I want to use Rasbery Pi for lecture capture.  Please advise how to do it.

Are you wanting camera (Getting to know the Raspberry Pi Camera and Pi Noir ) and microphone (A Slice of Raspberry Pi: Adding an Audio Input Device )?

Clem

Yes, I would like to record both audio and video.  I could use an external camera source and a line source for the audio.

Yes, the budget is a constraining factor.  The lecturer would be moving so I guess I will need a tracking camera.  All 20 classrooms will be running at the same time.  All of them need recording as I want to give the students the opportunity to go back home and refer to the lecture in case they want tor revise the same.  They all start practically at the same time but this could vary.  Audio quality can be good as I would take the line out of my audio mixer for the feed.  The teachers use the conventional black board 95% of the time and projectors rarely.

Please watch this video

https://www.youtube.com/watch?v=fr6-6EHl-bo

Wow. Then expect the budget to increase by an order of magnitude, $200-$300k would not be unreasonable!

Alternatively, you could train the teachers to present using a PC, and then use something like webex..

The teachers could be trained to use laptops for presentation but all may not agree to.  Further, this process takes time.

You've described a couple of different scenarios. In the video, they showed the setup that Clem initially proposed. A raspberry pi, with a camera in a microphone in a room. That is pretty easy to setup.

You then added the complexity of sending that video/audio data to a central location to be controlled by an operator. Clem pointed out the the Pi probably doesn't have the IO bandwidth for that.

It would be inexpensive to setup 1 pi per room, then transfer the recorded video after the fact via network.

You could easily mimic the setup they show in the video, and compromise on the central control and data capture.

Mike

So there's your answer(!).

If you think that solution is available for download or purchase, why not obtain or purchase it?

Otherwise, you'd have to either design a solution using the Pi, or expect to pay what an off-the-shelf solution costs.

I like this suggestion.  However, the classrooms continue for 4 hours and I wonder how long a footage can be captured by the raspberry PI.  Secondly, how do I get the Pi to start and stop recording.  I guess I could feed the rasperry PI and audio feed from my mixer to enable high quality audio being recorded too.  I am open to all options.

You could even run a web server on the Pi and have the lecturer start the recording via smartphone or PC. Or it could be started remotely by the operator in a remote location, but they might need a cue to be gin recording, you might be able to stream the audio to the operator, or put a keyframe on the web site to cue them when to start the recording.

Mike

I think I've answered a couple of the questions. Duration of recording will be determined by the quality of the recording. 64gb and 128gb sd cards are available.

http://studiopost.com/contact/tech-specs/calculating-disk-space-requirements

That is a link to storage requirements for recording hd video.

You might have to compromise on the quality, but if this is for web quality viewing it may be doable.

Mike

What is the recording capacity of the PI ?

What is the recording capacity of the PI ?

It's only limited to the size of the attached storage. As I said you can get very large SD cards, or hook a drive up via usb. But that might limit your usb bandwidth if that is also the source of your camera, but if you went with the pi camera you would have no such limit, and the external storage could be a multi terabyte drive.

Mike

How far from the PI can the storage device be kept while being connected by a USB cable?

Man, is google broken where you live?

http://lmgtfy.com/?q=max+usb+length

Mike

Thank you.  Now to revise everything, I need to purchase the raspberry PI and its camera and a USB flash drive.  Then I would need to feed the Raspberry PI with an audio feed from the audio mixer that is in every classroom and then I have everything I need.  Am I right? 

I am unable to understand how the recording will be started, paused and stopped though.  How will the raspberry get the command?   Our teachers do not carry with them laptops. 

A smartphone could work, or as I said you could add a little web program that would allow a remote operator to start the recording, but they would need to know when. Also, you could add a simple circuit with a button and a resistor to start the recording, there are really a number of possibilities, read up a little bit while you are waiting for you RasPi's, etc to show up. If you have questions, open a new thread and ask for help. There are a lot of people here that are willing to help if you are willing to gain a little knowledge to ask the right questions.

I'd advise you to start small, prototype the process and components, then replicate when you think you have a system in place that is satisfactory.

Good luck on this,

Mike

BTW, the circuitry and programming required to do this isn't real difficult. Anyone with a desire to learn can have this going pretty quickly.

Mike

Naresh,

"I'd advise you to start small, prototype the process and components, then replicate when you think you have a system in place that is satisfactory."

What Michael says here is so important!

You need to consider taking your time in finding the right solution to your needs. Prototype it, try various alternatives. Personally, i would not use HD video, but if the text that is written on the blackboard needs to be legible in the video then you might not have any other choice. For four hours of HD video you are looking at 6GB minimum, and I am just guessing. This page might help:

http://studiopost.com/contact/tech-specs/calculating-disk-space-requirements

Test at various definitions, use the minimum that meets your needs. Test it by watching a test video (needs to be 4 hours) to determine how usable it will be.

Good luck! Sgarciav

Where can I purchase the raspberry PI and the case and the camera?

You can find links right on this site to buy the pi and accessories.Click on the element14 logo on the top left to get to the home page, then click on the big ras pi ad on the front page. That should eventually send you to a Farnell distributor in your locality.

Mike

I would like to learn more about the circuitry that could be used to start/pause/stop the recording.  Should I start a new thread for this or can the knowledge be shared here?