mcwhorpj
Posts: 2
Joined: Tue May 06, 2014 4:51 pm

Save and Stream Video?

Tue May 06, 2014 5:03 pm

We are using the pi and camera module on a High Altitude Balloon to stream live video from the balloon back to ground station in real time. We configured the camera based on the very helpful forum post here:

http://www.raspberrypi.org/forums/viewt ... 43&t=45368

We use the command indicated in the post to initiate the stream, namely:

raspivid -t -0 -w 1280 -h 720 -fps 25 -b 2000000 -o - | ffmpeg -i - -vcodec copy -an -f flv -metadata streamName=myStream tcp://0.0.0.0:6666

This creates a stream which we beam back to earth over Ethernet radios, so can watch video from the balloon back on the ground in real time. The problem is that at some point we reach such large distances that we lose radio contact with the balloon. Is there a way to modify the raspivid command line above where it will both stream (as it does now) AND save a local copy of the video on the Pi SD card?

We are very new to the Raspberry Pi, so would really appreciate some help.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: Save and Stream Video?

Tue May 06, 2014 5:09 pm

Look up the 'tee' command - that's what epople use for this use case.

Although intrigued by live video - in the UK that's not really possible due to limits in sending power. See Dave Akerman's HAB efforts.
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mcwhorpj
Posts: 2
Joined: Tue May 06, 2014 4:51 pm

Re: Save and Stream Video?

Tue May 06, 2014 11:17 pm

Thanks for the guidance! Looked up "tee" command, and have it working with the above example. We are now able to stream live from the balloon, while saving a copy on the pi.

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daveake
Posts: 184
Joined: Thu Jul 12, 2012 12:07 am

Re: Save and Stream Video?

Fri May 09, 2014 9:04 pm

Yes, what country is this in?

You should check that it's actually legal for you to use WiFi frequencies/powers from an airborne device.

Also you'd probably get better results using ATV transmitters and receivers, again depending on legality. This is done a lot in the USA where it's legal with even a basic amateur radio licence.

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