Has anyone any advice on getting the optimum video quality, in terms of which workflow to use for camera video recording resolutions, when the final video output reqired from editing is 1080P resolution?
ie. Presuming all other aspects are equal, Which of the following workflows would give the best final video quality results from a Phantom Advanced?

1) Shoot video on Phantom at 1080P resolution, 30fps, which uses a bitrate of circa 40Mbps and then edit on a 1080P timeline.

or

2) Shoot video on Phantom at 2.7k resolution 30fps, which uses a bitrate of circa 45Mbps and then down-convert from 2.7k to 1080p in editing

Background - Although the 2.7k video only has approximately half the data bitrate of the 1080p recording (when comparing pixels per video frame) I'm wondering if the down-converting from 2.7k to 1080 will more than make up for that and give a better final video quality?

Views? Advice?

Thanks.

I would suggest that any un-necessary conversion can potentially degrade the video, as it is totally dependant upon how the image is decoded and rendered again. The editing program may not be able to render the final product all that well. Using something like Resolve will increase your chances, but you will have to use an intermediate file, usually of very large size, to do that. Having said that, I have had good success using Resolve to colour grade and edit 2.7K footage that was later output at 1080p.

Ok, I performed a few video tests today, nothing scientific, but enough to see what works best.

Mounting the P3A on a table outside (not flying), I shot some video in 1080P 30fps (40Mpbs bitrate) and also in 2.7k both in 25fps and 30 fps (45Mbps bitrate).  I then used Adobe Premiere CC 2017 to render out the video in H264 in 1080P @ 35Mbps so that both clips ended up at 1080P resolution and with the same encoding/bitrate etc applied.

Looking at some zoomed-in stills from the resulting H264 video, the 1080P 30fps original video clip wins hands-down in terms of detail/clarity.

It seems that 1080P 30fps gives the best quality video on a Phantom 3 Advanced. Which makes sense, as this is using the highest bitrate per frame of video, when also taking into account the pixel resolution.
...I was hoping downscaling the 2.7k video down to 1080 would give even better quality, but it seems the bitrate at 2.7k isn't quite good enough to enable that.

If your cp can handle processing 2,7k record with that resolution. This will ensure you a better image if you need to do any zooming in post production.

MJLSTDIOS - using 2.7k recording on a P3A doesn't give as high image quality as recoding in 1030P 30fps.

I'd far rather have the best video quality I can, than have more flexibility in post for pan/scan/zoom

If the 2.7k was equal or better video quality it would be a no-brainer and I would definitely use it.

Gibbo Posted at 2016-11-7 06:49
MJLSTDIOS - using 2.7k recording on a P3A doesn't give as high image quality as recoding in 1030P 30 ...

'MJLSTDIOS - using 2.7k recording on a P3A doesn't give as high image quality as recoding in 1030P 30fps.'

It it totally dependant upon what you are shooting. The lower bitrate is only an issue if there is a lot of detail in the images, as it forces the MPEG compression to work harder. One way to get around this is to reduce the in-camera sharpening, that makes it easier on the compression engine, then when rendering the final product out, you can add the sharpening at a level that suits you.

One other issue is that the 2.7K resolution is an in-between value, the native resolution of the sensor is 4K, and most sensors work better at the native resolution.

>>One way to get around this is to reduce the in-camera sharpening, that makes it easier on the compression engine, then when rendering the final product out, you can add the sharpening at a level that suits you<<

Thanks for the tip, I'll give this a try and see how it works for me.

I can speak about Phantom 4 only but general recommendations can be applied to any camera.

1. There can be different fields of view in different modes. Phantom 4's 1080p mode is just a crop from 4K mode so it works like a teleconverter is attached. So if you're after wideangle shots, there is no choice.

2. If 1080p mode is a crop from 4K mode, per-pixel image quality will not be better. In fact, on Phantom 4 it is even worse. Less sharp, less details (a lot!)

3. 1080p may have higher bitrate, but by downsampling 4:1 from 4K you get a lot more details thus effectively raising the bitrate.

On Phantom 4, 4K is the best option for 1080p output. Even if you recode it two times, one time for downsample and the second time for final output, it is still very very good as long as you use good codecs. You might as well use lossless codecs or all-intra codecs so recoding will not be an issue at all. Also, I do downscale because my laptop chokes on 4K. But if your hardware is fast enough, you can edit in 4K and only output in 1080p thus removing one unnecessary recoding.

Here's the final shot (recoded twice, graded etc.) from my P4 4K footage and it is WAY better tnan if it would have been shot in 1080p natively.

  

Thanks nandakoryaaa, useful feedback.

On the P3A the FOV doesn't seem to alter with different resolutions (or at least not between 2.7k and 1080), so i'm guessing the sensor cropping usage is different when compared to P4 (?)

What camera settings do you use in terms of Color profile (D-Log, None, Art, etc) and sharpness/Contrast/saturation please?

nandakoryaaa Posted at 2016-11-8 05:16
I can speak about Phantom 4 only but general recommendations can be applied to any camera.

1. There ...

I think you will find that sensor crop is only employed at 1080p 120 fps. All other rates and resolutions are properly downscaled. But when shooting at 1080p 120 fps, the quality is noticeably poor in comparison to other frame rates. I am guessing the crop mode is used in order to accomodate the higher frame speed in order to reduce image processing time.

Geebax Posted at 2016-11-8 06:22
I think you will find that sensor crop is only employed at 1080p 120 fps. All other rates and reso ...

Yes, I confirm. I had my P4 set on 120fps accidentally while I checked for the crop. Normal 1080p is not cropped.

I just did tests for every mode and I will post the corrected results.

Gibbo Posted at 2016-11-8 05:23
Thanks nandakoryaaa, useful feedback.

On the P3A the FOV doesn't seem to alter with different resol ...

Crop issue is cleared since it happens only on 120fps.

> What camera settings do you use in terms of Color profile (D-Log, None, Art, etc) and sharpness/Contrast/saturation please?

I use minimum sharpness and somewhat lower contrast if I plan to process the footage further.

Ok, the result for P4 is the following:
- 4K downsampled and 1080p are virtually equal detail-wise
- 1080p even seems to have marginally better clarity but that's due to more sharpening I think
- 1080p has considerably less noise!
- 1080p has a little bit more visible compression artefacts
- 4K downsampled seems to preserve color information better: the sewing seams in the top case are red in reality, in 1080p they are bleached
- native 4K has just a little bit more details, it does not utilize the camera's resolution well. That means you can even upsample the 1080p to 4K and get very similar image quality.

Overall, 1080p seems to be quite solid alternative to 4K. I will be shooting in it. Thank all for bringing this up.

Thanks for taking the time to run the test, much appreciated.

I also ran some more tests today between 1080 and downscaled 2.7k ....and the 1080 was again the winner (only just).

Like you I saw the 1080 seems to be also slightly sharper ( in my case compared to 2.7k).

Initial conclusions - it's a shame the P4's 4k and P3A's 2.7k resolutions don't have a higher bitrate, as this would probably see a very different end result to these tests. The downscaled 4k and 2.7k should be far better, all other things being equal., but they are not in this case.

fwiw - I used both 'None' and 'Art' settings with Sharpness -1, Contrast -1 and Saturation -1 @ 30fps, ISO100, 60fps for my tests

Informative thread, this i what iv been struggling with, 4k 2.7k down sampling to 1080 comes out rubbish, rest and back to the drawing board, with information gained from these posts.

Gibbo Posted at 2016-11-8 09:33
Thanks for taking the time to run the test, much appreciated.

I also ran some more tests today betw ...

Aloha Gibbo,

     Your original post regarded video conversions, and I wish I had caught this thread back five days ago.  There are two forms of video, static and dynamic.  Static video, like photos are much less challenging than dynamic videos where noise, recording and codex compression issues come into play.  This all has a part in the conversion process and the static video style was well covered and very appreciated in this thread.  For myself as a newbie to these video issues, I wish you had tested with dynamic videos of busy scenes.

     It is obvious to even the casual observer that faster straight movement over busy terrain or faster rotations or PANs of busy terrain cause major resolution issues where smudges occur rather than the proper detail of the scene.  If you and the other contributors to this thread could address these "smudges" and discuss ways to reduce them, it would be a significant contribution to this Forum.  Even in color correction, only Resolve seems to get rid of these smudge artifacts left by lesser quality programs.

     We have some talented flying videographers on this forum that would really benefit from resolving these issues.  So much of the problem is involved in the conversion process.  Although more Forum members are posting higher resolution videos, so many convert down to 1080p as a compromise needed for Internet bandwidth for uploads.  It would really benefit the quality of our videos to have this video process information as it is relevant in a dynamic flying environment.

     Mahalo in advance for extending this discussion to dynamic video issues.

Aloha and Drone On!

nandakoryaaa Posted at 2016-11-8 08:44
Ok, the result for P4 is the following:
- 4K downsampled and 1080p are virtually equal detail-wise
- ...

Aloha nandakory,

     Could you look at what I wrote to Gibbo just above.  You input in an extension of this discussion would be helpful.

     Mahalo in advance!

Aloha and Drone On!

Geebax Posted at 2016-11-7 12:22
I think you will find that sensor crop is only employed at 1080p 120 fps. All other rates and reso ...

Aloha Geebax,

     Could you look at what I wrote to Gibbo and nandakory above?  A lot of us on this Forum would benefit from an extension of this thread discussion.  Mahalo in advance!

Aloha and Drone On!

MPEG compression schemes are good for broadcasting, but not brilliant where there is a lot of detail and high compression rates. This seems to be the case with the P4 against the P3, the P3 seems to be better with fine detail than the P4. The best improvement DJI could make, or more pertinently, their chipset provider, would be to give owners the option of higher bit rates providing they were prepared to use higher speed and therefore more expensive SD cards.

Resolve does help reduce these artifacts by converting the images to a much higher bit rate intermediate form, but it cannot work miracles on the footage, it needs to have a higher quality starting point.

Geebax Posted at 2016-11-11 12:26
MPEG compression schemes are good for broadcasting, but not brilliant where there is a lot of detail ...

Aloha Geebax,

     So, with our current equipment and software, what recording settings, codecs and rates would you recommend for those of us who speed through PANs and turns too fast?  Also, those who want to record a P4 at 40 mph looking at the water, grass or trees to give them the best chance of reducing the blur while filming at 2K or 4K?  I mean besides slow down!  (That is my line!)

     With the P3P & P4, we have the choice of video in .mpg or .mov, should we record in .mov?  Above, the conclusion with static video seems to be emphasis on bitrate vs frames per second and resolution.  I can see the obvious need for high bitrate, but in dynamic video, fps seems critical because you can edit in slower motion to reduce jerkiness and blur so that when converting to 1080p the video is cleaner and smoother.

     (BTW, one disadvantage of living way back in the jungle is the Internet has very low bandwidth.  Way faster than it used to be but not even capable of reaching the higher speeds of my plan, yet I have to use that plan because the next lower plan is way too slow.  Would you believe my land line has lead sheath!  Not even copper!  But, they promise to have fiber-optic in a year or so.)

     So, you can see that I am one of those Forum members that can only post video at 1080p for now.  Any suggestions and the suggestions of other contributors will be greatly appreciated since I am not the only one interested in this issue.

Aloha and Drone On!

Cetacean Posted at 2016-11-12 13:34
Aloha Geebax,

     So, with our current equipment and software, what recording settings, codecs a ...

The first thing to say is that it does not matter at all whether you use MOV or MP4, the pictres are the same. the MOV or MP4 bit is what is called a 'container' for video encoded using a H.264 encoder.

As far as pans are concerned, slow down, there is not much option. And try to keep the shutter speed down as low as possible using ND filters. If you watch professional films, they avoid using pans because of the problems they cause.

Where there is a lot of fine detail, better to shoot in 1080p, as the encoder does not do a good job at 4K with all that detail because of the reduced bit rate.

And slow down the speed of yaw and gimbal tilt as well. Some of the most jarring video material comes from sudden jerky adjustments of those two controls.

Oh, and BTW, most underground cables had/have lead sheathing. The copper refers to the actual signal conductors, not the sheathing. Lead sheathing allows cables to be sealed extremely well using a blow torach.

Geebax Posted at 2016-11-11 20:30
The first thing to say is that it does not matter at all whether you use MOV or MP4, the pictres a ...

Aloha Geebax,

     Mahalo for the information on 1080p and shutter speed.  The slow-down, yaw and tilt has been my mantra when critiquing videos (mostly because it is all I know works).  Apparently, the MOV or MP4 option applies to what your first stage of post normally uses, i.e. GoPro Studio uses MOV to process new videos.  

     I have seen bitrate in a table with the various video settings, probably as part of a settings choice with post software.  Is there anywhere DJI has that includes their bitrate with their recording settings?  The P3P / P4 manuals only say that the max is 60 Mbps (appendix).

     Regarding my land line issues, the old lead sheath lining for insulation has crystallized and is causing no end of problems.  One of the linesmen told me that copper was used for insulation, which I though was strange for a conductor.  So, what insulation is normally used in modern non-fiber optic telephone lines?

     Mahalo again for the help, Geebax!

Aloha and Drone On!

Smudges are (mostly) not related to video codec. They happen because the object is changing its size/position in the frame by the noticeable amount within the shutter time interval. Here is an example of frame taken from fast rotation footage. It does not have any bitrate-related issues, just the speed-induced smudging.




So the only way you can eliminate smudges is to set shutter speed short enough. Manually if possible, or by selecting the highest fps available (that naturally speeds up the shutter) or by choosing a very well lit scene.

But also, reducing smudges would not be generally a good idea. The "cinematic" effect of 24fps is achieved because of the smudging. Without it the footage will look artificial and choppy.

1920x1080 60fps works best for me.goes in raw gets edited comes out same 1920x1080p 60fps
ready for bl-ray disk

Cetacean Posted at 2016-11-12 20:36
Aloha Geebax,

     Mahalo for the information on 1080p and shutter speed.  The slow-down, yaw and ...

Where I live, all copper  cable is still in use, but in the new estates that are like islands in our rural area, the cables going in are pure optic fibre, no copper at all in those areas. You are expected to use VOIP phones or Cellular, phones using copper land lines in those areas are not provided for.

Geebax Posted at 2016-11-12 13:06
Where I live, all copper  cable is still in use, but in the new estates that are like islands in o ...

Aloha Geebax,

     So how is copper used as an insulation?

Aloha and Drone On!

Cetacean Posted at 2016-11-13 10:10
Aloha Geebax,

     So how is copper used as an insulation?

Don't know, maybe the information you were given was wrong. Copper is an excellent conductor, both electrically and thermally, so the words 'insulator' and 'copper' are almost never used together.

Geebax Posted at 2016-11-12 14:27
Don't know, maybe the information you were given was wrong. Copper is an excellent conductor, both ...

Aloha Geebax,

     Well, what is used to insulate copper land lines?

Aloha and Drone On!

Cetacean Posted at 2016-11-13 12:13
Aloha Geebax,

     Well, what is used to insulate copper land lines?

Plastic, or in older times, woven cotton or rubber. In the case of woven cotton, this is why the cables were sheathed in lead, to keep moisture out. Wet cotton does not work well.

Geebax Posted at 2016-11-12 15:49
Plastic, or in older times, woven cotton or rubber. In the case of woven cotton, this is why the c ...

Aloha Geebax,

     Well, apparently, my land line is woven cotton!  And in a jungle no less!  Mahalo for the help.

Aloha and Drone On!

nandakoryaaa Posted at 2016-11-12 00:10
Smudges are (mostly) not related to video codec. They happen because the object is changing its size ...

Aloha Nandakory,

     Mahalo for jumping back in!  Your comments are right in line with other information I have received recently regarding this thread.  I am beginning to understand how this technology works.  

     If you should want to cut down on your typing, I came across a good commentary on the subject from May 2015 by FantomDK;

http://forum.dji.com/forum.php?m ... mp;page=1#pid131205

     But your posted image really shows the drawbacks of fast rotation.  The information and examples provided by you and the other commentators will really help me pass on and use the technology better.

     Mahalo Nui Loa!

Aloha and Drone On!

JACKODOG-ANDROI Posted at 2016-11-12 05:58
1920x1080 60fps works best for me.goes in raw gets edited comes out same 1920x1080p 60fps
ready for  ...

Aloha JACK,

     Attached is the meat from the link below.  This is really what I wanted to find out.  Very interesting.

http://forum.dji.com/forum.php?mod=viewthread&tid=16179&page=1#pid131205

     Hope this helps!

Aloha and Drone On!

nandakoryaaa Posted at 2016-11-12 00:10
Smudges are (mostly) not related to video codec. They happen because the object is changing its size ...

Aloha nandakoty,

     Attached is the meat from the link I posted earlier.  Along with your commentary, this is really what I wanted to find out.  Very interesting.  The .pdf file is just concise enough but broad enough to print out and keep around during the learning period for me.  Feel free to pass it on so others can benefit from your efforts.

Aloha and Drone On!

Sky Mike Posted at 2016-11-10 21:13
Informative thread, this i what iv been struggling with, 4k 2.7k down sampling to 1080 comes out rub ...

Aloha Mike,

     Attached is the meat from the link below.  Much of it deals with related issues.  Apparently, the bitrate is critical in the down sampling process.  If you can use / choose a higher bitrate, the end product will be much better.  That is what I am working on now.  Very interesting.  Feel free to print out and pass around the attached .pdf file (2 pages).

http://forum.dji.com/forum.php?mod=viewthread&tid=16179&page=1#pid131205

     Hope this helps!

Aloha and Drone On!

Gibbo Posted at 2016-11-8 09:33
Thanks for taking the time to run the test, much appreciated.

I also ran some more tests today betw ...

Aloha Gibbo,

     Attached is the meat from the link below.  Very interesting.  Feel free to print out and pass around the attached .pdf file (2 pages).  We are going to get this yet!

http://forum.dji.com/forum.php?m ... 79&page=1#pid131205

     Hope this helps!

Aloha and Drone On!

MJLSTUDIOS Posted at 2016-11-6 06:50
If your cp can handle processing 2,7k record with that resolution. This will ensure you a better ima ...

Aloha MJL,

     Attached is a .pdf file that summarizes some of the issues involved in this thread.  It is from a year or so ago, but still useful.  Feel free to print it out and / or pass it around to people like me who can appreciate the information.

Aloha and Drone On!