[FFmpeg-user] DeckLink Output Controls

Reuben Martin reuben.m at gmail.com
Wed Oct 12 03:24:05 EEST 2016

On Tuesday, October 11, 2016 11:37:38 AM CDT Marcelo Boufleur wrote:
> > Although that is in the official spec, I have never seen any SDI equipment
> > use
> > anything other than 48k. Doesn’t mean any doesn’t exist, but if so it’s
> > not
> > very common.
> I agree. I have seen some SDI converters and embedders/de-embedders working
> with 32Khz, 44.1Khz and 48Khz, but so far I haven't seen any real world
> practical situation where I would need sampling frequencies other than
> 48Khz (which does not mean there aren't any).

 I think one big reason nobody uses 44100 is that when you pull up/down you 
drop/gain .001 seconds of audio samples. That works out nicely with 48000 
because the difference works out to +/-48. But with 44100 you get a fractional 
+/-44.1 samples which doesn’t work. And I think most broadcast engineers would 
not be too fond of the idea of dropping the audio fidelity to 32k.

-Reube n

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