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Information on content playback.

Machine Requirements​

For playback at the high-quality video resolution 7680x3840 (8k), your machine must have a capable enough GPU.

Tested Systems​

System A​

  • OS: Windows 11
  • GPU: RTX 2060
  • CPU: AMD Ryzen 5 3600 6-Core / Intel-i7
  • Memory: 16.0 GB

System B​

  • OS: Windows 10
  • GPU: RTX 3080 10GB 2.0 PCIe 4.0 Gigabyte
  • CPU: AMD Ryzen 7 5800X AM4
  • Memory: 32 GB DDR4-3200

Audiovisual Spatial Alignment​

caution

4th-order Ambionsics .WAV files have a -90° spatial rotation in Yaw. This is to spatially align audio with Unity's projection mapping of 360° images using skyboxes.

Read below for explination.

Playback Compatability​

Many 360° video players have limitations in either the maximum video resolution, or spatial audio compatability. There are few plug-and-play tools available that will be compatible with both higher-order Ambisonics above 3rd order, and high-resolution video files above 4K.

To render higher-order Ambisonics, many VST plug-ins are available that can be used to decode and render Ambisoncs audio channels independently of the video. See the SPARTA spatial audio real-time applications, or IEM Plug-in suite for more information. To render 8K video, the Unity game engine was used in conjuction with the VideoPlayer component.

Using Unity​

Unity can be used to send real-time head tracking information to incoming OSC ports of any of the spatial audio plug-ins above, to rotate the Ambisonics audio with respect to head movements. The main draw-back of this approach is that the unwraping of a 360° image to a Skybox in Unity will cause a +90° shift in Y rotation. As the audio is rendered independently, it is unaware of this shift resulting in audio visual spatial misalignment of 90°.

Current Implementation​

The current solution provided by default is a -90° rotational shift in the 4th-order Ambisonics audio files. When used in conjuction with Unity and the Unity VideoPlayer component, audio and video will be already correctly alligned. The 1st-order Ambisonics contained in the YouTube videos do not have this spatial rotation.

To use the 4th-order Ambisoncis with no spatial rotation, re-render the audio files using a Ambisonics scene rotator (see above plug-ins) with a +90° rotation in Yaw.

Creating Degradations​

Many studies wish to use databases to investigate the effect of changing paramaters, often representative of the processing or transmission chain, on objective or subjective quality measures. Here's a few examples of how to create degaraded versions of the provided database for both audio and video.

Video​

Examples of creating video degradations using FFmpeg

Reducing the bit-rate

ffmpeg -i Input_file.mkv -preset slow -c:v hevc -x265-params "pass=1" -b:v 25000k Output_file_Pass1.mp4

ffmpeg -i Input_file.mkv -preset slow -c:v hevc -x265-params "pass=2" -b:v 25000k Output_file_Pass2.mp4

Reducing the framerate 

ffmpeg -i Input_file_60fps.mp4 c:v libx265 -crf 18 -r 30 Output_file_30fps.mp4

Reducing the resolution

ffmpeg -i Input_file_7680x3840.mkv -c:v libx265 -crf 1 -vf scale=3840x1920 Output_file_3840x1920.mkv