I am using Wowza Engine 4.5.0 and I am trying to change the chunk ID numbering based on incoming packet time, instead of the default sequential number that cause problems when restarting the encoder.
From something like this
...media_w112312312_b1024000_7.ts
...media_w112312312_b1024000_8.ts
to a timestamp notation where the chunks continue even after a restart
I read about the property cupertinoCalculateChunkIDBasedOnTimecode, I follow the instructions in this guide to configure it:
https://www.wowza.com/docs/how-to-configure-apple-hls-packetization-cupertinostreaming#livepropref
but it does not work or I am doing something wrong. Has anyone used the property
cupertinoCalculateChunkIDBasedOnTimecode successfully?
many thanks
I have used 'cupertinoCalculateChunkIDBasedOnTimecode' property and even if I restart my encoder, players are able to pick up the stream and play successfully.
The below page will help you in using it properly
http://thewowza.guru/how-to-set-stream-timecodes-to-absolute-time/
Related
I try to access frames of RTCVideoRenderer without success, can you help me please ?
I noticed that there is a "didCaptureVideoFrame" method in RTCVideoCapturerDelegate, but not in RTCVideoViewDelegate.
I have never done objc, I added a method in RTCVideoViewDelegate to get frames (bellow "didChangeVideoSize"), but it do not get fired, I guess it do not work like that.
I am able to access frames from the remote using Android using the "onFrame" of VideoSink, I thought it would be that easy using ios.
PS: To add the method, I took the framework from the pod and put it in the project, because I noticed that when you modify a pod, changes do not apply.
Here is the line I added :
- (void)videoView:(id<RTCVideoRenderer>)videoView didRenderVideoFrame:(RTCVideoFrame *)frame;
I will now try to compile the library with the changes I want.
EDIT:
I am now compiling the library, I noticed the need to change several files to be able to access frames, it will not be done just by adding 10 lines.
Solved thanks to this : How to get frame data in AppRTC iOS app for video modifications?
I used this line instead (because names changed since) :
#property(atomic, strong) RTCVideoFrame* videoFrame;
I wanted a "onFrame" like VideoSink on Android, but it will be ok for now.
I'm trying to stream (large) files over HTTP into a database. I'm using Tomcat and Jersey as Webframework. I noticed, that if I POST a file to my resource the file is first buffered on disk (in temp\MIME*.tmp} before it is handled in my doPOST method.
This is really an undesired behaviour since it doubles disk I/O and also leads to a somewhat bad UX, because if the browser is already done with uploading the user needs to wait a few minutes (depending on file size of course) until he gets the HTTP response.
I know that it's probably not the best implementation of a large file upload (since you don't even have any resume capabilities) but so are the requirements. :/
So my questions is, if there is any way to disable (disk) buffering for MULTIPART POSTs. Mem buffering is obviously too expensive, but I don't really see the need for disk buffering anyway? (Explain please) How do large sites like YouTube handle this situation? Or is there at least a chance to give the user immediate feedback if the file is sent? (Should be bad, since there could be still something like SQLException)
In case anybody is still interested, I solved the same issue by using the Apache Commons Streaming api
The code example on that page worked just fine for me.
Ok, so after days of reading and trying different stuff I stumbled upon HTTPServletRequest. At first I didn't even want to try since it takes away all the convenience methods from #FormDataParam but since i didn't know what else to do...
Turns out it helped. When I'm using #Context HTTPServletRequest request and request.getInputStream() i don't get disk buffering at all.
Now I just have to figure out how to get to the FormDataContentDisposition without #FormDataParam
Edit:
Ok. MultiPartFormData probably has to buffer on disk to parse the InputStream of the Request. So it seems I have to manually parse it myself, if I want to prevent any buffering :(
Your best bet is to take full control and write your own servlet that just grabs request.getInputStream (or request.getWriter if you are consuming text) and does the streaming itself. Most frameworks make your life "easy" by handling all the upload, temporary storage, etc. for you and often make it difficult to do things like streaming. It's quite easy to grab the stream yourself and do whatever you want.
I'm pretty sure Jersey is writing the files to disk to ensure memory is not flooded. Since you know exactly what you need to do with the incoming data -> stream into the database you probably have to write your own MessageBodyReader and get Jersey to use that to process your incoming multipart data.
I'm trying to test the happy-path for a piece of code which takes a long time to respond, and then begins writing a file to the response output stream, which prompts a download dialog in browsers.
The problem is that this process has failed in the past, throwing an exception after this long amount of work. Is there a way in selenium to wait-for-download or equivalent?
I could throw in a Thread.sleep, but that would be inaccurate and unnecessarily slow down the test run.
What should I do, here?
I had the same problem. I invented something to solve the problem. A tempt file is created by Python with '.part' extension. So, if still we have the temp, python can wait for 10 second and check again if the file is downloaded or not yet.
while True:
if os.path.isfile('ts.csv.part'):
sleep(10)
elif os.path.isfile('ts.csv'):
break
else:
sleep(10)
driver.close()
So you have two problems here:
You need to cause the browser to download the file
You need to measure when the downloaded file is complete
Neither problemc an be directly solved by Selenium (yet - 2.0 may help), but both are solvable problems. The first problem can be solved by GUI automation toolkits, such as AutoIT. But they can also be solved by simply sending an automated keypress at the OS level that simulates the enter key (works for Firefox, a little harder on some versions of Chrome and Safari). If you're using Java, you can use Robot to do that. Other languages have similar toolkits to do such a thing.
The second issue is probably best solved with some sort of proxy solution. For example, if your browser was configured to go through a proxy and that proxy had an API, you could query the proxy with that API to ask when network activity had ended.
That's what we do at http://browsermob.com, which is a a startup I founded that uses Selenium to do load testing. We've released some of the proxy code as open source, available at http://browsermob.com/tools.
But two problems still persist:
You need to configure the browser to use the proxy. In Selenium 2 this is easier, but it's possible to do it with Selenium 1 as well. The key is just making sure that your browser launcher brings up the browser with the right profile/settings.
There currently is no API for BrowserMob proxy to tell you when network traffic has stopped! This is a big hole in the concept of the project that I want to fix as soon as I get the time. However, if you're keen to help out, join the Google Group and I can definitely point you in the right direction.
Hope that helps you identify your various options. Best of luck!
This is Chrome-testing-only solution for controlling the downloads with javascript..
Using WebDriver (Selenium2) it can be done within Chrome's chrome:// which is HTML/CSS/Javascript:
driver.get( "chrome://downloads/" );
waitElement( By.CssSelector("#downloads-summary-text") );
// next javascript snippet cancels the last/current download
// if your test ends in file attachment downloading
// you'll very likely need this if you more re-instantiated tests left
((JavascriptExecutor)driver).executeScript("downloads.downloads_[0].cancel_();");
There are other Download.prototype.functions in "chrome://downloads/downloads.js"
This suites you if you just need to test some info note eg. caused by file attachment starting activity, and not the file itself.
Naturally you need to control step 1. - mentioned by Patrick above - and by this you control step 2. FOR THE TEST, not for the functionality of actual file download completion / cancel.
See also : Javascript: Cancel/Stop Image Requests which is relating to Browser stopping.
This falls under the "things that can't be automated" category. Selenium is built with JavaScipt and due to JavaScript sandbox restrictions it can't access downloads.
Selenium 2 might be able to do this once Alerts/Prompts have been implemented but that this won't happen for the next little while yet.
If you want to check for the download dialog, try with AutoIt. I use that for uploading and downloading the files. Using AutoIt with Se RC is easier.
def file_downloaded?(file)
while File.file?(file) == false
p "File downloading in progress..."
sleep 1
end
end
*Ruby Syntax
I'm trying to read variables from memory. Variables, that doesn't belong to my own program. For instance, let's say I have this Adobe Shockwave (.dcr) application running in browser and I want to read different variables from it. How it's being done? Do I need to hook the process? But it's running under virtual machine, so I don't know how to do it.
This task is pretty much trivial in normal w32 applications (as it is mainly just
CBT-hooking / subclassing), but as I mentioned before, I've got no idea how it's being
done with flash / shockwave.
I'm using C++ (VS9) as my development-environment, in case you wish to know.
Any hints would be highly appreciated, so thank you in advance.
Best regards,
nhaa123
If you're trying to do it manually just for one or two experiments, it's easy.
Try a tool like Cheat engine which is like a free and quick and simple process peeker. Basically it scans the process's memory space for given key values. You can then filter those initial search hits later as well. You can also change those values you do find, live. The link above shows a quick example of using it to find a score or money value in a game, and editing it live as the game runs.
without having debug Binaries/DLLs of the Apps, your only chance is asking some hackers.
Normally you can connect to a process with a debugger, but without the debugging symbols of the binaries you don't see any variable names - just memory addresses.
Further the Flash/Shockwave code runs inside a sandbox inside the browser to prevent security holes by manipulated Flash code. So you don't have a real chance to get access to the running Flash code / to the plugin executing the Flash code - except you have a manipulated version of such a plugin.
So your task is quite hard to solve without using less legal methods. The next hard thing is the virtual machine - this could be solved by implementing your app as a client/server solution, where the "inspector" / watchdog runs as server inside the virtual machine and the client requesting the variable status/content running on your normal host. The communication could be done as simple socket connection.
If you have the chance to write your own Flash/Shockwave plugin, you maybe could be able to see contents of variables.
Sorry, that I cannot help you any further.
ciao,
3DH
Trying to honor a feature request from our customers, I'd like that my application, when Internet is available, check on our website if a new version is available.
The problem is that I have no idea about what have to be done on the server side.
I can imagine that my application (developped in C++ using Qt) has to send a request (HTTP ?) to the server, but what is going to respond to this request ? In order to go through firewalls, I guess I'll have to use port 80 ? Is this correct ?
Or, for such a feature, do I have to ask our network admin to open a specific port number through which I'll communicate ?
#pilif : thanks for your detailed answer. There is still something which is unclear for me :
like
http://www.example.com/update?version=1.2.4
Then you can return what ever you want, probably also the download-URL of the installer of the new version.
How do I return something ? Will it be a php or asp page (I know nothing about PHP nor ASP, I have to confess) ? How can I decode the ?version=1.2.4 part in order to return something accordingly ?
I would absolutely recommend to just do a plain HTTP request to your website. Everything else is bound to fail.
I'd make a HTTP GET request to a certain page on your site containing the version of the local application.
like
http://www.example.com/update?version=1.2.4
Then you can return what ever you want, probably also the download-URL of the installer of the new version.
Why not just put a static file with the latest version to the server and let the client decide? Because you may want (or need) to have control over the process. Maybe 1.2 won't be compatible with the server in the future, so you want the server to force the update to 1.3, but the update from 1.2.4 to 1.2.6 could be uncritical, so you might want to present the client with an optional update.
Or you want to have a breakdown over the installed base.
Or whatever. Usually, I've learned it's best to keep as much intelligence on the server, because the server is what you have ultimate control over.
Speaking here with a bit of experience in the field, here's a small preview of what can (and will - trust me) go wrong:
Your Application will be prevented from making HTTP-Requests by the various Personal Firewall applications out there.
A considerable percentage of users won't have the needed permissions to actually get the update process going.
Even if your users have allowed the old version past their personal firewall, said tool will complain because the .EXE has changed and will recommend the user not to allow the new exe to connect (users usually comply with the wishes of their security tool here).
In managed environments, you'll be shot and hanged (not necessarily in that order) for loading executable content from the web and then actually executing it.
So to keep the damage as low as possible,
fail silently when you can't connect to the update server
before updating, make sure that you have write-permission to the install directory and warn the user if you do not, or just don't update at all.
Provide a way for administrators to turn the auto-update off.
It's no fun to do what you are about to do - especially when you deal with non technically inclined users as I had to numerous times.
Pilif answer was good, and I have lots of experience with this too, but I'd like to add something more:
Remember that if you start yourapp.exe, then the "updater" will try to overwrite yourapp.exe with the newest version. Depending upon your operating system and programming environment (you've mentioned C++/QT, I have no experience with those), you will not be able to overwrite yourapp.exe because it will be in use.
What I have done is create a launcher. I have a MyAppLauncher.exe that uses a config file (xml, very simple) to launch the "real exe". Should a new version exist, the Launcher can update the "real exe" because it's not in use, and then relaunch the new version.
Just keep that in mind and you'll be safe.
Martin,
you are absolutely right of course. But I would deliver the launcher with the installer. Or just download the installer, launch it and quit myself as soon as possible. The reason is bugs in the launcher. You would never, ever, want to be dependent on a component you cannot update (or forget to include in the initial drop).
So the payload I distribute with the updating process of my application is just the standard installer, but devoid of any significant UI. Once the client has checked that the installer has a chance of running successfully and once it has downloaded the updater, it runs that and quits itself.
The updater than runs, installs its payload into the original installation directory and restarts the (hopefully updated) application.
Still: The process is hairy and you better think twice before implementing an Auto Update functionality on the Windows Platform when your application has a wide focus of usage.
in php, the thing is easy:
<?php
if (version_compare($_GET['version'], "1.4.0") < 0){
echo "http://www.example.com/update.exe";
}else{
echo "no update";
}
?>
if course you could extend this so the currently available version isn't hard-coded inside the script, but this is just about illustrating the point.
In your application you would have this pseudo code:
result = makeHTTPRequest("http://www.example.com/update?version=" + getExeVersion());
if result != "no update" then
updater = downloadUpdater(result);
ShellExecute(updater);
ExitApplication;
end;
Feel free to extend the "protocol" by specifying something the PHP script could return to tell the client whether it's an important, mandatory update or not.
Or you can add some text to display to the user - maybe containing some information about what's changed.
Your possibilities are quite limitless.
My Qt app just uses QHttp to read tiny XML file off my website that contains the latest version number. If this is greater than the current version number it gives the option to go to the download page. Very simple. Works fine.
I would agree with #Martin and #Pilif's answer, but add;
Consider allowing your end-users to decide if they want to actually install the update there and then, or delay the installation of the update until they've finished using the program.
I don't know the purpose/function of your app but many applications are launched when the user needs to do something specific there and then - nothing more annoying than launching an app and then being told it's found a new version, and you having to wait for it to download, shut down the app and relaunch itself. If your program has other resources that might be updated (reference files, databases etc) the problem gets worse.
We had an EPOS system running in about 400 shops, and initially we thought it would be great to have the program spot updates and download them (using a file containing a version number very similar to the suggestions you have above)... great idea. Until all of the shops started up their systems at around the same time (8:45-8:50am), and our server was hit serving a 20+Mb download to 400 remote servers, which would then update the local software and cause a restart. Chaos - with nobody able to trade for about 10 minutes.
Needless to say that this caused us to subsequently turn off the 'check for updates' feature and redesign it to allow the shops to 'delay' the update until later in the day. :-)
EDIT: And if anyone from ADOBE is reading - for god's sake why does the damn acrobat reader insist on trying to download updates and crap when I just want to fire-it-up to read a document? Isn't it slow enough at starting, and bloated enough, as it is, without wasting a further 20-30 seconds of my life looking for updates every time I want to read a PDF?
DONT THEY USE THEIR OWN SOFTWARE??!!! :-)
On the server you could just have a simple file "latestversion.txt" which contains the version number (and maybe download URL) of the latest version. The client then just needs to read this file using a simple HTTP request (yes, to port 80) to retrieve http://your.web.site/latestversion.txt, which you can then parse to get the version number. This way you don't need any fancy server code --- you just need to add a simple file to your existing website.
if you keep your files in the update directory on example.com, this PHP script should download them for you given the request previously mentioned. (your update would be yourprogram.1.2.4.exe
$version = $_GET['version'];
$filename = "yourprogram" . $version . ".exe";
$filesize = filesize($filename);
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: post-check=0, pre-check=0");
header("Content-type: application-download");
header('Content-Length: ' . $filesize);
header('Content-Disposition: attachment; filename="' . basename($filename).'"');
header("Content-Transfer-Encoding: binary");
This makes your web browser think it's downloading an application.
The simplest way to make this happen is to fire an HTTP request using a library like libcurl and make it download an ini or xml file which contains the online version and where a new version would be available online.
After parsing the xml file you can determine if a new version is needed and download the new version with libcurl and install it.
Just put an (XML) file on your server with the version number of the latest version, and a URL to the download the new version from. Your application can then request the XML file, look if the version differs from its own, and take action accordingly.
I think that simple XML file on the server would be sufficient for version checking only purposes.
You would need then only an ftp account on your server and build system that is able to send a file via ftp after it has built a new version. That build system could even put installation files/zip on your website directly!
If you want to keep it really basic, simply upload a version.txt to a webserver, that contains an integer version number. Download that check against the latest version.txt you downloaded and then just download the msi or setup package and run it.
More advanced versions would be to use rss, xml or similar. It would be best to use a third-party library to parse the rss and you could include information that is displayed to your user about changes if you wish to do so.
Basically you just need simple download functionality.
Both these solutions will only require you to access port 80 outgoing from the client side. This should normally not require any changes to firewalls or networking (on the client side) and you simply need to have a internet facing web server (web hosting, colocation or your own server - all would work here).
There are a couple of commercial auto-update solutions available. I'll leave the recommendations for those to others answerers, because I only have experience on the .net side with Click-Once and Updater Application Block (the latter is not continued any more).