[FFmpeg-user] ffmpeg in jailshell encoding with libx264

[Fred]

Hi Guys,

I am running ffmpeg (statically linked) in a jailshell of a hosted 
server to encode webcam pictures into a movie using libx264 codec. Until 
recently all was working fine now after a CPanel upgrade (which also 
seems to have impacted the jailshell) it's suddenly not working. I still 
can encode e.g. to MPEG4 or Theora. But when using libx264 I always get 
this error.

#################
[libx264 @ 0x70a0400] using SAR=1/1
[libx264 @ 0x70a0400] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 
AVX FMA3 BMI2 AVX2 AVX512
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
#################

Command Line used:
#################
./ffmpeg -f image2 -framerate 12 -pattern_type glob -i 
"./2019-09-27/*.jpg" -filter:v scale=960:-1 -c:v libx264+ -crf 30 
-preset slow day_2019-09-27.mkv
#################

FFMPEG version used:
#################
ffmpeg version 4.2.1-static https://johnvansickle.com/ffmpeg/ Copyright 
(c) 2000-2019 the FFmpeg developers
   built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
   configuration: --enable-gpl --enable-version3 --enable-static 
--disable-debug --disable-ffplay --disable-indev=sndio 
--disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r 
--enable-gnutls --enable-gmp --enable-libgme --enable-gray 
--enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf 
--enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb 
--enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband 
--enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis 
--enable-libopus --enable-libtheora --enable-libvidstab 
--enable-libvo-amrwbenc --enable-libvpx --enable-libwebp 
--enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d 
--enable-libxvid --enable-libzvbi --enable-libzimg
   libavutil      56. 31.100 / 56. 31.100
   libavcodec     58. 54.100 / 58. 54.100
   libavformat    58. 29.100 / 58. 29.100
   libavdevice    58.  8.100 / 58.  8.100
   libavfilter     7. 57.100 /  7. 57.100
   libswscale      5.  5.100 /  5.  5.100
   libswresample   3.  5.100 /  3.  5.100
   libpostproc    55.  5.100 / 55.  5.100
#################

Anyone some idea what limitation in the jailshell might impact the 
encoding capability of certain encoders?

Cheers

Fred