| Jeff Brown | 8f3b130 | 2013-05-29 14:59:46 -0700 | [diff] [blame] | 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 | |