Does higher bitrate matters? #499
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Compression is weird math, with increasing resolution it gets more efficient, same with increasing frame rate. This is the case if you sharing the same FOV and FPS as your capture. However, if you crop 8:7 to 16:9 or zoom in you are only sharing a sub region. So this is why a bump on compression can help. e.g. if you cropped 4K 16:9 from a 8:7 5.3K frame, you are using only 33.6% of the data (pixels and bits.) Sharing 4kp30 at 40Mb/s HEVC is excellent (Netflix is 15Mb/s for 4K, for a not completely fare comparison.) 33.6% of 190Mb/s is 64Mb/s so very very good, even overkill. The same goes for high frame rates, 60fps does not need more bitrate when presented at 60fps, as the frames update faster, compression issues are less visible, so the main issue of concern is slow motion. If you shoot 5.3kp60 16:9 (highest res for 10-bit), but share slow motion crop at 4Kp30, your effective bits are 26.1% (per second, using fuzzy math here.) So 26.1% of 170Mb/s is 44Mb/s, still excellent. Pretty much 150Mb/s is all you need to never have a compression concern for the most aggressive crop and time remap. |
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Hi,
Before someone answers that "GoPro has a tiny sensor and please don't expect much from it", I would like to ask a question regarding bitrate.
In terms of editing (I am using LOGB and applying Leeming LUT), 190 Mbps works great for 5.3K 30fps but when using 5.3K 60fps, it has to be reduced to 170 Mbps.
In terms of quality from the tiny GoPro 11 sensor, is 190 Mbps differ much from 170 Mbps?
:-)
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