Hex to DFU: when does a new image element start? - hex

I'm making a program that converts hex files to dfu files.
The DFU file manager (by st) splits my hex file up into 3 different image elements for the dfu file. However, there is just one "address jump" in the hex file.
:1011E0009901000800200008006CDC02EC110000EE
:102000000080002069A10008B9A10008B9A100085A
Here in the hex file there is a "adress jump" from 11E0 to 2000. It's easy to detect since the jump is bigger than 16. However. The dfu file manager also makes jumps in this area:
:10CB900008BF0B4618441060184670471016002056
:10CBA000D01A0020F8B500BFF8BC08BC9E467047FC
:0CCBB000F8B500BFF8BC08BC9E467047FA
:10CBC0007800420042047A007A04A90069006900F2
:10CBD0006900A9006900A900A900A9006900A900CD
:10CBE000A90049007A0042017A0440044004A200EE
at no point is the difference between any of the lines' adresses in this area more than 16. So how do i detect that there is a new image element in the hex file?

I figured it out.
Looping through the hex lines, line by line and figure out each lines address and length of the data for that address.
When the address does not fall after the previous address + lenght, then it's a new image element.
if (previousAddress + previousLength != address){
//new image element
}

Related

Where is the value in HEX for the file size in a jpg (exif)

I can carve out images no problem, but I remember a long time ago being shown where to find the file length of a jpg (in bytes) so that if i had issue with an auto recovery i can do it manually.
where in a jpg exif header in HEX are the values (which i know needs converting into little endian?) that tell me the size of the file, so i can scroll to the end of the file, find FF d9 and recover the image.
Can anyone point me to where those HEX values are in these types of JPG's?
Thank you!

Given final block not properly padded. Such issues can arise if a bad key is used during decryption

Hi guys I encrypted school project but my AES saved txt has been deleted, I pictured it before and I filled a new file. But new AES key file is not equal to the typed in jpeg file. Which character is wrong I couldn't find it. Could you please help me.
Pic : https://i.stack.imgur.com/pAXzl.jpg
Text file : http://textuploader.com/dfop6
If you directly convert bytes with any value to Unicode you may lose information because some bytes will not correspond to a Unicode character, a whitespace character or other information that cannot be easily distinguished in printed out form.
Of course there may be ways to brute force your way out of this, but this could easily result in very complex code and possibly near infinite running time. Better start over, and if you want to use screen shots or similar printed text: base 64 or hex encode your results; those can be easily converted back.

Using com.opencsv.CSVReader on windows stops reading lines prematurely

I have two files that are identical except for the line ending codes. The one that uses the newline (linux/Unix)character works (reads all 550 rows of data) and the one that uses carriage return and line feed (Windows) stops returning lines after reading 269 lines. In both cases the data is read correctly up to the point where they stop.
If I run dos2unix on the file that fails, the resulting file works.
I would like to be able read CSV files regardless of their origin. If I could at least detect that the file is in the wrong format before reading part of the data that would be helpful
Even if I could tell at any time in the middle of reading the file that it was not going to work, I could output an error.
My current state of reading half the file and terminating with no error is dangerous.
The problem is that under the covers openCSV uses a BufferedReader which reads a line from the stream until it gets to the Systems line.seperator.
If you know beforehand what the line separator of the file is then in your application just do a System.setProperty("line.separator", newLine) where newLine is either "\n" or "\r\n" based on the file you are about to parse. Or you can pass that in as a parameter.
If you want to automatically detect the file character. Create a method that will take the file you want, create a BufferedReader and read a single line. If the last character is a '\r' then your system system uses "\n" but you want to set it to "\r\n". Else if line.contains("\n") returns true then you are on a system that uses "\r\n" and you want to set it to "\n". Otherwise the system and the file you are reading have compatible line feed characters.
Just note if you do change the system line feed character be sure to set it back after processing the file in case your program is processing multiple files.

Using netbeans digitalclock sample

I am a Java beginner with a question about the operation of the Digitalclock.java example in Netbeans 8.0.2
I want to alter the display to show only Hours and Minutes and change the color. I have found within the code a way to eliminate the display of the Seconds digits and change the color. What I can't do is get rid of the ":" or center the display.
1) Where is the ":" being generated from?
2) How would I center the display?
Thank you,
The colon ":" in this case is not an actual character rather it is being generated by using multiple instances of the java circle class and can be found in line 114 - 117 of the DigitalClock.java file. Centering the the new four digit clock can be accomplished by changing the clock.setLayoutX at line 78. – Six just now edit

How can I convert MathType equation into MathML format?

I want to convert MathType equation saved as GIF format to MathML. Firstly, I opened these GIF files and saved them within MathType 6.7. As a result, MathML text is inserted into the end of GIF files. However, when I extracted MathML text from these GIF files using Perl script, I found some garbled characters in the MathML text as following text:
<mn>xxx</mn>
In the above line, a garbled character  is inserted before 'mn' label. Is this MathType 's BUG? How can I work around this problem? I have uploaded my test GIF files. URL is: http://ubuntuone.com/p/1352/
Update:
I have tried to paste full block of MathML here, but I found the syntax format of MathML text was messed. So I pasted the MathML on GitHub: https://gist.github.com/1068723.
There is a garbled character in the seventh line of MathML text: "  ?#x00A0;".
The original GIF file which doesn't contain MathML text: http://ubuntuone.com/p/13Ba/
Perl script that extracts MathML from GIF image generated by MathType: https://gist.github.com/1068749
Thanks,
thinkhy
Thanks thinkhy. It could be you extracting the data incorrectly (we haven't looked at your script yet). Only one of your GIFs had MathML -- the one that has a file name starting 106R. In that one, if you just grab all the bytes from the first bit that looks like MathML until the end, you do periodically get odd bytes in there, mostly 255's except the last one. (This however doesn't appear to be the junk character you're seeing.) The reason for the 255's is that the MathML is distributed over multiple comment records, each one of which starts with a count of the bytes in the record. From the MathType SDK (free download; link below):
GIF Image Files
MathML text is embedded into a GIF file as an Application Extension Record, which consists of a 14-byte header (Application Extension Descriptor), followed by the MTEF data. The header contains:
Byte Introducer = 0x21;
Byte ExtensionLabel = 0xFF;
Byte BlockSize = 0x0B;
Byte ApplicationId[8] = "MathType";
Byte AuthenticationCode[3] = "003";
The data follows this header and is written as a series of blocks each containing 255 bytes or less. Each block starts with a single byte count followed by the data. The end is marked as a block with length 0.
The header is unique enough that the easiest way to extract the data might be to scan the file for the 14-byte header, then expect the MathML data blocks to follow. Properly decoding the GIF records isn't that hard either, but obviously requires you read the GIF specification.
You may already be using the SDK, but you didn't say whether you were or not, so here's the link: http://www.dessci.com/en/reference/sdk/.

Resources