[FFmpeg-trac] #8414(ffmpeg:new): Oversized EBML headers for WebM live stream with IceCast

FFmpeg trac at avcodec.org
Thu Dec 5 02:57:50 EET 2019

#8414: Oversized EBML headers for WebM live stream with IceCast
             Reporter:  flipflop     |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffmpeg       |                  Version:
             Keywords:  webm         |  unspecified
  icecast                            |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
 This is what I used to stream to an icecast relay with ffmpeg 4.0.5:

 ffmpeg -f x11grab -probesize 8000000 -video_size 1280x720 -framerate 60 -i
 :0 -an -c:v libvpx-vp9 -r 60 -pix_fmt yuv420p -keyint_min 60 -g 60 -qmin 0
 -qmax 63 -b:v 3M -minrate:v 3M -maxrate:v 3M -bufsize 3M -deadline
 realtime -quality realtime -tile-columns 6 -threads:v 4 -speed 8 -cpu-used
 8 -static-thresh 0 -max-intra-rate 10000 -frame-parallel 1 -f webm
 -cluster_size_limit 2M -cluster_time_limit 5000 -content_type video/webm

 However, since 4.1, icecast will kick ffmpeg with:
 EBML Header too large, failing

 By default, Icecast restricts the EBML header to 131072 bytes.

 I have recompiled Icecast to increase the value and I am now able to
 stream with ffmpeg master.

 I am reporting this to both ffmpeg and icecast as I am not sure which of
 the two projects should make changes.

Ticket URL: <https://trac.ffmpeg.org/ticket/8414>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker

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