| Thanks for your answer. > the compression algorithm needs knowledge of the video stream, which would be impossible if it's compressed. That makes perfect sense and I guess my theory of secure encryption + post-re-compression fails because of this. But what if we didn't need perfectly secure encryption, but just per-block encryption. So the server knows that you've sent 60 frames, but doesn't know what is in those frames. What if the codec was made in such a way that the server knew that certain blocks in the stream could be discarded to reduce size while the stream without those blocks still makes sense to the recipient. For example: the stream is composed of 64 byte blocks, but the codec says that every 2 blocks there's a discardable block that adds image quality but is not essential. So, with this knowledge, the server discards every 2 blocks when sending that data to people with low bandwidth and sends the original stream with all its blocks to those with high bandwidth. It's an extremely naive scheme, but maybe this principle could be applied to more complicated codecs, so the server only needs to know metadata about the stream (where each block is and whether it's essential), but not the content of the block itself (framebuffer and audio sample values). I'm sorry if this idea is too dumb (and my English skills are not the best). |
Anyways, the wikipedia page linked above links to this about the same concept, for video: https://en.wikipedia.org/wiki/Scalable_Video_Coding so it might be feasible. Not sure how feasible/secure encrypting this would be.