Barry_Green
Moderator
But that only works if the overall length of the program doesn't change. That's the part I'm having trouble verifying. If you take an hour-long program, it's constructed of 7200 15-frame GOP's. Now, if you snip out one second in the middle (two GOPs) and smush the rest of the timeline together, I can see how it could turn around and deliver that to broadcast with no re-rendering. Maybe. Not 100% sure it could, but I can see how in theory it's possible. None of the other GOPs would have been affected.
But: if you instead snip out just one frame -- let's say, the first frame, then you disrupt the entire 15-frame boundaries of every GOP in the program. And so those GOPs will need to be re-rendered to a new, 15-frame-bounded GOP structure. The GOPs can't be left alone, because they no longer would abide by the old frame boundaries. They'd have to be uncompressed and then have new groupings of 15-frames be re-compressed.
The only way this could be avoided is if there was some provision for dynamic GOP-length changes permitted within a program stream. Something that lets it say "okay, this GOP is 15 frames, the next one is 12 frames, the next one is 8 frames, the next one is 15 frames", etc. In the reading I did, I never came across such a concept.
I think I'll drop a line over to Pinnacle and see if they make such a claim, and if so, if I can get to the bottom of how it works.
But: if you instead snip out just one frame -- let's say, the first frame, then you disrupt the entire 15-frame boundaries of every GOP in the program. And so those GOPs will need to be re-rendered to a new, 15-frame-bounded GOP structure. The GOPs can't be left alone, because they no longer would abide by the old frame boundaries. They'd have to be uncompressed and then have new groupings of 15-frames be re-compressed.
The only way this could be avoided is if there was some provision for dynamic GOP-length changes permitted within a program stream. Something that lets it say "okay, this GOP is 15 frames, the next one is 12 frames, the next one is 8 frames, the next one is 15 frames", etc. In the reading I did, I never came across such a concept.
I think I'll drop a line over to Pinnacle and see if they make such a claim, and if so, if I can get to the bottom of how it works.