Audio Cutter in Silverlight - asp.net

1.
I have created a audio player in silverlight.
within that player user is able to select a portion of song to save as ringtone.
but i got the time duration from .. but I have to cut the partial portion of stream or audio stream and save it to the server dick.
Plz suggest me how I can convert the selected audio time duration into the stream or byte array..?
-- Additional information on this question:
2.
I have created a ringtone audio player in silverlight. Within that user can select a portion which can be cut and save as a audio file.
I am unable to save the stream to the disk.. it is giving following errors:
Error 1. Attempt to access the method failed System IO FileInfo OpenWrite
Plz help
-- Additional information on this question:
3.
What are the use of MediaStreamSample & MediaStreamSource class in silverlight with respect to MediaElement?
Will it help in cutting a portion of audio file in order to create the ringtone out of a song?

If you need to save to the server, then you need to get that data to the server.
Just saving it (as answered) will try to save to the client's machine. What you need to do is upload the data to the server either via a WCF service or an ASHX handler or such. I've done something similar -- uploading MP3 files from a Silverlight client to a WCF service via a Stream, works well.
Next: You need to make sure that whatever splitting process you use accommodates the audio format-- ie you probably just can't split the binary file. What format are you using, mp3?
I've used something called mp3plt, before to split mp3s. You may be able to recompile the source into a Silverlight-compatible library, assuming it's written in something you can use, source here.
Or you can look into the mp3 specs to see if it is possible to just split the binary file, in which case taking the duration to cut (the one the user chose), and multiplying by the bitrate, (kb/s * seconds = kb) will give you the place in the file byte[] you can cut at.

Error 1. Attempt to access the method failed System IO FileInfo OpenWrit, you getting this error coz of security reasons. Before saving to disk you should promt SaveFileDialog to user, and then only save file to disk.

Related

Avro "Invalid sync!" exception in nextRawBlock()

I am streaming a Avro encoded file over the network from a S3 compliant object store and trying to read it and put it in some data-structure.
Issue: The issue I am facing sometimes ( one or two times in one / two days in test node when running continuously) is that half way through the file it hits this exception Invalid sync! in the nextRawBlock() method in DataFileStream class.
I would like to detect the root-cause of this and fix. I have been trying to
reproduce this in a test app but unable to do so successfully. I am looking for ideas on
what might potentially cause this ?
any better ways of reproducing this.
More details
a) The Avro file is not downloaded to disk , I get a handle to the file stream using S3ObjectInputStream and feed it to DataFileStream constructor
and then read from the stream directly.
b) The app tries to read records from the Avro encoded file in batches
of 500 records at a time.
c) The file contains a header section containing a Long count and a KV Map of String to Integer. After that it contains a array of records where each record contains a String and a long array. The schema uses Avro's union construct for enabling this.
d) Number of records in the file on average is around 5M
e) This entire download happens in separate thread and not in any user request.
f) The file is uploaded to the store by a separate process.
Other observation:
a) Upon failure the app closes the stream and tries to again download and read the stream. What I observe is this takes the node to a high oldgen state slowing down user requests.

What would be the best practice downloading all the files from a directory using Sftp

I would like to implement the following functionality:
downloading all the files from a specified remote directory to a local directory.
after downloading all the files I need a list file which contains all the downloaded files.
(I only want this list file when all the files were downloaded successfully.)
Point 1:
Let's say we have around 10 files in the remote directory.
I can use an int-sftp:inbound-channel-adapter component to download all the files but 10 poll cycles are needed to download all of them since the inbound component is only able to download 1 file per poll request.
Spring Integration creates 10 File messages one by one.
Questions:
How can I identify the last file (message) received from the FTP server?
I don't want let users access to list file till all the files from the FTP is successfully received.
How can I achive this?
I can write file names into a list file using the int-file:outbound-channel-adapter but users can read temorary information from that file before the download process is finished.
How can I trigger the event that all files which are on the FTP are downloaded?
Thanks for your advices
Ferenc
First of all this isn't correct:
the inbound component is only able to download 1 file per poll request
You can configure it to to download infinitely during the single poll - max-messages-per-poll=-1. Anyway it is a default option on <poller>.
Anyway if it is your case to dowload one file per poll, you can go ahead with that requirements.
Since any Messaging system tries to achieve stateless paradigm, it is normal that one message doesn't know anything about another. And with that they all don't impact each other. The async scenario is the best for Messaging. With that we can process the second message quicker, than the first one.
Your requirement is enough interest and I won't dare to call it strange. Because any business may have place.
Since you are going to process several download files as one group, there will be need to have some marker on the remote server. Or it can be some timeframe, which we can extract from file timestamp. Or there will be need to store on the remote server some marker file to point that a set of files are finished and you can process them from your application using their local version. Would be great, if that marker file can contain a list of file names of that group.
Otherwise we don't have any hook to group messages for those files.
From other side you can consider to use <int-sftp:outbound-gateway> with MGET command: http://docs.spring.io/spring-integration/docs/latest-ga/reference/html/sftp.html#sftp-outbound-gateway

CommonCrypto in iOS [sqlite file encryption]

I'm using Core Data API in my iOS application. Also, I'm using the commoncrypto library (CCCrypt()) to encrypt/decrypt the database file(.sqlite file) that resides in the documents folder when the application state changes (Background/Foreground).
The problem which i'm facing is... some of the records in the database gets lost when the application is killed manually by the user from the background state and this issue is inconsistent.
I'm just converting the sqlite file contents into NSData and used as an input to CCCrypt() function to encrypt/decrypt and I'm not decoding the any input data in the crypt operation.
Can someone please help me .....what could be reason for the data loss ? that too only when the application gets killed manually from the background state ..... For both encryption and decryption operation, the CCCrypt function returns the status as kCCSuccess...
Does it needed to use any sort of decoding the input data (raw bytes) before CCCrypt operation ?
Probably you should use the life cycle methods to save your data before it gets killed.
Try saving data in applicationWillTerminate. Go through this discussion for more details about
[enter link description here][1]
[1]: applicationWillTerminate when is it called and when not"Save data before getting Killed"

Adobe AIR HTTP Connection Limit

I'm working on an Adobe AIR application which can upload files to a web server, which is running Apache and PHP. Several files can be uploaded at the same time and the application also calls the web server for various API requests.
The problem I'm having is that if I start two file uploads, while they are in progress any other HTTP requests will time out, which is causing a problem for the application and from a user point of view.
Are Adobe AIR applications limited to 2 HTTP connections, or is something else probably the issue?
From searching about this issue I've not found much but one article did indicated that it wasn't limited to just two connections.
The file uploads are performed by calling the File classes upload method, and the API calls are done using the HTTPService class. The development web server I am using is a WAMP server, however when the application is released it will be talking to a LAMP server.
Thanks,
Grant
Here is the code I'm using to upload the file:
protected function btnAddFile_clickHandler(event:MouseEvent):void
{
// Create a new File object and display the browse file dialog
var uploadFile:File = new File();
uploadFile.browseForOpen("Select File to Upload");
uploadFile.addEventListener(Event.SELECT, uploadFile_SelectedHandler);
}
private function uploadFile_SelectedHandler(event:Event):void
{
// Get the File object which was used to select the file
var uploadFile:File = event.target as File;
uploadFile.addEventListener(ProgressEvent.PROGRESS, file_progressHandler);
uploadFile.addEventListener(IOErrorEvent.IO_ERROR, file_ioErrorHandler);
uploadFile.addEventListener(Event.COMPLETE, file_completeHandler);
// Create the request URL based on the download URL
var requestURL:URLRequest = new URLRequest(AppEnvironment.instance.serverHostname + "upload.php");
requestURL.method = URLRequestMethod.POST;
// Set the post parameters
var params:URLVariables = new URLVariables();
params.name = "filename.ext";
requestURL.data = params;
// Start uploading the file to the server
uploadFile.upload(requestURL, "file");
}
Here is the code for the API calls:
private function sendHTTPPost(apiFile:String, postParams:Object, resultCallback:Function, initialCallerResultCallback:Function):void
{
var httpService:mx.rpc.http.HTTPService = new mx.rpc.http.HTTPService();
httpService.url = AppEnvironment.instance.serverHostname + apiFile;
httpService.method = "POST";
httpService.requestTimeout = 10;
httpService.resultFormat = HTTPService.RESULT_FORMAT_TEXT;
httpService.addEventListener("result", resultCallback);
httpService.addEventListener("fault", httpFault);
var token:AsyncToken = httpService.send(postParams);
// Add the initial caller's result callback function to the token
token.initialCallerResultCallback = initialCallerResultCallback;
}
If you are on a windows system, Adobe AIR is using Microsofts WinINet library to access the web. This library by default limits the number of concurrent connections to a single server to 2:
WinInet limits the number of simultaneous connections that it makes to a single HTTP server. If you exceed this limit, the requests block until one of the current connections has completed. This is by design and is in agreement with the HTTP specification and industry standards.
... Connections to a single HTTP 1.1 server are limited to two simultaneous connections
There is an API to change the value of this limit but I don't know if it is accessible from AIR.
Since this limit also affects page loading speed for web sites, some sites are using multiple DNS names for artifacts such as images, javascripts and stylesheets to allow a browser to open more parallel connections.
So if you are controlling the server part, a workaround could be to create DNS aliases like www.example.com for uploads and api.example.com for API requests.
So as I was looking into this, I came across this info about using File.upload() in the documentation:
Starts the upload of the file to a remote server. Although Flash Player has no restriction on the size of files you can upload or download, the player officially supports uploads or downloads of up to 100 MB. You must call the FileReference.browse() or FileReferenceList.browse() method before you call this method.
Listeners receive events to indicate the progress, success, or failure of the upload. Although you can use the FileReferenceList object to let users select multiple files for upload, you must upload the files one by one; to do so, iterate through the FileReferenceList.fileList array of FileReference objects.
The FileReference.upload() and FileReference.download() functions are
nonblocking. These functions return after they are called, before the
file transmission is complete. In addition, if the FileReference
object goes out of scope, any upload or download that is not yet
completed on that object is canceled upon leaving the scope. Be sure
that your FileReference object remains in scope for as long as the
upload or download is expected to continue.
I wonder if something there could be giving you issues with uploading multiple files. I see that you are using browserForOpen() instead of browse(). It seems like the probably do the same thing... but maybe not.
I also saw this in the File class documentation
Note that because of new functionality added to the Flash Player, when publishing to Flash Player 10, you can have only one of the following operations active at one time: FileReference.browse(), FileReference.upload(), FileReference.download(), FileReference.load(), FileReference.save(). Otherwise, Flash Player throws a runtime error (code 2174). Use FileReference.cancel() to stop an operation in progress. This restriction applies only to Flash Player 10. Previous versions of Flash Player are unaffected by this restriction on simultaneous multiple operations.
When you say that you let users upload multiple files, do you mean subsequent calls to browse() and upload() or do you mean one call that includes multiple files? It seems that if you are trying to do multiple separate calls that that may be an issue.
Anyway, I don't know if this is much help. It definitely seems that what you are trying to do should be possible. I can only guess that what is going wrong is perhaps a problem with implementation. Good luck :)
Reference: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/FileReference.html#upload()
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/FileReference.html#browse()
Just because I was thinking about a very similar question because of an error in one of my actual apps, I decided to write down the answer I found.
I instantiated 11
HttpConnections
and was wondering why my Flex 4 Application stopped working and threw an HTTP-Error although it was working pretty good formerly with just 5 simultanious HttpConnections to the same server.
I tested this myself because I did not find anything regarding this in the Flex docs or on the internet.
I found that using more than 5 HTTPConnections was the reason for the Flex application to throw the runtime error.
I decided to instantiate the connections one after another as a temporally workaround: Load the next one after the other has received the data and so on.
Thats of course just temporally since one of the next steps will be to alter the responding server code in that way that it answers a request that contains the results of requests to more then one table in one respond. Of course the client application logic needs to be altered, too.

Programmatically open an email from a POP3 and extract an attachment

We have a vendor that sends CSV files as email attachments. These CSV files contain statuses that are imported into our application. I'm trying to automate the process end-to-end, but it currently depends on someone opening an email, saving the attachment to a server share, so the application can use the file.
Since I cannot convince the vendor to change their process, such as offering an FTP location or a Web Service, I'm stuck with trying to automate the existing process.
Does anyone know of a way to programmatically open an email from a POP3 account and extract an attachment? The preferred solution would reside on a Windows 2003 server, be written VB.NET and secure. The application can reside on the same server as the POP3 server, for example, we could setup the free POP3 server that comes with Windows Server and pull against the mail file stored on the file system.
BTW, we are willing to pay for an off-the-shelf solution, if one exists.
Note: I did look at this question but the answer points to a CodeProject solution that doesn't deal with attachments.
Try Mail.dll email component, it's very affordable, supports attachments national characters and is easy to use, it also supports SSL:
Using pop3 As New Pop3()
pop3.Connect("mail.server.com")
pop3.Login("user", "password")
Dim builder As New MailBuilder()
For Each uid As String In pop3.GetAll()
' Receive email message'
Dim mail As IMail = builder.CreateFromEml(pop3.GetMessageByUID(uid))
'Write out received message'
Console.WriteLine(mail.Subject)
'Here you can use mail.Attachmets collection'
For Each attachment As MimeData In mail.Attachments
Console.WriteLine(attachment.FileName)
attachment.Save("c:\" + attachment.FileName)
' you can also use attachment.Data here'
Next attachment
Next
pop3.Close(true)
End Using
You can download it here: http://www.lesnikowski.com/mail.
possible duplication of Reading Email using Pop3 in C#
Atleast, there's a shed load of suggestions there that you may find useful
I'll throw in a late suggestion for a more generalized "download POP3 messages and extract attachments" solution using existing software and minimal programming. I needed to do this for a client who switched to receiving faxes via email and was not pleased with manually saving the attachments to a location where they could be imported into an application.
For downloading messages on *nix systems fetchmail seems to be the standard and is very capable, but I chose mpop for both simplicity and Windows compatibility (but it is cross-platform). If mpop hadn't done the trick for me, I probably would have ended up doing something with the Python-based getmail, which was created when fetchmail's development stalled for a time (it's since resumed).
Mpop is controlled either via command line or configuration file, so I simply created multiple configuration files and specify via command line which file to load. I'm using it in "Exchange pickup directory" mode, which means it simply downloads the messages and drops them as text (.eml) files in a specified directory.
For extraction of the message attachments, UUDeview appears to be the standard (I'm using the Windows port of UUDeview) across just about any system you could want with just about any features you could want. My main alternative to this was a much-less-capable Python script that I'd developed for a different client back in 2007, but I'm happy to go with a precompiled executable over either installing Python or packaging with any of the Python-to-exe options.
Finally there's the configuration - along with the two mpop configuration files mentioned above (which I could do away with by using command-line options), I also have two 2-line .cmd files launched every 10 minutes by scheduled task - the first line to launch mpop to download into a working directory and the second line to launch UUDeview and extract attachments of specified types (.pdf or .tif) then delete each file from which it extracted attachments. Output is sent to another directory from which staff can directly attach files as needed.
This is overall not the most elegant way to reach these ends, but it was quick, simple, functional and reasonably robust - at each stage if something goes wrong it fails such that no data is lost. The only places where data could be lost are any non-attachment messages being sent to the dedicated fax email addresses, and even those will sit in the processing directory and be caught eventually.

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