You can get USB capture devices that will take HDMI video in and encode it to e.g. H264. You can get Android devices that can USB master. So then it's a matter of drivers. It looks like it's doable if you can choose the device and supply your own kernel: http://stackoverflow.com/questions/12334612/analog-video-capture-to-android-phonehttps://stackoverflow.com/questions/12334612/analog-video-capture-to-android-phone