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Understanding SRT file data
2765 6 2018-12-3
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gregmihran
lvl.2
Flight distance : 50187 ft
United States
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I am a DJI newbie and am enjoying my M2P! For now while I'm learning how to fly, I'm shooting H.265 videos in Normal HQ Manual (ISO100 30fps f4.5 1/60) and viewing my videos/SRT files in VLC with subtitles activated. I figured out a lot of the SRT data but am not sure about a few below - perhaps someone can explain these from a recent video.

THESE VALUES I UNDERSTAND:
FrameCnt: (frame number)
DiffTime: (33.3ms = 30fps)
iso: (ISO = 100)
shutter: (1/60.0 = 1/60th sec)
fnum: (FStop = 450 = f4.5)
ev: (0 = exposure value)
ct: 5502 (color temperature = 'Sunny')
focal_len: (280 = f2.8 lens)
latitude: (obvious)
longtitude (btw, spelled wrong with an extra 't')

COULD SOMEONE EXPLAIN: (with my real-time values)
tar: 163
luma: 174
dg: 4899
u_xhs: 3288
k_xhs: 1142
RGBGain: (2816, 1000, 1710)
color_md: (default)

Any insights into these values would be appreciated. Thanks so much!  Greg
2018-12-3
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gregmihran
lvl.2
Flight distance : 50187 ft
United States
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Here are the SRT file subtitles I see in my VLC video player.  I indicated the parameters I understand and am not sure about the others labeled in red.  Anyone know or could guess?

2018-12-3
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gregmihran
lvl.2
Flight distance : 50187 ft
United States
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I have enlarged the SRT file data in the VLC subtitles.  I'm still wondering what 'tar', 'luma', 'dg', 'u_xhs', and 'k_xhs' indicate.  'luma' must have something to do with light level but would enjoy learning what all these mean.  Any thoughts?

2018-12-6
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0Kajuna0
Captain
Flight distance : 249606 ft
Spain
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Wow! I didn't know they had implemented the missing location data in the M2 SRT files. That's great news!

I created this tool to read those data on the M1P:
https://forum.dji.com/thread-140031-1-1.html

It probably does not work with the M2 yet due to the typo and maybe something else. Would you mind sending me a sample srt file so that I can update the tool for the M2?

Thanks
2018-12-8
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0Kajuna0
Captain
Flight distance : 249606 ft
Spain
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By the way. The values I'm missing compared to other drones are white balance (could be ct, colour temperature, maybe color_md is related to that too) and altitude/barometer (I wouldn't know what to match that to). Maybe by having a look at the full log and comparing it with the video we can deduce more.
2018-12-8
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gregmihran
lvl.2
Flight distance : 50187 ft
United States
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0Kajuna0 Posted at 12-8 07:28
By the way. The values I'm missing compared to other drones are white balance (could be ct, colour temperature, maybe color_md is related to that too) and altitude/barometer (I wouldn't know what to match that to). Maybe by having a look at the full log and comparing it with the video we can deduce more.

Hi 0Kajuna0, thanks so much for your reply!  First of all, you nailed one of the parameters I didn't understand: 'ct' = 'color temperature'.  I always use a White Balance of 'Sunny' or 'Cloudy'.  In the sample above, I was using 'Sunny' so a 'ct' of 5502 makes perfect sense (mid-day sun is around 5500).

I'd be happy to share my files with you.  Even though I selected a short video, the MOV H.265 file size 612MB which I can't upload here. Do you have a cloud share I can upload to?  But for the related SRT file, I zipped it from its native 'txt' format and attached DJI_0089.zip 27KB to this message.  You should be able to see each of the parameters that I showed above in a frame-by-frame text file.  Let me know if you can upgrade your program to this M2P SRT data.  Thanks so much, Greg
2018-12-9
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0Kajuna0
Captain
Flight distance : 249606 ft
Spain
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gregmihran Posted at 12-9 11:41
Hi 0Kajuna0, thanks so much for your reply!  First of all, you nailed one of the parameters I didn't understand: 'ct' = 'color temperature'.  I always use a White Balance of 'Sunny' or 'Cloudy'.  In the sample above, I was using 'Sunny' so a 'ct' of 5502 makes perfect sense (mid-day sun is around 5500).

I'd be happy to share my files with you.  Even though I selected a short video, the MOV H.265 file size 612MB which I can't upload here. Do you have a cloud share I can upload to?  But for the related SRT file, I zipped it from its native 'txt' format and attached DJI_0089.zip 27KB to this message.  You should be able to see each of the parameters that I showed above in a frame-by-frame text file.  Let me know if you can upgrade your program to this M2P SRT data.  Thanks so much, Greg

I've been playing with a Mavic 2 Zoom SRT file and, as suspected, there's nothing that looks like altitude. The good news is that precision and frequency are much higher than on the Mavic 1.

You can visualise them now with my app (not tested with M2P yet): https://djitelemetryoverlay.com/

The M2 Zoom is missing these fields, so they must be related to the Hasselblad camera: tar, luma, dg, u_xhs, k_xhs

The zoom adds instead: [dzoom_ratio: 10000, delta:0]
2018-12-9
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