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• ffmpeg h264 interesting bright video fail ?

  23 novembre 2019, par Max Paython

  I am trying streaming with ffmpeg using the information I found here.

  • Server

    ffmpeg -f dshow -i video="john":audio="doe" -vcodec libx264
    
    -preset ultrafast -tune zerolatency -acodec aac -f mpegts udp://localhost:1234

  • Client

    ffmpeg -i udp://localhost:1234?listen test.mp4

  The client will actually live stream the video, but for testing purposes I am writing the output to a file for now.

  Here comes the interesting part. I began the stream(video and audio) in a dark room, everything is fine. I turn on the room’s lights and the client cries with many errors. I later checked the output, it is very corrupted indeed on the light turned-on parts. What could be the reason behind this ? I am posting the errors here if it could be of assistance.

  Some of the errors :

  udp://localhost:1234?listen: corrupt decoded frame in stream 0trate= 845.6kbits/s dup=1250 drop=0 speed=1.08x
  
      Last message repeated 1 times
  
  [h264 @ 0000026c4af69400] Invalid NAL unit 1, skipping.7.61 bitrate= 864.7kbits/s dup=1441 drop=0 speed=1.07x
  
  [h264 @ 0000026c4af69400] Invalid level prefix
  
  [h264 @ 0000026c4af69400] error while decoding MB 18 8
  
  [h264 @ 0000026c4af69400] concealing 911 DC, 911 AC, 911 MV errors in P frame
  
  [h264 @ 0000026c4af4b780] Invalid NAL unit 1, skipping.
  
  [h264 @ 0000026c4af4b780] negative number of zero coeffs at 10 14
  
  [h264 @ 0000026c4af4b780] error while decoding MB 10 14
  
  [h264 @ 0000026c4af4b780] concealing 679 DC, 679 AC, 679 MV errors in P frame
  
  udp://localhost:1234?listen: corrupt decoded frame in stream 0
  
      Last message repeated 1 times
  
  [h264 @ 0000026c4ba1e1c0] Invalid NAL unit 1, skipping.8.21 bitrate= 858.0kbits/s dup=1460 drop=0 speed=1.07x
  
  [h264 @ 0000026c4ba1e1c0] out of range intra chroma pred mode
  
  [h264 @ 0000026c4ba1e1c0] error while decoding MB 34 18
  
  [h264 @ 0000026c4ba1e1c0] concealing 495 DC, 495 AC, 495 MV errors in P frame
  
  [h264 @ 0000026c4bb16840] top block unavailable for requested intra mode
  
  [h264 @ 0000026c4bb16840] error while decoding MB 10 0
  
  [h264 @ 0000026c4bb16840] concealing 160 DC, 160 AC, 160 MV errors in P frame
  
  udp://localhost:1234?listen: corrupt decoded frame in stream 0
  
  [h264 @ 0000026c4bb16cc0] Invalid NAL unit 0, skipping.8.58 bitrate= 853.9kbits/s dup=1463 drop=0 speed=1.06x
  
  [h264 @ 0000026c4bb16cc0] corrupted macroblock 16 28 (total_coeff=-1)
  
  [h264 @ 0000026c4bb16cc0] error while decoding MB 16 28
  
  [h264 @ 0000026c4bb16cc0] concealing 113 DC, 113 AC, 113 MV errors in P frame
  
  [h264 @ 0000026c4bb17140] cbp too large (84) at 12 0
  
  [h264 @ 0000026c4bb17140] error while decoding MB 12 0
  
  [h264 @ 0000026c4bb17140] concealing 160 DC, 160 AC, 160 MV errors in P frame
  
  [mpegts @ 0000026c4aeb8d80] PES packet size mismatch

  Edit : As suggestion, I added these parameters to the server.

  -b:v 1M -bufsize 2M

  Now the errors are mostly gone. Except one time where it seemed like it occured just as I was turning off the lights, although I could not reproduce it after trying 4-5 times.

  Errors :

  [h264 @ 000002646f0d2f80] cbp too large (118) at 23 1422.25 bitrate= 659.5kbits/s dup=368 drop=0 speed=1.33x
  
  [h264 @ 000002646f0d2f80] error while decoding MB 23 14
  
  [mpegts @ 000002646e578d80] PES packet size mismatch
  
  [h264 @ 000002646f0d2f80] concealing 666 DC, 666 AC, 666 MV errors in P frame
  
  [h264 @ 000002646f0d0f80] concealing 160 DC, 160 AC, 160 MV errors in P frame
  
  [aac @ 000002646e64d640] Number of bands (59) exceeds limit (43).
  
  Error while decoding stream #0:1: Invalid data found when processing input
  
  [aac @ 000002646e64d640] Multiple frames in a packet.
  
  [aac @ 000002646e64d640] Reserved bit set.
  
  [aac @ 000002646e64d640] Number of bands (31) exceeds limit (29).
  
  Error while decoding stream #0:1: Invalid data found when processing input
  
  [h264 @ 000002646e5e11c0] concealing 160 DC, 160 AC, 160 MV errors in P frame
  
  udp://localhost:1234?listen: corrupt decoded frame in stream 0trate= 633.1kbits/s dup=368 drop=0 speed=1.35x
  
      Last message repeated 2 times

  The errors decreased because I increased the bitrate ? (I don’t know the default bitrate by the way). Bright decoding fails because it carries more information, data ? (same in raw video, but maybe file is heavier encoded bright frames)

• Convert simple Bash script to PowerShell ?

  9 septembre 2019, par vulcan raven

  I have pulled the Bash script from here, which checks the AVI file for bad frames using ffmpeg and cygwin extension. I am able to execute the code in Mingw. I put ffmpeg.exe (ren ffmpeg), cygwin1.dll & cygz.dll in Mingw’s bin dir (/c/mingw/bin/). Now, I am looking to port this bash code to PowerShell. Can anyone shed some PowerShell light on this one ?

  Script : (path : /c/mygw/bin/AviConvert)

  #!/bin/bash
  
  
  
  FFMPEG="ffmpeg"
  
  LIST=`find | grep \.avi$`
  
  
  
  for i in $LIST; do
  
      OUTP="$i.txt"
  
      OUTP_OK="$i.txt.ok"
  
      TMP_OUTP="$i.tmp"
  
      if [ -f "$OUTP" -o -f "$OUTP_OK" ] ; then
  
      echo Skipping "$i"
  
      else
  
      echo Checking "$i"...
  
      RESULT="bad"
  
      ffmpeg -v 5 -i "$i" -f null - 2> "$TMP_OUTP" && \
  
          mv "$TMP_OUTP" "$OUTP" && \
  
          RESULT=`grep -v "\(frame\)\|\(Press\)" "$OUTP" | grep "\["`
  
      if [ -z "$RESULT" ] ; then
  
          mv "$OUTP" "$OUTP_OK"
  
      fi
  
      fi
  
  done

• FFmpeg compose, multi layers and filters, need kindly help 

  9 octobre 2019, par jadeshohy

  Pretty new to FFmpeg. We would like to use FFmpeg as a important part of an AR project.

  Currently, we find it is not easy for us.

  We want to compose the footages with FFmpeg.

  We got 5 layers, wanted to blend them with specific mode, like the things in After Effects.

  • layer-1/ [A.webm] video，vp9 codec, which has a transparent BG,has to be added as [normal mode]

  • layer-2/ [B.mp4] video, optical-flare things with black BG,has to be added as [screen mode]

  • layer-3/ [C.mp4] video, some motion graphic things with light BG,has to be added as [overlay mode]

  • layer-4/ [BG.MP4], backgound things, has to be added as [normal mode]

  After we blend those 4 (like pre-compose,use blend filter), we want to add another layer-5/[icon.png] which is the special icon.

  Layer-5 need to overlay the pre-compose. We have to overlay it at the special position (use overlay filter ?).

  Cause [icon.png] may change frequently. we want to deal with that after the 4 layer blending.

  But at the first step, when we set normal mode for layer-1 in blend filter, layer-1 [A.webm] lost the transparent BG，it gave us a black BG which block all other things.
  Blend filter can not handle the alpha channel of vp9 webm ?
  When we set the mode of layer-1 to screen mode,the translucent thing was not what we need.

  Could you please give us some commands to achieve the blend above ?

  The commands that are really work will be extremely useful for our FFmpeg initiation.