Sending an image via a socket

[jorm]

So I am working on a different kind of web camera plugin. One that works for security systems and video phones (sound is still something I need to figure out). I have a few questions that hopefully others might know the answer to.

First I have a windows application that reads the camera and collects still images. Fast enough to appear like full video.

I need a windows application since I need the windows handle. I do not know if it would work if sub exposed it but my idea is that he would not need to.

Now the application is capturing frames with a size of 304128 bytes. (352x288).

I want this to work with the MVP (without sound) as well as the PC.

So this application connects to a set of cameras and sends the images to the client (client and server in the same application) client connects to remote server, remote server connects to local client.

I am debating about using the gbpvr as the client itself but that will break the support for multiple MVPs with this plugin.

Now I have an image (Which is a bmp?) that I am trying to serialize to the remote client. I have not figured out

1. How to compress the image to a jpg and send its data across. I can not get to the data directly. I have the data as a bmp but that is 300K a jpg would be about 14k. So ideally I want this as an jpg image.

I found a save method on an image but that does not stream well. I can write it to a file but that adds additional I/O overhead.

I would eventually like sound, I think the mvp does not support wav so the sound would have to be mpeg and thus delayed by a few seconds. For the PC it should be possible though.

[jorm]

In the mean time I have serialized the images across a stream as bitmaps

And I have a web cam (on the same machine) showing up in a gbpvr plugin.

The refresh rate is slow for updating images. It seems to be at rendering at most 2 or 3 frames a second. But functional.

[HenkH]

Why not construct a MPEG stream, it's an area in whicht the MediaMVP excels. The 352x288 exactly matches the size of a VCD MPEG1 stream. Make each separate bitmap an I-frame and let the P&B frames 'blank'. The audio should be encoded as MP3.

You will just have to find a suitable library to do the encoding for you, maybe sourceforge.net can provide some usable links.

[KingArgyle]

Jorm, if you need a JPEG library or other image compression library you might want to start by looking here:

http://datacompression.info/SourceCode.shtml

or here

http://www.yov408.com/html/tutorials.php?s=85

Also, something like this might help.

http://www.eggheadcafe.com/articles/20030706.asp

[CodeMonkey]

jorm:

Here is a link to some C++ code that captures the image from a webcam in memory (as a DIB) instead of as a BMP on the hard drive. It also shows how to convert it to a jpg. So in theory you could do the same, then pump it to the client without having to use the hard drive at all.

[joshley]

Jorm,

See my thread:
http://forums.nextpvr.com/showthread.php?t=5799

I have written software that is capable of caputring the image of a particular WINDOW (specified by the user in a server based app) and sending the images (well, any file for that matter) to a mobile phone using sockets via Bluetooth.
The images captured can be saved in any format, and manipulated very easily in C++ using a great image processing library called NexgenIPL:

http://www.binary-technologies.com/nexgenipl.html

NexgenIPL is effing fantastic! And best of all.. completely FREE!! .jpegs or .png files are usually the smallest in size.

Let me know if this is any use to you!

josh