[FFmpeg-user] Testing transcode speeds on Raspberry Pi 4

MediaMouth communque at gmail.com
Thu Apr 16 20:50:33 EEST 2020


On Apr 15, 2020, at 10:02 PM, Ted Park <kumowoon1025 at gmail.com> wrote:
> 
> Hey,
> 
>> An attempt to do some hardware acceleration...
>>> ffmpeg -i path/to/source.mp4 -c:v h264_omx -b:v 9000k -vf scale=1280:720,format=yuv420p path/to/dest.mp4
>> Gave the exact same same results
> 
> That sounds to me like the encoder is waiting for filtered frames in both cases. Did you try without the -vf ?
> 
> Regards,
> Ted Park
> 
> 

Apologies for the top-post on the prior response.
I was able to go with your suggestion after a slight tweak:

The following worked w/o errors (though it didn't improve the speed)
	ffmpeg -y -i SourcePath -s 1280*720 -b:v 9000k -c:v h264_omx DestPath

The following generated the "deprecated pixel format used" error.
	ffmpeg -y -i SourcePath -b:v 9000k -c:v h264_omx DestPath

The difference is the -s flag.  Why would leaving that out result in an error?

In any event, the -v:f doesn't seem to slow the speed in his instance.


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