21 Mb/s 4K 10 bit H.265

alex_markov · Oct 26, 2020

Usually, I always have 104 Mb/s for my 4K 10-bit H.265 output from E2P but today start very shooting a very long clip of passing clouds from my window Without starting motors - what a surprise having All those 20+ minutes in One file 3+ GB with 21Mb/s thruput - great, but I don't know whether this is because the drone was Not fling or because of the easily compressible subject (see below)

Jagerbomb52 · Oct 26, 2020

alex_markov said:
Usually, I always have 104 Mb/s for my 4K 10-bit H.265 output from E2P but today start very shooting a very long clip of passing clouds from my window Without starting motors - what a surprise having All those 20+ minutes in One file 3+ GB with 21Mb/s thruput - great, but I don't know whether this is because the drone was Not fling or because of easily

Have you checked to see if it is 10 bit? One of the members said the new firmware upgrade he lost the 10 bit video.

alex_markov · Oct 26, 2020

Agustine said:
Have you checked to see if it is 10 bit? One of the members said the new firmware upgrade he lost the 10 bit video.

Yes see attached picture

Micander · Oct 26, 2020

alex_markov said:
Usually, I always have 104 Mb/s for my 4K 10-bit H.265 output from E2P but today start very shooting a very long clip of passing clouds from my window Without starting motors - what a surprise having All those 20+ minutes in One file 3+ GB with 21Mb/s thruput - great, but I don't know whether this is because the drone was Not fling or because of the easily compressible subject (see below)

It's because of how the compression works. It takes full pictures from time to time and only writes changes to that picture for some frames. If there isn't much change, the compression rate is very, very good.

alex_markov · Oct 26, 2020

Micander said:
It's because of how the compression works. It takes full pictures from time to time and only writes changes to that picture for some frames. If there isn't much change, the compression rate is very, very good.

This is how Variable bit rate compression works - But E2P as other drones use a Constant bit rate which is usually 104 Mb/s for 4K 30 fps and this is why I suspect Not flying as another option for this strange but great in this case approach

Micander · Oct 26, 2020

alex_markov said:
This is how Variable bit rate compression works - But E2P as other drones use a Constant bit rate which is usually 104 Mb/s for 4K 30 fps and this is why I suspect Not flying as another option for this strange but great in this case approach

They use a constant frame rate, not a constant bit rate. H.264 default is variable bit rate ;-)

alex_markov · Oct 26, 2020

Micander said:
They use a constant frame rate, not a constant bit rate. H.264 default is variable bit rate ;-)

That explains it all - Thank You! I was with the impression that they use a constant bit rate

Rubik3x · Oct 31, 2020

alex_markov said:
That explains it all - Thank You! I was with the impression that they use a constant bit rate

Alex, have you compared the bit rate of your cloud video with other, more complex videos? Is the data you're showing for the original camera file or an edited file?
I've found the E2P camera records pretty consistent 119-125 Mbps for 6K/30, 4K/24, 4K/48 and 98-108 Mbps for 4K/30 and 4K/60 (even with no motion). This is true for both H.264 and H.265 recordings. HOWEVER, output from DaVinci Resolve crushes bit rate to 20-34 Mbps for H.265 10-bit productions while H.264 8-bit productions retain the original higher recorded bit rates. Confused yet?
I was unable to determine which codecs use variable bit rate recording. It make sense, though, that VBR would produce much lower bit rate for something like clouds and sky that don't change much from frame to frame.

alex_markov · Oct 31, 2020

Rubik3x said:
Alex, have you compared the bit rate of your cloud video with other, more complex videos? Is the data you're showing for the original camera file or an edited file?
I've found the E2P camera records pretty consistent 119-125 Mbps for 6K/30, 4K/24, 4K/48 and 98-108 Mbps for 4K/30 and 4K/60 (even with no motion). This is true for both H.264 and H.265 recordings. HOWEVER, output from DaVinci Resolve crushes bit rate to 20-34 Mbps for H.265 10-bit productions while H.264 8-bit productions retain the original higher recorded bit rates. Confused yet?
I was unable to determine which codecs use variable bit rate recording. It make sense, though, that VBR would produce much lower bit rate for something like clouds and sky that don't change much from frame to frame.

Yes there slight deviation between 95 to 104 but usually 103-104 obviously VBR as this one was 21 - all are out of the camera original 4K 30 fps log 10 bit files.

Micander · Oct 31, 2020

Rubik3x said:
Alex, have you compared the bit rate of your cloud video with other, more complex videos? Is the data you're showing for the original camera file or an edited file?
I've found the E2P camera records pretty consistent 119-125 Mbps for 6K/30, 4K/24, 4K/48 and 98-108 Mbps for 4K/30 and 4K/60 (even with no motion). This is true for both H.264 and H.265 recordings. HOWEVER, output from DaVinci Resolve crushes bit rate to 20-34 Mbps for H.265 10-bit

You do realize you can choose the output bitrate in Resolve? You can set it to whatever value you like.

Rubik3x · Oct 31, 2020

Micander said:
You do realize you can choose the output bitrate in Resolve? You can set it to whatever value you like.

No! In Deliver, all I see for H.265 is Quality, Automatic (Best, Medium, Least, etc.) or Restrict to ___ Kb/s and Rate Control (VBR High Quality, Constant Bitrate and others). I have only used Quality = Best and Rate Control = VBR HQ thinking that would give the best results in H.265. Under Encoding Profile, I use Main10 to get 10-bit output.
For H.264, it's the same except no Rate Control options.
Am I missing something? I'm still very much in the learning process with this software.

Micander · Nov 1, 2020

Rubik3x said:
No! In Deliver, all I see for H.265 is Quality, Automatic (Best, Medium, Least, etc.) or Restrict to ___ Kb/s and Rate Control (VBR High Quality, Constant Bitrate and others). I have only used Quality = Best and Rate Control = VBR HQ thinking that would give the best results in H.265. Under Encoding Profile, I use Main10 to get 10-bit output.

Don't say not when you don't know what you're talking about. Even in "Best" settings the output in Resolve is pretty crappy. Bump the rate to at least 80.000 kb/s and you will have your quality.

Rubik3x · Nov 1, 2020

Micander said:
Don't say not when you don't know what you're talking about. Even in "Best" settings the output in Resolve is pretty crappy. Bump the rate to at least 80.000 kb/s and you will have your quality.

OK. My "No" was to your question; "You do realize you can choose the output bitrate in Resolve?" No, I didn't know that.
So I tried delivering in H.265, Main10 and Quality: "Restricted to 100,000 kb/s" on a short H.265 video and sure enough, it produced at 97.1 Mbps and 10-bit depth. Set to Best, the same video produced at only 19 Mbps (and 1/5th the file size). Now I'll look to see if the higher bit rate solves a quality problem I was having previously with H.265 productions. Thank you very much!

Micander · Nov 1, 2020

Rubik3x said:
OK. My "No" was to your question; "You do realize you can choose the output bitrate in Resolve?" No, I didn't know that.

Sorry mate, then i got that wrong. Like i said, the default "best" settings for h.265 in Resolve are an insult to the capabilities of almost every proper drone of the last 3 years. I usually use 80 Mbit for YT uploads. Higher than that isn't really necessary because it's already better than YT quality.

Rubik3x · Nov 1, 2020

Micander said:
Sorry mate, then i got that wrong. Like i said, the default "best" settings for h.265 in Resolve are an insult to the capabilities of almost every proper drone of the last 3 years. I usually use 80 Mbit for YT uploads. Higher than that isn't really necessary because it's already better than YT quality.

No worries.
I am doing more tests and finding that the higher bit rate in H.265 productions does indeed solve the image quality problem I was having. Unfortunately, if I pick a bit rate to match the input file, the output file size goes up to match the H.264 productions. I'm not sure what other benefits H.265 offers in this case. Perhaps faster render? Ability to set bit rate no higher than necessary for YT posts?
BTW, is there any way to know what bit rate we are seeing in YT videos?

Micander · Nov 2, 2020

Rubik3x said:
No worries.
I am doing more tests and finding that the higher bit rate in H.265 productions does indeed solve the image quality problem I was having. Unfortunately, if I pick a bit rate to match the input file, the output file size goes up to match the H.264 productions. I'm not sure what other benefits H.265 offers in this case. Perhaps faster render?

h.265 was developed to use about 25% less data in comparison with h.264 with the same quality. On a lot of devices you won't see any difference north of 80-100 Mbit/s. Render two files with 30 Mbit/s. One h.264, one h.265, then compare them - you should see a difference in quality.

YT recommends 44-56 Mbit/s for 4k with 24-30fps and 66-85 Mbit/s for 4k 48-60 fps.