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• Error when transcoding MPEG-TS Stream with MISB KLV Data to HLS via FFM

  6 mai 2023, par Rockwell_Lancer

  I hope you are doing well !

  


  I'm currently working on a project that is intended to receive, and store in HLS/H.264 format, an MPEG-TS video feed transmitted over UDP multicast. This video stream contains two channels ; a video-only MPEG-TS/mpeg2video (no audio) stream and a data-only MISB KLV datastream.

  


  I receive this UDP stream, convert to HLS, and then parse the KLV data out of the generated .ts files as they are created, and use it further down the pipeline of the application. The timing of this KLV data is critical to the functionality of the application, as the data must remain synchronized with the video. As such, presentation time stamps (PTS) on KLV packets need to be relatively close to those of their corresponding video counterparts.

  


  The current implementation makes use of the following Ffmpeg command :

  


  ffmpeg -i "udp://239.255.0.1:10089?reuse=1&fifo_size=5000000&overrun_nonfatal=1" \
  -map 0:0 -noautoscale -profile:v main \
  -map 0:1 -hls_time 5000ms -hls_list_size 0 -r 30 -g 150 -f hls out.m3u8


  


  This command is very effective for handling the transcoding of the video under normal circumstances, however, the UDP stream is not guaranteed to be reliable, and can be expected to drop for several seconds at times. When this happens, and the stream resurfaces, the above command fails catastrophically with the output below :

  


  [mpegts @ 0x7fce3a004a80] Packet corrupt (stream = 0, dts = 8949000).
udp://127.0.0.1:10089?reuse=1&fifo_size=5000000&overrun_nonfatal=1: corrupt input packet in stream 0

frame= 2937 fps= 27 q=29.0 size=N/A time=00:01:55.36 bitrate=N/A dup=805 drop=0 

[hls @ 0x7fce3a017240] Application provided invalid, non monotonically increasing dts to muxer in stream 1: 10386000 >= 8829000
av_interleaved_write_frame(): Invalid argument


  


  Ffmpeg goes on to indicate Conversion Failed! and exits with code 1. The PTS difference in the error message appears to be approximately equivalent to the amount of time the UDP stream was interrupted.

  


  Does anyone know what might be the issue causing, and if so, are there any suggestions that might help mitigate this issue ? The value of the PTS on the KLV doesn't matter so much as whether it matches the video PTS. Any assistance with this matter would be greatly appreciated.

  


  Thank you in advance !

  


• yuv420p pixel format in GStreamer ?

  5 août 2022, par cubecubed

  I am trying to stream a video from opencv/python to rtsp-simple-server via GStreamer. I am able to view the video fine in vlc, but the online streaming application I am using is very picky. I need the stream to have a pixel format of yuv420p. How do I convert a stream to this format with GStreamer ?

  


  This is my current code which creates a stream with the yuv444p :

  


  out = cv2.VideoWriter('appsrc ! videoconvert' + \
' ! x264enc speed-preset=ultrafast bitrate=600 key-int-max=40' + \
' ! rtspclientsink location=rtsp://localhost:554/video',
cv2.CAP_GSTREAMER, 0, fps, (width, height), True)


  


  I am looking for the GStreamer equivalent of -pix_fmt yuv420p

  


• fftools/ffmpeg : remove OutputStream.encoding_needed

  3 août 2022, par Anton Khirnov

  fftools/ffmpeg : remove OutputStream.encoding_needed
  It is unnecessary, as it is always exactly equivalent to !!ost->enc_ctx
  

  • [DH] fftools/ffmpeg.c
  • [DH] fftools/ffmpeg.h
  • [DH] fftools/ffmpeg_opt.c