HEVC視頻

簡介

HEVC的優勢

高效視頻編碼（HEVC），也稱為H.265，是一種視頻壓縮標準，是對廣泛使用的視頻標準 高級視頻編碼（AVC / H.264）。 與AVC相比，HEVC在相同視頻質量水平下可提供約20％的數據壓縮，或者在相同比特率下可顯著提高視頻質量。

這種改進的壓縮的好處包括減少帶寬使用，以較低的比特率實現更高的視頻質量，以及縮短到第一幀的時間（TTFF），所有這些都可以提高最終觀看者的滿意度。

弊端

主要缺點是，由於它是一項新技術，因此HEVC視頻尚未得到客戶端（即設備+ OS +瀏覽器/應用程序）的廣泛支持。 另外，某些客戶端能夠在回放期間在HEVC和AVC段之間切換，而其他客戶端則不能。

此外，HEVC視頻的轉碼時間比H.2長約4-264倍。

產品狀況

HEVC支持是 付費附件 Video Cloud。 如果您對HEVC支持感興趣，請與您的客戶經理聯繫。

Brightcove的HEVC解決方案

為了給您帶來HEVC的好處，同時仍允許觀看者使用不支持HEVC的技術，Brightcove開發了一種全面的解決方案，既支持較舊的非HEVC客戶端，也優化了帶寬使用。 此解決方案包含多個部分：

• 在轉碼過程中同時創建HEVC和AVC編碼的演繹文件（還可以選擇創建MP4以進行漸進式下載）
• 包含對HEVC和AVC演繹的引用的清單的生成：
  • HLS：混合變體流（按比特率排序）
  • DASH：用於HEVC和H.264的單獨的適應集，以及聲明它們可切換的補充屬性
• 基於查看器客戶端類型的過濾邏輯：
  • 如果請求設備是舊版，不支持HEVC的設備，則從清單中刪除HEVC流
  • 從清單清單中刪除H.264流到支持HEVC的不可切換設備
  • 如果設備能夠解碼兩個編解碼器並在它們之間進行切換，則將保留HEVC和H.264流的最佳子集

受支持的客戶

當前，使用Brightcove Web或本機設備在以下客戶端上端到端支持HEVC players:

筆記

• ^[1-1] 有關詳細信息，請參見 使用Android的本地SDK進行HEVC選擇

HEVC攝取檔案

如果為您的帳戶啟用了HEVC，則要獲取HEVC副本以進行播放，您要做的就是選擇其中一種HEVC接收配置文件（上下文感知編碼或動態Delivery），當您使用“上傳”模塊或 Dynamic Ingest API:

這些配置文件的完整JSON詳細信息已包括在內 下面。 我們建議您使用CAE（上下文感知編碼）配置文件為您的源創建最佳再現集並優化存儲。 由於CAE需要較長的處理時間來檢查源，因此，如果優先考慮盡快獲得可發布的再現文件，則可以使用 快速發布 選項。

請注意，如果出於快速發布選項或其他原因需要創建自定義HEVC配置文件，則必須使用 高級編輯 在Studio管理員頁面中，或 Ingest Profiles API。 HEVC副本不會顯示在Studio的“簡單編輯器”中。 您會找到可用的動態Delivery演繹 下面.

另請注意，HEVC的標準格式為1920px或更小。 但是，我們確實支持UHD格式（4K或更大）。 如果您需要UHD複製，可以向Brightcove支持提交請求以創建一個或多個。

自定義CAE配置文件

標準CAE攝取配置文件不包括混合的HEVC / H.264再現。 但是，您可以創建一個自定義主題。 目前，您必須使用 Ingest Profiles API 為HEVC創建這些自定義CAE配置文件。

字段（下 dynamic_origin > dynamic_profile_options）必不可少的是：

video_codecs

為其創建演繹的編解碼器數組。 當前僅支持編解碼器值 h264 以及 hevc

video_codec_options

video_codecs中指定的每個編解碼器的輸出選項。 的屬性 video_codec_options 是具有包含的編解碼器名稱（當前為h264或hevc）的對象。 每個對象的允許屬性為

• min_renditions 必須要戴上
• max_bitrate
• max_first_rendition_bitrate
• min_resolution
• max_resolution
• max_first_rendition_resolution

樣本

以下是具有混合格式的樣本CAE配置文件：

{
  "name": "multi-platform-extended-dynamic-hevc-mixed-codec",
  "display_name": "Multiplatform Extended HEVC (CAE) mixed-codec",
  "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop and large screens.",
  "account_id": 1486906377,
  "digital_master": {
    "rendition": "passthrough",
    "distribute": false
  },
  "renditions": [],
  "packages": [],
  "dynamic_origin": {
    "renditions": [
      "default/audio64",
      "default/audio128",
    ],
    "images": [
      {
        "label": "thumbnail",
        "height": 90,
        "width": 160
      },
      {
        "label": "poster",
        "height": 720,
        "width": 1280
      }
    ],
    "dynamic_profile_options": {
      "max_renditions": 10,
      "min_renditions": 2,
      "max_bitrate": 12000,
      "max_first_rendition_bitrate": 1000,
      "max_first_rendition_resolution": {
        "width": 1280,
        "height": 720
      },
      "video_codecs": [
        "h264",
        "hevc"
      ],
      "video_codec_options": {
        "h264": {
          "min_renditions": 2,
          "max_resolution": {
            "width": 1280,
            "height": 720
          }
        },
        "hevc": {
          "min_renditions": 2,
          "max_resolution": {
            "width": 1920,
            "height": 1080
          }
        }
      }
    }
  }
}

限制

以下是目前對HEVC支持的限制-請注意，隨著我們進行增強，這些限制將會改變。

1. 目前，標準CAE提取配置文件包括HEVC格式說明-僅在您知道自己將要刪除的情況下才應使用這些格式。live僅將視頻響鈴到支持HEVC的設備。 可以創建自定義配置文件，以包含HEVC和H.264格式。 見 自定義CAE配置文件 以上部分。
2. 僅支持AAC音頻，不支持帶有HEVC的EAC3或AC3音頻編解碼器。
3. 不支持HDR和10位視頻。
4. Media UI當前顯示所有格式，並且不在每個格式旁邊顯示編解碼器信息。

附錄1：HEVC攝取配置文件

以下是JSON中HEVC配置文件的完整屬性。

• 多平台擴展HEVC（CAE）
• 帶有MP4的多平台擴展HEVC（CAE）
• 多平台擴展靜態H.264 + HEVC
• 帶有MP264的多平台擴展靜態H.4 + HEVC
• 帶有MP4的多平台擴展HEVC

上下文感知編碼（CAE）配置文件

多平台擴展HEVC（CAE）

  {
      "version": 1,
      "name": "multi-platform-extended-dynamic-hevc",
      "display_name": "Multiplatform Extended HEVC (CAE)",
      "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop and large screens.",
      "account_id": -1,
      "brightcove_standard": true,
      "date_created": 1581706195164,
      "date_last_modified": 1581706195164,
      "digital_master": {
        "rendition": "passthrough",
        "distribute": false
      },
      "renditions": [

      ],
      "packages": [

      ],
      "dynamic_origin": {
        "renditions": [
          "default/audio64",
          "default/audio128"
        ],
        "images": [
          {
            "label": "thumbnail",
            "height": 90,
            "width": 160
          },
          {
            "label": "poster",
            "height": 720,
            "width": 1280
          }
        ],
        "dynamic_profile_options": {
          "min_renditions": 2,
          "max_renditions": 8,
          "min_resolution": {
            "width": 320,
            "height": 180
          },
          "max_resolution": {
            "width": 1920,
            "height": 1080
          },
          "max_frame_rate": 30,
          "max_bitrate": 4200,
          "max_first_rendition_bitrate": 250,
          "video_codec": "hevc",
          "fixed_frame_rate": true,
          "bitrate_cap_to_bitrate_ratio": 1.5,
          "buffer_size_to_bitrate_ratio": 2,
          "bitrate_cap_offset": 0,
          "buffer_size_offset": 0,
          "sample_aspect_ratio": "1:1"
        },
        "hevc": true
      },
      "id": "5e470e014b23617ad079c486"
    }

帶有MP4的多平台擴展HEVC（CAE）

{
      "version": 1,
      "name": "multi-platform-extended-dynamic-hevc-with-mp4",
      "display_name": "Multiplatform Extended HEVC (CAE) with MP4",
      "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop, large screens, and syndication.",
      "account_id": -1,
      "brightcove_standard": true,
      "date_created": 1581706195164,
      "date_last_modified": 1581706195164,
      "digital_master": {
        "rendition": "passthrough",
        "distribute": false
      },
      "renditions": [

      ],
      "packages": [

      ],
      "dynamic_origin": {
        "renditions": [
          "default/audio64",
          "default/audio128",
          "default/progressive2000"
        ],
        "images": [
          {
            "label": "thumbnail",
            "height": 90,
            "width": 160
          },
          {
            "label": "poster",
            "height": 720,
            "width": 1280
          }
        ],
        "dynamic_profile_options": {
          "min_renditions": 2,
          "max_renditions": 8,
          "min_resolution": {
            "width": 320,
            "height": 180
          },
          "max_resolution": {
            "width": 1920,
            "height": 1080
          },
          "max_frame_rate": 30,
          "max_bitrate": 3200,
          "max_first_rendition_bitrate": 200,
          "video_codec": "hevc",
          "fixed_frame_rate": true,
          "bitrate_cap_to_bitrate_ratio": 1.5,
          "buffer_size_to_bitrate_ratio": 2,
          "bitrate_cap_offset": 0,
          "buffer_size_offset": 0,
          "sample_aspect_ratio": "1:1"
        },
        "hevc": true
      },
      "id": "5e470e0c4c881c16fffdb88d"
    }

動態設計livery個人資料

多平台擴展靜態H.264 + HEVC

{
      "version": 1,
      "name": "multi-platform-extended-static-mixed-codec",
      "display_name": "Multiplatform Extended Static H.264 + HEVC",
      "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop and large screens.",
      "account_id": -1,
      "brightcove_standard": true,
      "date_created": 1581706195164,
      "date_last_modified": 1581706195164,
      "digital_master": {
        "rendition": "passthrough",
        "distribute": false
      },
      "renditions": [

      ],
      "packages": [

      ],
      "dynamic_origin": {
        "renditions": [
          "default/video450",
          "default/video700",
          "default/video900",
          "default/video1200",
          "default/video2000",
          "default/video2500",
          "default/video3500",
          "default/video3800",
          "default/video300hevc",
          "default/video550hevc",
          "default/video1000hevc",
          "default/video1300hevc",
          "default/video1600hevc",
          "default/video2850hevc",
          "default/audio64",
          "default/audio128"
        ],
        "images": [
          {
            "label": "thumbnail",
            "height": 90,
            "width": 160
          },
          {
            "label": "poster",
            "height": 720,
            "width": 1280
          }
        ],
        "hevc": true
      },
      "id": "5e46e57f305eb2517f27a543"
    }

帶有MP264的多平台擴展靜態H.4 + HEVC

{
      "version": 1,
      "name": "multi-platform-extended-static-mixed-codec-with-mp4",
      "display_name": "Multiplatform Extended Static H.264 + HEVC with MP4",
      "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop and large screens, and syndication.",
      "account_id": -1,
      "brightcove_standard": true,
      "date_created": 1581706195164,
      "date_last_modified": 1581706195164,
      "digital_master": {
        "rendition": "passthrough",
        "distribute": false
      },
      "renditions": [

      ],
      "packages": [

      ],
      "dynamic_origin": {
        "renditions": [
          "default/video450",
          "default/video700",
          "default/video900",
          "default/video1200",
          "default/video2000",
          "default/video2500",
          "default/video3500",
          "default/video3800",
          "default/video300hevc",
          "default/video550hevc",
          "default/video1000hevc",
          "default/video1300hevc",
          "default/video1600hevc",
          "default/video2850hevc",
          "default/progressive2000",
          "default/audio64",
          "default/audio128"
        ],
        "images": [
          {
            "label": "thumbnail",
            "height": 90,
            "width": 160
          },
          {
            "label": "poster",
            "height": 720,
            "width": 1280
          }
        ],
        "hevc": true
      },
      "id": "5e46e59b135b6662f386559d"
    }

帶有MP4的多平台擴展HEVC

{
      "version": 1,
      "name": "multi-platform-extended-static-hevc-with-mp4",
      "display_name": "Multiplatform Extended HEVC with MP4",
      "description": "Deliver high quality content for a wide range content types and screen sizes including mobile, desktop, large screens, and syndication.",
      "account_id": -1,
      "brightcove_standard": true,
      "date_created": 1581706195164,
      "date_last_modified": 1581706195164,
      "digital_master": {
        "rendition": "passthrough",
        "distribute": false
      },
      "renditions": [

      ],
      "packages": [

      ],
      "dynamic_origin": {
        "renditions": [
          "default/video300hevc",
          "default/video550hevc",
          "default/video1000hevc",
          "default/video1300hevc",
          "default/video1600hevc",
          "default/video2850hevc",
          "default/progressive2000",
          "default/audio64",
          "default/audio128"
        ],
        "images": [
          {
            "label": "thumbnail",
            "height": 90,
            "width": 160
          },
          {
            "label": "poster",
            "height": 720,
            "width": 1280
          }
        ],
        "hevc": true
      },
      "id": "5e46e57e708a441e00a7ba1a"
    }

附錄2：HEVC動態設計livery演繹

以下是JSON中HEVC格式的完整屬性。

• 默認HEVC 300
• 默認HEVC 550
• 默認HEVC 1000
• 默認HEVC 1300
• 默認HEVC 1600
• 默認HEVC 2850

默認HEVC 300

{
      "id": "default/video300hevc",
      "version": 0,
      "name": "Default HEVC 300",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T17:57:49.622898302Z",
      "updated_at": "2020-02-20T17:57:49.622898302Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 450,
        "decoder_buffer_size": 600,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 270,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 300,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 480
      }
    }

默認HEVC 550

{
      "id": "default/video550hevc",
      "version": 0,
      "name": "Default HEVC 550",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T17:58:08.602132077Z",
      "updated_at": "2020-02-20T17:58:08.602132077Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 825,
        "decoder_buffer_size": 1100,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 360,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 550,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 640
      }
    }

默認HEVC 1000

{
      "id": "default/video1000hevc",
      "version": 0,
      "name": "Default HEVC 1000",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T17:58:24.768036423Z",
      "updated_at": "2020-02-20T17:58:24.768036423Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 1500,
        "decoder_buffer_size": 2000,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 432,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 1000,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 768
      }
    }

默認HEVC 1300

{
      "id": "default/video1300hevc",
      "version": 0,
      "name": "Default HEVC 1300",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T17:58:51.222403657Z",
      "updated_at": "2020-02-20T17:58:51.222403657Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 1950,
        "decoder_buffer_size": 2600,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 576,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 1300,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 1024
      }
    }

默認HEVC 1600

{
      "id": "default/video1600hevc",
      "version": 0,
      "name": "Default HEVC 1600",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T18:00:00.347383018Z",
      "updated_at": "2020-02-20T18:00:00.347383018Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 2400,
        "decoder_buffer_size": 3200,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 720,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 1600,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 1280
      }
    }

默認HEVC 2850

{
      "id": "default/video2850hevc",
      "version": 0,
      "name": "Default HEVC 2850",
      "kind": "video",
      "account_id": "default",
      "created_at": "2020-02-20T18:00:42.036123319Z",
      "updated_at": "2020-02-20T18:00:42.036123319Z",
      "encoding_settings": {
        "aspect_mode": "preserve",
        "decoder_bitrate_cap": 4275,
        "decoder_buffer_size": 5700,
        "fixed_keyframe_interval": true,
        "fragment_duration": 2000,
        "height": 1080,
        "keyframe_rate": 1,
        "segment_seconds": 2,
        "speed": 3,
        "video_bframes": 3,
        "video_bitrate": 2850,
        "video_codec": "hevc",
        "video_codec_profile": "main",
        "video_reference_frames": 6,
        "width": 1920
      }
    }