It the live feed you see in the app via USB.
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Phantom 3 Advanced Lightbridge not the same as Pro
- Thread starter Cactus
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I'm calling BS on this response. NO product specs (on DJI or at online stores) mentioned the reduced bit rate except for one obscure comparison page found by someone in response to my research into the problem. DJI tech support does not even understand this nor did they admit that was likely the cause of the issue.
Anyway, this is water under the bridge. The light-bridge bit rate for the Advanced will never go up because it does not have the same processing power as the Pro unit. I don't think the Adv model is going to be around for much longer.
I reiterate my previous question: if the bitrate of the Advanced were only 2 Mbps, then it would probably be possible to go a lot more distant (and I mean miles) than the P3P. Minimum setting on the Pro is 4 Mbps. There is a huge difference between 2 and 4 Mbps and it is only logical that 2 Mbps would carry further. Just the way like 6 or 8 or 10Mbps carry a lot less far than 4 Mpbs.
Has anyone ever compared?
Has anyone ever compared?
Less Mb/s, less error bitrate, more distance .. this is the theorical equation. In 2Mb/s you can easly transport good 768p video, again, in theory.
The P3A and P3P share EXACTLY THE SAME lightbridge logic. The difference is just in a missing dedicated live-video DSP on a P3A, so the main Camera CPU does both job live video encoding and SD card encoding. That's it. I don't see any significant difference on my P3A and P3P live video, in any case, unless I'm in a very jammed 2.4ghz area.
I do not think 2mbps will make the Advanced model fly further than the Pro at 4mbps. Here is my reasoning.
The lightbridge protocol is *likely* able to handle transmission rates of at least 4mbps as long as the wireless link can support it. So if a Pro model is 1000ft away encoding at 4mbps and an Advanced model is 1000ft away encoding at 2mbps they should both have the same signal under the same conditions, but the Pro will have more detail in the live feed with fewer compression blurs because it has more pixel data to fill in the 720p transmission.
Has anyone installed a P3P camera on their P3A that can confirm that this is all that is needed to get higher than 2Mbps for the live feed?
No, it doesn't work in this way. Math is math. 2Mb/s need less infos per second than 4mb/s, so error rate raises at a 2 factor. In our case, distance rapresent a loss in the trasmission line, so 2mbps double the distance of a 4mbps (theory), but with less video quality.
What it can happen, is that lightbridge has flat encoding logic so if the rc/p3 desync, they have problems to get in sync again with a new I-frame due to high error rate on the rf signal.
I just do not think you are going to see this play out in real tests between Pro and Adv models in similar conditions....
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Hey Cactus, I read this thread before and now that I was watching your uploaded video concerning the pixelation that you put up in Skypixel, I thought, I just got my stock DJI P3A and it looks 100 times better than what you showed on your video. The only thing I did different from the beginning is that I bought a 32GB micro sd card where it's speed is 90mbps. This may make a difference. Are you using a high speed micro sd card? If not, it may be worth a try. Thanks for sharing the video. Sorry I don't have a video to share but I would be sorely disappointed if my videos looked like yours. Not being mean, just found yours to be less than my out of the box video's except for the sd card. I would like to hear if this helps or if you are using a high speed sd card or what the difference may be. Thanks again.
[EDIT] I have a short clip of one of my video's that I was able to capture. I did notice when I checked this link and played my own link, that a very small amount of pixelation happened on some of the leaves but not too much. This however, I did not see on running the video directly on my pc. Anyway, check it out and see what you see. Remember, this is my out of the box DJI P3A with the only change being a HiSpeed micro sd card at 32GB 90Mbps. Link below:
Dropbox - Stock DJI P3A with HiSpeed MicroSD.mp4
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From user reports I've read, the increased pixelation is viewable in the app on larger devices (iPad mini, for example).
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True but in the video that Cactus put up, it is a recorded video. The ability of the sd card to receive the signal and not be backed up in cache memory may be an issue. I'm just saying that my stock out of the box DJI P3A looks 100 times better than his video. That's why I asked if he is using a high speed sd card. Nobody else has solid answer yet, so lets see if this is the smoking sd card. Also, if there is pixelation on a tablet or cell phone, it many times has to do with the device. I have a Samsung Galaxy Tab 4. At first it was lagging really bad. Then I turned on airport mode and it worked about 90% better.
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Oh, that makes sense. Sorry, I must have flown in a ditch on that one. Thanks for the clarification.
Hey,
As Brent10 was saying, we are referring to pixelation of the live view (FPV feed) on the application or from the HDMI port. The recording I posted that you mentioned was from the iPad application cache AFTER it was transmitted via the lightbridge to the remote. My on board HD recording (from the mSD card) looks very good and I am using the stock card.
Correct, for me I could not see pixelation when I used an iPhone 6, but when I installed the HDMI board I could see it when outdoors looking at grass, tress, etc. After two RMA's thinking my P3 was defective, someone posted the information about the reduced bit rate of the live feed and the fact that it was due to not having the additional chip set to encode the lightbridge at a higher bit rate. If tech support would have known this, they could have saved allot of time, money and hassle on both are parts.
If you only use a phone size screen with the P3A, then you will likely not see the difference.
Cactus,
Can you explain to me how to get these cached files off of my iphone or ipad? Do you need to record video to have these cache files created, or are they created naturally on their own?
Thanks!
I'll see what I can dig up tonight. I don't remember if I pulled the file from the application or if I grabbed the file off the iPad when it was connected to iTunes.
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