[FFmpeg-user] Thread message queue blocking: when pipe and use filter complex

[Carl Eugen Hoyos]

2018-02-18 22:56 GMT+01:00 Jonathan Baecker <jonbae77 at gmail.com>:

> when I use pipe to ffmpeg in combination with *filter_complex
> overlay, *I always get the message:
>
>    Thread message queue blocking; consider raising the
>    thread_queue_size option (current value: 256)

What exactly is the problem when FFmpeg shows this message?

I suspect your command line will always fill the buffer which
hopefully doesn't matter for you (because it isn't entirely
clear why you are using the pipe) but does typically matter.

[...]

>    ffmpeg -v error -hide_banner -nostats -i "input.mp4" -s 1024x576
>    -pix_fmt yuv420p -c:v rawvideo -c:a pcm_s16le -f avi - | ffmpeg
>    -thread_queue_size 256 -i pipe:0 -i "logo.png" -filter_complex
>    overlay -pix_fmt yuv420p -c:v libx264 -crf 26 -preset ultrafast
>    -c:a aac -f flv -y /dev/null

Please understand that reports with "-hide_banner" are useless
unless you want to report an issue with this option.

Carl Eugen