对直播进行加密

本页介绍了如何加密直播内容。Live Stream API 不会直接创建或管理加密密钥或许可。您必须改用第三方数字版权管理 (DRM) 提供商来使用这些功能。为媒体创建加密密钥后，使用 Secret Manager 将这些密钥传递给 Live Stream API。

加密设置在 Channel 设置中指定。开始直播后，Live Stream API 视频流水线会开始加密您的内容。输出清单包含在所选媒体播放器中解密内容所需的信息。

受支持的配置

流式传输协议 容器 DRM 系统 加密方案
HLS TS ClearKey aes128
HLS TS ClearKey sampleAes
HLS TS FairPlay sampleAes
HLS fMP4 FairPlay 仅限 mpegCenc cbcs
MPEG-DASH fMP4 ClearKey mpegCenc cenc 或 cbcs
MPEG-DASH fMP4 Widevine mpegCenc cenc 或 cbcs
HLS fMP4 Widevine mpegCenc cenc 或 cbcs
MPEG-DASH fMP4 PlayReady mpegCenc cenc 或 cbcs
HLS fMP4 PlayReady mpegCenc cenc 或 cbcs

将加密密钥添加到 Secret Manager

在开始之前，请使用您选择的第三方 DRM 提供商创建加密密钥。

Live Stream API 要求您的密钥包含以下 JSON 格式的加密密钥以及其他必要信息。

如需查看每个字段的说明，请参阅 DRM 协议文档。请注意，您需要将蛇形命名法转换为驼峰式大小写，才能使用 JSON 格式。

示例 JSON

{
  "encryptionKeys": [
    {
      // Key for FairPlay configuration.
      "keyId": "d569cb35bd0548c7a99d92feb381df13",
      "key": "f1967daca83e81f38d80aa741e7b32c2",
      "iv": "8d80aa741e7b32c2f1967daca83e81f3",
      "keyUri": "skd://d569cb35bd0548c7a99d92feb381df13",
      "matchers": [
        {
          "muxStreams": ["ts_fairplay"]
        }
      ]
    },
    {
      // Key for Widevine configurations.
      "keyId": "44ec248b048c43a6a6ee58a752c6f9f8",
      "key": "f1967daca83e81f38d80aa741e7b32c2",
      "keyUri": "skd://44ec248b048c43a6a6ee58a752c6f9f8",
      "matchers": [
        {
          "muxStreams": [
            "fmp4_widevine_cenc_video",
            "fmp4_widevine_cenc_audio",
            "fmp4_widevine_cbcs_video",
            "fmp4_widevine_cbcs_audio"
          ]
        }
      ]
    },
    {
      // Key for PlayReady configurations.
      "keyId": "8beed229709f480bb6004ec0f33e82d1",
      "key": "ad20cd838f354dcc8a77c443d08ff09f",
      "keyUri": "skd://8beed229709f480bb6004ec0f33e82d1",
      "matchers": [
        {
          "muxStreams": [
            "fmp4_playready_cenc_video",
            "fmp4_playready_cenc_audio",
            "fmp4_playready_cbcs_video",
            "fmp4_playready_cbcs_audio"
          ]
        }
      ]
    },
    {
      // Key for all ClearKey configurations.
      "keyId": "3d9dccb479c64adbb6e514790caa7822",
      "key": "f1967daca83e81f38d80aa741e7b32c2",
      "keyUri": "https://example.com/keys/3d9dccb479c64adbb6e514790caa7822.bin",
      "iv": "8d80aa741e7b32c2f1967daca83e81f3"
      // No `matchers` field. This is the default key to use when none of the keys above match.
    }
  ]
}

如果您的加密配置（例如 FairPlay）需要显式初始化向量 (IV)，但未包含该向量，则 API 会将 keyId 的值用作 iv 的值。

如需添加加密密钥，请执行以下任一操作：

  • 手动添加和配置密钥。使用上述 JSON 数据，按照创建 Secret 中的步骤将加密密钥添加到 Secret Manager。

  • 实现一个 key publisher，用于获取任何所需的加密密钥并将其作为密文版本写入 Secret Manager。查看作为 Cloud Run functions 运行的示例实现。

然后，执行以下操作来配置加密密钥：

  1. 为您的 Secret 配置 IAM 权限，以便 Live Stream API 可以访问 Secret 内容。为此，请向 service-PROJECT_NUMBER@gcp-sa-livestream.iam.gserviceaccount.com 服务账号授予 secretmanager.secretAccessor 角色（这与服务账号有权访问您的 Cloud Storage 存储分区的方式类似）。
  2. 找到您创建的 Secret 版本的资源名称（例如 projects/PROJECT_NUMBER/secrets/SECRET_ID/versions/VERSION_ID）。您需要此名称来配置渠道。

配置渠道

加密设置使用 Channel 级别的 encryptions 数组中的对象指定。系统会为每种不同的配置分配一个唯一标识符 (id)。每个 muxStream 都使用一个标识符来指明要使用哪个加密配置，或者省略该字段以保持未加密状态。

JSON 格式

{
  // other channel settings …
  "encryptions": [
    {
      // Identifier for this encryption configuration, to be specified in muxStream(s).
      "id": string,
      // Configuration for secrets stored in Google Secret Manager.
      "secretManagerKeySource": {
        // The name of the Secret Version containing the encryption key.
        // `projects/{project}/secrets/{secret_id}/versions/{version_number}`
        // Using {version_number} of `latest` is not supported.
        "secretVersion": string
      },
      // DRM system(s) that will be used. At least one must be specified. If a DRM system
      // is omitted, it will be considered disabled.
      "drmSystems": {
        // Widevine configuration.
        "widevine": {},
        // FairPlay configuration.
        "fairplay": {},
        // PlayReady configuration.
        "playready": {},
        // ClearKey configuration.
        "clearkey": {}
      },
      // Union field encryption_mode can be only one of the following:
      // Configuration for HLS AES-128 encryption.
      "aes128": {},
      // Configuration for HLS SAMPLE-AES encryption.
      "sampleAes": {},
      // Configuration for MPEG-DASH Common Encryption (MPEG-CENC).
      "mpegCenc": {
        // Specify the encryption scheme. Supported schemes:
        // - `cenc` - AES-CTR subsample
        // - `cbcs`- AES-CBC subsample pattern
        "scheme": string
      }
      // End of list of possible types for union field encryption_mode.
    }
    // Any other encryption configurations.
  ],
  "muxStreams": [
    {
      // Unique identifier for the muxStream.
      "key": string,
      // Identifier of the encryption configuration for the muxStream.
      "encryptionId": string
      // … other muxStream settings.
    }
    // Other muxStreams.
  ],

  // Other channel settings.
}

示例 (ClearKey)

以下示例在 HLS 清单中配置了 AES-128 和 SAMPLE-AES muxStream，并在 DASH 清单中配置了 MPEG-CENC muxStream（cenc 和 cbcs）：

"elementaryStreams": [
  {
    "key": "es_video",
    "videoStream": {
      "h264": {
        "profile": "main",
        "heightPixels": 600,
        "widthPixels": 800,
        "bitrateBps": 1000000,
        "frameRate": 60,
      },
    },
  },
  {
    "key": "es_audio",
    "audioStream": {
      "codec": "aac",
      "channelCount": 2,
      "bitrateBps": 160000
    }
  }
],
"encryptions": [
  {
    "id": "aes-128",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"clearkey": {}},
    "aes128": {}
  },
  {
    "id": "sample-aes",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"clearkey": {}},
    "sampleAes": {}
  },
  {
    "id": "cenc",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"clearkey": {}},
    "mpegCenc": {
      "scheme": "cenc"
    }
  },
  {
    "id": "cbcs",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"clearkey": {}},
    "mpegCenc": {
      "scheme": "cbcs"
    }
  }
],
"muxStreams": [
  {
    "key": "ts_aes128",
    "container": "ts",
    "elementaryStreams": ["es_video", "es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "aes-128"
  },
  {
    "key": "ts_sampleaes",
    "container": "ts",
    "elementaryStreams": ["es_video", "es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "sample-aes"
  },
  {
    "key": "fmp4_cenc_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "cenc"
  },
  {
    "key": "fmp4_cenc_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "cenc"
  },
  {
    "key": "fmp4_cbcs_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "cbcs"
  },
  {
    "key": "fmp4_cbcs_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "cbcs"
  }
],
"manifests": [
  {
    "key": "manifest_aes128_hls",
    "fileName": "manifest_aes128.m3u8",
    "type": "HLS",
    "muxStreams": ["ts_aes128"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_sampleaes_hls",
    "fileName": "manifest_sampleaes.m3u8",
    "type": "HLS",
    "muxStreams": ["ts_sampleaes"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_cenc_dash",
    "fileName": "manifest_cenc.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_cenc_video", "fmp4_cenc_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_cbcs_dash",
    "fileName": "manifest_cbcs.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_cbcs_video", "fmp4_cbcs_audio"],
    "maxSegmentCount": 10
  }
]

示例 (FP/PR/Widevine)

以下示例配置了 FairPlay/SAMPLE-AES、Widevine/MPEG-CENC（cenc 和 cbcs）和 PlayReady/MPEG-CENC（cenc 和 cbcs）muxStreams。Widevine 和 PlayReady muxStream 同时包含在 HLS 和 DASH 清单中。

"elementaryStreams": [
  {
    "key": "es_video",
    "videoStream": {
      "h264": {
        "profile": "main",
        "heightPixels": 600,
        "widthPixels": 800,
        "bitrateBps": 1000000,
        "frameRate": 60,
      },
    },
  },
  {
    "key": "es_audio",
    "audioStream": {
      "codec": "aac",
      "channelCount": 2,
      "bitrateBps": 160000
    }
  }
],
"encryptions": [
  {
    "id": "fairplay",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"fairplay": {}},
    "sampleAes": {}
  },
  {
    "id": "widevine-cenc",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"widevine": {}},
    "mpegCenc": {
      "scheme": "cenc"
    }
  },
  {
    "id": "widevine-cbcs",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"widevine": {}},
    "mpegCenc": {
      "scheme": "cbcs"
    }
  },
  {
    "id": "playready-cenc",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"playready": {}},
    "mpegCenc": {
      "scheme": "cenc"
    }
  },
  {
    "id": "playready-cbcs",
    "secretManagerKeySource": {
      "secretVersion": "projects/12345/secrets/key-1/versions/1"
    },
    "drmSystems": {"playready": {}},
    "mpegCenc": {
      "scheme": "cbcs"
    }
  }
],
"muxStreams": [
  {
    "key": "ts_fairplay",
    "container": "ts",
    "elementaryStreams": ["es_video", "es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "fairplay"
  },
  {
    "key": "fmp4_widevine_cenc_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "widevine-cenc"
  },
  {
    "key": "fmp4_widevine_cenc_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "widevine-cenc"
  },
  {
    "key": "fmp4_widevine_cbcs_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "widevine-cbcs"
  },
  {
    "key": "fmp4_widevine_cbcs_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "widevine-cbcs"
  },
  {
    "key": "fmp4_playready_cenc_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "playready-cenc"
  },
  {
    "key": "fmp4_playready_cenc_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "playready-cenc"
  },
  {
    "key": "fmp4_playready_cbcs_video",
    "container": "fmp4",
    "elementaryStreams": ["es_video"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "playready-cbcs"
  },
  {
    "key": "fmp4_playready_cbcs_audio",
    "container": "fmp4",
    "elementaryStreams": ["es_audio"],
    "segmentSettings": {"segmentDuration": "2s"},
    "encryptionId": "playready-cbcs"
  }
],
"manifests": [
  {
    "key": "manifest_fairplay_hls",
    "fileName": "manifest_fairplay.m3u8",
    "type": "HLS",
    "muxStreams": ["ts_fairplay"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_widevine_cenc_hls",
    "fileName": "manifest_widevine_cenc.m3u8",
    "type": "HLS",
    "muxStreams": ["fmp4_widevine_cenc_video", "fmp4_widevine_cenc_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_widevine_cbcs_hls",
    "fileName": "manifest_widevine_cbcs.m3u8",
    "type": "HLS",
    "muxStreams": ["fmp4_widevine_cbcs_video", "fmp4_widevine_cbcs_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_widevine_cenc_dash",
    "fileName": "manifest_widevine_cenc.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_widevine_cenc_video", "fmp4_widevine_cenc_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_widevine_cbcs_dash",
    "fileName": "manifest_widevine_cbcs.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_widevine_cbcs_video", "fmp4_widevine_cbcs_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_playready_cenc_hls",
    "fileName": "manifest_playready_cenc.m3u8",
    "type": "HLS",
    "muxStreams": ["fmp4_playready_cenc_video", "fmp4_playready_cenc_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_playready_cbcs_hls",
    "fileName": "manifest_playready_cbcs.m3u8",
    "type": "HLS",
    "muxStreams": ["fmp4_playready_cbcs_video", "fmp4_playready_cbcs_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_playready_cenc_dash",
    "fileName": "manifest_playready_cenc.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_playready_cenc_video", "fmp4_playready_cenc_audio"],
    "maxSegmentCount": 10
  },
  {
    "key": "manifest_playready_cbcs_dash",
    "fileName": "manifest_playready_cbcs.mpd",
    "type": "DASH",
    "muxStreams": ["fmp4_playready_cbcs_video", "fmp4_playready_cbcs_audio"],
    "maxSegmentCount": 10
  }
]

确定要使用的 JSON 配置后，请照常创建频道。

开始直播

创建频道后，启动频道并发送输入源。

当频道开始直播时，Live Stream API 会从 Secret Manager 中提取由 secretVersion 标识的加密密钥。如果 Live Stream API 无法获取密钥或密钥格式无法识别，则频道状态会变为 STREAMING_ERROR。如果成功提取密钥，则渠道的状态会像往常一样变为 AWAITING_INPUT。

开始直播后，Live Stream API 会根据创建时提供的配置开始加密输出内容。

监控输出

加密的输出流包含修改后的清单，其中包含解密内容以进行播放所需的信息。

清单示例

以下清单显示了解密关联内容所需的信息。

HLS AES-128/ClearKey

#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-KEY:METHOD=AES-128,URI="https://example.com/keys/3d9dccb479c64adbb6e514790caa7822.bin",IV=0x8d80aa741e7b32c2f1967daca83e81f3
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:22.870Z
#EXTINF:2.576778
segment-0000000000.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:25.447Z
#EXTINF:2.000000
segment-0000000001.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:27.447Z
#EXTINF:2.000000
segment-0000000002.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:29.447Z
#EXTINF:2.000000
segment-0000000003.ts

HLS SAMPLE-AES/FairPlay

#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-KEY:METHOD=SAMPLE-AES,URI="skd://d569cb35bd0548c7a99d92feb381df13",KEYFORMAT="com.apple.streamingkeydelivery",KEYFORMATVERSIONS="1"
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:22.870Z
#EXTINF:2.576778
segment-0000000000.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:25.447Z
#EXTINF:2.000000
segment-0000000001.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:27.447Z
#EXTINF:2.000000
segment-0000000002.ts
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:29.447Z
#EXTINF:2.000000
segment-0000000003.ts

HLS MPEG-CENC/Widevine

#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-KEY:METHOD=SAMPLE-AES-CTR,URI="data:text/plain;base64,AAAAOHBzc2gAAAAA7e+LqXnWSs6jyCfSEAB3Gcrj/8kFtioyiVbJMh9I49yVmwY=",KEYFORMAT="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed",KEYFORMATVERSIONS="1"
#EXT-X-MAP:URI="segment-initialization_segment_0000000000.m4s"
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:22.870Z
#EXTINF:2.576778
segment-0000000000.m4s
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:25.447Z
#EXTINF:2.000000
segment-0000000001.m4s
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:27.447Z
#EXTINF:2.000000
segment-0000000002.m4s
#EXT-X-PROGRAM-DATE-TIME:2022-10-12T20:08:29.447Z
#EXTINF:2.000000
segment-0000000003.m4s

DASH MPEG-CENC/Widevine

<AdaptationSet segmentAlignment="true" maxWidth="800" maxHeight="600">
  <Representation mimeType="video/mp4" id="fmp4_widevine_cenc_video" codecs="avc1.4d001f">
    <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="44ec248b-048c-43a6-a6ee-58a752c6f9f8"/>
    <ContentProtection schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed" value="Widevine">
      <cenc:pssh>AAAAOHBzc2gAAAAA7e+LqXnWSs6jCfc1R0h7QAAABgSEAB3Gcrj/8kFklokiVbJMh9VmwY=</cenc:pssh>
    </ContentProtection>
  </Representation>
</AdaptationSet>
<AdaptationSet segmentAlignment="true" mimeType="audio/mp4" id="1" label="fmp4_widevine_cenc_audio">
  <Representation id="fmp4_widevine_cenc_audio" codecs="mp4a.40.2">
    <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="44ec248b-048c-43a6-a6ee-58a752c6f9f8"/>
    <ContentProtection schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed" value="Widevine">
      <cenc:pssh>AAAAOHBzc2gAAAAA7e+LqXnWSs6jCfc1R0h7QAAABgSEAB3Gcrj/8kFklokiVbJMh9VmwY=</cenc:pssh>
    </ContentProtection>
  </Representation>
</AdaptationSet>

建议使用基于 HLS.js 的播放器进行 HLS/TS 解密。建议使用基于 Shaka Player 的播放器进行 DASH/fMP4 解密。

PlayReady“cenc”方案受以下设备支持：搭载 Microsoft Edge 浏览器的 Windows 10 实体机、Xbox One（版本 1703 或更低版本）以及某些非 Windows 设备（例如智能电视）。PlayReady“cbcs”方案仅在 Xbox One 版本 1709 或更高版本上受支持。如需了解详情，请参阅 PlayReady 内容加密模式。

更新加密密钥

您可以切换频道以使用新的加密密钥，而无需停止直播或重启频道。

如需更新密钥，请先将新密钥添加到 Secret Manager。新密钥可以是现有密文的新版本，也可以是新密文。如果您创建新的 Secret，请确保 Live Stream API 拥有该 Secret 的 secretmanager.secretAccessor 角色。

新密钥进入 Secret Manager 后，创建更新加密事件。系统会更新请求正文中指定的任何加密设置。未指定的任何设置都将保持不变。