Flying manually with Litchi and chaos-read what happened

[Afremont]

Are you saying that H.264/AVC files are limited to less that 4GB? I'm going to have to disagree on that if so. I do agree that FAT32 file size is limited to that, regardless of the content, but I'm going to need to see some kind of link claiming that MP4 containers have a constraint like that.

 

[Afremont]

I am seeing done stuff about DJI arbitrarily imposing a 3.67GB limit, but that's not a compression format limit. It does look like there is some kind of further patent license charges for devices that record for more than 12 minutes continuous.

 

[danCER]

What I have noticed about SD cards in the past.
If I move the mp4s off the microSD card onto my laptop, there seems to be no issue with card next flight. However, if I delete an mp4 on the microSD card while in laptop, there might be problems with next flight if I don't reformat it.
The same for renaming mp4 on SD card.

 

[BossBob]

The 4GB limit is simply the limit on addresible memory locations imposed by the use of a 32 bit operating system.
Also, in the European Union there is a limit on the length of video a stills camera capable of video can take before it has to be called a video camera and more taxes have to be paid.

 

[dvarapala]

Basically it's a hardware fault. If it happens too often or bothers you too much send it for repair.

Can it actually be repaired? It's so common I thought it might be a design flaw, like the excessive noise reduction in the video compression.

 

[Kilrah]

Sure. It's "common" as in forum common, but it's still only likely a tiny percentage affected.
My Nov 2016 Mavic never did that even once.

 

[danCER]

Even if only it's a "a tiny percentage affected," DJI needs to be aware of this serious flaw.
I will be aware of it whenever I fly manually from now on. It doesn't happen often but when it does you have limited control of the Mavic.
I am beginning to think that the gimbal reset issue is not my problem. Since I mainly fly with just Litchi app, I have no idea how the DJI Go app would handle it. My camera did not just go through the startup camera action again. It lasted much longer with gimbal rotating in every direction. Plus my Litchi app constantly said, video stopped...video started...etc.
Hope it doesn't happen again, but I'll see if happens just randomly or something triggers it.

 

[ksmusa]

I am seeing done stuff about DJI arbitrarily imposing a 3.67GB limit, but that's not a compression format limit. It does look like there is some kind of further patent license charges for devices that record for more than 12 minutes continuous.

This not a DJI issue.

 

[Afremont]

This not a DJI issue.

Then could you please explain, as technical as you wsnt, where the restriction is? I'm just trying to understand why the files are being split on an exfat file system. There is no technical limit on the final size of an Mpeg4 or h.264 file. This limit is being imposed by DJI firmware, or possibly some hardware encoder chip limitation (doubtful). I can understand if they are chaptering the file just for reliability or recovery reasons, or patent/licensing restrictions, or even internal hardware reasons, but it's not because of an Mpeg4 limitation. It certainly becomes an issue if frames are dropped during the switch over.

Even if it's a 32 bit processor or OS, that doesn't preclude being able to do 64 or 128 bit math. Even an 8 bit Arduino can deal with it, albeit not in one machine instruction.

 

[ksmusa]

Then could you please explain, as technical as you wsnt, where the restriction is? I'm just trying to understand why the files are being split on an exfat file system. There is no technical limit on the final size of an Mpeg4 or h.264 file. This limit is being imposed by DJI firmware, or possibly some hardware encoder chip limitation (doubtful). I can understand if they are chaptering the file just for reliability or recovery reasons, or patent/licensing restrictions, or even internal hardware reasons, but it's not because of an Mpeg4 limitation. It certainly becomes an issue if frames are dropped during the switch over.

Even if it's a 32 bit processor or OS, that doesn't preclude being able to do 64 or 128 bit math. Even an 8 bit Arduino can deal with it, albeit not in one machine instruction.

Yes, this from my earlier post with some additional information.... Again, this is not a DJI issue.

Fat32 file size is limited to 4 gigs. Each time you record a video in your flight, the flight is always captured in two files. The first portion is always 3.91 GB and then a second file captures the last half of the flight.

FAT32 is a file system architecture once widly used on many computer systems. Due to its popularity, and cross platform support FAT32 is still required by many devices such as game consoles and digital cameras. FAT32 does have several major limitations. The most important limitation to keep in mind is that the maximum size of a file on a FAT32 volume is 4 GiB minus 1 byte or 4,294,967,295 bytes. Files of a larger size will require the use of another filesystem, such as NTFS or HFS+ or ExFAT. FAT32 is supported by WD on both Windows and macOS.
Windows Confidential: A Brief and Incomplete History of FAT32
What’s the Difference Between FAT32, exFAT, and NTFS?
FAT32 Systems and 2GB File Size Limit

 

[Afremont]

I know about FAT32 limititations, I've been around since before FAT12 or PCs but that's not what I'm asking about. EXFAT is quite capable of handling files bigger than 4GB. You said earlier that it was something to do with ICT. I'm not sure what you're referring to on that, but I'm thinking that you are referring to the cosine transfers in the compression algorithm.

My point is that DJI most certainly is limiting the file size on EXFAT formatted cards. I say DJI is doing that because there is no real size limit on recording MP4 files, given that the filesystem can handle it. EXFAT has no trouble, though FAT32 certainly does.

That said, if DJI is doing it as a least common denominator, one size fits all, implementation because they are supporting FAT32 and EXFAT from one I/O library, that's understandable. Or, if some hardware chip, or even some Android limitation is responsible, then that explains it, but there is absolutely no internal file format (MP4, Mpeg-4 or h.264) limititation that precludes recording a continuous file larger than 4GB. Maybe, like GoPro, they create chapters for reliability and recoverability.

I'm not trying to anger you, I just want to be clear on the who, what and why of the limit. I don't think, Microsoft, Linux or Mac OS have anything to do with it. I have MPEG2 videos on my old mythtv box larger than 4GB and they were "recorded" in one fell swoop. Thanks for your response.

I tend to suspect that DJI just didn't want to deal with file sizes larger than a 32-bit unsigned int could hold. The effects would be widespread throughout all of their software, not just during recording, but during file transfers, data logging, and tons of things Im sure I can't even imagine. Maybe years ago, in 640*480 days, someone arbitrarily decided that there would never be a file larger than 4GB, kinda like programmers, like myself many years ago, that thought two digits for the year was fine. It certainly was at that time.

 

[ksmusa]

To my knowledge file type does not change the limitations of fat32. I have the same issue with my camera (Canon EOS-1D X Mark II) and my PS3 which also incorporates exFAT technology licensed from Microsoft. There are many threads covering this issue on the Canon camera forums.
Please forgive me if I am misinterpreting your point.

 

[Afremont]

To my knowledge file type does not change the limitations of fat32. I have the same issue with my camera (Canon EOS-1D X Mark II) and my PS3 which also incorporates exFAT technology licensed from Microsoft. There are many threads covering this issue on the Canon camera forums.
Please forgive me if I am misinterpreting your point.

FAT32 definitely imposes a 4GB limit on all files, regardless of their content. Just trying to get to the real reason behind all these devices splitting files on filesystems that don't have a size limit of 4GB, such as EXFAT. There's a lot of discussion and speculation about it in various forums, but no links to actual facts.

Apparently in the EU, there are rules about still cameras that record video for more than 10-12 minutes. It seems they would be classified as video recorders and have extra licensing fees or patent restrictions. It's all really vague and I'm just trying to edumacate myself on it. Thanks again.

 

[ksmusa]

I personally think it’s a money issue. I believe that manufacturers would be able to transition to the NTFS formatting system. The main problem with this is that any company deciding to pursue this route would have to pay royalty fees to Microsoft.

I use a proprietary program to access NTFS drives when using my Mac computers.
Microsoft NTFS for Mac | Paragon Software

Happy flying[emoji4]