[FFmpeg-user] h264_v4l2m2m not working properly

twge lltwgell lltwgell at gmail.com
Mon Jun 13 08:07:17 EEST 2022

Software encoding was verified.
*Changed to shorter m2ts clips due to speed issues!

Console output for hardware and software encoding.

Software encoding finished encoding successfully. Playback was also

But I want to do hardware encoding because software encoding only gives me
about 0.5x.

Is there anything I can find out from this log?


2022年6月9日(木) 17:52 Adam Nielsen <a.nielsen at shikadi.net>:

> > I am trying to use h264_v4l2m2m on a Raspberry pi 4B to do M2TS to H264
> > hardware encoding, but it is not working properly. The log is below.
> > http://0x0.st/oMOa.txt
> >
> > If I don't use hardware encoding or if the source is not m2ts (tested
> with
> > mpeg-1 to h264(v4l2m2m)) I can encode.
> It looks a bit surprising, it seems it's bailing because the audio is
> corrupted.  What happens if you add -an to try the hardware encode but
> without any audio?  I don't see why the audio would affect hardware vs
> software video encoding though.
> Maybe you could post an equivalent log showing the software H264 encode
> so we can compare which messages are the same and which are different?
> Do you get any errors in dmesg from the Pi H264 hardware encoder?
> Sometimes it can fail if there isn't enough GPU memory, so you could
> also try increasing gpu_mem in /boot/config.txt to see if it has any
> effect.  It should work with 128 and definitely with 256.
> Cheers,
> Adam.

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