Uploading fails to process says unsupported format

[jill88]

Description

I was uploading a pre-recorded local video i made with Camtasia. It uploads, but then fails to process saying it is an unsupported format, even though it's a regular mp4 file. I then uploaded the same file using the desktop app and it worked fine (using the export button). I tried both on firefox and chrome and it didn't work on either.

Reproduction

upload a local mp4 video to the web app.

Additional Context

• Cap version: latest docker install
• Operating system, version: Windows 11
• Device (optional): Windows desktop

[linear]

CAP-642

[tembo]

Thanks for the detailed report. This is helpful context for debugging.

Looking at the codebase, the web upload and desktop export paths have different processing pipelines:

Web upload path (apps/web/app/(org)/dashboard/import/file/ImportFilePage.tsx):

• Uploads to raw-upload.mp4 with hardcoded Content-Type: "video/mp4" (see apps/web/actions/video/create-for-processing.ts:92)
• Creates video with source: { type: "webMP4" }
• Sends to the media server at /video/process for full processing (apps/web/workflows/process-video.ts:132)

Desktop export path:

• Creates video with source: { type: "desktopMP4" }
• Uses different upload endpoints and may use remuxOnly: true for already-encoded MP4s

The key difference is that web uploads go through full media server processing, while desktop exports (which are already in a known format from Cap's recording pipeline) may bypass some processing.

Related issues:

• #1539 - Similar "detached ArrayBuffer" errors during video processing on self-hosted Docker
• #1550 - Workflow failures on Docker with Node 24, same ArrayBuffer error pattern
• #1108 - "Failed to process video file. This format may not be supported for upload" error on dashboard uploads

Since you're on a self-hosted Docker install, this might be related to the Node 24 compatibility issue mentioned in #1550. The workflow package appears to have issues with newer Node versions. You could try checking if your Docker image is using Node 24 (node --version in the container) - if so, this may be the root cause.

For Camtasia-exported MP4s specifically, it would help to know the video codec (H.264/H.265) and container details (you can check with ffprobe). Some encoder combinations produce MP4 files that need additional processing that the media server may not handle well.