drawtext- limitation on number of drawtext filters used in a single command?

[akhil]

I am using multiple draw text filter in a single command.These filters are generated at run time.If the number of draw text filters increases , (>600), processing fails. Error is:

[Parsed_drawtext_509 @ 0000000003bba440] Cannot find a valid font for the family Sans
[AVFilterGraph @ 000000000047bce0] Error initializing filter 'drawtext' with args 'enable=between(n,0,0):fontsize=40 :fontcolor=black:fontfile=Chn_Prop_Arial_Normal.ttf:text=Hello John!:x=100:y=100-th:shadowcolor=blue:shadowx=1:shadowy=1'
Error initializing complex filters.
No such file or directory


ffmpeg version: 3.4.2

[Carl Eugen Hoyos]

To make this a valid ticket, please test current FFmpeg git head and provide the failing command line you tested together with the complete, uncut console output.
Your operating system or your shell likely limits the length of the command line, I don't think this can be fixed within FFmpeg.

[akhil]

Hi. I have tested with latest ffmpeg version- 3.3.1.
The problem still exists. It is not able to open more than 512 drawtext filters after that ffmpeg writes that it cannot find default "Sans" font.
PFB complete console output:

D:\psv\node-ffmpeg-try\frame annotation test>ffmpeg -f concat -i input.txt -y -r 10 -filter_complex_script fc.txt -crf 22 -threads 2 -preset ultrafast
 output_video.mp4
ffmpeg version 3.3.1 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 6.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-a
visynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable
-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --en
able-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspe
ex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-
libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
Input #0, concat, from 'input.txt':
  Duration: 00:00:02.75, start: 0.000000, bitrate: 0 kb/s
    Stream #0:0: Video: mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 1280x720 [SAR 72:72 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
Fontconfig error: Cannot load default config file
[Parsed_drawtext_0 @ 000000000064de80] Cannot find a valid font for the family Sans
[AVFilterGraph @ 00000000006cfec0] Error initializing filter 'drawtext' with args 'enable=between(n,0,0):fontsize=40 :fontcolor=black:text=Hello John!
:x=100:y=100-th:shadowcolor=blue:shadowx=1:shadowy=1'
Error initializing complex filters.
No such file or directory

[Elon Musk]

Please provide fc.txt and reopen bug.