多个画布上多个音视频文件的目录

翻译：羊牧东岭

原文地址：https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/

用例

一场歌剧表演可能耗时很长，从而用多张磁带或胶卷等物理介质来分别存放。在进行数字化时，这些物理介质可以分别形成单个文件，然后每个文件分别映射到一个画布 (Canvas) 上。这个现实生活中的例子展示了如何使用多个画布对此进行建模。

实施说明

本例的实现与单一画布上多个音视频文件的目录基本相同，不同之处在于，本例中的两个文件(分别代表歌剧的一幕)，每个文件都对应有自己的画布，并如此地在相应结构中被引用。使用两个画布时，播放器将仅显示当前播放的这个文件的持续时长。在切换播放文件时，时间将从零开始。如果你希望针对文件而非整部歌剧来建立时间参考，那么这种实现方法会有所帮助。

限制条件

由于播放器在播放下一个文件时需要切换上下文环境，所以实际上会导致分开播放。为确保连续播放，所有文件应注释到共同的某个画布 (Canvas) 上，就像单一画布上多个音视频文件的目录例子中所示的那样。

例子

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{
  "@context": "http://iiif.io/api/presentation/3/context.json",
  "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/manifest.json",
  "type": "Manifest",
  "label": {
    "it": [
      "L'Elisir D'Amore"
    ],
    "en": [
      "The Elixir of Love"
    ]
  },
  "metadata": [
    {
      "label": {
        "en": [
          "Date Issued"
        ]
      },
      "value": {
        "en": [
          "2019"
        ]
      }
    },
    {
      "label": {
        "en": [
          "Publisher"
        ]
      },
      "value": {
        "en": [
          "Indiana University Jacobs School of Music"
        ]
      }
    }
  ],
  "items": [
    {
      "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1",
      "type": "Canvas",
      "width": 1920,
      "height": 1080,
      "duration": 3971.24,
      "label": {
        "en": [
          "Atto Primo"
        ]
      },
      "items": [
        {
          "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1/annotation_page/1",
          "type": "AnnotationPage",
          "items": [
            {
              "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1/annotation_page/1/annotation/1",
              "type": "Annotation",
              "motivation": "painting",
              "target": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1",
              "body": {
                "id": "https://fixtures.iiif.io/video/indiana/donizetti-elixir/vae0637_accessH264_low_act_1.mp4",
                "type": "Video",
                "format": "video/mp4",
                "height": 1080,
                "width": 1920,
                "duration": 3971.24
              }
            }
          ]
        }
      ],
      "thumbnail": [
        {
          "id": "https://fixtures.iiif.io/video/indiana/donizetti-elixir/act1-thumbnail.png",
          "type": "Image"
        }
      ]
    },
    {
      "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/2",
      "type": "Canvas",
      "width": 1920,
      "height": 1080,
      "duration": 3307.22,
      "label": {
        "en": [
          "Atto Secondo"
        ]
      },
      "items": [
        {
          "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/2/annotation_page/1",
          "type": "AnnotationPage",
          "items": [
            {
              "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/2/annotation_page/1/annotation/1",
              "type": "Annotation",
              "motivation": "painting",
              "target": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/2",
              "body": {
                "id": "https://fixtures.iiif.io/video/indiana/donizetti-elixir/vae0637_accessH264_low_act_2.mp4",
                "type": "Video",
                "format": "video/mp4",
                "height": 1080,
                "width": 1920,
                "duration": 3307.22
              }
            }
          ]
        }
      ],
      "thumbnail": [
        {
          "id": "https://fixtures.iiif.io/video/indiana/donizetti-elixir/act2-thumbnail.png",
          "type": "Image"
        }
      ]
    }
  ],
  "structures": [
    {
      "type": "Range",
      "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/range/1",
      "label": {
        "it": [
          "Gaetano Donizetti, L'Elisir D'Amore"
        ]
      },
      "items": [
        {
          "type": "Range",
          "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/range/2",
          "label": {
            "en": [
              "Atto Primo"
            ]
          },
          "items": [
            {
              "type": "Range",
              "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/range/3",
              "label": {
                "it": [
                  "Preludio e Coro d'introduzione – Bel conforto al mietitore"
                ]
              },
              "items": [
                {
                  "type": "Canvas",
                  "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1#t=0,302.05"
                }
              ]
            },
            {
              "type": "Range",
              "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/range/4",
              "label": {
                "en": [
                  "Remainder of Atto Primo"
                ]
              },
              "items": [
                {
                  "type": "Canvas",
                  "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/1#t=302.05,3971.24"
                }
              ]
            }
          ]
        },
        {
          "type": "Range",
          "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/range/5",
          "label": {
            "en": [
              "Atto Secondo"
            ]
          },
          "items": [
            {
              "type": "Canvas",
              "id": "https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/canvas/2#t=0,3307.22"
            }
          ]
        }
      ]
    }
  ]
}

相关专题

• 简单清单 - 视频
• [缩略图][0012]
• 音视频内容的目录 - 使用嵌套范围表示歌剧目录的另一个示例。
• 单一画布上多个音视频文件的目录 - 本示例中的相同歌剧，但在一个画布上采用视频格式。