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.