Multiple high-priority issues across audio, video, and AI features.

[PotatoAnimal]

Describe the bug
Multiple high-priority issues across audio, video, and AI features.

1. No audio in editor after recording finishes
2. Can't add more than 1 audio track (e.g. mic + system audio)
3. Caption/CC generation fails with an error
4. Can't open an existing video file in editor
5. Can't add a second video to the timeline

To Reproduce

Audio (issue 1):

1. Start a recording with microphone enabled
2. Stop recording
3. Editor opens - no audio track present

Audio (issue 2):

1. Add microphone audio in editor
2. Try to add system audio or music over it
3. No option available / blocked

Note: Works fine if the voice track is cut first and new audio beside

AI Captions (issue 3):

1. Open any recording in editor
2. Attempt to generate CC/captions
3. See error: "Failed to generate auto captions"

Expected behavior

• Audio from recording should appear in editor automatically
• Multiple audio tracks should be supported (for different audio sources)
• CC generation should work without error
• Videos and images should be openable in the editor
• Multiple video tracks should be supported on the timeline

Screenshots

*Here trying to add .mp4

Desktop:

• OS: Windows 11 23H2 (Build 22631) · macOS Apple Silicon
• Version: v1.1.24 & v1.2.0-beta.1

Smartphone:
N/A

Additional context
Issues reproduced on both Windows 11 23H2 (Build 22631) and macOS Apple Silicon across v1.1.24 and v1.2.0-beta.1.

[webadderall]

Are all these issues reproducible in source?

[meiiie]

I do not think this should stay bundled as one issue, because the 5 items point to different buckets:

• 1 looks related to Microphone audio recorded but not available in editor or export #250, which was fixed by fix(recording): preserve mic companion audio in editor/export #280, so it is worth retesting on current main / the next build first.
• 3 matches the existing captions issue in [Bug]: Failed to generate auto captions #220.
• 4 looks very close to Failed to load video network error ? #307, which was fixed by fix(media): approve loopback video paths when minting URLs #308, so that is also worth retesting on current main / the next build first.
• 2 and 5 look like separate editor/timeline limitations rather than the same regression.

So the first question is whether all 5 are still reproducible from current source. If they are, I would track them separately instead of keeping them bundled into one report.

[meiiie]

Opened #322 to track item 2 separately, since this looks like a focused add-audio flow bug rather than the same bundled issue.

[meiiie]

Opened #323 to track item 5 separately, since this looks like its own editor/timeline limitation instead of the same bundled regression.

[meiiie]

Closing this bundled report in favor of focused tracking. Item 2 is now tracked in #322, item 5 in #323, and item 3 already belongs on #220. Items 1 and 4 should be retested on current main / the next build first, since #280 and #308 already landed. If any of those are still reproducible on the latest build or source, please open or reopen focused follow-ups instead of keeping them bundled together.