I have a database with data packed with LZRW1 algorithm and I need to read this data in a C# application. Does anyone know if there is a ready implementation of the LZRW1 decompression for C#?
I had a good look, I can't find any in C# or Java. I suspect it's a generational issue - that specific algorithm has been surpassed by ZIP etc and there was little reason to write the code in newer languages.
Below are some implementations in C++ and Pascal:
http://www.ross.net/compression/lzrw1.html
http://www.programmersheaven.com/download/14494/download.aspx
Related
I have a script in MATLAB that writes a CSV, the CSV is read by a c# script which writes a few more CSVs that I go back and read in MATLAB.
Is there any way to automate this so I don't have to call the c# code by hand each time?
It's very easy to call into .net from Matlab. The official documentation is at http://www.mathworks.co.uk/help/matlab/matlab_external/load-a-global-net-assembly.html You should be aware that Matlab is case-sensitive (even when it comes to specifying the assembly path) and that it is also limited in the kinds of objects it can pass back and forth across the boundary.
If you pass an array into your C# dll from Matlab, it will appear to be an array of bare objects rather than an array of numbers. In Matlab, you may need to use the char and cell methods to convert strings and arrays back into the form you are expecting.
To answer the title question, e.g. "Is it possible to call C# functions from MATLAB": yes, it is. Mathworks provides decent documentation on calling .NET assemblies from MATLAB on their website. Of course, there are limitations and some awkward quirks to take into account but basically you can create instances of .NET classes and interact with .NET applications from MATLAB.
To advise on automating this process, you could perhaps dive into the MATLAB COM Automation Service?
In the extension of this: it's also possible to call MATLAB functions in a .NET application. The other way around, sort of speak. This will be no problem with basic data types, but when it gets a bit more advances it can put you through some gnarly COM challenges, though.
I have prototyped a library with some image-processing algorithms in Python/Numpy/Scipy, and now I want to port the code to C# and WPF.
I have realized that, although the input files are images (photographs), conceptually what matters to my domain problem is that they are bidimensional arrays of floats, and the operations I perform (grayscale conversion, blur, blob detection, skeletonization), and even persistence, are best performed in floating-point "space", rather than in integer space (which means bytes - uint8 -, usually).
So, I took a look at .NET namespaces, and there are a lot of "Drawing" this, "Imaging" that, "Media" something, and I am utterly confused.
So, the question is: Which .NET class is the most obvious and commonly used "image data container" for floating point image processing.
I know about AForge, but since I am learning C# and my image-processing needs are not so heavy at this point, I'd like to give native .NET a chance (but that could be a bad idea anyway, so please let me know if it is).
Based on what you already have, why not looking for the same libraries you used in Python but for C#/.NET? for example, for numeric calculations look at:
Project:
http://numerics.mathdotnet.com/
Examples: https://github.com/mathnet/mathnet-numerics/tree/master/src/Examples
And for examples of image processing, maybe looking at the source code of Paint.NET (its latest open sourced version - openpdn Fork of Paint.NET 3.36.7) may give you an idea of what libraries to use for images:
http://code.google.com/p/openpdn/source/browse/#hg%2Fsrc
Both libraries are in C#.
after long time of reading on google I still don't know how can I work with this EDB http://msdn.microsoft.com/en-us/library/aa912256 at C#. I read a lot of about wrapers and SWIG solution. But how can I wrap functions which are at windbase.h.
I want to make EDB in my c# program. Can I make some way dll from <.h>?
After some effort I think now, it is not good idea try to use windbase.h in C#. There are great and useful articles about P/invok. Just write "Call Unmanaged DLLs from C#" to google. One of best for me was:
http://msdn.microsoft.com/en-us/magazine/cc301501.aspx
But because our unmanaged function requires a structure as a parameter, the structure needs to be defined in the managed code as well as in the unmanaged code. In other words, it is needed to rewrite all structures and constants and stuffs to c#. And there are also other dependencies on windbase_edb.h, winnt.h, windef.h, winbase.h...
From my point of view it is too difficult way. Or it can be done differently?
Does anyone know of an open source H.264 encoder in C# (or any other managed language)? I might be able to make do with a python implementation as well.
The libraries that I’ve found (e.g. x264) are written in pretty low level c (procedural with lots of macros) and assembly. Tweaking them is turning out to be far more complex than I'd thought. My project has no concern for performance or compatibility. We just want to test how some ideas will impact the perception of the outputted video.
We’d be willing to pay for or license the code if need be.
Thanks in advance!
Edit - Some important points:
I don't care about performance (e.g. real time encoding) at all. It could take 10 days to encode for all I care.
A wrapper isn't helpful since I want to actually modify the encoder itself.
No one would likely spend the time to develop the codec in those languages because they would be hopelessly slow for actual encoding. However, the reference implementation should be less optimized and more useful to you. It is still in C.
http://iphome.hhi.de/suehring/tml/download/
I don't think there is already such a port you need - you'll find wrappers for any langugae but a pure implementation does not have the critical mass. I'd recommend to port it yourself, document your port well and then start tweakening it.
If you'd want to port some encoder to C#, this should be easier to start with - about 8k LOC: http://sourceforge.net/projects/fevh264/
How about http://www.ffmpeg-csharp.com/?
I'm building an network application that needs to be able to switch from normal network traffic to a zlib compressed stream, mid stream. My thoughts on the matter involve boolean switch that when on will cause the network code to pass all the data through a class that I can feed IEnumerable<byte> into, and then pull out the decompressed stream, passing that on to the already existing protocol parsing code.
Things I've looked at:
ZLib.NET - It seems a little... Ecclectic, and not quite what I want. Would still make a decent start to build off though. (Jon Skeet's comments here hardly inspire me either.)
SharpZipLib - This doesn't seem to support zlib at all? Can anyone confirm or deny this?
I would very much prefer and all managed solution, but let's have at it... are there any other implementations of this library out there in .NET, that might be better suited to what I want to do, or should I take ZLib.NET and build off that as a start?
PS:
Jon's asked for more detail, so here it is.
I'm trying to implement MCCP 2. This involves a signal being sent in the network stream, and everything after this signal is a zlib compressed data stream. There's links to exactly what they mean by that in the above link. Anyway, to be clear, I'm on the recieving end of this (client, not server), and I have a bunch of data read out of the network stream already, and the toggle will be in the middle of this (in all likelyhood atleast), so any solution needs to be able to have some extra data fed into it, before it takes over the NetworkStream (or I manually feed in the rest of the data).
SharpZipLib does support ZLib. Look in the FAQ.
Additionally, have you checked whether the System.IO.Compression namespace supports what you need?
I wouldn't use an IEnumerable<byte> though - streams are designed to be chained together.
EDIT: Okay... it sounds like you need a stream which supports buffering, but with more control than BufferedStream provides. You'd need to "rewind" the stream if you saw the decompression toggle, and then create a GZipStream on top of it. Your buffer would need to be at least as big as your biggest call to Read() so that you could always have enough buffer to rewind.
Included in DotNetZip there is a ZlibStream, for compressing or decompressing zlib streams of data. You didn't ask, but there is also a GZipStream and a DeflateStream. As well as a ZlibCodec class, if that is your thing. (just inflates or deflates buffers, as opposed to streams).
DotNetZip is a fully-managed library with a liberal license. You don't need to use any of the .zip capability to get at the Zlib stuff. And the zlib stuff is packaged as a separate (smaller) DLL just for this purpose.
I can recommend you Gerry Shaw's zlib wrapper for .NET:
http://www.organicbit.com/zip/
As far as I know the ZLib (gzip) library doesn't support listing the files in the header. Assuming that matters to you, but it seems a big shortcoming. This was when I used the sharp zip library a while ago, so I'm willing to delete this :)
Old question, but System.IO.Compression.DeflateStream is actually the right answer if you need proper zlib support:
Starting with the .NET Framework 4.5, the DeflateStream class uses the
zlib library. As a result, it provides a better compression algorithm
and, in most cases, a smaller compressed file than it provides in
earlier versions of the .NET Framework.
Doesn't get better than that.