Developer Libraries » IOCipher

Here's an example of how MediaRecorder is used:
http://stackoverflow.com/questions/1817742/how-can-i-capture-a-video-recording-on-android/4379320#4379320

I am currently working on sth. like that.
i use IOCipher to encrypt a video recorded with the MediaRecorder.

So if you want i can contribute to this feature
it is a open source development and i can upload it in a few days to github,
but i need to cleanup the code a bit first.
der_die_das_jojo

yes! We'd love to see that. We had some luck recording live audio input directly to IOCipher using this technique:

https://lists.mayfirst.org/pipermail/guardian-dev/2013-July/002031.html

It might be possible to do that with certain video formats too, like mp4/h264.

according to this:
http://developer.android.com/guide/appendix/media-formats.html

i think H.264 AVC with MPEG-TS would be the right choice.
unfortunately my current dev. smartphone doesn´t have android 3 and the CyanogenMod doesn´t support camera feature.

currently i am using H263 with 3GP which creates broken videos playable with vlc.
so i suppose it is a possible workaround for low-cost phones to offer something like recoring with h263 + 3gp and postprocessing with ffmpeg
after recording, but it´s not nice.

maybe one of you guys can try out H264 + MPEG-TS ?

So there is a technique here that should be very useful for this problem. You can write out a standard mp4/h264 out to an unseekable file, then later correct the header information, and the mp4 will then be fully playable. I'm probing Shawn for the details.

That sounds promising, are you able to update the header through a stream too?

I don't think you can update the header via the stream, it needs to happen in a different channel. So for your camera application, MediaRecorder would stream the video to IOCipher. Then when its complete, a separate class would working directly with IOCipher, reading the misplaced header in the newly recorded video, then writing the correct header.

thx a lot for the further information. i think some more research about the video format headers will be necessary. i can look this up. but i don´t have a lot of time the next 2-3 weeks. so if someone else is faster in contributing to this, i am also happy about it.