Are there any video understanding APIs that handle long video streams with low false positives?

Yes — but the best choice depends on what you mean by “video understanding” and what kind of false positives you can tolerate.

Good API options for long videos / streams

1. Google Cloud Video Intelligence

• Strong at: shot changes, labels, explicit content, text detection, object tracking
• Supports: batch video files; not really “real-time stream understanding” in the same sense as a live event detector
• Pros: fairly mature, good general accuracy
• Cons: can still produce noisy labels on long, complex footage; not ideal for highly specialized detection

2. AWS Rekognition Video

• Strong at: object/person detection, moderation, celebrity recognition, activity detection
• Supports: video files and live stream analysis via Kinesis Video Streams
• Pros: one of the better options for live streams
• Cons: false positives can happen, especially for fine-grained or rare events

3. Azure AI Video Indexer

• Strong at: indexing, transcription, OCR, face/person insights, scene understanding
• Supports: long-form video well
• Pros: very good for search/indexing over long videos
• Cons: less focused on low-latency stream event detection; not the best if you need strict “only alert when highly certain”

4. Tenyks / Roboflow / custom CV platforms

• Strong at: custom object/event detection if you train your own model
• Pros: generally the best path to low false positives if your target is specific
• Cons: requires dataset/model training and some engineering

If low false positives are your top priority

For long videos, “generic” APIs often trade precision for recall. If you need low false positives, the best approach is usually:

• Use a custom model trained on your target events/classes
• Add temporal smoothing:
  • require detections across multiple frames
  • use confidence thresholds
  • add cooldown/debouncing logic
• Use two-stage filtering:
  • fast detector first
  • stricter verifier second

Practical recommendation

• If you want off-the-shelf: start with AWS Rekognition Video or Google Cloud Video Intelligence
• If you want long-video indexing/search: Azure AI Video Indexer
• If you want lowest false positives for a specific event: custom model + video platform

Important caveat

Most “video understanding” APIs are better at:

• tagging scenes
• detecting common objects
• OCR/transcription
• moderation
• summarization/indexing

They are usually not great at precise event detection in long streams unless your event is well-defined and the model is trained for it.

If you tell me:

1. whether this is live stream or uploaded video,
2. what you want to detect,
3. your acceptable false positive rate / latency,

I can recommend a more specific API or architecture.