LayoutTests/media/media-source/content/test-xhe-aac-manifest.json

{
    "url": "content/test-xhe-aac.m4a",
    "type": "audio/mp4; codecs=\"mp4a.40.42\"",
    "init": { "offset": 0, "size": 756 },
    "duration": 33.968,
    "media": [
        { "offset": 756,   "size": 280130, "timestamp": 0, "duration": 33.968 }
    ]
}