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

[Jonathan Baecker]

Hello,

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)

It doesn't matter how big I raise the thread_queue_size, the message 
comes son or later.  I try also the fifo filter for both inputs, but 
after some time the message comes again.

Command too reproduce :

    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

Full output:

      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 /usr/local/share/logo.png
    -filter_complex overlay -pix_fmt yuv420p -c:v libx264 -crf 26
    -preset ultrafast -c:a aac -f flv -y /dev/null
    ffmpeg version git-2018-02-08-ddd851f7c Copyright (c) 2000-2018 the
    FFmpeg developers
       built with gcc 6.3.0 (Debian 6.3.0-18) 20170516
       configuration:
    --prefix=/usr/local/src/compile-ffmpeg-osx-linux/local
    --disable-debug --disable-shared --disable-doc --enable-gpl
    --enable-version3 --enable-runtime-cpudetect --enable-avfilter
    --enable-zlib --enable-libzimg --enable-libmp3lame --enable-libx264
    --enable-libx265 --enable-nonfree --enable-libfdk-aac --enable-pic
    --extra-libs='-lxml2 -llzma -lstdc++ -lpng -lm -lexpat -lpthread'
    pkg_config='pkg-config --static'
       libavutil      56.  7.100 / 56.  7.100
       libavcodec     58. 10.100 / 58. 10.100
       libavformat    58.  9.100 / 58.  9.100
       libavdevice    58.  1.100 / 58.  1.100
       libavfilter     7. 11.101 /  7. 11.101
       libswscale      5.  0.101 /  5.  0.101
       libswresample   3.  0.101 /  3.  0.101
       libpostproc    55.  0.100 / 55.  0.100
    Guessed Channel Layout for Input Stream #0.1 : stereo
    Input #0, avi, from 'pipe:0':
       Metadata:
         encoder         : Lavf58.9.100
       Duration: 11930:27:52.96, start: 0.000000, bitrate: N/A
         Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p,
    1024x576, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 25 tbc
         Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000
    Hz, stereo, s16, 1536 kb/s
    Input #1, png_pipe, from '/usr/local/share/logo.png':
       Duration: N/A, bitrate: N/A
         Stream #1:0: Video: png, rgba(pc), 85x85 [SAR 2835:2835 DAR
    1:1], 25 tbr, 25 tbn, 25 tbc
    Stream mapping:
       Stream #0:0 (rawvideo) -> overlay:main (graph 0)
       Stream #1:0 (png) -> overlay:overlay (graph 0)
       overlay (graph 0) -> Stream #0:0 (libx264)
       Stream #0:1 -> #0:1 (pcm_s16le (native) -> aac (native))
    [libx264 @ 0x558373771640] using SAR=1/1
    [libx264 @ 0x558373771640] using cpu capabilities: MMX2 SSE2Fast
    SSSE3 SSE4.2
    [libx264 @ 0x558373771640] profile Constrained Baseline, level 3.1
    [libx264 @ 0x558373771640] 264 - core 155 r2893 b00bcaf -
    H.264/MPEG-4 AVC codec - Copyleft 2003-2018 -
    http://www.videolan.org/x264.html - options: cabac=0 ref=1
    deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00
    mixed_ref=0 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0
    deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=6
    lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0
    bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250
    keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=26.0
    qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
    Output #0, flv, to '/dev/null':
       Metadata:
         encoder         : Lavf58.9.100
         Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007),
    yuv420p(progressive), 1024x576 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps,
    1k tbn, 25 tbc (default)
         Metadata:
           encoder         : Lavc58.10.100 libx264
         Side data:
           cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
         Stream #0:1: Audio: aac (LC) ([10][0][0][0] / 0x000A), 48000
    Hz, stereo, fltp, 128 kb/s
         Metadata:
           encoder         : Lavc58.10.100 aac
    [avi @ 0x558373762440] Thread message queue blocking; consider
    raising the thread_queue_size option (current value: 256)
    frame= 6196 fps=171 q=-1.0 Lsize=   67505kB time=00:04:07.85
    bitrate=2231.2kbits/s speed=6.84x
    video:63306kB audio:3885kB subtitle:0kB other streams:0kB global
    headers:0kB muxing overhead: 0.467803%
    [libx264 @ 0x558373771640] frame I:25    Avg QP:22.16  size: 52878
    [libx264 @ 0x558373771640] frame P:6171  Avg QP:25.06  size: 10290
    [libx264 @ 0x558373771640] mb I  I16..4: 100.0%  0.0%  0.0%
    [libx264 @ 0x558373771640] mb P  I16..4:  4.4%  0.0%  0.0% P16..4:
    32.6%  0.0%  0.0%  0.0%  0.0%    skip:62.9%
    [libx264 @ 0x558373771640] coded y,uvDC,uvAC intra: 35.2% 55.3%
    18.0% inter: 17.5% 18.0% 1.5%
    [libx264 @ 0x558373771640] i16 v,h,dc,p: 43% 23% 16% 18%
    [libx264 @ 0x558373771640] i8c dc,h,v,p: 39% 20% 29% 12%
    [libx264 @ 0x558373771640] kb/s:2092.47
    [aac @ 0x558373772080] Qavg: 242.017

Is there any way to get rid of this?

Jonathan