Recherche avancée

Sur d’autres sites (10385)

• Join two videos with unmatching audio streams in ffmpeg

  1er janvier 2013, par graup

  I already know how to concat multiple files using ffmpeg (e.g. like this).

  However, I have a specific problem. Due to an error while recording, the first video's video stream ends after about 14 minutes, while the audio stream is about 20 minutes long.
  The second video has complete video and audio streams.

  I hope this will make my situation clear :

  File 1:
  
  V1: vvvvvvvvvvvvvvv________
  
  A1: aaaaaaaaaaaaaaaaaaaaaaa
  
  
  
  File 2:
  
  V2: vvvvvvvvvvvv
  
  A2: aaaaaaaaaaaa
  
  
  
  Result after converting to MPEG-TS, concatting and encoding to mp4:
  
      vvvvvvvvvvvvvvvvvvvvvvvvvvv________
  
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  
  
  
  Expected:
  
      vvvvvvvvvvvvvvv________vvvvvvvvvvvv
  
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

  Anyone know how to do that ?

• Playing and recording a live stream from another computer webcam using VLC/FFmpeg [closed]

  22 octobre 2012, par user573014

  I was trying lately to set a video server on one machine and play it in a differen machine, it works with me.. but the problem is that it always stuck and become jammed in the middle .. and it is very slow comparing to the original stream.. something like 5 seconds delay which is not acceptable at all !
  The warning messages I get usually includes something like that :
  in the client side, which is the one which is jammed

  [0x24d1ab0] ts demux warning: discontinuity received 0x5 instead of 0xe (pid=68)
  
  [0x7f4340015e50] rtp demux warning: 2 packet(s) lost
  
  reference picture missing during reorder
  
  Missing reference picture
  
  mmco: unref short failure
  
  Reference 4 >= 4 (H264 - MPEG-4 AVC (part 10)) stopped
  
  error while decoding MB 34 14, bytestream (575)

  and that is the picture of the streaming when it is jammed

  

  and that is what it looks like when it is running smoothly

  

  This is the error message I got on the server

  [0x2513820] main generic debug: auto hidding mouse
  
  [0x2296230] main mux warning: late buffer for mux input (1840085)

  and Finally here is my command line that I am using >
  on the server :

  vlc -vvv v4l2:///dev/video1:v4l2-width=640:v4l2-height=480 --sout 
  
  '#duplicate{dst=display,dst="transcode{vcodec=h264,vb=800,ab=128}
  
  :duplicate{dst=rtp{mux=ts,dst=172.22.2.87,port=50004}'

  on the client :

  vlc -vvv rtp://@:50004 

  I thought that it might be from VLC or from my command .. I tried different protocol for transmission, with no luck I also tried FFmpeg and I got similar results + warning messages .. I thought then that both of them are using the same libraries in Linux

  here is the command using FFMpeg :

  ffmpeg -f video4linux2 -i /dev/video1 -vcodec libx264 -s 320x240 -pix_fmt 
  
  yuv420p -vb 200000 -minrate 200000 -maxrate 200000 -bufsize 2000000 -acodec 
  
  libmp3lame -ab 128k -ar 44100 -ac 2 -f mpegts udp://172.22.2.87:5544 

  In conclusion, I would like to find a solution for the latency of the streaming (which is very high) and the jamming problem
  I appreciate anyone's input, thank you

• ffmpeg H264 - How to add user unregistered SEI Message while encoding stream

  19 avril 2022, par cruxeon

  I'm working on an application where I need to insert some user unregistered SEI data in every frame before encoding it. I can't seem to find any API to add the SEI data. What I need to do is probably option 1 to the answer of this post ; but I'm not sure on how to proceed.?

  



  I've tried setting "sei" through the AvCodecContext priv_data, using av_opt_set as follows : (as well as changing the parameters quite a bit).

  



  AVCodecContext* c;

char *sei_msg = (char *)malloc(lenData);   // just a sample usage of how...
memcpy(sei_msg, data, lenData);            // ...i have my sei_message

av_opt_set(c,"sei", sei_msg, 0)


  



  Not sure if this is the correct direction for this ?

  



  How do I set the data that i'm adding is a Nal of type SEI (6) and that the SEI is of type User_Data_Unregistered (5). And then go about adding this data ?