I understand "high quality" mode gives you 720p at 60fps on your goggles.  Alternatively, "low latency" mode gives you 720p at 120fps on the goggles.  Given this, is my assumption correct that "low latency" mode is actually higher quality than"high quality" mode given they are both 720p but "low latency" mode gives you double the framerate?  I've been confused by this in their documenation from the beginning.  any clarification appreciated.  thanks.

I thought high quality was 1080 60 FPS and low latency is 720 120fps.

freehotdawgs Posted at 6-11 10:31
I thought high quality was 1080 60 FPS and low latency is 720 120fps.

According to their documentation goggles live view mode:
Live View Mode:
Low Latency Mode (720p/120fps)
High-Quality Mode (720p/60fps)


1080P is for on-board recording on the FPV Air unit....

I'll take the low latency for my quad. For fixed wing, the high quality would probably work ok.

As you mentioned, they are both 720p at different frame rates.  My assumption is that HQ mode sacrifices the FPS and latency for a higher bitrate ( or less compressed, less blocky ) looking image.  low latency mode gives you a little less latency, a higher frame rate, but a more compressed, lower quality looking image.  And if you have focus mode enabled you will see even more of that along the edges.

fans3c0fa099 Posted at 6-11 19:47
As you mentioned, they are both 720p at different frame rates.  My assumption is that HQ mode sacrifices the FPS and latency for a higher bitrate ( or less compressed, less blocky ) looking image.  low latency mode gives you a little less latency, a higher frame rate, but a more compressed, lower quality looking image.  And if you have focus mode enabled you will see even more of that along the edges.

Thanks.   Is this based on official DJI literature or just a guess?  

This is not an assumption this is fact. To prove it just put on your goggles and see for yourself. The difference in image quality is obvious.
https://dl.djicdn.com/downloads/ ... _User_Manual_EN.pdf   - Page 27

Fritz Wlan Posted at 6-12 04:09
This is not an assumption this is fact. To prove it just put on your goggles and see for yourself. The difference in image quality is obvious.
https://dl.djicdn.com/downloads/DJI_Digital_FPV_System/20190731/DJI_Digital_FPV_System_User_Manual_EN.pdf   - Page 27

The manual says:
"Preferences
Select the live view mode. In Low Latency mode (720p 120fps), the latency is 18-28 ms, while in
High Quality mode (720p 60fps), the latency is within 40 ms.".  

It doesn't say High Quality is better.  I'd like to hear from DJI as the difference isn't so obvious to me at least.

fans8e299cb6 Posted at 6-11 19:51
Thanks.   Is this based on official DJI literature or just a guess?

This is based on just my opinion gathered from my experience with streaming digital video and what I can observe from looking through the goggles.  Often resolution, quality, and bitrate go hand in hand, but they don't have to.  Basically they have a certain amount of bandwidth they can use and you get to choose how you want to use it.  Lower latency, higher frame rates, blocky edges, are all trade-offs you can make.

What a moron this dude who doesn’t believe you and says he needs to hear it from DJi. As he said just try it yourself obviously they say “High Quality” mode for a reason and he explained it perfectly. You must literally be retarded to say you have to “hear it yourself from DJi” lmao

djiuser_8hlRPvRXD80I Posted at 3-21 20:45
What a moron this dude who doesn’t believe you and says he needs to hear it from DJi. As he said just try it yourself obviously they say “High Quality” mode for a reason and he explained it perfectly. You must literally be retarded to say you have to “hear it yourself from DJi” lmao

The only retard I see is the moron who is reviving an almost year old post.  Get a life chump.

fans8e299cb6 Posted at 3-22 11:15
The only retard I see is the moron who is reviving an almost year old post.  Get a life chump.

Do you still not believe it or did you finally figure it out.

The difference is bitrate.  Bitrate effects image quality.  In order to get higher framerates and lower latency, you need to lower the bitrate.  This will reduce the image quality.  

If the resolution and bitrate is the same but twice as high fps, then the "quality" is half.

Some people think of bitrate as "quality" but forget that 120fps is twice as many frames that has to be sent with the same amount of data. So if you have 60fps 50mbps bitrate, each frame is, on average, 210 KB, while for 120fps 50mbps it's 105KB.

Maths:
50mbps / 60fps = 6400KB/s / 60fps = ~210KB per frame
50mbps / 120fps = 6400KB/s / 60fps = ~105KB per frame