I'm new to sdr, dsp, and GNU Radio. My goal is to create an FSK demodulator for a project at work (described in this question), but since I haven't been making progress, I'm trying to teach myself some of the basics.
For practice, I'm trying to set up a GNU Radio flowchart that reads a text file, modulates it, then demodulates it, returning the same text as output.
Basic question: is it possible to read a text file, mod/demod, then return plain, readable text using GNU Radio? I'm trying to send and receive something simple, like "Test, one two three."
Next question: if the above is possible, where am I going wrong in the following flowchart (the output file has size (~200 kb), but appears blank)?
Thanks for any advice!
The file sink acts as a giant buffer for the data type that you choose.
To output a readable text, I chose to use a byte file sink and convert the binary data to ASCII/UTF-8 values ie add 48 to the stream.
Related
I was wondering how can i save the result from a matlab function and use it in VB.net (if not possible then save the result in a .txt file and then use it in VB.net). thanks in advance.
MATLAB can be linked by many software such HSPICE, ANSYS , ...
There are special toolbox for these software , But I do not know ant toolbox for VB.
A simple solution is the save your result in text file.
Text file can be read in any programming language.
A important note in saving, pay attention to encoding. Source and Destination encoding must be same.
I want to create a file type that contains objective c code and image data. But I want it not readable by a text editor. How best do I do this?
Assuming you already know how to append the code and the image in a file (which, however, should be a pretty easy task), you just need to crypt the data before storing. You can easily do it using, i.e., AES encryption.
I have a Serial number string "1080910" embedded in a programmable device which has been downloaded to a binary file using the ALL-100 programmer. This is my Master file as it were. I need to change this serial number to that of the unit that I need to re-flash using the Master file - the ALL-100 programmer uses XACCESS User Interface which has Edit feature showing Address location, Hex data field and Ascii field. Somewhere in this file is the serial number string - can anybody assist me in how to locate and edit the serial number string as I have been unable to locate it using the search function and have not been able to visually pick up the sequence of numbers. Help !!!
If the data has a symbolic address in the source code, and is not a local variable, its address will appear in the map file generated by the linker. If it is a local variable initialised with a literal constant, then the data will exist in the static initialisation data the location of which should also be identified in the map file.
Another possibility is that your application image is compressed and the start-up code expands it into RAM at run-time. This will be obvious in the map file if the data and code addresses are in RAM rather than ROM. If this is the case then what you are attempting will be very difficult. You would have to know the compression algorithm used, and which part of the image is the commpressed part (part of it will be the decompression code that runs from ROM). You would then have to decompress the image, modify the string, and then recompress it. Further, if the decompression performs any kind of checksum on the compressed or decompressed data, you will have to recalculate and modify that too.
If this was a requirement from the outset, you would have done better to reserve the space in the linker script or use compiler specific extensions to absolutely locate the data at a specific location.
Maybe it is stored in Unicode, so alternate chars are 00.
I'm writing a quick front end to display guitar tablature. The front end is in Flash but I want to store the tab in some human-readable format. Anyone know of something that already exists? Any suggestions on how to go about it? One idea I got from reading some stackoverflow posts was to use a strict ASCII tab format like so:
e||-1------3--------------0--|----2-------0---
B||--1-----3------------1----|----3-------0---
G||---2----0----------0------|----2-------1---
D||----3---0--------2--------|----0-------2---
A||----3---2------3----------|------------2---
E||----1---3----3------------|------------0---
It has advantages. I can gain a lot of info from the structure (how many strings, their tunings, the relative placement of notes) but it is a bit verbose. I'm guessing the '-'s will compress away pretty well when sent over the wire.
If anyone knows of an existing data-format for describing guitar tab I'll take a look as well.
edit:
I should note that this format is 90% for me and may not ever been seen by anyone other than myself. I want an easy way to write tab files that will be displayed eventually as graphics in a Flash front-end and I don't want to have to write an editor front end.
Check out the ASCII tab format. Also great description of the format is here:
http://www.howtoreadguitartabs.net/
ASCII export would be a great feature, but using ASCII as internal data format is not a good idea. For example, note durations would be extremely hard to express (hou would you store 32nds or even 16ths?, not to mention triplets...), so parsing those files would be extremely difficult. Moreover, users would be tempted to load ASCII files created outside your app, which will be likely to fail.
To sum up, i'd recommend to either try to reuse existing format or invent your own if that's not feasible. You may try to use XML for that.
EDIT: Beside DGuitar, i know of TuxGuitar and KGuitar, which support Guitar Pro files. You can look into their sources or ask their authors about file formats. I think there is also open source PowerTab-to-ASCII converter.
See Supported file formats in TuxGuitar.
TuxGuitar is open-source multiplatform software for reading, writing and playing the guitar tabs.
It supports the mentioned Guitar Pro and PowerTab format, and it also has its own TuxGuitar (.tg) format.
If you need the backend data structure to remain in human readable form I would probably stick it in a CDATA inside of XML. That could be inserted into a relational database with song/artist/title information and become searchable. Another option is to save it as zipped text files and insert links to those files in a database with the main artist info still searchable by sql.
These are not human readable:
Most common formats are Guitar Pro (proprietary) and PowerTab (freeware). DGuitar and TuxGuitar are open source viewers for Guitar Pro format. I'm sure that they have documentation for the format somewhere (at least in the code).
Advantage for using a common format would be the easiness of making tabs with those programs.
The Guitar Pro 4 format is described here http://dguitar.sourceforge.net/GP4format.html
I wrote a quick utility for displaying tab. For personal use. You can happily take the internal format I used.
I use a very simple string based format. There are three important structures.
Column, a vertical column in the output tab - all notes played simultaneously.
Bar, a collection of Columns
Motif, a collection of Bars
A Column looks like ':#|:#|*:#' where each * is a string number and each # is a fret number. If you are playing a chord you separate each string:fret with a '|'
A Bar looks like '[,,-,*]' where each * is a Column. A - indicates an empty column where no notes are played.
A Motif looks is just many Bars running back to back. For instance
"[1:5,-,3:7,-,3:5,-,3:7,-,-,3:5,3:7,-,1:8,-,1:5]"
e||---------------|---------------||
B||---------------|---------------||
G||---------------|---------------||
D||--7-5-7--57----|--7-5-7--57----||
A||---------------|---------------||
E||5-----------8-5|5-----------8-5||
"[-,-,1:3|2:2|3:0|4:0|5:3|6:3,-,-][-,-,3:0|4:2|5:3|6:2,-,-]"
e||--3--|--2--||
B||--3--|--3--||
G||--0--|--2--||
D||--0--|--0--||
A||--2--|-----||
E||--3--|-----||
I have a PDF file which has the marklist of certain exam.
I am particularly interested in the first list, but which unfortunately has 2112 entries. And they aren't properly formatted. I need to sort all these entries (based on marks in last 2 columns- sum of marks in Aptitude and Computer), to know what my rank is.
I tried to copy in in MS Word and Excel, but if you try it, you can see it won't help. After pasting it in a plain text file, I tried to format it using regular expressions (in Notepad++), wrote a code in C to properly separate each field by '\t' (so that later I can properly copy them in an Excel sheet), but the inconsistency made me fail (some entries are spawned multiple lines, the "names" do not have fixed no. of fields).
Can someone come up with any idea that will make it possible to copy the first list in PDF to a spreadsheet in tabular form exactly as the original file?
For a background about why the PDF file format should never, ever be thought of as suitable for hosting extractable, structured data, see this article:
Why Updating Dollars for Docs Was So Difficult
For an amazing open source family of tools that gets better and better from week to week for extracting tabular data from PDFs (unless they are scanned pages) -- contradicting point '1.' above! -- see these links:
Introducing Tabula: Upload a PDF, get back tabular CSV data. Poof!
Tabula-Extractor: A Command Line Interface to Tabula
Tabula source code repository
Tabula API (upcoming, not ready yet)
Well I sort of managed it. I first copied it to a plain text file, deleted all letters from it leaving only the serial number and corresponding marks, separated by spaces or tabs. Then using "import" in an OpenOffice Spreadsheet, told it the delimiters are spaces and tabs (combine them if necessary) and bingo! I got my rank.
But I would still like to know if it's possible to copy the whole table as it is. So keeping this question open.
I once was tasked with building a parser which would extract data from a pdf with tabular and non-tabular data in a number of different encodings and with a mix a rtl and ltr text. That project took quite the effort but with a simple English table you should be able to dissect the pdf in no time. Look for the PDF specs on adobe.com and if it is that desperate start digging in.
Also you'll first need to use pdftk.exe to uncompress the file.
A shortcut that me be of aid:
http://www.adobe.com/devnet/pdf/pdf_reference.html
This is the shortcut I meant: http://www.codeproject.com/KB/cs/PDFToText.aspx