thunderous71 said:
Just asked Drift about this...
To help you out here, this isn't in fact a bug but the way the camera has been designed to record. The Drift Ghost, along with our other model cameras will record in up to 30 minute max intervals, with 2-3 seconds in-between each video, giving you separate video files on your SD card. This may appear as though your camera has turned off in-between videoing, but in fact this is normal.
Well I know the VIO POV.HD doesn't have this 'feature' as I own that camera too.
The bigger the file, the longer it will take the camera's processor to handle saving it. A 30 minute file is over 2GB of data. Unfortunately it takes the processor a second to save this before moving on to start a new recording. This is why the team have designed the cameras to actually force the files to stop at 28 minutes and not continue on longer, so that the save time is as low as possible.
So it seems its a limitation of the BUS within some of these cameras, not being able to buffer while saving / closing the files. A simple RAM buffer would sort this I would have thought, but also push the cost up somewhat.
But that's plain wrong, first of all, drift or gopro or Liq or JVC or anybody else using ambarella sh*tset didn't design the recording hardware or firmware on the camera, they just modified the frontend that handles user interaction and maybe they designed the exterior look and feel of the camera. Feature-wise they added or removed some recording scripts or a piece of hardware (wifi, radio, LED's, IR remote).
Ambarella provided the chip, suggested hardware design and provided the firmware.
The manufacturer cannot touch the proprietary ambarella firmware blob, they can touch everything around it (like the parts handled by the linux kernel running on top of the Ambarella RTOS) but cannot modify or touch the part that handles image capturing.
Now I'm talking out of my imagination but I cannot be too far from the truth.
The video capturing and encoding process doesn't take place entirely on RAM, having 4GiB of RAM in a camera is not practical and encoding to ram and then dumping to card makes no sense. A power glitch can render the entire RAM contents unusable.
The RAM is used to run the OS, as scratchpad for the capturing and encoding and once enough blocks of data are encoded, interleaved and ready to be saved to the SD card, they're dumped there.
The video finalization that takes place once the STOP button is pressed just consists of making the random blocks of data in the card, compliant to some format (MOV in some cameras) and writing the header and trailing bits and metadata.
Just think about how much time will it take to dump 4GiB of video at 6MiB/s from RAM to card, that gives the hint that small blocks of data are transferred while recording and not once the recording stopped.
thunderous71 said:
Perhaps they should do a pro range with CCD rather than CMOS also
It doesn't appear to be a chip set limitation or DRM (DRM makes no sense at all).
Oh my tip to make the last frames as short as possible is to make sure you use a fast card!
Yeah, GoPro's are touted to be "pro" cameras but they don't even have a proper lens with a mechanical iris. Outdoor video easily gets burned. You cannot handle basic things like exposure, video bitrate or anything. They should be called toycameras because they don't have any "Pro" features.
Think about DRM a little. Small camera, can be mounted anywhere, can be hidden almost anywhere, put a big card and you can record up to 8 hours, you can use external power, there's no theoric limit to avoid in-cinema movie recording.
Somebody has to put a limit, ambarella comes to the rescue with the 29 minute max. JVC does the same by avoiding the use of external power, the camera turns off when USB power is provided. They took it one step further by making the battery non-removable (even if the battery inside is shaped as removable, labeled and put into a cradle for quick replacement) so you cannot hack external power on the battery slot.
Tell me is a filesystem limitation and I may believe you if the camera records 4GB files, like the Drift HD. It's not the case with all ambarella cameras I got and it's not the case on the drift ghost which I don't own. The 29 minute files are less than 3GB in size.
Also, a C6 or C10 SD card is not needed at all, the camera doesn't record at a bitrate high enough to get any benefit from a faster card. It can work without any problems on a class 4 card, I know this, I have been using all my cameras with an 8GB Class 4 Verbatim card and haven't run into any problems, the video quality is exactly the same as using a 32GB Sandisk Ultra. I even used a 2GB class 2 card on the Liq cameras, again, no problems at all, my first vlog was made using that combo because I couldn't afford bigger cards, 8GB class 4 inside the drift recording 720p 60fps and 2GB class 2 on the Liq camera recording 1080p at 30fps. I even mentioned that in a part of the vlog that ended up being cut, I said something like "I gotta do this fast because this camera [points to the liq camera] is about to run out of memory very soon."
I'm writing this not to get to any user here but to ambarella, drift, liq and any other manufacturer that conveniently forgets to include that valuable piece of information in the user's manual that should say "This camera records up to 29 minutes and then stops". This case got me completely mad with my Liq Ego's because that renders the camera useless. I wanted those cameras to film the whole trip mounted to the bike's fairing or wherever, using external power to get around the internal battery limitation. First surprise was that they don't get past 29 minutes and after fiddling with the different firmware versions, the last one does restart the camera after it stops but it has a horrible case of jello vision and if you provide external power, instead of restarting the camera, the camera switches to USB mode. :evil: :evil: :evil: :evil: :evil: :evil:
WHAT A PIECE OF F****** S***.
--- Edit ---
Everyone forgive me about that, I may seem like an ass and I tend to be like that when talking about technology.
