Originally Posted by wmhjr
Actually, S-Video is at 480i or 576i resolution - and is an analog - not digital - signal. It has two ground connections, one intensity and one color connection (of the 4 total standard s-video connections on an S-Video port). S-Video can be better than composite because of increased bandwidth and low cross-talk - primarily because color and intensity are separated removing the requirement for low pass filtering.
I appreciate the response, however. As you note, what I'm really trying to determine is what the specific SA8300HD will do. I've heard both sides, that it will simultaneously send output to all ports, and that it will not. I'm also interested to find out if the DVR will actually send downgraded but viewable output from HD content out the S-Video connector. I'm afraid it might just disable the port. You never know.
My SA8300HD (Time Warner/ Passport v.48) outputs Svideo of very good quality and stereo sound from both SD and HD source content. Passport does not have the dedicated "Copy" function that the SA OS has, so I have to play the program. I believe the svideo output is always live, even with HDMI/1080i output, I think.
I'm using the component video outputs for my TV, with the 8300 set to 720p output. 16:9 HD content is formatted as 4:3 with top/bottom letterboxing; SD 4:3 is output as full screen 4:3.
I use it with an MPEG2 capture box to archive and make DVDs. The Svideo output is probably as good as svideo gets, which is certainly not close to HD, but not all that bad and quite appropriate for computer playback or making DVDs.