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Confused with Leica's HDMI data streams - SL2-S, SL3

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Maybe someone who knows more than me can help... or even someone working with an SL and e.g. an Atomos. 

Leica's list of video resolutions adds information over what's possible on SD or on HDMI... 
But I'm confused about what the Mbps information means... shouldn't these over HDMI be dictated by the recorder and video codec being used?

For example:
Leica states the SL2-S can only do Long-GOP 150 Mbps when using UHD and 24fps (while C4K 24fps strangely uses All-I 400 Mbps). That definitely is the internal .mp4, but is that also applicable to HDMI recording? I hope that doesn't mean the SL2-S can only push 150 Mbps through the HDMI when choosing UHD 24fps? (ProRes422 HQ has target data rate of 707 Mbps in UHD 24...)
I mean it should be possible theoretically, because the SL2-S can do C4K 24fps ProRes Raw recording over HDMI after all...

The SL2-S can do 150 Mbps in UHD 24fps, 400 Mbps in C4K 24fps. The SL3 can do 400 Mbps in UHD 24fps and 600 Mbps in C4K 24fps. That is interesting... nice one SL3, but over HDMI they all should be equal... right? Is it a raw stream over HDMI that then will be recorded as 707 Mbps ProRes422 HQ? 

To make matters worse, some of the information is split between SD and HDMI in the list of the SL3.
(Have mercy on me I never had an SL but consider the SL2-S now)
My head spins 😂 
I hope someone has the answers! 

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Posted (edited)

They are Uncompressed 10-bit 4:2:2 over HDMI. Limited by external recorder in terms of recording bitrate.

The 48/24 and 47.95/23.98 splits are because 48 and 47.95 are not part of the HDMI standard, so to display a signal while recording it sends out half the FPS. You cannot record 48 or 47.95 externally. 

Hope that helps!

Edited by Geoff C. Bassett
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Ohhh! That makes sense... I just learned something new without even knowing that I needed it... Great! Thank you so much!
Opens a new gate of information knowing about the 48fps 47.95fps not being part of the HDMI standard...

And just as you said, over HDMI the SL2-S sends uncompressed data stream, asking the official Leica product support email also confirmed that to me. 
That is great to know moving forward... 

Thank you for your help!

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