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• vcodec copy does not work when start/duration is messed up in video file

  25 janvier 2014, par anishsane

  My Video file shows below meta-data with ffprobe/ffmpeg :

  Duration: 00:44:27.52, start: 1333.760000, bitrate: 335 kb/s
  
    Stream #0.0(und): Video: h264 (Main), yuv420p, 640x480, 25 tbr, 90k tbn, 50 tbc

  Note : The file does not contain audio.

  I am trying to convert this video file to other video file, using ffmpeg/avconv.

  This works : (but encodes h.264 video to mpeg4)

  ffmpeg -i input.mp4 output.mp4

  & it generates output file of proper duration (44:27 - 1333 seconds = 22:14)

  This does not work :

  ffmpeg -i input.mp4 -vcodec copy output.mp4

  Generates file without video.

  The output contains :

  $ avconv -i input.mp4 -vcodec copy output.mp4
  
  
  
  avconv version 0.8.9-6:0.8.9-0ubuntu0.13.10.1, Copyright (c) 2000-2013 the Libav developers
  
    built on Nov  9 2013 19:09:46 with gcc 4.8.1
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  
    Metadata:
  
      major_brand     : dash
  
      minor_version   : 0
  
      compatible_brands: iso6avc1mp41
  
      creation_time   : 2014-01-19 22:43:21
  
    Duration: 00:44:27.52, start: 1333.760000, bitrate: 335 kb/s
  
      Stream #0.0(und): Video: h264 (Main), yuv420p, 640x480, 25 tbr, 90k tbn, 50 tbc
  
      Metadata:
  
        creation_time   : 2014-01-19 22:43:21
  
  Output #0, mp4, to 'output.mp4':
  
    Metadata:
  
      major_brand     : dash
  
      minor_version   : 0
  
      compatible_brands: iso6avc1mp41
  
      creation_time   : 2014-01-19 22:43:21
  
      encoder         : Lavf53.21.1
  
      Stream #0.0(und): Video: ![0][0][0] / 0x0021, yuv420p, 640x480, q=2-31, 90k tbn, 90k tbc
  
      Metadata:
  
        creation_time   : 2014-01-19 22:43:21
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  Press ctrl-c to stop encoding
  
  frame=    0 fps=  0 q=-1.0 Lsize=       0kB time=10000000000.00 bitrate=   0.0kbits/s    
  
  video:0kB audio:0kB global headers:0kB muxing overhead inf%

• How do I make audio work with pulseaudio in systemd ? [migrated]

  1er avril 2022, par user5827693

  I'm trying to live stream my website to the rtmp server via pulseaudio, ffmpeg and chromium in ubuntu 20.04. Everything works great if I execute the following commands in shell :

  


  pulseaudio&
ffmpeg -y -f x11grab -draw_mouse 0 -s 1280x720 -i :1.0+0,0 -f pulse -ac 2 -i default -c:v libx264 -c:a aac -b:a 128k -f flv MY_SERVER &> /dev/null < /dev/null &
DISPLAY=:1.0 chromium-browser --autoplay-policy=no-user-gesture-required --disable-gpu --user-data-dir=/tmp/test --window-position=0,0 --window-size=1280,720 --app=MY_URL &


  


  However if I try to setup the same logic via systemd - everything works fine, except there is no audio. Below are my systemd files.

  


  pulseaudio.service

  


  [Unit]
Description=PulseAudio system server

[Service]
User=ubuntu
Type=notify
ExecStart=/usr/bin/pulseaudio --daemonize=no
Restart=always

[Install]
WantedBy=multi-user.target


  


  chromium.service

  


  [Unit]
Description=start chromium browser
After=pulseaudio.service

[Service]
User=ubuntu
Type=simple
Environment=DISPLAY=:1.0
ExecStart=/usr/bin/chromium-browser --autoplay-policy=no-user-gesture-required --disable-gpu --user-data-dir=/tmp/test --window-position=0,0 --window-size=1280,720 --app=MY_URL
Restart=always

[Install]
WantedBy=multi-user.target


  


  ffmpeg.service

  


  [Unit]
Description=start ffmpeg
Requires=display.service pulseaudio.service
After=pulseaudio.service

[Service]
User=ubuntu
Type=simple
ExecStart=/usr/bin/ffmpeg -y -f x11grab -draw_mouse 0 -s 1280x720 -i :1.0+0,0 -f pulse -ac 2 -i default -c:v libx264 -c:a aac -b:a 128k -f flv MY_SERVER
Restart=always

[Install]
WantedBy=multi-user.target


  


  I do not see any errors in my syslog regarding the audio. I can't figure out why it would work from shell but not from systemd.

  


  I tried the following :

  


  

  • Ran pulseaudio systemwide

  


  • Tried to setup systemd under root user

  


  • Tried to setup systemd under non root user

  


  • Tried all possible pulseaudio params

  


  


• cannot get screenshot from ffmpeg, but the url is work for vlc

  6 septembre 2021, par littlefish

  I am a newbie on FFmpeg, and it is a very powerful tool.
  
I am trying to do a snapshot every 30 seconds from the RTSP stream video, therefore I find a
public RTSP URL for testing.

  


  Here is the RTSP URL I try : rtsp://demo:demo@ipvmdemo.dyndns.org:5541/onvif-media/media.amp?profile=profile_1_h264&sessiontimeout=60&streamtype=unicast - [a]

  


  However, I can get the screen by using the VLC player.

  


  VLC player image

  


  But I try to do it on FFmpeg. It fails.&#xA;Do I do something wrong or anything I misunderstand ? ><
  &#xA;below is FFmpeg code. all are fail and get error.

  &#xA;

  ffmpeg -rtsp_transport tcp -y -i "rtsp://demo:demo@ipvmdemo.dyndns.org:5541/onvif-media/media.amp" -frames:v 1 test.jpg

# try remove `rtsp_transport`
ffmpeg -y -i "rtsp://demo:demo@ipvmdemo.dyndns.org:5541/onvif-media/media.amp" -frames:v 1 test.jpg


  &#xA;

  FFmpeg error

  &#xA;

  —

  &#xA;

  p.s. my computer is windows. but I get the same error on ubuntu.

  &#xA;

  [a] - https://ipvm.com/forums/video-surveillance/topics/need-rtsp-url-to-test-with
  &#xA;this URL can be found from here.

  &#xA;