ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

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rajkumar3bj
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ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by rajkumar3bj » Thu Apr 16, 2020 3:33 am

Hello Geeks,

I have a project to broadcast recorded videos or audios using WIFI frequency channels. Please help me in this. The details of the project is as follows.
Image
The broadcast mechanism is like DTH Service (DVB S2 type). But not exactly the same. A regular 2.4GHz WIFI contains 14 channels, and I want to broadcast videos or audios through these channels to the receivers. The receivers should be able to change the channels as per their wish and receive the data. The communication is unidirectional only, from transmitter to receiver.

TRANSMITTER SIDE: DEVICE ODROID C2 with a WIFI Dongle Antenna.
The device has pre recorded videos and audios in compressed digital format. Odroid device should able to broadcast separate data in each channel.

RECEIVER SIDE: Devices such as mobiles, Laptops, Tabs with in-build WIFI. An application will be there to change channels and receive the data.

I have gone through these links but all the solutions is based on single channel.
https://befinitiv.wordpress.com/wifibro ... ideo-data/
https://github.com/rodizio1/EZ-WifiBroadcast/wiki
https://dev.px4.io/v1.9.0/en/qgc/video_ ... dcast.html
https://www.youtube.com/watch?v=X8Aila0LjFo
https://www.youtube.com/watch?v=XSOfBWc ... Cj-iMOoFLv

Any kind of help is highly appreciated.

KR,
RAJKUMAR

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Re: ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by odroid » Thu Apr 16, 2020 2:41 pm

I have no idea indeed.
But I just think you need to connect multiple WiFi dongles to C2 for each channel transmitting since the dynamic channel switching takes a lot of time.

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mad_ady
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Re: ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by mad_ady » Thu Apr 16, 2020 3:25 pm

Also, note that wifi normally uses several consecutive channels (has overlapping). You'll need to space out your streams to avoid congestion.
I'd go with a powered usb hub with several wifi dongles in AP mode on the server side, each one with a different ip subnet (e.g. wlan0 - 10.0.0.0/24, wlan1 - 10.1.0.0/24, etc). Your clients should have 2 wifi adapters (for seamless switching). When changing channels use the secondary wifi to connect to the target ap (while primary is still running) and once connected, direct the player to play the other video stream (different ip, different connection). There will be a 2-5s delay in changing streams, but the stream gap shold be small.

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Re: ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by mad_ady » Thu Apr 16, 2020 3:31 pm

Also note - the talk is about broadcast, but most solutions (video players, etc) are using multicast. So you have 3 clients, you're using 3* bandwidth.
You will need to add multicast support over wifi (not sure how that is implemented at link layer) and use multicast to join players to the stream. By using PIM-SM you shoulc be able to multiplex multiple streams over the same wifi link, provided your clients mostly watch the same channel. When a client requests a new channel and there's nobody else looking at that stream, the stream will be created and stat flowing. If there are no clients watching, the stream stops and frees up bandwidth.

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Re: ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by rajkumar3bj » Fri Apr 17, 2020 6:36 am

Thank you for your inputs.
So if I mux multiple streams and broadcast, does that mean, all the streams will travel through same one channel of wifi frequency?
If client receivers are receiving the signal then, will they able to switch to different streams?

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Re: ODROID C2 with WIFI to Broadcast Recorded Video/Audio : WIFIBROADCAST

Post by mad_ady » Fri Apr 17, 2020 4:16 pm

If a channel's bandwith is greater than your total data rate, it would be the simplest option, since connecting to a different network would take 2-4s.

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