Geebax
First Officer
Australia
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DanMan32 Posted at 2017-1-29 15:34
If you read my second paragraph of my last post, I did indeed analyze the details of the video files transferred from the SD cards, and the bit rate was different for two files yet same resolution/frame rate. Therefore the compression is variable. I found that ExFAT can handle files above 4GB, the limit being 16 Exabytes, which doesn't make sense since the volume limitation is 128 Petabytes.
It is not impossible for the AC to have a video buffer. RAM is cheap so a 2-10GB buffer in RAM would not be unheard of. Do recall that the manual says if you think you lost the last video because you powered off/pulled the card out too soon, to put the card back in and power on the AC within 24 hours of shooting. Being they indicate to power on within 24 hours, the RAM buffer probably has an internal battery or multi-farad capacitor backup.
Please, there is no buffer, period. If you know anything about recording video, it is not possible to have a buffer for an open-ended video event. It is OK for stills because the approximate file size of a still is known, but for video that is not the case. Any buffer would eventually be over-run by the process. It has got nothing to do with the cost of RAM.
And the file issue is simply that the process records a stream to the card, and when you finish recording, it has to finalise the recording and terminate the file. If that process is not done, the file does not even appear on the card, so it is possible to over-write it the next time you press record. However if you place the SD card back in the aircraft, or leave it there, and power cycle the aircraft, the file will be finalised and able to be seen and read.
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