Bruce M
Member
In case you were wondering, the metadata potentially available in the MX system shown is MISB 0601 For the UAS Local data set, and MISB 0605 for inserting the time code.
MISB Metadata, Sitrec Support
- Thread starter Bruce M
- Start date
In case you were wondering, the metadata potentially available in the MX system shown is MISB 0601 For the UAS Local data set, and MISB 0605 for inserting the time code.
I use MISB 0601 as the basis of a general internal format in Sitrec for storing video metadata (or time-series data derived from other sources, like ADS-B). I'd like to support the actual MISB format, as it seems to be used by official/military drones, but I'm having a hard time finding any good examples.
MISB 0601 has a packet timestamp, and the 0601 standard references 0605:
https://upload.wikimedia.org/wikipedia/commons/1/19/MISB_Standard_0601.pdf
I can find 0604, https://sightlineapplications.com/misb-standards/MISB-ST-0604.6.pdf6.9 Motion Imagery/Metadata SynchronizationSynchronization or time-alignment of a Motion Imagery frame with metadata is highly desired and is the responsibility of the system designer. The Precision Time Stamp, referenced in this document, is based on UTC and the POSIX Epoch; requirements for its use is outlined in MISB ST 0603 [4]. Requirements for time stamping compressed Motion Imagery with a Precision Time Stamp are outlined in MISB ST 0604 [5]. Methods and requirements for synchronizing compressed Motion Imagery and metadata within an MPEG-2 Transport Stream are discussed in MISB ST 1402 [6]. Requirements for time stamping and metadata carriage in high definition uncompressed Motion Imagery are outlined in MISB ST 0605 [7].
but not 0605. 0604 seems to relate to correlating precision timestamps with individual frames. 0605 might be similar. But ultimately that's only going to relate to a small, off-by-one-frame error. Right now I just assume frame zero starts at the first timestamp. It would be nice to be more correct. But I'm kind of coding in the dark with the limited examples.
So, if anyone has some raw unclassified MX video with MISB data, send it over!
Bruce M
Member
Found on google:
https://github.com/tayre/klv-decoder/blob/master/README.md#demoarea
samples.ffmpeg.org/MPEG2/mpegts-klv/Day%20Flight.mpg
http://samples.ffmpeg.org/MPEG2/mpegts-klv/
I confirmed it has metadata in it, but its only a couple of updates, not every frame as expected.
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Excellent, thank you! My Google-fu failed!
Not ideal, but it's more than I had before.
Bruce M
Member
You dont really need to decode 0605 timestamps. The time in 0601 is the 'system' provided time, usually sync'd to a GPS. the 0605 time is, I think, just referenced to Useconds in the hour, without an overall reference to real time. Useful, i guess, if you are running some process to calculate time between two events and want to count it in frame times. But you could also manually calculate that, if you arent doing it multiple times and want to automate.
I think all MX videos contain 0605, but only some will have 0601, based on both the capabilities of the MX system and the recorder.
Found a better one!
https://www.arcgis.com/home/item.html?id=55ec6f32d5e342fcbfba376ca2cc409a
And it was only somewhat painful to get it working.
Source: https://www.youtube.com/watch?v=tgVHb3Dgp_c
I say "somewhat" as I found a node.js library that did some conversion. I needed a ES Module version, and luckily found someone had done one. But when I added it I found it's was only 80% done, so I had to finish that first.
https://www.metabunk.org/sitrec/?sitch=misb
As I'd hoped, the data is very high resolution. I don't do any smoothing, just linear interpolation between points.
Ideally I'd make this drag-and drop. But for now it needs a a bit of help splitting the video into .klv (the Key-Length-Value encoded metadata) and .mp4 (a video format supported by Sitrec).
https://www.arcgis.com/home/item.html?id=55ec6f32d5e342fcbfba376ca2cc409a
And it was only somewhat painful to get it working.
Source: https://www.youtube.com/watch?v=tgVHb3Dgp_c
I say "somewhat" as I found a node.js library that did some conversion. I needed a ES Module version, and luckily found someone had done one. But when I added it I found it's was only 80% done, so I had to finish that first.
https://www.metabunk.org/sitrec/?sitch=misb
As I'd hoped, the data is very high resolution. I don't do any smoothing, just linear interpolation between points.
Ideally I'd make this drag-and drop. But for now it needs a a bit of help splitting the video into .klv (the Key-Length-Value encoded metadata) and .mp4 (a video format supported by Sitrec).
Bruce M
Member
Very nice!
I had a look and its very impressive. It has a 'import file' button - is it able to actually accept uploaded files? I have some .ts and .mpg I'd be interested in trying out if it works like that.
I’m working on that. In a few days.
