I just bought a RPI3 B+ with the hopes of using it as a media encoding box. I built ffmpeg, and use the following to transcode media from h264 to h265

ffmpeg -i "$i" -c:v libx265 -crf 28 -c:a aac -b:a 128k -preset slow output.mp4

The issue is that regardless of what I use as the preset, it runs at about 1 FPS. Is there any way to speed it up, or is it just a limitation of the RPI?

  • 1
    I'd say that's a limitation of the RPi - I've never been able to get better than about 1.5fps on a Pi1 with h265 Aug 14, 2018 at 9:38

1 Answer 1


The Raspberry Pi has no accelerators for H.265. The Raspberry Pi can accelerate H.264 in both directions (encode/decode) by default.

ffmpeg calls the accelerated decoder "h264_mmal" and the accelerated encoder "h264_omx". Not all versions of ffmpeg support them, but the one in Raspbian Stretch should.

I have not seen any benchmarks in the context of ffmpeg. Benchmark results would be very interesting ....

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