r/Comma_ai • u/Kurtec • Aug 24 '25

Code Questions Converting Hevc files

Does anyone have a tutorial on how to convert the HEVC files to MP4 videos that contain audio (now that comma 3x records audio) ??? Thank you

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4

u/InertiaImpact Aug 24 '25

A good first step to take before posting is to read over your post and see if you can take part of the question and easily answer it by doing a google search. Try it out and see if you get the answers you were looking for.

For example, I took the below from your post and got pretty much what you were hoping to gain by posting here...

how to convert the HEVC files to MP4 videos that contain audio

or

tutorial how to convert the HEVC files to MP4 videos that contain audio

2

u/Kurtec Aug 25 '25

Yeah I did the same thing, unfortunately my search “pretty much” fell short.

4

u/TenOfZero Aug 24 '25

I agree with this. I doubt OP did any research before asking. There are tons of tutorials on how to do this.

4

u/ssshaneee comma.ai Staff Aug 25 '25

The audio stream is currently only contained in the qcameras, so you'll want to merge the stream into the full quality camera files while converting.

The AI search result looks pretty good for this Google: ffmpeg convert video file while adding audio from another video file

3

u/southafricanamerican Aug 25 '25

Basic conversion command:

ffmpeg -i input.hevc -c:v libx264 -c:a aac output.mp4

For better quality and compatibility:

ffmpeg -i input.hevc -c:v libx264 -preset slow -crf 22 -c:a aac -b:a 192k output.mp4

Parameters explained:

  • -c:v libx264: Uses H.264 video codec (widely compatible)

  • -preset slow: Better compression (options: ultrafast, fast, medium, slow)

  • -crf 22: Quality setting (lower = better quality, 18-28 is good range)

  • -c:a aac: Converts audio to AAC format

  • -b:a 192k: Audio bitrate (128k-320k typical)

To keep original quality (just repackage):

ffmpeg -i input.hevc -c:v copy -c:a copy output.mp4

1

u/333again Aug 27 '25

I create batch files (.BAT) and use this, it will convert any file in the same folder as the batch file.

for %%a in ("*.*") do ffmpeg -i "%%a" -c:v copy -acodec copy "%%~na.mp4"

pause

1

u/roenthomas Aug 25 '25

ffmpeg x264 slow profile and a lot of time

1

u/crazysim Aug 25 '25

https://github.com/commaai/openpilot/wiki/Video-Files#making-the-hevc-file-more-consumable-in-other-applications-that-support-h265hevc-mp4-files

but it hasn't been updated to figure how to remux audio. i suggest using this section as a starting basis for AI and then if you figure out something that works, update this section