Narrowband HD™ 1.0 and Narrowband HD™ 2.0 - ApsaraVideo VOD

Narrowband HD™ transcoding is a proprietary Alibaba Cloud technology that intelligently analyzes every scene, action, content, and texture in a video. It delivers the same visual quality at a lower bitrate, which reduces bandwidth costs. Compared with standard transcoding, Narrowband HD^TM 1.0 reduces bitrates by 20% to 40%. Narrowband HD^TM 2.0 not only lowers bitrates but also provides lightweight video quality repair and enhancement. Compared with Narrowband HD^TM 1.0, it achieves even lower bitrates and better resolution.

Benefits

Benefit	Narrowband HD^TM 1.0	Narrowband HD^TM 2.0
Narrowband: Eliminating redundant bits	✔️	✔️
Allocate bits where they create the most value	✔️	✔️
Weaken areas ignored by the human eye, out-of-focus regions, and scattered minor details	✔️	✔️
Strengthen details the human eye notices, focused areas, and regular textures	❌	✔️
Fix glitches, flickering, and mosaics that annoy viewers	❌	✔️

Billing

Video transcoding is a paid service. Fees are calculated based on the specifications and duration of the output video. For more information, see Media transcoding billing.

Limits

Narrowband HD^TM 1.0 and Narrowband HD^TM 2.0 are available in all regions. For more information about the regions where ApsaraVideo VOD is available, see Service regions.
Narrowband HD^TM 1.0 and Narrowband HD^TM 2.0 transcoding support only the HLS and MP4 output formats.

Usage notes

Video parameters such as resolution and bitrate in Narrowband HD^TM 1.0 transcoding templates are preset by the system and cannot be edited. The preset template configurations are as follows:

Definition	Bitrate range (Kbps)	Resolution – width (px)
Low definition – Narrowband HD 1.0	≤ 400	640
Standard definition – Narrowband HD 1.0	≤ 800	848
High definition – Narrowband HD 1.0	≤ 1500	1280
Ultra high definition – Narrowband HD 1.0	≤ 3000	1920
2K – Narrowband HD 1.0	≤ 4000	2048
4K – Narrowband HD 1.0	≤ 8000	3840

Narrowband HD^TM 2.0 transcoding is slower. For testing, we recommend that you use a video that is shorter than 3 minutes.

How to use

Transcode using the console

Step 1: Create a Narrowband HD™ transcoding template group

Before you submit transcoding jobs, you must create a Narrowband HD™ transcoding template group. For more information, see:

Step 2 (Optional): Create a workflow and associate it with the transcoding template group

You can orchestrate media processing tasks, such as transcoding, review, and snapshot capture, into a workflow. When triggered during upload or media processing, the workflow automatically executes the predefined sequence of tasks.

You can create a workflow, add a media transcoding node, and associate the node with the Narrowband HD™ transcoding template group that you created in Step 1. For more information, see Workflow management.

Step 3: Start transcoding

You can use the Narrowband HD™ transcoding template group or workflow that you created to transcode videos. You can trigger transcoding during or after you upload media.

Automatically trigger transcoding during upload

Log on to the ApsaraVideo VOD console.
In the navigation pane on the left, choose Media Files > Audio/Video and click Upload Audio/Video.
Click Add Audio/Video. After you set parameters such as the upload method and storage address, select Use Transcoding Template Group or Use Workflow and specify the corresponding group or workflow.
For more information about the supported upload formats and parameter descriptions, see Upload media in the console.
After you add the audio or video files, click Upload.

Manually start transcoding after upload

This operation is commonly used for re-transcoding existing videos, applying standard encryption, or overriding watermark parameters.

Log on to the ApsaraVideo VOD console.
In the navigation pane on the left, choose Media Files > Audio/Video.
On the Audio/Video page, find the media file to transcode and click Processing in the Actions column.
Select Use Transcoding Template Group or Use Workflow, and specify the Narrowband HD™ transcoding template group or workflow that you created.
Click OK.

Step 3: View transcoding results

After you start a transcoding job, you can use one of the following methods to check the transcoding status and obtain the video playback URL. You can use the URL with ApsaraVideo Player or a third-party player to play the transcoded video.

Important

If you have not configured an accelerated domain name in ApsaraVideo VOD, playing or downloading videos using the URL incurs outbound traffic charges. For more information, see Outbound traffic billing.

Method 1: View in the console

Log on to the ApsaraVideo VOD console.
In the navigation pane on the left, choose Media Files > Audio/Video.
On the Audio/Video page, check the status of the transcoded media file.
The Normal status indicates that transcoding succeeded. For information about other statuses, see Status: Video status.
Click Manage in the Actions column for the transcoded media file, then select the Video URL tab.
A successful transcoding job generates video streams for each definition and their corresponding playback URLs.

Method 2: Event notifications

ApsaraVideo VOD supports event notifications using HTTP callbacks and MNS callbacks. After you configure event notifications, ApsaraVideo VOD sends a notification using your specified callback method when a media processing task, such as an upload or transcoding task, is complete. You can extract the transcoding status and video playback URLs from the callback response. For more information, see Event notifications.

Transcoding-related events include the following:

Transcode using OpenAPI

Usage notes

To call API operations, see ApsaraVideo VOD API overview. You can use Alibaba Cloud's online command line interface (CLI), OpenAPI Explorer, for debugging. OpenAPI Explorer runs ApsaraVideo VOD API operations directly without requiring manual signature calculations. Upon successful execution, it automatically generates SDK code samples.

Step 1: Create a Narrowband HD™ transcoding template group

Before you submit transcoding jobs, you must create a Narrowband HD™ transcoding template group.

Call the CreateTranscodeTemplateGroup operation and set the Definition parameter in TranscodeTemplate to a Narrowband HD™ value.

Step 2 (Optional): Create a workflow and associate it with the transcoding template group

You can create workflows only in the ApsaraVideo VOD console. For more information, see Workflow management.

Step 3: Start transcoding

You can use the Narrowband HD™ transcoding template group or workflow that you created to transcode videos. You can trigger transcoding during or after you upload media.

Automatically trigger transcoding during upload

Note

The CreateUploadVideo operation only retrieves upload URLs and credentials and creates basic media asset information. It does not upload files. You must implement the complete upload logic. For a complete upload example that uses APIs, see Upload media files using ApsaraVideo VOD APIs.

When you call the CreateUploadVideo or UploadMediaByURL operation, specify the Narrowband HD™ transcoding template group ID in the TemplateGroupId parameter or the workflow ID in the WorkflowId parameter. The workflow must contain a media transcoding node. After the audio or video files are uploaded, the ApsaraVideo VOD service automatically transcodes them based on the specified template group or workflow.