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Valkka
0.17.0
OpenSource Video Management
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Notes on the block and timestamp scheme
A, a = frames from source A (mayor letter = KEY frame. Designates time start, i.e. sps packet, etc.)
B, b = frames from source B
etc.
Assume that if cameras are on-line, there is a key-frame from each camera in every block
BlockTable
k-max, maximum KEY frame timestamp in block
max, maximum frame timestamp in block
time ->
k-max max block
01 02 03 04 05 06 07 08 09 10 11 12 13 14 12 14 10
b b d D a A a c c a C B b b
15 16 17 18 19 20 21 22 23 24 25 26 27 28 26 28 11
a a B c A C b b c b a D d a
29 30 31 32 33 34 35 36 37 38 39 40 41 42 37 42 12
A b B c d C d d D a a b c aRequest time (21, 29)
==>
Lower limit: we need that all cameras have stamped a key frame with =< 21. This way we can seek to t = 21.
if any of the cameras has stamped > 21, needs earlier block
–> start from block 10 (search: last block of all blocks that have k-max =< 21)
Higher limit: all cameras have stamped >= 29 for any frame
if any of the cameras has stamped < 29, needs later block
–> last block to include is 12 (search: first block of all blocks that have max >= 29)
1.8.13