[FFmpeg-user] zmq example

[Michael Koch]

Hello,

I'm testing this command line which is copied from the documentation:
https://www.ffmpeg.org/ffmpeg-all.html#zmq_002c-azmq

ffplay -dumpgraph 1 -f lavfi 
"color=s=100x100:c=red[l];color=s=100x100:c=blue[r];nullsrc=s=200x100,zmq[bg];[bg][l]overlay[bg+l];[bg+l][r]overlay at my=x=100"

The problem is that ffplay exits after 1-2 seconds without any error 
message. I don't understand why. Shouldn't this command run forever? I'm 
not sending any commands to the zmq filter. The console output is below.

Michael

P.S. It works when I change the sizes to 200x200 and 400x200 !



C:\Users\astro\Desktop>c:\ffmpeg\ffplay -dumpgraph 1 -f lavfi 
"color=s=100x100:c=red[l];color=s=100x100:c=blue[r];nullsrc=s=200x100,zmq[bg];[bg][l]overlay[bg+l];[bg+l][r]overlay at my=x=100"
ffplay version 2020-10-21-git-289e964873-essentials_build-www.gyan.dev 
Copyright (c) 2003-2020 the FFmpeg developers
   built with gcc 10.2.0 (Rev3, Built by MSYS2 project)
   configuration: --enable-gpl --enable-version3 --enable-static 
--disable-w32threads --disable-autodetect --enable-fontconfig 
--enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp 
--enable-lzma --enable-zlib --enable-libsrt --enable-libssh 
--enable-libzmq --enable-avisynth --enable-sdl2 --enable-libwebp 
--enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom 
--enable-libopenjpeg --enable-libvpx --enable-libass 
--enable-libfreetype --enable-libfribidi --enable-libvidstab 
--enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm 
--enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc 
--enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libgme 
--enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame 
--enable-libtheora --enable-libvo-amrwbenc --enable-libgsm 
--enable-libopencore-amrnb --enable-libopus --enable-libspeex 
--enable-libvorbis --enable-librubberband
   libavutil      56. 60.100 / 56. 60.100
   libavcodec     58.111.101 / 58.111.101
   libavformat    58. 62.100 / 58. 62.100
   libavdevice    58. 11.102 / 58. 11.102
   libavfilter     7. 88.100 /  7. 88.100
   libswscale      5.  8.100 /  5.  8.100
   libswresample   3.  8.100 /  3.  8.100
   libpostproc    55.  8.100 / 55.  8.100
+----------------+0 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0
| Parsed_color_0 |default--[100x100 1:1 yuva420p]--Parsed_overlay_4:overlay
|    (color)     |
+----------------+

+----------------+
| Parsed_color_1 |default--[100x100 1:1 yuva420p]--overlay at my:overlay
|    (color)     |
+----------------+

+------------------+
| Parsed_nullsrc_2 |default--[200x100 1:1 yuva420p]--Parsed_zmq_3:default
|    (nullsrc)     |
+------------------+

+--------------+
Parsed_nullsrc_2:default--[200x100 1:1 yuva420p]--default| Parsed_zmq_3 
|default--[200x100 1:1 yuva420p]--Parsed_overlay_4:main
                                                          | (zmq)     |
+--------------+

+------------------+
Parsed_zmq_3:default----[200x100 1:1 yuva420p]-----main| 
Parsed_overlay_4 |default--[200x100 1:1 yuva420p]--overlay at my:main
Parsed_color_0:default--[100x100 1:1 yuva420p]--overlay| (overlay)     |
+------------------+

+------------+
Parsed_overlay_4:default--[200x100 1:1 yuva420p]-----main| overlay at my 
|default--[200x100 1:1 yuva420p]--out:default
Parsed_color_1:default----[100x100 1:1 yuva420p]--overlay| (overlay)  |
+------------+

                                                    +--------------+
overlay at my:default--[200x100 1:1 yuva420p]--default|     out      |
                                                    | (buffersink) |
                                                    +--------------+

Input #0, lavfi, from 
'color=s=100x100:c=red[l];color=s=100x100:c=blue[r];nullsrc=s=200x100,zmq[bg];[bg][l]overlay[bg+l];[bg+l][r]overlay at my=x=100':
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: rawvideo (Y4[11][8] / 0x80B3459), yuva420p, 
200x100 [SAR 1:1 DAR 2:1], 25 tbr, 25 tbn, 25 tbc