The OTA will probably be 1 second or so behind the Sat feed.......
I'm curious why you say this. I've seldom seen much sync difference between OTA and raw sat feeds, and if you're looking at HD video from sat, and audio from a SD OTA feed, I'd expect the audio to come through first, just because I'd guess more processing time for the HD signal.
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Just my experience, nothing more than that. I can flip from the Main Feed to the OTA, it's about 1-2 seconds behind.
Thanks. I was curious about this, because if anything, I've observed the opposite, and a few years ago I had done an extensive study of the delays associated with 6 or 8 different ways of viewing TV. However then it occurred to me that MY observations have been using the OTA *ANALOG* signal, so I concluded that you must be using the OTA *DIGITAL ATSC* signal, so that receiver processing speeds would be involved. So I did a comparison to test this.
(1) OTA ANALOG.... analog receiver Fastest
(2) AMC-18 S2 MPEG4 digital less than 0.1 sec delay
(3) OTA ATSC... Samsung TV ~0.9 sec del
(4) OTA ATSC...Diamond 9000---> Samsung TV via HDMI ~1.1 sec delay
(5) OTA ATSC...Coolsat 8100-----> Samsung TV via HDMI ~1.2 sec delay
(6) OTA ATSC...Air2PC card-->TSREADER--->Roku--->Samsung TV via analog A/Component-V 2.8 sec delay.
(7) DirecTV local--->TIVO---> Samsung TV via A/V ~8.5 sec delay.
So my OTA digital results correspond to the 1 second offset you describe, and it also seems to suggest that the delays are due to the digital processing of the signal in our receivers. Ie I think it suggests that the local stations have receivers that have about the same processing time that our receivers do (maybe a tenth of a second faster), but when they re-encode the satellite signal and send it out ATSC, there must be nearly a second delay.
I did a similar comparison a while ago, back when I *THINK* the local stations still got their analog signal separate from the digital signal, but I forget what the results were. Too bad, because there just isn't enough data here to really pinpoint just where all the delays are. I'm also not sure just how many times the local channel processes the digital signal. I'm assuming that they process it once at the station, then probably re-encode it to send it to their transmitter site, and it's possible that there is decoding and re-encoding there too, I don't know.
Interesting topic.