Evaluation Scenes

Making an Evaluation Scene

Scenes are defined in the configuration file using a set of identifiers, parameters, and audio and visual material.

Object-based Audio + CGI

Here's an example scene configuration for a CGI scene. The evaluation scene uses individual audio files which are associated with audio objects in virtual reality, and are rendered using an object-based audio workflow.

"Scenes" : [
    {
        "stimuli_ID" : "Scene_stereo_bongos_interaction",
        "unityScene_ID" : "_bongos_demo",
        "visualStimuliType" : "CGI",
        "dimensions" : [ 30.0, 8.0, 30.0 ],
        "multichannelAudio" : {
            "multichannelAudioFile" : null
        },
        "objectAudio" : {
            "objectAudioFolder" : "audio/_bongos/edited",
            "objectAudioRouting" : [
                {
                    "pathToFile" : "1_bongos_L.wav",
                    "inputChannel" : 0,
                    "autoplay" : 1
                },
                {
                    "pathToFile" : "2_bongos_R.wav",
                    "inputChannel" : 1,
                    "autoplay" : 1
                }
            ]
        }
    }
]

Let's break it down...

• scene_ID → A string to define the test item (e.g., "Scene_stereo_bongos_interaction", to help us identify certain aspects of the item quickly)
• unityScene_ID → A string entry used to inform the Unity client which Unity scene should be loaded
• VisualStimuli → Either CGI or ODV entry to determine which further config entries are of interest
• dimensions → X, Z, Y dimensions of the virtual scene, used for paramater input normalizion for VSTs
• multichannelAudioFile → path to the multichannel audio file(s)
• objectAudioFolder → path to the folder containing the mono audio files used for audio objects
• objectAudioRouting → An array entry of nested data regarding specific audio files. For each audio file, we provide
  • pathToFile → name/path of the audio file relative to the audio objectAudioFolder
  • inputChannel → input channel to the VST
  • autoplay → 1 or 0 to say if the file should continuously loop from start or be triggered by event

Object-based + 360 Video

An example using a 360 which has been augments by audio objects with the object rendering pipeline.

"audioRendering" : {
    ...
    "renderingPipeline" : "Objects",
    ...
},

"Scenes" : [
    {
        "scene_ID" : "Scene_sax_video_audio_object",
        "unityScene_ID" : "_videoPlayer", // <- Specific scene for video playabck.
        "visualStimuliType" : "ODV",
        "videoFiles" : [ // <- List allows multiple video files per scene.
            {
                "pathToFile" : "saxophone/video/saxophonePlayer.mp4", 
                "video_ID" : 1
            }
        ],
        "dimensions" : [ 5, 5, 5 ], 
        "multichannelAudio" : {
            "multichannelAudioFile" : null
        },
        "objectAudio" : {
            "objectAudioFolder" : "saxophone/objects",
            "objectAudioRouting" : [
                {
                    "pathToFile" : "saxophone.wav",
                    "inputChannel" : 0,
                    "autoplay" : 1
                }
            ]
        }
    }
]

A scene that is recorded via a 360 camera doesn't change in terms of the content that is recorded. However, it CAN change in terms of encoding, resolution, or frame-rate, for example. Therefore, multiple recordings can be classified as the same scene.

Allowing multiple video files to be assigned to a single scene is an efficient way of creating test items for ACR video quality evaluation, where all other parameters would remain the same.

Ambisonics audio + 360 Video

An example using the multichannel rendering pipline with Ambisoncis audio and 360 video...

"audioRendering" : {
    ...
    "renderingPipeline" : "Multichannel", // <- Set rendering pipeline for Multichannel audio.
    ...
},

"Scenes" : [
    {
        "scene_ID" : "Scene_sax_video_audio_object",
        "unityScene_ID" : "_videoPlayer", // <- Specific scene for video playabck.
        "visualStimuliType" : "ODV",
        "videoFiles" : [ // <- List allows multiple video files per scene.
            {
                "pathToFile" : "saxophone/video/saxophonePlayer.mp4", 
                "video_ID" : 1
            }
        ],
        "dimensions" : [ 5, 5, 5 ], // <- This is ignored in multichannel audio rendering
        "multichannelAudio" : {
            "multichannelAudioFile" : "saxophone/ambisonics/4OA_Saxophone.wav"
        },
        "objectAudio" : {
            "objectAudioFolder" : "null",
            "objectAudioRouting" : [ ]
        }
    }
]

Here, we've removed information regarding audio objects and object routing, and have inlcuded a path to the Ambisonics audio file.

Ambisoncs audio + CGI

An example using a CGI scene and Ambisonics audio

"audioRendering" : {
    ...
    "renderingPipeline" : "Multichannel", // <- Set rendering pipeline for Multichannel audio.
    ...
},

"Scenes" : [
    {
        "scene_ID" : "Scene_city_1OA_audio",
        "unityScene_ID" : "_city",
        "visualStimuli" : "CGI",
        "dimensions" : [ 50.0, 8.0, 50.0 ],
        "multichannelAudio" : {
            "multichannelAudioFile" : "city/ambisonics/4OA_City.wav"
        },
        "objectAudio" : {
            "objectAudioFolder" : "null",
            "objectAudioRouting" : [ ]
        }
    }
]