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

[Ted Park]

Hey,

> Well, without the -vf scale=1280:720,format=yuv420p I get the following error
> [swscaler @ 0x222c910] deprecated pixel format used, make sure you did set range correctly
> [h264_omx @ 0x1b31010] Using OMX.broadcom.video_encode
> [h264_omx @ 0x1b31010] OMX error 80001000
> [h264_omx @ 0x1b31010] err 80001018 (-2147479528) on line 561
> Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
> [aac @ 0x1b50d90] Qavg: 7615.820
> [aac @ 0x1b50d90] 2 frames left in the queue on closing
> Conversion failed!
> 
> 
> Full output...
> ffmpeg version 4.1.4-1+rpt7~deb10u1 Copyright (c) 2000-2019 the FFmpeg developers
>  built with gcc 8 (Raspbian 8.3.0-6+rpi1)
>  configuration: --prefix=/usr --extra-version='1+rpt7~deb10u1' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared --libdir=/usr/lib/arm-linux-gnueabihf --cpu=arm1176jzf-s --arch=arm
> WARNING: library configuration mismatch

That's kind of wacky, how did you install ffmpeg? The error apparently indicates insufficient resources (https://github.com/raspberrypi/userland/blob/a246147c21ae5be92ad1b85199b5b0bb447e0544/interface/vmcs_host/khronos/IL/OMX_Core.h#L142) This was an RPi 4 right? 4B? How much memory did you split to video?

I thought it could do 4k encode in hardware, but maybe it was only decode. In any case I feel like you should fix that library mismatch warning if only as a cosmetic improvement, either reinstall from apt or some static build.

I don't think there's much difference whether you specify -s or use scale filter if all you're doing in the end is scaling the frame size.

Regards,
Ted Park