1 This directory contains sample code to test the use of virtual 2 displays created over an Android Open Accessories Protocol link. 3 4 --- DESCRIPTION --- 5 6 There are two applications with two distinct roles: a sink 7 and a source. 8 9 1. Sink Application 10 11 The role of the sink is to emulate an external display that happens 12 to be connected using the USB accessory protocol. Think of it as 13 a monitor or video dock that the user will want to plug a phone into. 14 15 The sink application uses the UsbDevice APIs to receive connections 16 from the source device over USB. The sink acts as a USB host 17 in this arrangement and will provide power to the source. 18 19 The sink application decodes encoded video from the source and 20 displays it in a SurfaceView. The sink also injects passes touch 21 events to the source over USB HID. 22 23 2. Source Application 24 25 The role of the source is to present some content onto an external 26 display that happens to be attached over USB. This is the typical 27 role that a phone or tablet might have when the user is trying to 28 play content to an external monitor. 29 30 The source application uses the UsbAccessory APIs to connect 31 to the sink device over USB. The source acts as a USB peripheral 32 in this arrangement and will receive power from the sink. 33 34 The source application uses the DisplayManager APIs to create 35 a private virtual display which passes the framebuffer through 36 an encoder and streams the output to the sink over USB. Then 37 the application opens a Presentation on the new virtual display 38 and shows a silly cube animation. 39 40 --- USAGE --- 41 42 These applications should be installed on two separate Android 43 devices which are then connected using a USB OTG cable. 44 Remember that the sink device is functioning as the USB host 45 so the USB OTG cable should be plugged directly into it. 46 47 When connected, the applications should automatically launch 48 on each device. The source will then begin to project display 49 contents to the sink. 50 51
