Error message in AS3

[Davey-T]

Running some solar images through AS3 and got  an error message on one, get this message in SER player, not important just wondered what it meant ?

Dave

[vlaiv]

It is about "endianness" and what is expected.

Endianness of numeric format on particular platform has to do with order of multi byte numeric formats. For example, let's say you have 32 bit integer. When written down, such number can be thought of 4 consecutive bytes (each byte has 8 bits and 32bits is formed by 4 groups of 8 bits). Order in which those bytes are written is endianness. There are two different ways to write it - little endian and big endian. One is from high to low and other is reverse - from low to high.

You can sort of think of it like this - you are writing a number one digit at a time. You can write it - left to right or right to left, so number one hundred can be written as 001 or 100 depending on direction.

Different processor manufacturers decided to hold numeric values in memory in different order and programmers did what is the easiest - when writing numbers from memory to a file - just write in the same order it was stored in memory. This lead to problems when trying to share data files between systems based on processor architectures with different endianness - as numbers were read and written differently - like in above example - if you read 001 the way we normally read it  - you'll read one and not one hundred.

For purpose of communications and file formats - it is important to define if numbers are stored in big endian or little endian format. For example internet uses big endian format (networking in general and it is often called networking order).

Here is what SER format specification states on endianness of data:

I think that above error has to do with the fact that expected value was not written in proper format (little endian specified in file header but value actually written as big endian or something like that).

Edited November 5, 2020 by vlaiv

[Davey-T]

 

6 minutes ago, vlaiv said:

I think that above error has to do with the fact that expected value was not written in proper format (little endian specified in file header but value actually written as big endian or something like that).

Thanks for the explanation Vlaiv, this was on only one video out of 25 so maybe just glitch.

Dave

[vlaiv]

2 minutes ago, Davey-T said:

 

Thanks for the explanation Vlaiv, this was on only one video out of 25 so maybe just glitch.

Dave

If you have mechanical drive - maybe think of changing it for new one. It might be nothing but sometimes when drive is about to fail - these sort of things start happening - wrong values written and checksums turning bad and similar.

[Davey-T]

9 minutes ago, vlaiv said:

If you have mechanical drive - maybe think of changing it for new one. It might be nothing but sometimes when drive is about to fail - these sort of things start happening - wrong values written and checksums turning bad and similar.

Good idea, I was thinking of changing it to SSD drive,

Dave

[JamesF]

Yes, looking at the code this is an error message that comes up when the file header value that indicates whether the data in the file is big- or little-endian is out of range.  It should either be 0 or 1, so the value you're getting makes it look like something has got corrupted in that file.

James