GH2 HDMI out

Posted on 25 February 2013

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To end the discussion about GH2’s HDMI output quality: the GH2 records to 4:2:0 8 bit AVCHD files, this standard results in a 4:2:0 8 bit recording.  I’m 99% sure that the chroma resolution of the HDMI output also is 4:2:0 8 bit.

4:2:0 8 bit

But wait you think: Others say the HDMI out is 4:2:2. Yes, this also is true because 4:2:0 is not part of the HDMI standard. Some more info about that: HDMI only supports uncompressed video. HDMI 1.1 defines 8bit sRGB or (optional) 4:2:2 YCC up to 1080p60 + 8ch PCM audio. HDMI 1.3 defines deep color (10bit and higher) and other color spaces like xvYCC. Timecode over HDMI is a non-standard addition by NXcam.

So what really happens is that the camera feeds the same 4:2:0 signal to the AVCHD encoder and to the HDMI output. The HDMI output converter in the GH2 is probably the same as in most Blu-ray players, up-converting the signal to 4:2:2 uncompressed YCC and sending this stream through the HDMI output. So saying the GH2 has uncompressed 4:2:2 output is like saying you have an uncompressed 4:2:2 blu-ray player.

Color shift

And what about the color shift when you hit record? This could mean that the HDMI output is a sRGB signal instead of YCC? It might be, I’ve tried to find out but in the end I really don’t know.

HDMI settings

On the GH2 you can select HDMI output settings. This is for playback mode. In life-view/recording mode it’s always 1080i.

ETC mode

Wondering about HDMI output in ETC mode? Look here.

 

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Posted in: GH2