Prebuilt audio and video analyzers keep running without output in Azure AI Content Analysis

The described behavior matches a likely service-side or region-specific problem rather than an issue with configuration or file size, especially because:

• Audio/video analyzers hang, but PDF/image analyzers work.
• The issue is intermittent and has previously resolved without changes.

Use the following steps to isolate and mitigate the problem.

1. Check service health and regional issues

• In the Azure portal, open Service Health and verify whether there are any incidents or advisories affecting Azure AI Content Understanding/Content Analysis in the region where the resource is deployed.
• If nothing is reported, create or use a Content Understanding (Foundry) resource in a different supported region and run the same audio/video files there. If the other region succeeds while the original region continues to hang, the problem is almost certainly regional/service-side.

2. Verify resource and analyzer configuration

• Confirm that the resource is a Microsoft Foundry resource in a supported region and that model deployment defaults are configured, as required for Content Understanding analyzers.
• Ensure that the correct prebuilt analyzers are being used for audio and video (for example, prebuilt-audio, prebuilt-video, or prebuilt-audioSearch / prebuilt-videoSearch) and that no recent analyzer definition changes were made that could affect processing.
• If custom analyzers were created on top of base analyzers, verify that they are updated to the current GA schema (for example, correct baseAnalyzerId and models configuration) as described in the migration guidance. Misconfigured analyzers can cause jobs to never complete.

3. Confirm request/response pattern and polling logic

• For REST calls, confirm that the pattern follows the documented asynchronous flow:
  1. POST to the Content Analyzers – Analyze API.
  2. Read the Operation-Location header from the response.
  3. Poll the Analyzer Results – Get API using the request ID from Operation-Location until status becomes Succeeded.
• Ensure the client is not stopping polling prematurely and that long-running operations are allowed to complete.
• If the GET result keeps returning Running or NotStarted for an extended period (while similar PDF/image jobs complete quickly), that is a strong indicator of a backend/service issue for audio/video.

4. Check content and technical constraints

• Validate that the audio/video files meet the documented input requirements and service limits (formats, duration, size) for Content Understanding video and audio solutions.
• Be aware of technical constraints such as frame sampling (~1 FPS) and frame resolution (512×512) for video. While these do not normally cause jobs to hang, they are important when evaluating whether the content is supported.

5. Network and connectivity checks

• If calls are made from an app (for example, Function App, web API, or backend service), verify outbound connectivity to the Content Understanding endpoint:
  • No firewall, proxy, VNet, or private endpoint configuration is blocking or intermittently dropping traffic.
  • If a proxy is used, ensure the storage or Foundry endpoints are allowed.
• However, if the same hanging behavior is observed both from code and from the portal/Studio UI, and other analyzer types work, a pure network issue on the client side is less likely.

6. Compare behavior across analyzer types

• Run a small test matrix:
  • Same resource, same region: run document/image analyzers and audio/video analyzers on small test files.
  • Different region: run the same tests.
• If only audio/video analyzers hang in one region while all analyzers succeed in another, document this as evidence of a regional backend issue.

7. Engage Microsoft support with correlation data

• When opening a support case, provide:
  • Resource name and region.
  • Approximate timestamps of failing requests.
  • Analyzer IDs used (for example, prebuilt-videoSearch, prebuilt-audioSearch, or custom analyzer IDs and their base analyzers).
  • Request IDs or operation IDs from the Operation-Location header and from any SDK logs.
  • Confirmation that PDF/image analyzers are working in the same resource and region.
• This information allows the support team to trace backend jobs that are stuck in Running and identify whether there is a known incident, capacity issue, or regression affecting audio/video pipelines.

8. Workarounds and longer-term mitigation

• Short-term:
  • Use a different region where tests show audio/video analyzers complete successfully.
  • If possible, reduce concurrency and test with a small number of files to rule out transient throttling or capacity constraints.
• Long-term:
  • Keep analyzers and custom definitions aligned with the GA API schema and recommended models.
  • Monitor Service Health and set alerts for the regions where audio/video workloads run.
  • If repeated regional issues occur, consider distributing workloads across multiple regions for resilience.

These steps help distinguish between configuration/network issues and genuine service-side problems. Given that document/image analyzers are functioning while audio/video intermittently hang and later recover without changes, the most probable root cause is a transient or regional backend issue in the audio/video analyzer pipeline, which should be investigated by Microsoft support using your operation IDs and timestamps.

References:

• Quickstart: Use Azure Content Understanding in Foundry Tools (programming-language-rest)
• What is a Content Understanding analyzer?
• Quickstart: Use Azure Content Understanding in Foundry Tools (programming-language-python)
• Quickstart: Use Azure Content Understanding in Foundry Tools (programming-language-java)
• Azure Content Understanding in Foundry Tools video solutions
• Migrate from Azure Content Understanding Preview to GA
• Troubleshooting silent testing
• Document Intelligence classification and extraction requests timing out - Microsoft Q&A