Help Center/ Video On Demand/ Service Overview/ Notes and Constraints
Updated on 2026-05-13 GMT+08:00
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Notes and Constraints

Before using VOD, you need to know the following constraints.

Resource Constraints

VOD has constraints on resources such as domain names and watermarks.

Table 1 Resource constraints

Item

Description

Constraint

Region

Users of the International website can use VOD only in CN North-Beijing4, AP-Singapore, and AP-Bangkok.

-

Domain name

Maximum number of self-owned domain names that you can add on the VOD console.

NOTE:
  • All domain names of the system have been assigned. If you do not have an assigned domain name after subscribing to VOD, you need to add licensed domain names to VOD for media file distribution acceleration.
  • The system automatically checks all domain names in your account and deletes domain names that have been idle for a long time. For details, see Configuring Domain Names.

5

Pull from URLs

Maximum number of media files that can be pulled at a time
  • Console: 100
  • API: 16

URL pull rate

Global maximum rate for pulling audio/video files offline to VOD using the URLs of source audio/video files

1 Gbit/s

Watermarking

Maximum number of watermarks that can be added to a video file at a time

2

Categorization

Maximum number of subcategories can be added to each category. A maximum of three levels of categories are allowed.

128

Labeling

Maximum number of labels that you can add to a media file

16

Referer validation

Maximum number of domain names that can be added to a referer blacklist or whitelist

100

Media pre-loading

Maximum number of times that you can pre-load media files in a day

1,000

Function Constraints

Table 2 Function constraints

Item

Description

Domain name

When you delete a domain name that has been idle for more than half a year, an error will be reported, and you need to submit a service ticket.

Transcoding

To retain transcoded outputs of different formats, you need to submit a service ticket.

HLS media file upload

HLS media files can be ingested and played, but processing operations (such as screenshot capturing, parsing, transcoding, and review) on HLS source files are not supported.

Subtitling
  • External subtitles are not supported for HLS outputs that are saved to a different OBS bucket but in the same directory as input files.
  • If the language you specify is not in the subtitle list in the HLS index file, the configuration will fail.
  • Subtitling is not supported if you use the original_template_group.
  • External subtitles are not supported when both HLS and DASH outputs are generated using a template group. For details about how to create a transcoding template group, see Creating a Transcoding Template Group.
  • The native iOS browser Safari does not support parsing and playing of VTT subtitle files.

Audio/Video review
  • Audio and video moderation is not available in the AP-Bangkok region.
  • Audio and video moderation is not available for HLS.
  • Since October 15, 2025, the audio and video moderation capabilities of VOD have been updated, as a part of the overall upgrade of Content Moderation, a Huawei Cloud EI service. For details, see Notice on Updates to the VOD Audio and Video Moderation Function.
    • To use audio and video moderation, you need to enable Content Moderation. The required moderation services vary with the region: text and single-image moderation for CN North-Beijing1; text, single-image, and audio moderation for CN North-Beijing4; and text, single-image, and audio moderation for AP-Singapore.
    • Using the audio and video moderation functions of VOD will incur charges from the Content Moderation service. For details, see Content Moderation Billing.
  • VOD uses only the text, image, and audio moderation capabilities of Content Moderation. You can buy the corresponding packages from Content Moderation.

APIs Supporting Cross-Origin Requests

Only the VOD APIs listed in Table 3 support cross-origin requests.

Table 3 APIs supporting cross-origin requests

API

URI

Uploading Media Files to VOD

/v1.0/{project_id}/asset

Confirming Media File Upload

/v1.0/{project_id}/asset/status/uploaded

Verifying the Upload

/v1.0/{project_id}/asset/duplication

Querying Media Assets

/v1.0/{project_id}/asset/info

Obtaining Authorization for Multipart Upload

/v1.0/{project_id}/asset/authority

API Constraints

VOD sets a limit on the number of API calls to prevent service interruption caused by repeated API calls in a short period of time.

Table 4 API request throttling

Category

API

API Calls for a Single Tenant Per Minute

API Calls for All Tenants Per Minute

Media upload
  • Uploading media files to VOD
  • Obtaining authorization for multipart upload
  • Confirming media file upload
  • Authorizing access to OBS
  • Replicating media files from OBS to VOD

1,500

12,000
  • Pulling media files from URLs
  • Verifying the upload

100

1,000

Media processing
  • Updating a video
  • Media processing
  • Canceling a media asset transcoding task
  • Extracting audio
  • Canceling an audio extraction task
  • Creating a media asset review task
  • Setting a thumbnail

100

1,000

Media management
  • Deleting media files
  • Publishing media files
  • Canceling media publish
  • Modifying media asset attributes
  • Querying media asset tasks

100

1,000

Querying media asset information

1,500

24,000
  • Querying file details
  • Querying media files

1,500

12,000

Media pre-loading

CDN pre-loading

10

250

Querying pre-loading results

100

1,000

Media file refresh
  • CDN cache refresh
  • Querying CDN cache refresh results

100

1,000

Media category
  • Creating a media category
  • Modifying a media category
  • Deleting a media category
  • Querying media categories

100

1,000

Key query

Querying a Key

1,500

12,000

Statistical analysis
  • Querying CDN statistics
  • Querying origin server statistics
  • Querying the most frequently requested content
  • Querying playback logs of a domain name
  • Querying daily playback statistics of a media asset

100

1,000

Watermark template management
  • Creating a watermark template
  • Modifying a watermark template
  • Querying watermark templates
  • Deleting a watermark template
  • Confirming watermark image upload

100

1,000

Subtitle management

Managing subtitles

100

1,000

Transcoding template management
  • Creating a custom transcoding template
  • Querying transcoding templates
  • Updating a transcoding template
  • Deleting a custom template

100

1,000

Transcoding template group management
  • Creating a transcoding template group
  • Modifying a transcoding template group
  • Querying custom template groups
  • Deleting a transcoding template group

100

1,000

Transcoded output management

Deleting transcoded outputs

100

1,000

Media asset storage mode management
  • Modifying the cold storage scope of a media asset
  • Changing the OBS storage class of a media asset
  • Querying the cold storage settings of a media asset
  • Querying data retrieval information

100

1,000

Media asset editing management
  • Creating an editing task
  • Querying an editing task
  • Canceling an editing task

100

1,000

Snapshot management
  • Querying snapshot task results
  • Querying snapshot details

1,500

12,000

Deleting snapshots of a media asset

100

1,000