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%3CLINGO-SUB%20id%3D%22lingo-sub-306400%22%20slang%3D%22en-US%22%3EGoPro%20Metadata%20question%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-306400%22%20slang%3D%22en-US%22%3E%3CP%3ESo...I%20am%20parsing%20the%20GoPro%20Metadata%20(delivered%20to%20me%20from%20ffmpeg).%20I%20get%20the%20following%20%22stream%22%20of%20data%20concerning%20the%20onboard%20accelerometer%3A%3C%2FP%3E%3CPRE%3E%20('STRM'%2C%20'%5Cx00'%2C%201%2C%201372)%20%0A%20('TSMP'%2C%20'L'%2C%204%2C%201)%20%5B4665%5D%0A%20('STNM'%2C%20'c'%2C%201%2C%2014)%20%5B'Accelerometer'%5D%0A%20('TMPC'%2C%20'f'%2C%204%2C%201)%20%5B25.0%5D%0A%20('SIUN'%2C%20'c'%2C%204%2C%201)%20%5B'm%2Fs%C2%B2'%5D%0A%20('SCAL'%2C%20's'%2C%202%2C%201)%20%5B418%5D%0A%20('MTRX'%2C%20'f'%2C%204%2C%209)%20%5B0.0%2C%200.0%2C%201.0%2C%200.0%2C%20-1.0%2C%200.0%2C%201.0%2C%200.0%2C%200.0%5D%0A%20('ORIN'%2C%20'c'%2C%201%2C%203)%20%5B'YxZ'%5D%0A%20('ORIO'%2C%20'c'%2C%201%2C%203)%20%5B'ZXY'%5D%0A%20('ACCL'%2C%20's'%2C%206%2C%20204)%20612%20%5B-1171%2C%20-1063%2C%204519%5D%3C%2FPRE%3E%3CP%3Efrom%3A%3CSPAN%3E%26nbsp%3B%3C%2FSPAN%3E%3CA%20href%3D%22https%3A%2F%2Fgithub.com%2Fgopro%2Fgpmf-parser%22%20target%3D%22_blank%22%20rel%3D%22nofollow%20noopener%20noreferrer%20noopener%20noreferrer%20noopener%20noreferrer%22%3EGoPro's%20Github%20of%20GPMF%3C%2FA%3E%3A%3C%2FP%3E%3CP%3ESTRM%20marks%20the%20begiining%20of%20the%20stream%20and%20total%20number%20of%20bytes.%3C%2FP%3E%3CP%3ETSMP%20is%20number%20of%20samples%20(not%20sure%20how%20they%20compute%20this)%3C%2FP%3E%3CP%3ESTNM%20is%20the%20stream%20name%3A%20Accelerometer%3C%2FP%3E%3CP%3ETMPC%20is%20the%20temperature%20of%20the%20sensor(s)%20in%20deg%20C%3A%2025%3C%2FP%3E%3CP%3ESIUN%20are%20the%20units%20for%20the%20samples%3A%20m%2Fs%5E2%3C%2FP%3E%3CP%3ESCAL%20is%20a%20divisor%20by%20which%20to%20scale%20down%20the%20raw%20data%3A%20418%3C%2FP%3E%3CP%3Eand%20ACCL%20is%20the%20raw%20data%20in%20this%20case%20612%20'tuples'%20the%20first%20of%20which%20is%3A%20%5B-1171%2C%20-1063%2C%204519%5D%3C%2FP%3E%3CP%3EThe%20question%20is%3A%20What%20are%20ORIN%2C%20ORIO%20and%20MTRX.%20I%20am%20assuming%20that%20MTRX%20is%20a%203x3%20matrix%20to%20transform%20the%20raw%20data%20tuples%2C%20but%20how%3F%20ORIO%20and%20ORIN%20are%20'orientations'%20but%20of%20what%3F%20Situation%20is%20very%20similar%20for%20gyroscope.%3C%2FP%3E%3C%2FLINGO-BODY%3E%3CLINGO-LABS%20id%3D%22lingo-labs-306400%22%20slang%3D%22en-US%22%3E%3CLINGO-LABEL%3EHERO6%20Black%3C%2FLINGO-LABEL%3E%3C%2FLINGO-LABS%3E
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Sightseer
Posts: 2

GoPro Metadata question

So...I am parsing the GoPro Metadata (delivered to me from ffmpeg). I get the following "stream" of data concerning the onboard accelerometer:

 ('STRM', '\x00', 1, 1372) 
 ('TSMP', 'L', 4, 1) [4665]
 ('STNM', 'c', 1, 14) ['Accelerometer']
 ('TMPC', 'f', 4, 1) [25.0]
 ('SIUN', 'c', 4, 1) ['m/s²']
 ('SCAL', 's', 2, 1) [418]
 ('MTRX', 'f', 4, 9) [0.0, 0.0, 1.0, 0.0, -1.0, 0.0, 1.0, 0.0, 0.0]
 ('ORIN', 'c', 1, 3) ['YxZ']
 ('ORIO', 'c', 1, 3) ['ZXY']
 ('ACCL', 's', 6, 204) 612 [-1171, -1063, 4519]

from: GoPro's Github of GPMF:

STRM marks the begiining of the stream and total number of bytes.

TSMP is number of samples (not sure how they compute this)

STNM is the stream name: Accelerometer

TMPC is the temperature of the sensor(s) in deg C: 25

SIUN are the units for the samples: m/s^2

SCAL is a divisor by which to scale down the raw data: 418

and ACCL is the raw data in this case 612 'tuples' the first of which is: [-1171, -1063, 4519]

The question is: What are ORIN, ORIO and MTRX. I am assuming that MTRX is a 3x3 matrix to transform the raw data tuples, but how? ORIO and ORIN are 'orientations' but of what? Situation is very similar for gyroscope.