Qwen 3.5 Plus Video Feedback

Overview

Analyze videos with OpenRouter using the qwen/qwen3.5-plus-02-15 model. Designed as the feedback loop for Veo 3.1 video generation — pass a generated video and a prompt to get structured analysis and quality feedback.

Analyze a public video URL

uv run {baseDir}/scripts/analyze_video.py \
  --video-url "https://example.com/generated.mp4" \
  --prompt "Does this video match the description: a cat jumping over a fence? Rate quality 1-10."

Analyze a local video file (auto-uploaded to S3)

uv run {baseDir}/scripts/analyze_video.py \
  --video-file /path/to/video.mp4 \
  --prompt "Describe what is happening in this video and assess its overall visual quality."

Save analysis to a file

uv run {baseDir}/scripts/analyze_video.py \
  --video-url "https://example.com/clip.mp4" \
  --prompt "Evaluate prompt adherence and suggest improvements." \
  --output feedback.txt

Arguments

| Argument | Required | Description | |----------|----------|-------------| | --prompt | Yes | Question or instruction for the model | | --video-url | One of these | Public or presigned URL to the video | | --video-file | One of these | Path to a local video file (uploaded to S3, then analyzed via presigned URL) | | --output | No | File path to save the analysis text |

--video-url and --video-file are mutually exclusive.

S3 Configuration (required for --video-file)

Local files are uploaded to an S3-compatible bucket and accessed via a presigned URL (valid 1 hour). Set these environment variables:

| Variable | Required | Description | |----------|----------|-------------| | S3_ENDPOINT_URL | Yes | e.g. https://s3.us-east-1.amazonaws.com or https://nyc3.digitaloceanspaces.com | | S3_ACCESS_KEY_ID | Yes | Access key ID | | S3_SECRET_ACCESS_KEY | Yes | Secret access key | | S3_BUCKET | Yes | Bucket name | | S3_REGION | No | Region (default: us-east-1) | | S3_KEY_PREFIX | No | Key prefix for uploads (default: video-analysis/) |

The bucket does not need to be public — presigned URLs are used.

Supported video formats

video/mp4, video/mpeg, video/mov, video/webm

System prompt customization

The skill reads an optional system prompt from assets/SYSTEM_TEMPLATE. Edit it to tune the model's feedback style (scoring rubric, artifact checklist, output format).

Behavior

• When --video-file is used: uploads the file to S3, generates a presigned URL, passes it to the model. Upload progress is printed to stderr.
• Prints the full analysis to stdout.
• If --output is provided, also writes the text to that file and prints Analysis saved to: <path>.

Chaining with veo3-1

VIDEO_URL=$(uv run veo3-1/scripts/generate_video.py --prompt "..." --url-only | grep '^VIDEO_URL:' | cut -d' ' -f2)
uv run {baseDir}/scripts/analyze_video.py \
  --video-url "$VIDEO_URL" \
  --prompt "Evaluate prompt adherence, list artifacts, rate 1-10."

Troubleshooting

| Symptom | Resolution | |---------|------------| | OPENROUTER_API_KEY is not set | export OPENROUTER_API_KEY="sk-or-..." | | S3_ENDPOINT_URL is not set | Set S3 env vars (see S3 Configuration above) | | Video file not found | Check the path passed to --video-file | | AuthenticationError / HTTP 401 | Key invalid or out of credits. Check https://openrouter.ai/settings/keys. | | Missing Content-Length / upstream error | The provider doesn't support base64 data URLs — use --video-file (S3 upload) or --video-url with a direct HTTP URL. | | uv: command not found | macOS/Linux: curl -LsSf https://astral.sh/uv/install.sh \| sh. Restart terminal. |

For transient errors (HTTP 429, network timeouts), retry once after 30 seconds. Do not retry the same error more than twice — surface it to the user instead.