本文为阿里云智能媒体服务IMS「云端智能剪辑」实践指南第二期，讲述围绕效率化内容生产需求，运用数字人视频合成能力，实现高效、便捷的数字人视频制作体验。

欧叔｜作者

随着虚拟数字人技术的发展，越来越多的企业把虚拟人应用到自己的业务场景中，通过创新的内容形态，提升制播效率和智能化水平。

比如：将虚拟人用于内容播报、讲解；创建企业虚拟形象（数字员工）代替传统文本式互动；驱动“虚拟主播”角色，实现7*24小时不间断直播……虚拟数字人在视频内容生产环节的应用也越来越多。

IMS云端智能剪辑已将数字人能力集成到了智能时间线Timeline中，客户可以通过使用IMS基础剪辑能力、调用IMS数字人视频合成接口、智能时间线Timeline。

本文，我们将围绕4大主要场景，展现从无到有合成出“数字人”成片。

场景一

数字人视频+绿幕抠图+文字/背景图

如果客户数字人视频是常见的带绿幕的mp4素材，可以使用IMS云端智能剪辑时间线中的绿幕抠图功能，给数字人视频添加“AI_Matting”效果，即可跟背景视频、文案做合成。这是该场景中使用的素材示例：

绿幕抠图功能按照“颜色相似度”进行主体识别，数字人身上尽量不要使用与绿色相近的颜色。

Timeline示例：

{
"VideoTracks": [{
"VideoTrackClips": [{
"Type": "GlobalImage",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/backgroundImage.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1    }]
  },{
"VideoTrackClips": [{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/avatar.mp4",
"X": 0.3,
"Y": 0.3,
"Width": 0.7,
"Height": 0.7,
"Effects": [{
"Type": "AI_Matting",
"Color" : "green",
"Auto" : 1,
"Thres" : 10      }]
    }]
  }],
"SubtitleTracks":[
    {
"SubtitleTrackClips": [
        {
"Type": "Text",
"X": 150,
"Y": 300,
"Content": "北京气象播报",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font/your-font.ttf",
"FontColor": "#e0ffff",
"FontColorOpacity": 1,
"FontSize": 100,
"Outline": 2,
"OutlineColour": "#000066",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        }
      ]
    },
    {
"SubtitleTrackClips": [
        {
"Type": "Text",
"X": 150,
"Y": 450,
"Font": "Alibaba PuHuiTi",
"Content": "昨天，北京晴转多云，西部、北部等地出现分散降雨，南郊观象台最高气温30.4摄氏度，中午前后体感较热",
"AdaptMode": "AutoWrap",
"FontColor": "#FFFFFF",
"FontSize": 70,
"TextWidth": 800,
"Outline": 2,
"TimelineIn": 0,
"TimelineOut": 9.5,
"OutlineColour": "#000066",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        },
        {
"Type": "Text",
"X": 150,
"Y": 450,
"Font": "Alibaba PuHuiTi",
"Content": "气象部门提醒，北京未来三天紫外线很强，“烧烤”模式将再次启动，公众请注意防暑降温，注意用火、用电安全，防范火灾的发生",
"AdaptMode": "AutoWrap",
"FontColor": "#FFFFFF",
"FontSize": 70,
"TextWidth": 800,
"Outline": 2,
"TimelineIn": 9.5,
"OutlineColour": "#000066",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        }
      ]
    }
  ]
}

成片效果视频：https://v.youku.com/v_show/id_XNTk5MTc5OTE3Mg==.html

本时间线示例中添加了字幕、背景图。此外，还有一些小技巧：

l Width:1、Height:1 的意思是素材的宽高分别占成片的100%，当客户指定的成片分辨率有变化时，背景素材也会跟着成片的分辨率变化。

l Type：GlobalImage是全局图片，全局图片不需要设置出、入场时间，图片默认从成片开始展示到成片结束，在背景图、水印、Logo场景中经常使用。

场景二

带透明通道的数字人视频 + ASR + 背景视频

场景二中，如果客户已有的数字人视频是一个带透明通道的webm格式视频，这类素材的是可以直接与背景图片叠加进行合成，IMS云端智能剪辑的数字人合成接口也可以输出webm格式的数字人视频。

数字人播报场景通常需要展示口播字幕，且字幕要跟随数字人人声播放。在剪辑中可以为数字人视频添加“AI_ASR”特效，剪辑合成中会识别视频中的人声，并作为字幕合成到成片里，客户还可以修改字幕在视频中的位置、样式等。

这是该场景中使用的素材示例：

成片效果视频：https://v.qq.com/x/page/b3525u1xuvv.html

Timeline示例：

{
"VideoTracks": [{
"VideoTrackClips": [{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/backgroundVideo.mov",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"AdaptMode": "Cover"    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/backgroundVideo.mov",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"AdaptMode": "Cover"    }]
  },{
"MainTrack": true,
"VideoTrackClips": [{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/avatar.webm",
"X": 0.05,
"Y": 0.1,
"Width": 0.9,
"Height": 0.9,
"Effects": [{
"Type": "AI_ASR",
"Font": "Alibaba PuHuiTi",
"Alignment": "BottomCenter",
"Y": 100,
"FontSize": 80,
"AdaptMode": "AutoWrap",
"FontColor": "#ffffff",
"Shadow": 2,
"ShadowColor": "#66ccff",
"BackColour": "#6666ff",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false        }
      }]
    }]
  }],
"SubtitleTracks":[
    {
"SubtitleTrackClips": [
        {
"Type": "Text",
"Y": 100,
"Content": "7月21日美股新闻",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font.TTF",
"Alignment": "TopCenter",
"FontColor": "#ffffff",
"FontSize": 100,
"Shadow": 3,
"ShadowColor": "#66ccff",
"BackColour": "#66ccff",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        },
        {
"Type": "Text",
"Y": 210,
"Content": "美股涨跌不一 道指九连阳 纳指大跌2.05%",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font/FZYanSJW_Da.TTF",
"Alignment": "TopCenter",
"FontColor": "#ffffff",
"FontSize": 50,
"Outline": 2,
"OutlineColour": "#000000",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        }
      ]
    }
  ]
}

本时间线示例中，还使用了一些小技巧：

l 如果我们使用的背景视频是横屏的，而我们所需的成片是竖屏的短视频，那么在剪辑中可以设置素材的适配模式。AdaptMode:Cover是将素材等比缩放填满画布区域，不会对素材拉伸，同时很好得适配了竖屏短视频。

l 如果视频中有两个视频轨，我们可以把数字人视频作为主轨道，这样其他轨道默认向数字人轨道对齐，客户无需手动设置其他轨道的时长。

场景三

智能时间线+IMS官方数字人形象

在场景三中，客户可以直接使用阿里云IMS的官方数字人形象，将时间线中的视频Clip类型设置为AI_Avatar，设置数字人朗读的文本和数字人ID，即可生成数字人视频，并通过智能时间线Timeline将数字人合成到成片中。

这是该场景中使用的素材示例：

成片效果视频：https://v.youku.com/v_show/id_XNTk5NDIyMzcxMg==.html

Timeline示例：

{
"VideoTracks": [{
"VideoTrackClips": [{
"Type":"GlobalImage",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/backgroundImage.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1    }]
  },{
"MainTrack": true,
"VideoTrackClips": [{
"Type": "AI_Avatar",
"AvatarId": "fanyu-sitting",
"Content": "保险通常设有10天的犹豫期\n犹豫期的起始日为投保人书面签收保单日\n投保人若发现购买的产品与自身需求不相符时\n在犹豫期内退保\n保险公司会全额或在扣除保单工本费后无息退还已交保险费\n并且自始不承担保险责任",
"X": 0.05,
"Y": 0.1,
"Width": 0.9,
"Height": 0.9,
"Effects": [{
"Type": "AI_ASR",
"Font": "Alibaba PuHuiTi",
"Alignment": "BottomCenter",
"Y": 200,
"Outline": 2,
"FontSize": 90,
"TextWidth": 980,
"AdaptMode": "AutoWrap",
"OutlineColour": "#000000",
"FontColor": "#ffffff",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false        }
      }]
    }]
  }],
"SubtitleTracks":[
    {
"SubtitleTrackClips": [
        {
"Type": "Text",
"X": 100,
"Y": 1300,
"Content": "保险经纪人：凡宇",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font.TTF",
"FontColor": "#ffffff",
"FontSize": 80,
"Shadow": 3,
"ShadowColor": "#66ccff",
"BackColour": "#3366cc",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        },
        {
"Type": "Text",
"Y": 150,
"Content": "重疾险买了后发现不合适自己，怎么办？",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font.TTF",
"Alignment": "TopCenter",
"FontColor": "#ffffe0",
"AdaptMode": "AutoWrap",
"FontSize": 100,
"TextWidth": 900,
"Outline": 3,
"TimelineIn": 0,
"TimelineOut": 5,
"OutlineColour": "#000000",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        }
      ]
    }
  ]
}

l Tips：使用AI_Avatar的同时还可以修改数字人的音色（VoiceId）、语速（SpeechRate）、音调（PitchRate）、音量（Volume）等。

场景四

综合使用多轨合成、转场、字幕合成数字人

在实际生产中，也存在数字人播报常伴随着主视频、背景内容的变化的复杂场景，在IMS云端智能剪辑中，客户可以通过一个Timeline将这些需求完整表达出来，仅提交一个剪辑任务即可得到想要的成片。

本场景使用多个素材视频、背景图片，同样使用智能时间线Timeline进行数字人视频合成。

这是该场景中使用的素材示例：

成片效果视频：https://v.youku.com/v_show/id_XNTk5NjA4OTAxNg==.html

Timeline示例：

{
"VideoTracks": [{
"VideoTrackClips": [{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg1.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "windowslice"      }]
    },{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg2.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "squareswire"      }]
    },{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg3.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "windowslice"      }]
    },{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg4.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "squareswire"      }]
    },{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg5.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "windowslice"      }]
    },{
"Type":"Image",
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bg6.png",
"X": 0,
"Y": 0,
"Width": 1,
"Height": 1,
"Duration": 5,
"Effects": [{
"Type": "Transition",
"SubType": "squareswire"      }]
    }]
  },{
"MainTrack": true,
"VideoTrackClips": [{
"Type": "AI_Avatar",
"AvatarId": "boyuan-marketing_standing",
"Content": "在2023LVS上海站，阿里云视频云专场\n将从面向未来的流媒体传输网络、智能化编码架构\n媒体服务重组与进化、媒体开发终端套件四大维度\n深度呈现阿里云视频云的全面进化和全智能演进\n以云之普惠、AI之智慧，加速音视频数智化创新落地\n打造“云智新生”的新景象",
"CustomizedVoice": "zhifan",
"X": 100,
"Y": 180,
"Width": 506,
"Height": 900,
"Effects": [{
"Type": "AI_ASR",
"FontColorOpacity": 1.0,
"TimelineIn": 20.496,
"OutlineColour": "#000000",
"FontColor": "#ffffff",
"Outline": 2,
"Font": "Alibaba PuHuiTi",
"TimelineOut": 22.43,
"Alignment": "BottomCenter",
"FontSize": 70,
"Y": 100.0,
"AdaptMode": "AutoWrap",
"TextWidth": 1720.0,
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false        }
      }]
    }]
  },{
"VideoTrackClips": [{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_6.mov",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_1.mp4",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_2.mp4",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_3.mp4",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_5.mp4",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    },{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/lvs_4.mp4",
"X": 0.4,
"Y": 0.2,
"MaxOut": 4,
"Width": 0.5,
"Height": 0.5,
"Effects": [{
"Type": "Volume",
"Gain": 0      }]
    }
    ]
  }],
"SubtitleTracks":[
    {
"SubtitleTrackClips": [
        {
"Type": "Text",
"X": 220,
"Y": 0.75,
"Font1": "Alibaba PuHuiTi",
"Font1": "SimSun",
"Content": "主持人：博远",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font/FZYanSJW_Da.TTF",
"Alignment1": "TopCenter",
"FontColor": "#ffffff",
"FontSize": 45,
"Shadow1": 3,
"ShadowColor1": "#66ccff",
"BackColour1": "#3366cc",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        },
        {
"Type": "Text",
"X": 0.45,
"Y": 0.72,
"Content": "「云智新生」_ 视频云的全智能进化",
"FontUrl":"https://your-bucket***.oss-cn-shanghai.aliyuncs.com/font/FZYanSJW_Da.TTF",
"FontColor": "#ffffff",
"FontColor1": "#ffffe0",
"Shadow": 3,
"ShadowColor": "#000000",
"BackColour": "#000000",
"FontSize": 55,
"Outline1": 3,
"OutlineColour1": "#000000",
"FontFace": {
"Bold": false,
"Italic": false,
"Underline": false          }
        }
      ]
    }
  ],
"AudioTracks": [{
"AudioTrackClips": [{
"MediaURL": "https://your-bucket***.oss-cn-shanghai.aliyuncs.com/bgmusic.aac",
"Effects": [{
"Type": "Volume",
"Gain": 0.1      }]
    }]
  }]
}