PDrAW - Parrot Drones Awesome Video Viewer

PDrAW (pronounced like the name "Pedro") is a video player for medias created by Parrot drones such as Anafi or Anafi Ai. The player supports both streamed (RTP/RTSP) and recorded (MP4) videos.

PDrAW was originally written by Aurélien Barre as a personal project and is now officially maintained by Parrot Drones SAS. PDrAW is the main video pipeline implementation of GroundSDK. We are using it in our FreeFlight6 and FreeFlight7 applications, both on iOS and Android. It is also usable on desktop platforms.

Supported platforms

• Linux PC
• macOS
• Android (5.0 minimum) (note: for sample code, see GroundSDK Android)
• iOS (8.0 minimum) (note: for sample code, see GroundSDK iOS)

Features

• Demuxing
  • Record demuxer
    • Playback of local replays
    • MP4 file format (ISO/IEC 14496-12, ISO Base Media File Format / ISO/IEC 14496-14, MP4 File Format)
    • Multi-track support on the video with user selection
  • Stream demuxer
    • Live video and streamed replays playback
    • RTP/AVP/UDP streams (RFC 3550, RFC 3551)
    • RTP/AVP/MUX streams with SkyController remotes (using Parrot libmux)
    • Unicast only
    • RTSP 1.0 protocol (RFC 2326)
    • Multi-track support on the video in RTSP with user selection
  • Playback control
    • Play/pause
    • Seeking (except for live streams)
    • Playback speed control (except for live streams)
    • Negative speeds for playing backward (except for live streams)
    • Frame-by-frame forward and backward on local replays (MP4 records)
  • Support of Parrot session and frame metadata (see libvideo_metadata)
• Decoding
  • H.264 video decoding (ITU-T H.264 / ISO/IEC 14496-10), baseline, main and high profiles
  • H.265 video decoding (ITU-T H.265 / ISO/IEC 23008-2), main and main 10 profiles
  • Frame output API for application-side processing on the video (either H.264 frames before decoding or YUV frames after decoding)
• Rendering
  • OpenGL ES 2.0 video rendering
  • Imaging features:
    • Overexposure zebras
    • RGB and luminance histograms computation
  • User rendering callback functions
    • Custom texture loading with provided video metadata
    • Video overlay with provided video metadata
  • HMD distortion correction
    • Support for Parrot Cockpitglasses 1 & 2
    • Device settings for screen pixel density and mechanical margins
    • User settings for video scale, placement and IPD

Software architecture and APIs

Main library: libpdraw

PDrAW is mainly libpdraw.

Available APIs

Available APIs for libpdraw are:

• C
• C++

Dependencies

The library depends on the following Alchemy modules:

• eigen
• libfutils
• libh264
• libh265
• libmp4
• libpomp
• librtsp
• libsdp
• libulog
• libvideo-buffers
• libvideo-buffers-generic
• libvideo-decode
• libvideo-metadata
• libvideo-streaming
• json (optional)
• libmux (optional)
• glfw3 (only on Linux and macOS)
• opengl (only on Linux)

Threading model

The library is designed to run on a libpomp event loop (pomp_loop, see libpomp documentation), except for rendering functions. All API functions must be called from the pomp_loop thread and all callback functions are called from the pomp_loop thread, except for rendering function which must be called on the rendering (OpenGL) thread and rendering callback functions which are called also on the rendering thread.

Helper libraries

libpdraw-backend

libpdraw-backend is a wrapper for libpdraw's API that allows calling functions from any thread, with the exception of rendering functions which must still be called from the rendering thread.

Available APIs for libpdraw-backend are:

• C
• C++

The library depends on the following Alchemy modules:

• libfutils
• libpdraw
• libpomp
• libulog

libpdraw-vsink

libpdraw-vsink is a helper library to easily create a libpdraw instance on a stream or record without rendering and get YUV frames, for example to process them with OpenCV in an application.

The API is available in C. The functions can be called from any thread but are not thread-safe: they should always be called from the same thread, or it is the caller's responsibility to synchronize calls if multiple threads are used.

The library depends on the following Alchemy modules:

• libfutils
• libpdraw
• libpomp
• libulog
• libvideo-buffers
• libvideo-buffers-generic
• libvideo-metadata

libpdraw-gles2hud

libpdraw-gles2hud is a helper library to draw an OpenGL ES 2.0 example HUD (Head-Up Display) on top of the rendered video using libpdraw's rendering overlay callback function.

The API is available in C. All functions must be called from the rendering thread.

The library depends on the following Alchemy modules:

• eigen
• libpdraw
• libulog
• libvideo-metadata
• glfw3 (only on Linux and macOS)
• opengl (only on Linux)

Applications

Applications are built on top of libpdraw or libpdraw-backend.

pdraw-desktop

pdraw-desktop is Linux PC and macOS application written in C using SDL2 for windowed display and the UI.

The application depends on the following Alchemy modules:

• eigen
• libpdraw
• libpdraw-backend
• libpdraw-gles2hud
• libpomp
• libulog
• libvideo-metadata
• sdl2
• glfw3
• opengl (only on Linux)