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Mini Converter UpDownCross HD

PostPosted: Sat Mar 06, 2021 4:20 pm
by Andy Coulthurst
I would normally use a decimator to convert between different frame standards.
However this time I needed to retain RP188 timecode packets ( feeding a Blackmagic recorder with timecode ).

So - I hooked the converter up to go from 3G-Level A 1080p50 to 1080P25 for the recorder , and great , timecode appeared to be correctly passed to the recorder.

Unfortunately when I came to unplug and re-power the converter - the output was gone , no video , nothing. There was a nice SDI lock led present , just no output.

After a load of further checks - what I found was that the converter would work if I changed the switch settings ( a different output standard and then back to 1080p25 ). But would never start up correctly.
Almost as though the converter didn't read the switches on powerup , only when they changed.

Anyone else use one of these ? Have the same issue ?

Note that I installed v7.5.1 of the converter utility to make sure I was on the latest firmware ( I was ).

Very confused.

Re: Mini Converter UpDownCross HD

PostPosted: Sat Mar 06, 2021 4:47 pm
by Andy Coulthurst
I'll also add to this that the timecode out of the converter is quite "funky"

I would expect when going from 50fps to 25fps , that it would be relatively easy for the converter to calculate the correct frame. This doesn't seem to be the case , and the output timecode jumps backwards and appears to be many seconds behind the input timecode.

I'll also note that the input timecode appears to get read only once , so changing the input timecode only affects the output at a change of configuration.

However going from 50p to 50i seems okay , but again the timecode is only corrected at a change of configuration.

Seems like there are quite a few bugs remaining.

Re: Mini Converter UpDownCross HD

PostPosted: Sun Apr 11, 2021 10:10 am
by Andy Coulthurst
Just an update on this - contacted support - unit was replaced and so far all seems good.
Even the timecode looks good.

Re: Mini Converter UpDownCross HD

PostPosted: Sun Apr 11, 2021 1:23 pm
by Andy Coulthurst
I spoke a little too soon :D
Left the converter running for a while , converting 1080p50 (B) to 1080p25 , and it would appear that the timecode on the output has started jumping again.

It looks like the timecode is internally generated by the converter , and synced at powerup to the input ( I assume ).
Because in this instance I'm using the converter free running , the input and output timecode references get out of sync and the converter seems to correct at the second change ( frame 24->0 ). I could of course use an external sync reference , but this shouldn't really happen for such a simple scenario ( IMHO ).

Edge cases are complex ehh?

Whats worse - inconsistent timecode or timecode not locked to output framerate ?
Perhaps for the future the output framerate could be derived from the input framerate when there is no reference.