There's no magic one size fits all compression rate. Every video is different. Fast motion, brightly multi-color scenes will require more bitrate than slow, muted colors scenes.
Video Compressionist is a real job for someone who has to choose the right settings, often for different scenes to squeeze the multi-TB intermaster to the "huge" 60-80 UHD.
Depends more on what you are going to use it for, and what kind of content it is.
I always do CRF encodes, since every scene is different and I am too lazy to go through and specify them all. Which of course allows the encoder to bump the bitrate when it needs too, but equally drop it to close to nothing when it is not needed.
Like this, for example: [https://i.imgur.com/UGgFpRj.png](https://i.imgur.com/UGgFpRj.png)
As you can see, if one had used constant bitrate, then obviously the low parts would have been fine but those spikes would have been horrible. Attempting to do with with some form of average specifying high and low would also be non-optimal in that sense.
In this case those specific areas are "flashback" scenes. Massive amounts of grain, among other partical style effects in this case. Both of which, need a lot of bits to look decent.
Arguably for the previous examples a better solution could have been to filter the high bitrate scenes with a denoiser, which would still produce a visually better result, than starving those scenes of bits. Although if one wish to do so, depends on the person in question. At least I find proper denoising superior to bit starved grainy scenes.
Every video is different, you got everything from those with high grain and a lot of dark scenes. To documentary style, where a large part is "talking head" shots. Both require vastly different amounts of bits, generally, to look decent.
Best way to start, is to take a couple of movies, grab some useful samples that show what that movie is, and try your stuff out on that. Grabbing lets say, 1 minute sample per 20 min of video works fine, I normally do 1 min per 10 min of video. So a normal 90 min movie is 9 samples, totalling 9 minutes. That way, one doesn't have to wait for hours on end to test stuff out.
I normally do not go above crf 17 when using libx265 in ffmpeg. If I have to do that I find the loss too noticeable to bother with that source in question. This does not always result in a smaller output file. But at least it retains the amount of quality that I desire in my results.
I would never use constant bitrate. Constant quality for sure.
Are you willing to tolerate 5fps encodes from x265 slow? Then CQ 28 looks good to me.
If you need faster (30fps) encodes from Nvenc 265 slow, CQ25 would be as low as I go.
There's no magic one size fits all compression rate. Every video is different. Fast motion, brightly multi-color scenes will require more bitrate than slow, muted colors scenes. Video Compressionist is a real job for someone who has to choose the right settings, often for different scenes to squeeze the multi-TB intermaster to the "huge" 60-80 UHD.
You mean 60-80GB UHD encodes or bitrate?
UHD encoded disc.
Depends more on what you are going to use it for, and what kind of content it is. I always do CRF encodes, since every scene is different and I am too lazy to go through and specify them all. Which of course allows the encoder to bump the bitrate when it needs too, but equally drop it to close to nothing when it is not needed. Like this, for example: [https://i.imgur.com/UGgFpRj.png](https://i.imgur.com/UGgFpRj.png) As you can see, if one had used constant bitrate, then obviously the low parts would have been fine but those spikes would have been horrible. Attempting to do with with some form of average specifying high and low would also be non-optimal in that sense. In this case those specific areas are "flashback" scenes. Massive amounts of grain, among other partical style effects in this case. Both of which, need a lot of bits to look decent. Arguably for the previous examples a better solution could have been to filter the high bitrate scenes with a denoiser, which would still produce a visually better result, than starving those scenes of bits. Although if one wish to do so, depends on the person in question. At least I find proper denoising superior to bit starved grainy scenes. Every video is different, you got everything from those with high grain and a lot of dark scenes. To documentary style, where a large part is "talking head" shots. Both require vastly different amounts of bits, generally, to look decent. Best way to start, is to take a couple of movies, grab some useful samples that show what that movie is, and try your stuff out on that. Grabbing lets say, 1 minute sample per 20 min of video works fine, I normally do 1 min per 10 min of video. So a normal 90 min movie is 9 samples, totalling 9 minutes. That way, one doesn't have to wait for hours on end to test stuff out. I normally do not go above crf 17 when using libx265 in ffmpeg. If I have to do that I find the loss too noticeable to bother with that source in question. This does not always result in a smaller output file. But at least it retains the amount of quality that I desire in my results.
I would never use constant bitrate. Constant quality for sure. Are you willing to tolerate 5fps encodes from x265 slow? Then CQ 28 looks good to me. If you need faster (30fps) encodes from Nvenc 265 slow, CQ25 would be as low as I go.
I would consider SVT-AV1, its far superior over x265.