[FFmpeg-trac] #2748(undetermined:closed): Inconsistent UDP output packet size

FFmpeg trac at avcodec.org
Fri Aug 8 12:57:12 CEST 2014


#2748: Inconsistent UDP output packet size
-------------------------------------+-------------------------------------
             Reporter:  lancey       |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mpegts udp   |               Resolution:  fixed
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by smallishzulu):

 Yesterday, I got the latest snaphot from GIT and tested the case.
 On a CBR test, if outpur bandwidth rate is high, some decoders/TS analyze
 SWs give PCR accuracy and repetition error (very rare).

 Example:
 ffmpeg -i pipe -aspect 16:9 -fflags +genpts -vcodec libx264 -preset
 ultrafast -vb 25000k -minrate 25000k -maxrate 25000k -bufsize 2500k
 -muxrate 27000k -tune stillimage -qmin 20 -pix_fmt yuv420p -vbsf
 h264_mp4toannexb -strict experimental -acodec libfdk_aac -ab 128k
 -flush_packets 0 -f mpegts 'udp://225.2.1.1:1234?pkt_size=1316'

 This works fine. Time to time on some decoders (like Ericsson) make black
 frame. But no PCR error.

 ffmpeg -i pipe -aspect 16:9 -fflags +genpts -vcodec libx264 -preset
 ultrafast -vb 50000k -minrate 50000k -maxrate 50000k -bufsize 10000k
 -muxrate 54000k -tune stillimage -qmin 20 -pix_fmt yuv420p -vbsf
 h264_mp4toannexb -strict experimental -acodec libfdk_aac -ab 128k
 -flush_packets 0 -f mpegts 'udp://225.2.1.1:1234?pkt_size=1316'

 In this case, it reports PCR accuracy and repetition error and decoders
 gives alarm as well.

 BR,

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Ticket URL: <https://trac.ffmpeg.org/ticket/2748#comment:20>
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