ApsaraVideo Media Processing:Perform HLS packaging

Procedure

1. Create an HLS packaging workflow. The following table describes the key objects. API details: Add a media workflow.

   Object	Description
   Topology	A business process defined as a directed acyclic graph (DAG).
   Activity	Nodes that constitute the topology. The following table describes the HLS packaging activities.
   Dependencies	Edges in the topology that define dependencies among activities.

   Table 1: HLS packaging activities

   Activity	Description	Dependency
   PackageConfig	Specifies the output location of the 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	Combines multi-bitrate video, audio, and caption streams into a master playlist.	Supported parent node: Transcode Supported child node: Report

2. Call the Add a media file operation to trigger the workflow:

   • Specify the HLS packaging workflow ID.

   • To override the caption file URL in the Transcode activity, use the OverrideParams parameter. Only WebVTT caption files are supported.

   • Set TriggerMode to NotInAuto.

Scenario

This example extracts two video streams, three audio streams, and two WebVTT caption streams from an MXF source file (MP4, FLV, M3U8, and TS formats are also supported), then generates a master playlist.

Specify the output location and name of the master playlist

• Specify the OSS bucket for the master playlist.

• Specify the location.

• Specify the name.

  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. Details: the "PackageConfig" section in Methods supported for media workflows.

  • Type: PackageConfig.

Specify an audio group

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

Extract audio streams

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

• Output audio stream configurations:

  • 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 transcoding template ID. Template S00000001-100020 extracts an M3U8 audio file at 80 Kbit/s. Preset template details.

  • AudioStreamMap: the audio stream sequence number. Details: the "Output" section in Parameter details.

  • Remove: whether to remove video streams from the output. Parameter details.

  • ExtXMedia: the media playlist information. URI specifies the playlist name. Details: the "ExtXMedia" section in Parameter details.

  • Type: 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"
}

Complete topology sample code:

{
"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