Android Question DIY 4CH Car DVR using Android phone

[rzv25]

Hello,

I would like to build a custom DVR system for my car. Searching over internet, I only found information about some devices made in China (eg) but I want to create something with lot more custom functions and very configurable.

What I have in mind is having a powerful Android phone device acting as the 'core' of the system, running most of the functionality.
What I am not sure is achievable is:
- having 4 USB cameras connected to a USB Hub and then the hub connected to the Android phone. Write software with B4A to capture images or start/stop recording 4 distinct movies from the 4 USB cameras, all stored on the Android's SD card.
- having a web server implemented on the Android device (which will have a SIM with a data plan), allowing me to access the pictures and the movies from basically anywhere in the world where I have a internet connection.

I appreciate any thought, idea, question you might have.

Thank you.

 

[Erel]

Communicating with a USB camera will require a low level implementation of the relevant protocol. It is not simple.

Consider a different approach. Create a local network with the Android device (tethering) and use the mjpeg client to retrieve the videos:
https://www.b4x.com/android/forum/threads/73702/#content

 

[rzv25]

Hello Erel,

Thank you for the quick reply.
If I understand correclty you suggest using wireless IP cameras instead of USB ones, please correct me if I am wrong. Then have 4 instances of mjpeg client connected to the local IP of each camera.
Looking in the captures images from the thread in your link, it seems that the quality of the image is not very good. Does this have anything to do with the quality of the camera or this is the best I can get using this class ?

I am not familiar at all with this class, does it have support for saving the received streams as video files on the SD card?
Also, how will I be able to access the saved video files in my phone, from another location ? This is why I asked the second question, the one about the web server. Should I implement a mjpeg server on the phone ? I apologize if this is a dumb question.


Thank you

 

[Erel]

If I understand correclty you suggest using wireless IP cameras instead of USB ones, please correct me if I am wrong

That's true.

The class returns the image as-is. The low quality is caused by the image source.

I am not familiar at all with this class, does it have support for saving the received streams as video files on the SD card?

It returns a stream of pictures. You can draw the 4 pictures on a single canvas and then use MJPEG server (this is the "web server") to serve it to connected clients.
You can also save the mjpeg stream to a file.