How to further compress the bag file?

[lubidkdh]

Hi ,I use the CLI command of mcap to compress my bag file.
.\mcap.exe convert input.bag out.mcap --compression zstd
The size of my input.bag file is 16G. After compression, the resulting out.mcap file is 10G. The main sensor information contained in my bag includes ten cameras and two radar devices. The scene duration of this data is 60 seconds.I trimmed the converted mcap file by time, keeping only the last 20 seconds of data. The final output mcap file size was 3.5G.However, I still think the size of the cropped file is still too large.
I noticed that the mcap files on https://foxglove.dev/examples contain most of the data for the scenes lasting 20 seconds. However, the mcap files are only a few hundred MB in size, and the file size does not exceed 1GB.
So, I am quite curious about how to further compress the files.

The following is the topic information of my bag data.

[jtbandes]

To reduce the size of the CompressedImage topics you should consider using CompressedVideo instead. Using a video encoding allows you to reduce duplicate information between multiple frames. Check these out:

• https://github.com/foxglove/mcap-videoify
• https://github.com/foxglove/mp42mcap