  0:00:00.000   DTS  0:00:00.000
VU: (B) length 20250  PTS  0:00:00.000   DTS  0:00:00.000
VU: (P) length 10125  PTS  0:00:00.000   DTS  0:00:00.000
VU: (P) length 12718  PTS  0:00:00.000   DTS  0:00:00.000
VU: Seq hdr GOP hdr (I) length 38465  PTS  0:00:00.747   DTS  0:00:00.647
VU: (P) length 10125  PTS  0:00:00.000   diff:-0:00:00.747   DTS  0:00:00.000   
diff:-0:00:00.647
VU: (P) length 10125  PTS  0:00:00.000   DTS  0:00:00.000
VU: (B) length 18225  PTS  0:00:00.000   DTS  0:00:00.000
VU: (P) length 10125  PTS  0:00:00.000   DTS  0:00:00.000
VU: (P) length 10125  PTS  0:00:00.000   DTS  0:00:00.000
VU: (B) length 18225  PTS  0:00:00.000   DTS  0:00:00.000
VU: (P) length 10125  PTS  0:00:00.000   DTS  0:00:00.000

From the PTS values of the original, it looks like the GOPs aren't flushed when a new I-frame comes through. The really disturbing part is that the PTS of the replex'd stream's I-frame is *different* from the original. Those are the frames that shouldn't change at all, I'd think, from a replex operation.

It's definately looking like the structure of what comes out is complicated enough to confuse simplistic players/cutters.

-Cory

*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
*************************************************************************



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