I am transmitting and receiving data using aux cable and GNU RADIO between two laptops.
I have implemented DQPSK using PSK mod block.
The problem is that while receiving I have to provide a delay, some integer value e.g 0,1,2 etc.
It is different every time.
Is there a way to dynamically check for the right delay value or any other workaround to this situation?
I have written 'start.' at the start of data being transmitted and 'end.' at the end.
I have to give a demo for this project and I dont want to manually change the delay at runtime.
I cannot find the .cc file of file sink in GNU RADIO, I can change the C++ code according my requirement but there is no such file.
Below is the screenshot of the grc file on the receive side.
Any help will be appreciated.
Since there's no way for the receiver to know when the transmitter started transmitting, it decodes stuff before there's actually anything to decode.
In essence, you need some kind of preamble or so to tell your receiver when to start – side effect of having something like that would be that you could correct some things (the two sound cards don't share the same oscillator, which leads to a symbol rate offset, and a center frequency offset).
You basically added that framing - your start. and end. strings.
I cannot find the .cc file of file sink in GNU RADIO, I can change the C++ code according my requirement but there is no such file.
It's in gr-blocks/lib; however, you shouldn't modify the file sink. Really,
I'd recommend you take the time to go through the guided tutorials, use gr_modtool to generate a general block which has a state machine that looks for the bits of your start string and drops everything before and including those, and then passes everything till it sees the stop string. That all can be done with a single state machine, and a bit of python or C++ code.
Related
I am using julius speech recognition for my application. I have one doubt regarding julius:
I have downloaded the latest version and was successful in using its lib and making it work. the problem I am facing is..once the app starts and I call the voice recognition function in my application...it takes the input from mic and displays whatever is said in the mic, but the function still continues to do so again and again. The control will never come out of that function. Here I am facing problem since the control is not returning back I am not able to proceed further. What I want is once the engine gets input from mic it should recognize and stop there.. which I tried to do by deleting the callback function but was unsuccessful.
Can anyone please guide me in this matter, what I need to do to get the desired output. It will be helpful for me.
As discussed in the same post on VoxForge:
You have a couple of choices: first to use the Julius -input control to get the sound data from a list of files (see the .jconf sample file), so that when the list (even if only length one) is exhausted then Julius stops. It is quite easy to record the voice input to a file and then feed the file into Julius. Second you can put a dialog manager in control. If you need more information on what a dialog manager does there are many posts on this forum on that subject accessible by a search.
The basic function of Julius is to start up and then keep on decoding input. When you get more experience you can run Julius as a server, and then tell the server to respond, not respond or shut down as required. It's more efficient than having Julius start and stop all the time.
When an avenue exists for a complex application to yield the required result by using an effective combination of options at run time, editing the application, while possible, might involve a lot of unnecessary work. The emphasis then shifts to passing the options correctly in whatever script is being used to access Julius.
I want to make an app which compiles Swift code, so how can I use a website named www.swiftstub.com or any similar website to retrieve the output of the code? I want my app to have a simple UITextView in which the user can type the code. If a UITextView cannot be used, what can be used?
I want my app to send the code typed to this website, and then retrieve the output back and display it. How can this be done? Thanks!
Make an app that sends text to a server.
Have the server compile this code, run it, and capture the output.
Send this output back to the app.
Have the app display the output.
This is an extreme oversimplification, there are lots of things to consider, but these are kind of the big sections of whats there to to. You need to understand very well on the app side: UI and networking, and on the server side: triggering a compilation of text, capturing that output (command line, maybe Swift or Python can help you here) and HTTP(S) responses and requests (or sockets, even harder).
This does not sound like an easy task, so you are very courageous.
Build all components locally:
App:
- write an app with a textView and a button, and on the tap of that button, save the output to a textile. This is to avoid any networking complications at this point, later, instead of saving, you would send this to a server.
Server: (just build the things on your computer)
- write some script/program that can read in that textfile that was saved.
- Then you need to compile this code (lookup 'xcrun' on google) and capture the output. Save this output to a textile. Have your app load this file and display it.
The important thing to consider is the real server machine you will run this code on later: it has to be a machine that can compile, and execute Swift code. Currently, this means it has to be an OS X machine. This is hard to find, as most servers run linux, and there is no Linux Swift compiler yet.
Getting this to work would be a proof of concept: you can capture text from the app, you can grab this text and compile it, you can capture the output of the compilation, and you can have the app read that output and display it.
Once you've got this working, you would need to find a server that can do the compilation part, and run what you build to do that. Then you would need to write some code in your app that sends an HTTP request to your server containing this text, to which your server would respond with the output of that compilation.
As I said, this is a big undertaking, with lots of difficult parts and unexpected surprises, so don't expect this to be done in a couple of weeks, it will most likely be more like over six months.
Try to find someone who has experience on programming and setting up a server, that will really help you a lot.
I run a successful Minecraft Tekkit modded server with computer craft on it.
I'm fairly new to lua and only know the basics, I'm trying to make a menu with pages to display the banned items list and rules list on. I've made a program with arrows that's optimized for advanced computers and monitors.
The code runs properly on my advanced computer but doesn't run on the monitor, when it shows and someone clicks the arrows it doesn't work either.
I just started using stack so I'm not sure on what to do, if you need any info please ask for it :)
The code: http://pastebin.com/gVtPeBCE
By the way I already tried using Mon.write and Mon = peripheral.wrap("top")
For those who don't have tekkit here is a computercraft emulator: https://goo.gl/J0dPq0
I'm sorry to inform you that I haven't read through all of your code. But judging based on your description, I would say that it's likely one of three issues, not including incorrect syntax as a possibility.
Note: Your question is exclusively asking about the programs ability to run on a monitor while the emulator you link to only provides the desktop ComputerCraft computers.
Peripheral
Although you already stated:
By the way I already tried using Mon.write and Mon = peripheral.wrap("top")
I would like to clarify that you can, as a way to simplify the code transition, set the peripheral function table equal to the term variable. For example: term = peripheral.wrap(string_side).
Note: When you use this method, you shouldn't execute the program with the command:
> monitor side program.
You should instead run it as a normal program with no special treatment.
I.e. > program.
Incorrect Mouse Event Detection
Simply put, when using a monitor, you're not supposed to pull for a mouse_click event. You have to pull for a monitor_touch event instead.
while true do
type, side, x, y = os.pullEvent()
if type == "monitor_touch" then
print("Monitor '"..side.."' has been pressed at "..x..", "..y.."!")
end
end
Monitor Size
This just simply means that the program you're trying to execute on the monitor takes up to much space and is therefore unusable when displayed on that size of monitor.
Suggestion: Either update your code for the monitor size or build the monitor to fit the program.
Please remember that all of these ideas might not answer your question, as the code you have provided to look over is too large and I haven't been able to find the time to experiment with it. Therefore, these are only general suggestions.
if i had to guess, it's because term is short for terminal and will auto work with computers so if you set term to be the monitor at the top of the file it should work correctly.
term = peripheral.wrap("SIDE OF MONITOR")
Put that at the top of your code and it should work. but this what i think it is after taking a look at your code (also its not that long of a code sample...)
we´ve created a custom push source / parser filter that is expected to work in a directshow
editing services timeline.
Now everything is great except that the filter does not stop to deliver samples when the current
cut has reached it´s end. The rendering stops, but the downstream filter continues to consume
samples. The filter delivers samples until it reaches EOF. This causes high cpu load, so the application
is simply unusable.
After a lot of investigation I’m not able to find a suitable mechanism that can inform my filter
that the cut is over so the filter needs to be stopped :
The Deliver function on the connected decoder pins always returns S_OK, meaning the attached decoder
is also not aware the IMediaSamples are being discarded downstream
there’s no flushing in the filter graph
the IMediaSeeking::SetPositions interface is used but only the start positions are set –
our is always instructed to play up to the end of the file.
I would expect when using IAMTimelineSrc::SetMediaTimes(Start, Stop) from the application
that this would set a stop time too, but this does not happen.
I’ve also tried to manipulate the XTL timeline adding ‘mstop’ attributes to all the clip in the
hope that this would imply a stop position being set, but to no avail
In the filters point of view, the output buffers are always available (as the IMediaSamples are being discarded downstream),
so the filter is filling samples as fast as it can until the source file is finished.
Is there any way the filter can detect when to stop or can we do anything from the application side ?
Many thanks
Tilo
You can try adding a custom interface to your filter and call a method externally from your client application. See this SO question for a bit more of details on this approach. You should be careful with thread safety while implementing this method, and it is indeed possible that there is a neater way of detecting that the capturing should be stopped.
I'm not that familiar with DES, but I have tried my demux filters in DES and the stop time was set correctly when there was a "stop=" tag for the clip.
Perhaps your demux does not implement IMediaSeeking correctly. Do you expose IMediaSeeking through the pins?
I had a chance to work with DES and custom push source filter recently.
From my experience;
DES actually does return error code to Receive() call, which is in turn returned to Deliver() of the source, when the cut reaches the end.
I hit the similar situation that source does not receive it and continues to run to the end of the stream.
The problem I found (after a huge amount of ad-hoc trials) is that the source needs to call DeliverNewSegment() method at each restart after seek. DES seems to take incoming samples only after that notification. It looks like DES receives the samples as S_OK even without that notification, but it just throws away.
I don't see DES sets end time by IMediaSeeking::SetPositions, either.
I hope this helps, although this question was very old and I suppose Tilo does not care this any more...
Looking for a little help getting started on a little project i've had in the back of my mind for a while.
I have log file(s) varying in size depending on how often they are cleaned from 50-500MB. I'd like to write a program that will monitor the log file while its actively being written to. when in use it's being changed pretty quickly easily several hundred lines a second or so. Most if not all of the examples i've seen for reading log/text files are simply open and read file contents into a variable which isn't really feasible to do every time the file changes in this situation. I've not settled on a language to write this in but its on a windows box and I can work in .net flavors / java / or php ( heh dont think php will fly to well for this), and can likely muddle through another language if someone has a suggestion for something well built for handling this.
Essentially I believe what I'm looking for would probably be better described to as a high speed way of monitoring a text file for changes and seeing what those changes are. Each line written is relatively small. (less than 300 characters, so its not big data on each line).
EDIT: to change the wording to hopefully better describe what i'm trying to do. Which is write a program to keep an eye on a log file for a trigger then match a following action to that trigger. So my question here is pertaining to file handling inside a programming language.
I greatly appreciate any thoughts/comments.
If it's incremental then you can just read the whole file the first time you start analyzing logs, then you keep the current size as n. Next time you check (maybe a timed action to check last modified date) just skip first n bytes, read all new bytes and update size.
Otherwise you could use tail -f by getting its stdout and using it for your purposes..
The 'keep an eye on a log file' part of what you are describing is what tail does.
If you plan to implement it in Java, you can check this question: Java IO implementation of unix/linux "tail -f" and add your trigger logic to lines read.
I suggest not reinventing the wheel.
Try using the elastic.co
All of these applications are open source and free and are capable of monitoring (together) and trigger actions based on input.
filebeats - will read the log file line by line (supports multiline log messages as well) and will send it across to logstash. There are loads of other shippers you can use.
logstash - will take the log messages, filter them, add tags and send the messages to elasticsearch
elasticsearch - will take the log messages and index them, the store them. It is also capable of running actions based on input
kibana - is a user friendly web interface to query and analyze the data. Or just simply put it up on a dashboard.
Hope this helps.