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3.13.3 Sending multimedia

3.13.3 Sending multimedia

Owned by Former user (Deleted)
Last updated: Oct 06, 2015

Supported multimedia include:

  • Picture
  • Short video
  • Audio note

The file sharing works only among the service users, does not work for OFFNET numbers.

The process is as follows:

  1. In a chat window a user creates a file to be sent, either selecting exsiting file or making new one
  2. The file is first uploaded over https to the EMCD, as a request’s parameter the list of recipients is sent
  3. The EMCD copies the received file to the database along with the list of recipients
  4. The EMCD confirms successful upload by sending a file identifier back to the client
  5. The client sends a SIP MESSAGE with a special system command which contains information on the type of the file and its identifier
  6. Receiving client displays information on the received file (type) or shows a thumbnail (for pictures)
  7. When the recipient taps on the message the application connects to the EMCD and requests the file with given identifier. The file is returned to the application.
  8. Once the file is downloaded the EMCD checks if there are more addressee who has not downloaded yet, if not the file is removed. If there are the file is kept until is download by all addresses

All files are stored in the storage schema in the database. The schema can be located on a different database server. Connection string to this schema is defined in the /var/www/emcd/DataBase.config i /var/www/emci/DataBase.config

The files are sent to the EMCD/upload.ashx. An example request looks as follows:

<form action="http://127.0.0.1:8080/upload.ashx" method="POST" enctype="multipart/form-data" name="cform">

 <input type="hidden" name="l" value="1000031">

 <input type="hidden" name="r" value="1000030;1000032">

 <input type="file" name="datafile" size="40">

 <input type="submit" value="Upload">

</form>

 

The EMCD checks the Content-Type parameter from the request header. The supported types include:

  • image/gif, image/jpeg, image/png
  • audio/mpeg, audio/aiff, audio/3gpp, audio/wav, audio/amr
  • video/mp4, video/quicktime, video/x-m4v, video/3gpp

The files are stored in the database in storage scheme. The maximal size of a sent file is defined in the /etc/mysql/my.cnf   in max_allowed_packet   parameter, by default its value is 96M.

On the receiver side the application sends request to the EMCD/download.ashx

The parameters will include the login, the file’s identifier and optionally for pictures there is width and height parameters which let the application to request a smaller version of the original file to be displayed as a thumbnail. In this case, when width and height is specified, the EMCD will not mark the file as downloaded.

As the file sharing is based on chat messages it inherits all its features such as deferred messages and PUSH.

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