Cinema Craft demo watermark - how did they do that?

[Lyris]

This is going back years, but I remember the trial version of Cinema Craft SP2 would overlay a Cinema Craft logo in one of the bottom corners, but it was done in a way which didn't affect the picture quality of the stream. In fact, if memory serves, the logo overlay came out with zero compression artefacts.

How did they do that?

(In case you're wondering... no, I'm not trying to do anything dodgy - I own licenses and dongles for CCE SP2 and SP3 legitimately! I just can't figure out how they did that.)

[jpsdr]

CCE has always been one of the best MPEG-2 encoder (in quality and speed) if not even the best. Probably if you reduce the bitrate you'll see artifact, or... memory don't realy serve ;)
There is no such thing as overlay in raw video mpeg2 stream as far as i know.

[Phanton_13]

There is the posibility that they add the logo after the DCT and quantification, adding basically a high quality logo without compromissing the encode quality and with a minimal bitrate penalization.

The technique is described here: https://www.researchgate.net/publication/221122553_DCT_Domain_Alpha_Blending

[LoRd_MuldeR]

For a video encoder it is trivial to add a logo, because it can be "burnt" into the raw RGB/YUV input image before the actual encoding.

Maybe CCE also employ some kind of ROI (Region of Interest) encoding (https://git.videolan.org/?p=x264.git;a=commit;h=7adf25b165b4c6c69c3bcba7ed949996dca6f116), so that the particular MB's carrying the logo won't get "blurred" too much even at very low bitrates?

[kolak]

Yes, they do something more than adding logo on uncompressed stage. Kono (he written CC-HDe) and other guy (SP3 programmer) were really good in what they did. Shame it did end.
CC-HDe has ROI feature where you can change quantisation for selected regions (many per frame) as you wish. There is no tracking though, so it's quite time consuming. For example when you have some forest with people walking and you want boost quality on them then you just specify region around them and lower relative quantisation. There is also some region edge feathering if I remember well.