[FFmpeg-user] Broken video in rtmp stream to Wowza using tee pseudo-muxer

Erwin Eggenberger eeggenberger+ffmpeg at techcast.com
Wed Jan 24 17:36:14 EET 2018


Hello everyone,

I'm trying to send a rtmp stream to our Wowza streaming server and
record that stream at the same time. I've followed the instructions from
https://trac.ffmpeg.org/wiki/Creating%20multiple%20outputs and
https://trac.ffmpeg.org/wiki/EncodingForStreamingSites. I'm experiencing
the same problem as another user did before:
http://www.ffmpeg-archive.org/rtmp-output-is-black-bitrate-N-A-td4670047.html

When I just upload the stream without the tee muxer, everything works as
expected, but with tee I only get audio but no video. In the Wowza logs
I can see errors like this:
H264Utils.decodeAVCC : java.lang.ArrayIndexOutOfBoundsException

Sounds to me like there's something wrong with the h.264 video. The
ffmpeg command looks like this:

ffmpeg -y -v info -f x11grab -draw_mouse 0 -r 25 -s 1280x720
-thread_queue_size 4096 -i :0.0+0,0 -f alsa \
  -thread_queue_size 4096 -i hw:0,1,0 -acodec aac -strict -2 -ar 44100
-c:v libx264 -preset veryfast \
  -maxrate 2976k -bufsize 5952k -pix_fmt yuv420p -r 25 -crf 25 -g 50
-tune zerolatency \
  -f tee -map 0:v -map 1:a
"[f=flv]rtmp://user:password@servername:1935/live/test_stream"

I can watch the rtmp stream using VLC, although it shows artifacts about
every 30 seconds. Flash won't play it and the transcoding to HLS in
Wowza fails with the errors mentioned above. I've compiled ffmpeg from
the latest snapshot to make sure I'm not encountering a bug that has
already been fixed.

Does anyone know how to solve this problem or at least has some hints on
how to debug it?

Thanks,

Erwin


More information about the ffmpeg-user mailing list