title: preventing FFmpeg from stoping mapping/muxing when input source is lost
body: <p>I have a few input streams. Some of them are not reliable. My inputs are received from multicast and put to fifo streams (created by &quot;mkfifo 239.0.0.1:4002_1.ts&quot;) by other tools than ffmpeg.
  FFmpeg is muxing all input streams from fifo and outputing them to output fifo.</p>
  <p>I am running ffmpeg with following command</p>
  <pre><code>ffmpeg -thread_queue_size 1024 -i fifo/239.0.0.1:4002_1.ts
  -thread_queue_size 1024 -i fifo/239.0.0.4:4005_1.ts -thread_queue_size 1024 -i fifo/239.0.0.3:4004_1.ts -thread_queue_size 1024 -i fifo/239.0.0.2:4002_1.ts -map 0:v -map 0:a:0 -map 1:v -map 1:a:0 -map 2:v -map 2:a:0 -map 3:v -map 3:a:0 -program program_num=3:st=0:st=1
  -program program_num=28:st=2:st=3 -program program_num=4:st=4:st=5 -program program_num=667:st=6:st=7 -c copy -f mpegts -mpegts_original_network_id 70 -mpegts_transport_stream_id 2 -muxrate 50000000 fifo/output_1.ts -y
  </code></pre>
  <p>Sometimes one of my input is lost and whole muxing is stopped. Is it possible to prevent ffmpeg from failing in that case?</p>