[FFmpeg-user] FFplay network stream with low latency

[Elliott Balsley]

I’m trying to use ffplay with a network stream from netcat.  It’s raw h.264, 1280x720, 30fps.  
When I play it with ffplay, there is about 10 seconds latency over the LAN.  Is there any way to reduce this?  I’ve tried -probesize 32 and —fflags nobuffer.  I notice it plays at 25fps, so maybe that’s part of the problem.  I can’t figure out how to force the rate to 30.

$ nc 192.168.3.3 8080 | ffplay -i pipe:0 -x 1280 -y 720 -probesize 32
ffplay version 3.4.git Copyright (c) 2003-2018 the FFmpeg developers
  built with Apple LLVM version 9.1.0 (clang-902.0.39.2)
  configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-libopus --enable-librsvg --enable-libtheora --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-libass --enable-libbluray --enable-lzma --enable-gnutls --enable-fontconfig --enable-libfreetype --enable-libfribidi --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --disable-indev=jack --enable-opencl --disable-outdev=xv --enable-audiotoolbox --enable-videotoolbox --enable-sdl2 --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --arch=x86_64 --enable-x86asm --enable-libx265 --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid --enable-nonfree --enable-libfdk-aac
  libavutil      56. 18.102 / 56. 18.102
  libavcodec     58. 19.102 / 58. 19.102
  libavformat    58. 16.100 / 58. 16.100
  libavdevice    58.  4.100 / 58.  4.100
  libavfilter     7. 24.100 /  7. 24.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
[h264 @ 0x7f807b023200] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x7f807b023200] decode_slice_header error
[h264 @ 0x7f807b023200] no frame!
[h264 @ 0x7f807a049000] Stream #0: not enough frames to estimate rate; consider increasing probesize
[h264 @ 0x7f807a049000] decoding for stream 0 failed
[h264 @ 0x7f807a049000] Could not find codec parameters for stream 0 (Video: h264, none): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, h264, from 'pipe:0':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: h264, none, 25 tbr, 1200k tbn, 50 tbc
[NULL @ 0x7f807b023200] non-existing PPS 0 referenced
    Last message repeated 5 times
[h264 @ 0x7f807d804000] non-existing PPS 0 referenced
[NULL @ 0x7f807b023200] non-existing PPS 0 referenced
[h264 @ 0x7f807d804000] decode_slice_header error
[h264 @ 0x7f807d804000] no frame!
[NULL @ 0x7f807b023200] non-existing PPS 0 referenced
    Last message repeated 10 times
    nan M-V:    nan fd=   0 aq=    0KB vq=  119KB sq=    0B f=0/0