This tutorial is an original manually prepared language version. It does not use the article live-translation service.
Quick answer
Start with a short local MP4 test, confirm the server and internet are active, check available disk space, use one duration mode, reduce the batch size and read the visible error or log before changing several settings at once.
Use the relevant BestAI tool with one short test file or paragraph first. Confirm the result, then process a larger batch. This prevents a small setting mistake from being repeated across many clips or a long narration.
Why this tutorial matters
Processing failures can come from the browser, source file, codec, storage, server, FFmpeg or conflicting settings. Randomly changing everything hides the cause. A controlled test narrows the problem quickly and creates a repeatable fix.
The BestAI workflow is designed around a simple rule: one active control should own one decision. When a mode overrides another setting, the conflicting control is disabled in the interface and ignored by the backend. This makes the plan shown on screen match the actual result.
Recommended starting settings
| Setting | Practical starting point |
|---|---|
| Test file | A short H.264/AAC MP4 with a simple filename. |
| Batch size | One or two clips during diagnosis. |
| Duration mode | Only normal or exact, never both. |
| Storage | Keep enough free space for source, temporary and output files. |
| Browser | Use a current browser and keep the tab open during upload. |
These values are starting points, not universal rules. Source quality, speaking style, platform, audience and the purpose of the video can require a different choice.
Step-by-step tutorial
Step 1: Confirm the website and processing server are running
Open the homepage and health route locally. If the public site uses a tunnel, confirm the tunnel is connected. A working page does not always prove the processing worker has enough resources.
Step 2: Test a simple known-good file
Use a short MP4 with H.264 video and AAC audio. Rename it with simple letters and numbers. If this works, the original file may contain an unusual codec, damaged metadata or a very large size.
Step 3: Check active settings
Turn off Exact Duration if you want normal Clip Duration. Reduce manual clip count and disable optional subtitle or audio processing during diagnosis. Add features back one at a time.
Step 4: Check disk space and temporary files
Video processing can require several times the source size while temporary files and outputs exist together. Clear old jobs and confirm the drive is not nearly full.
Step 5: Read the error and logs
Use the exact error message, job status and server log. A codec error, permission error, missing FFmpeg and timeout require different fixes.
Step 6: Retry with a small batch
After one change, process one or two outputs. If successful, increase the count gradually. This identifies the capacity limit without repeating a large failure.
Quality-control checklist
- The server, tunnel and internet connection are active.
- A known-good MP4 test succeeds.
- Disk space is sufficient.
- Only one duration rule is active.
- The batch size is small during diagnosis.
- The exact error and timestamp are recorded.
Common mistakes to avoid
- Retrying the same large file without reading the error.
- Changing codec, duration, crop, subtitles and audio at the same time.
- Closing the tab during upload.
- Ignoring low disk space and old temporary jobs.
- Assuming every MP4 file uses the same internal codec.
Frequently asked questions
Why does one MP4 work while another fails?
MP4 is a container. The video or audio codecs, metadata or file integrity inside it can be different.
Can a high clip count cause failure?
A larger batch uses more processing time, temporary storage and output space. Test a small count to separate file problems from capacity problems.
Where should I look after a server error?
Check the visible job message and the application logs at the same timestamp. Preserve the source filename and settings used for the failed test.
Practical example
A large phone video fails after upload. A 30-second H.264 test succeeds, proving that the server and FFmpeg path are working. The original file uses a less common codec and the drive is nearly full. Converting a short sample and clearing old outputs identifies the actual causes without changing crop or subtitle settings.
Record a reproducible bug report
Save the source filename, duration, browser, active settings, job time and exact error. A reproducible report is far more useful than saying only that processing stopped. ## Final takeaway
Troubleshoot with one simple file, one active duration mode and one small batch. Change one variable, read the evidence and only increase complexity after the basic path succeeds.