Ingeniously simple!

#1
by Bernte - opened

Hi! I love your tool — it’s really fantastic, useful, and ingeniously simple! ❤️

I have one question, though. You mention: “MP4 is used when the browser supports it, otherwise WebM.”

Is there any way to change this in Firefox? I feel like the WebM output is noticeably worse than MP4.

Or would it be possible to add something like FFmpeg to convert the output to MP4?

Thanks for making this! 🙏

Okay, so I downloaded Chrome and used the video trimmer there. I exported a 30-second video with a fixed frame rate and an H3-compliant frame count (17n+5).

The new video plays fine in VLC and Media Player, but in ComfyUI/H3 Director it shows up as only 0.5 seconds long. DaVinci Resolve detects the video, but labels it as “offload media.”

Bernte changed discussion status to closed

Okay, so I downloaded Chrome and used the video trimmer there. I exported a 30-second video with a fixed frame rate and an H3-compliant frame count (17n+5).

The new video plays fine in VLC and Media Player, but in ComfyUI/H3 Director it shows up as only 0.5 seconds long. DaVinci Resolve detects the video, but labels it as “offload media.”

Bernte changed discussion status to open

I will have a look, apparently it was built off of the chrome's media record feature and Firefox did not want to pay the license fee for the h264. I have also encountered the empty media bug sometimes. I have been trying to fix it. I will try my best.

Hi,

I tried troubleshooting this with the help of GPT, and we found a workaround that works reliably for me.

The actual video data appears to be fine. The problem seems to be how Chrome's MediaRecorder is packaging/muxing the MP4 container. The MP4 contains the correct video, audio and duration, but some applications don't interpret the container metadata/structure correctly.

The working solution is:

ffmpeg -i "test.mp4" -c copy -movflags +faststart "test_fixed.mp4"

This remuxes the MP4 container without re-encoding the video or audio, so there is no quality loss.

I made a small BAT file using my existing portable FFmpeg build. I simply drag the exported MP4 onto it, and it creates the _fixed.mp4 file. This works for me and confirms that the remux is what fixes the compatibility issue.

We also tested changing rec.start(200) to rec.start() and rec.start(1000), but neither made a difference, so I restored rec.start(200).

The current MediaRecorder codec and recording logic can remain unchanged. The main requirement is to reproduce the equivalent of:

-c copy -movflags +faststart

automatically after the MediaRecorder export.

The BAT file is only my temporary workaround, but it's working.

Best regards

Bernte changed discussion status to closed

opps closed, nono

Bernte changed discussion status to open

I think with the issues I’ve have I may switch to a ffmpeg option soon with the same UI. It’s useful and ffmpeg version will make it more compatible with less issues. Thanks for bringing it up!

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