====== Audio, Video and Desktop Capture Library Specification ======

This is a specification of [[developers:gsoc:2015:ideas#Modular_library_for_platform-dependent_audio_video_and_desktop_capture|Modular library for platform-dependent audio video and desktop capture]] GSoC idea.

====== Modules ======


===== Video =====

Should be written using platform native APIs, i.e. no GStreamer, OpenCV, QtMultimedia, etc.

**Windows**:

  * [[https://msdn.microsoft.com/en-us/library/windows/desktop/ms696274.aspx|Windows Media Foundation]] (Windows Vista+), C++ API
  * [[https://msdn.microsoft.com/en-us/library/windows/desktop/dd375454.aspx|DirectShow]] (Windows XP+), C++ API

**OS X**:

  * [[https://developer.apple.com/library/ios/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/00_Introduction.html|AV Foundation]] (OS X 10.7+), Obj-C API

==== Expected functionality to be implemented ====

  * Get a list of all camera devices, with their respected camera ids and UI-friendly device names.
  * Specify which camera to use, based on the camera id from the camera list.
  * Use multiple cameras at once.
  * Capture a single frame (a still image).
  * Capture a continuous stream (a video).
  * All capturing should be done in YUV and RGB.
  * Get list of supported camera resolutions.
  * Set resolution of capturing images.
  * Get notified when a camera is connected to/disconnected from the computer.
  * Change image brightness, contrast, saturation.


===== Audio =====

Should be written using platform native APIs (what about OpenAL?).

==== Expected functionality to be implemented ====

  * Get a list of all audio recording devices, with their respected device ids and UI-friendly device names.
  * Specify which audio recording device to use, based on the device id from the device list.
  * Capture audio in 48khz 16bit signed PCM.
  * Get a list of all audio playback devices, with their respected device ids and UI-friendly device names.
  * Specify which audio playback device to use, based on the device id from the device list.
  * Audio playback.
  * Audio mixing.
  * Get notified when an audio device is connected to/disconnected from the computer.


===== Desktop =====

Should be written using platform native APIs.
On Linux it should support X11, Wayland and Mir.

==== Expected functionality to be implemented ====

  * Get a list of all monitors.
  * Specify which monitor to capture, based on the list.
  * Capture a single frame.
  * Capture a continuous stream. Some(?) APIs provide this, which is different from manually capturing frame by frame.
  * All capturing should be done in YUV and RGB.
  * Get monitor's properties, such as resolution.
  * Get notified when a monitor is added/removed.