command:
ffmpeg -f mpegts -i udp://... -map p:1 -vcodec libx264 -strict experimental -map p:1 -acodec aac -f flv "rtmp://a.rtmp.youtube.com/live2/..."

results:
h264 @ 0x138b920] no frame!
[mpegts @ 0x136f9c0] max_analyze_duration reached
[mpegts @ 0x136f9c0] Estimating duration from bitrate, this may be inaccurate
Input #0, mpegts, from 'udp://239.11.11.100:1026':
  Duration: N/A, start: 72402.659978, bitrate: 15768 kb/s
  Program 1
    Metadata:
      service_name    : Sentech CoJ
      service_provider: Harmonic
    Stream #0.0[0x21]: Video: h264 (High), yuv420p, 720x576 [PAR 16:11 DAR 20:11], 25.42 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0.1[0x27]: Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
  Program 2
    Metadata:
      service_name    : Mindset Health
      service_provider: Harmonic
    Stream #0.2[0x24]: Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
    Stream #0.3[0x25]: Video: h264 (High), yuv420p, 720x576 [PAR 16:11 DAR 20:11], 31.89 fps, 25 tbr, 90k tbn, 50 tbc
  Program 7
    Metadata:
      service_name    : Mindset Learn Generic 16x9
      service_provider: Harmonic
    Stream #0.5[0x20]: Audio: mp2, 48000 Hz, stereo, s16, 384 kb/s
    Stream #0.4[0x22]: Video: mpeg2video (Main), yuv420p, 720x576 [PAR 16:15 DAR 4:3], 15000 kb/s, 29.32 fps, 25 tbr, 90k tbn, 50 tbc
Could not find sync stream #1.0