ffmpeg throwing "Output file #0 does not contain any stream" when trying to make a slideshow out of images

Question

Im trying to create video streaming using phantomjs that create screenshots from a url then it will pipe the frames to ffmpeg so he can use it to stream the video to an rtmp url . here is what i tried so far :

phantomjs runner.js | ffmpeg -f image2pipe  -vcodec png -c:a copy -c:v libx264  -f flv rtmp://localhost/mystream

and here is the script :

var page = require('webpage').create();
page.viewportSize = { width: 640, height: 480 };

page.open('http://www.goodboydigital.com/pixijs/examples/12-2/', function () {
  setInterval(function() {
    page.render('/dev/stdout', { format: "png" });
  }, 25);
});

and this is the output :

ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.29)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-vda
  libavutil      55. 17.103 / 55. 17.103
  libavcodec     57. 24.102 / 57. 24.102
  libavformat    57. 25.100 / 57. 25.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 31.100 /  6. 31.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Output #0, flv, to 'rtmp://localhost/mystream':
Output file #0 does not contain any stream

Answer 1

Your present command doesn't specify any input, so use

phantomjs runner.js | ffmpeg -f image2pipe -i pipe:.png -c:a copy -c:v libx264  -f flv rtmp://localhost/mystream

There's no audio input, so setting an audio codec is pointless. If your output needs an audio stream, use

phantomjs runner.js | ffmpeg -f image2pipe -i pipe:.png -f lavfi -i anullsrc -c:v libx264 -c:a aac -f flv rtmp://localhost/mystream