ApsaraVideo Media Processing:Perform HLS packaging

Procedure

1. Create an HLS packaging workflow. When you create an HLS packaging workflow, take note of the objects described in the following table. For more information about the API operation that is used to create a workflow, see AddMediaWorkflow.

   Object	Description
   Topology	The business process that is defined by using a directed acyclic graph (DAG).
   Activity	The nodes that constitute the topology. When you create an HLS packaging workflow, pay attention to the activities described in the following table.
   Dependencies	The edges in the topology. The edges indicate the dependencies among activities.

   Table 1: HLS packaging activities

   Activity	Description	Dependency
   PackageConfig	Specifies the location for storing the output master playlist.	Supported parent node: Start Supported child nodes: SubtitleGroup, AudioGroup, and Transcode for video streams only
   SubtitleGroup	Specifies the ID and language of each caption group.	Supported parent node: PackageConfig Supported child node: Transcode for caption streams only
   AudioGroup	Specifies the ID and language of each audio group.	Supported parent node: PackageConfig Supported child node: Transcode for audio streams only
   Transcode	Extracts video, audio, or caption streams.	Supported parent node: PackageConfig, SubtitleGroup, and AudioGroup. Supported child node: GenerateMasterPlayList
   GenerateMasterPlayList	Specifies the multi-bitrate video streams, audio streams, and caption streams to generate a master playlist.	Supported parent node: Transcode Supported child node: Report

2. Call the AddMedia operation to trigger the HLS packaging workflow. Take note of the following items:

   • You must specify the ID of the HLS packaging workflow when you call the AddMedia operation.

   • For caption stream extraction, you can configure the OverrideParams parameter to override the URL of the caption file specified by the WebVTTSubtitleURL parameter in the Transcode activity. Only Web Video Text Tracks (WebVTT) caption files are supported.

   • Set the TriggerMode parameter of the workflow to NotInAuto.

Scenario

In this example, two video streams and three audio streams are extracted from a source file in the MXF format. The source file can also be in the MP4, FLV, M3U8, or TS format. Then, two WebVTT caption streams are extracted, and a master playlist is generated for the video streams, audio streams, and caption streams.

Specify the output location and name of the master playlist

• Specify the Object Storage Service (OSS) bucket in which the master playlist file is to be stored.

• Specify the location of the master playlist.

• Specify the name of the master playlist.

  Sample code:

  {
  "Parameters" : {
  "Output" : "{\"Bucket\": \"processedmediafile\",\"Location\": \"oss-cn-hangzhou\",\"MasterPlayListName\": \"{MediaId}/{RunId}/hls/master.m3u8\"}"
  },
  "Type" : "PackageConfig"
  }

  • Output: the output location and name of the master playlist. For more information, see the "PackageConfig" section of the Methods supported for media workflows topic.

  • Type: the activity type. In this example, this parameter is set to PackageConfig.

Specify an audio group

{
"Parameters" : {
"GroupId" : "audios"
},
"Type" : "AudioGroup"
}

Extract audio streams

• To extract audio streams from the MXF source file, you must remove the video streams.

• Configurations of output audio streams:

  • Codec: AAC

  • Sample rate: 48000 Hz

  • Format: Stereo

  Sample code:

  
  {
  "Name" : "audio-extract-1",
  "Parameters" : {
  "Outputs" : "[{\"TemplateId\":\"S00000001-100020\",\"AudioStreamMap\":\"0:a:0\",\"Video\":{\"Remove\":\"true\"}}]",
  "ExtXMedia" : "{\"URI\": \"sd/audio-en.m3u8\",\"Name\": \"audio-en\",\"Language\": \"en-US\"}"
  }

  • TemplateId: the ID of the template to be used to extract the audio stream. In this example, the template whose ID is S00000001-100020 is used. This template extracts an audio file in the M3U8 format. The bitrate of the audio is 80 Kbit/s. For more information, see Preset template details.

  • AudioStreamMap: the sequence number of the audio stream. For more information, see the "Output" section of the Parameter details topic.

  • Remove: specifies whether to remove video streams from the output. For more information, see Parameter details.

  • ExtXMedia: the information about the media playlist. The URI parameter specifies the name of the media playlist. For more information, see the "ExtXMedia" section of the Parameter details topic.

  • Type: the activity type. In this example, this parameter is set to Transcode.

Extract video streams

{
"Name" : "video-extract",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"1fe5393bdb7b2b883f0a0fc91e81****\",\"Audio\":{\"Remove\":\"true\"}}]",
"MultiBitrateVideoStream" : "{\"URI\": \"sd/video1.m3u8\"}"
},
"Type" : "Transcode"
}

Specify a caption group

{
"Parameters" : {
"GroupId" : "subtitles"
},
"Type" : "SubtitleGroup"
}

Extract caption streams

{
"Name" : "subtitle-extract-1",
"Parameters" : {
"WebVTTSubtitleURL" : "http://example-bucket-****.oss-cn-hangzhou.aliyun-inc.com/ShawshankRedemption****.vtt",
"ExtXMedia" : "{\"URI\": \"zh/subtitle1-cn.m3u8\",\"Name\": \"subtitle-cn\",\"Language\": \"cn\"}"
},
"Type" : "Transcode"
}

Generate a master playlist

{
"Parameters" : {
"MasterPlayList" : "{\"MultiBitrateVideoStreams\": [{\"RefActivityName\": \"video-extract\",\"ExtXStreamInfo\": {\"BandWidth\": \"1110000\",\"Audio\": \"audios\",\"Subtitles\": \"subtitles\"}}]}"
},
"Type" : "GenerateMasterPlayList"
}

Sample code of the complete topology:

{
"Activities" : {
"package-node" : {
"Name" : "package-node",
"Parameters" : {
"Output" : "{\"Bucket\": \"processedmediafile\",\"Location\": \"oss-cn-hangzhou\",\"MasterPlayListName\": \"{MediaId}/{RunId}/hls/master.m3u8\"}"
},
"Type" : "PackageConfig"
},
"audioGroupNode" : {
"Name" : "audioGroupNode",
"Parameters" : {
"GroupId" : "audios"
},
"Type" : "AudioGroup"
},
"subtitleGroupNode" : {
"Name" : "subtitleGroupNode",
"Parameters" : {
"GroupId" : "subtitles"
},
"Type" : "SubtitleGroup"
},
"video-extract-1" : {
"Name" : "video-extract-1",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"1fe5393bdb7b2b883f0a0fc91e81344a\",\"Audio\":{\"Remove\":\"true\"}}]",
"MultiBitrateVideoStream" : "{\"URI\": \"sd/video1.m3u8\"}"
},
"Type" : "Transcode"
},
"video-extract-2" : {
"Name" : "video-extract-1",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"1fe5393bdb7b2b883f0a0fc91e81344b\",\"Audio\":{\"Remove\":\"true\"}}]",
"MultiBitrateVideoStream" : "{\"URI\": \"sd/video2.m3u8\"}"
},
"Type" : "Transcode"
},
"audio-extract-1" : {
"Name" : "audio-extract-1",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"S00000001-100020\",\"AudioStreamMap\":\"0:a:0\"}]",
"ExtXMedia" : "{\"URI\": \"sd/audio-en-1.m3u8\",\"Name\": \"audio-en\",\"Language\": \"en-US\"}"
},
"Type" : "Transcode"
},
"audio-extract-2" : {
"Name" : "audio-extract-2",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"S00000001-100020\",\"AudioStreamMap\":\"0:a:1\"}]",
"ExtXMedia" : "{\"URI\": \"sd/audio-cn.m3u8\",\"Name\": \"audio-cn\",\"Language\": \"cn\"}"
},
"Type" : "Transcode"
},
"audio-extract-3" : {
"Name" : "audio-extract-3",
"Parameters" : {
"Outputs" : "[{\"TemplateId\":\"S00000001-100020\",\"AudioStreamMap\":\"0:a:2\"}]",
"ExtXMedia" : "{\"URI\": \"sd/audio-de.m3u8\",\"Name\": \"audio-de\",\"Language\": \"de\"}"
},
"Type" : "Transcode"
},
"subtitle-extract-1" : {
"Name" : "subtitle-extract-1",
"Parameters" : {
"WebVTTSubtitleURL" : "http://example-bucket-****.oss-test.aliyun-inc.com/1****.vtt",
"ExtXMedia" : "{\"URI\": \"zh/subtitle1-cn.m3u8\",\"Name\": \"subtitle-cn\",\"Language\": \"cn\"}"
},
"Type" : "Transcode"
},
"subtitle-extract-2" : {
"Name" : "subtitle-extract-2",
"Parameters" : {
"WebVTTSubtitleURL" : "http://example-bucket-****.oss-cn-hangzhou.aliyun-inc.com/ShawshankRedemption****.vtt",
"ExtXMedia" : "{\"URI\": \"zh/subtitle1-en.m3u8\",\"Name\": \"subtitle-en\",\"Language\": \"en-US\"}"
},
"Type" : "Transcode"
},
"masterPlayListGenerate" : {
"Name" : "masterPlayListGenerate",
"Parameters" : {
"MasterPlayList" : "{\"MultiBitrateVideoStreams\": [{\"RefActivityName\": \"video-extract-1\",\"ExtXStreamInfo\": {\"BandWidth\": \"1110000\",\"Audio\": \"audios\",\"Subtitles\": \"subtitles\"}}, {\"RefActivityName\": \"video-extract-2\",\"ExtXStreamInfo\": {\"BandWidth\": \"5000000\",\"Audio\": \"audios\",\"Subtitles\":\"subtitles\"}}]}"
},
"Type" : "GenerateMasterPlayList"
},
"activityEnd" : {
"Name" : "activityEnd",
"Parameters" : {
"PublishType" : "Manual"
},
"Type" : "Report"
},
"activityStart" : {
"Name" : "activityStart",
"Parameters" : {
"PipelineId" : "900ededca77641ecbecd4f44cc3a2965",
"Role" : "AliyunMTSDefaultRole",
"InputFile" : "{\"Bucket\":\"videouploaded\",\"Location\":\"oss-cn-hangzhou\",\"ObjectPrefix\":\"uploaded/\"}"
},
"Type" : "Start"
}
},
"Dependencies" : {
"video-extract-1" : [ "masterPlayListGenerate" ],
"video-extract-2" : [ "masterPlayListGenerate" ],
"audio-extract-1" : [ "masterPlayListGenerate" ],
"audio-extract-2" : [ "masterPlayListGenerate" ],
"audio-extract-3" : [ "masterPlayListGenerate" ],
"subtitle-extract-1" : [ "masterPlayListGenerate" ],
"subtitle-extract-2" : [ "masterPlayListGenerate" ],
"package-node" : [ "video-extract-1", "video-extract-2","subtitleGroupNode", "audioGroupNode" ],
"audioGroupNode" : [ "audio-extract-1", "audio-extract-2","audio-extract-3"],
"subtitleGroupNode" : [ "subtitle-extract-1", "subtitle-extract-2" ],
"masterPlayListGenerate" : [ "activityEnd" ],
"activityEnd" : [ ],
"activityStart" : [ "package-node" ]
}
}

Sample code

• Create an HLS packaging workflow.

  • Sample code in Java

  • Sample code in Python

  • Sample code in PHP

• Add a media file.

  • Sample code in Java

  • Sample code in Python

  • Sample code in PHP