Can I record video 720p at 120fps? (rear camera)
Camera app, which is a development preview, does not yet do video capture, only stills.
The package name is
Millipixels, which is forked from
Megapixels, as I understand it.
It says that 120 fps probably won’t be possible.
720p at 120fps raw at 8-bit depth is about 105MB/s, which should be manageable. The question is - how fast would you be able to compress it to store it on slower eMMC, or much slower SD card. If you stay uncompressed and want to just record short videos (~20 seconds) this way, this won’t be a problem since they can be stored in RAM and processed later. For longer videos, you may be able to store them uncompressed in real-time on a USB 3.0 drive for as long as drive capacity allows. Otherwise, it all boils down to compression (and I’m not knowledgeable enough in this field to assess performance there).
FWIW, the sensor allows to grab 120 FPS at 1280x720 (it goes down to 60 FPS at 1920x1080 and 30 FPS at full 13MP resolution), so I’d say - it’s technically possible.
I remember that NXP published an OpenCL library for video encoding together with some benchmarks on the imx8. I don’t have the links, but if anyone wants to investigate, this could serve as some basis for estimating the theoretical performance.
Why not compress to the libre AV1 format to reduce MBs transfering to eMMC?
Do you know approximately when it will be possible to make videos with the Librem5?
About 2 weeks.