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• ffmpeg Segmentation fault5 when video bit rate increasead

  17 novembre 2014, par sridhar govindaraj

  I’m trying to use ffmpeg for streaming directly from camera to mobile through wifi.So i would like increase the bit rate as 10Mbps for 720p.Is it possible do using ffmpeg ?
  When I tried to increase the bitrate I’m facing the following issue : "Segmentation fault5" the below is my command log :

  root@arm:~# ffmpeg -f video4linux2 -s 320x240 -i /dev/video0 -r 26 -b 1200k  -f mpegts       "udp://30.0.0.13:5050"
  
  ffmpeg version 0.8.16-6:0.8.16-1, Copyright (c) 2000-2014 the Libav developers
  
  built on Sep 17 2014 13:57:48 with gcc 4.6.3
  
  The ffmpeg program is only provided for script compatibility and will be removed
  
  in a future release. It has been deprecated in the Libav project to allow for
  
  incompatible command line syntax improvements in its replacement called avconv
  
  (see Changelog for details). Please use avconv instead.
  
  [video4linux2 @ 0x40660] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, video4linux2, from '/dev/video0':
  
  Duration: N/A, start: 1416222103.881697, bitrate: 27648 kb/s
  
  Stream #0.0: Video: rawvideo, yuv420p, 320x240, 27648 kb/s, 30 tbr, 1000k tbn, 30 tbc
  
  [buffer @ 0x40da0] w:320 h:240 pixfmt:yuv420p
  
  [mpegts @ 0x410c0] muxrate VBR, pcr every 2 pkts, sdt every 200, pat/pmt every 40 pkts
  
  Output #0, mpegts, to 'udp://30.0.0.13:5050':
  
    Metadata:
  
      encoder         : Lavf53.21.1
  
      Stream #0.0: Video: mpeg2video, yuv420p, 320x240, q=2-31, 1200 kb/s, 90k tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press ctrl-c to stop encoding
  
  Segmentation fault5 q=7.0 size=   19220kB time=118.28 bitrate=1331.2kbits/s dup=0 drop=8 

• ffmpeg error : "Missing ')' or too many args in 'if(gt(a,1),650,-1)'"

  23 février 2015, par Remini me

  I am trying to run this ffmpeg command in linux shell, to scale down the video (if portrait, than to maximum height of 650, while adjusting the width. And if landscape, then 650 maximum width, and adjust the height with aspect ratio) :

  ffmpeg -i 1.mp4 -r 30 -vf scale="'if(gt(a,1),650,-1)':'if(gt(a,1),-1,650)'" -vcodec libx264 output_file1.mp4

  But I get the following error :

  [scale @ 0x1d48a40] [Eval @ 0x7fff53a49340] Missing ’)’ or too many
  args in ’if(gt(a,1),650,-1)’ [scale @ 0x1d48a40] [Eval @
  0x7fff53a49340] Missing ’)’ or too many args in ’if(gt(a,1),-1,650)’
  Error when evaluating the expression ’if(gt(a,1),-1,650)’

  **EDIT : I have tried using the new @slhck syntax :

  -vf "scale=if(gt(a\,1)\,650\,-2):if(gt(a\,1)\,-2\,650)"

  The result I got was :

  ffmpeg version 0.8.16-4:0.8.16-0ubuntu0.12.04.1, Copyright (c)
  2000-2014 the Libav developers built on Sep 16 2014 18:33:49 with
  gcc 4.6.3 The ffmpeg program is only provided for script compatibility
  and will be removed in a future release. It has been deprecated in the
  Libav project to allow for incompatible command line syntax
  improvements in its replacement called avconv (see Changelog for
  details). Please use avconv instead.

  Seems stream 0 codec frame rate differs from container frame rate :
  180000.00 (180000/1) -> 90000.00 (180000/2) Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ’1.mp4’ : Metadata :
  major_brand : isom
  minor_version : 0
  compatible_brands : isom3gp4
  creation_time : 2015-02-05 14:54:24 Duration : 00:00:45.30, start : 0.000000, bitrate : 17058 kb/s
  Stream #0.0(eng) : Video : h264 (High), yuv420p, 1920x1080, 17021 kb/s, 30.01 fps, 90k tbr, 90k tbn, 180k tbc
  Metadata :
  creation_time : 2015-02-05 14:54:24
  Stream #0.1(eng) : Audio : aac, 48000 Hz, stereo, s16, 124 kb/s
  Metadata :
  creation_time : 2015-02-05 14:54:24 File ’output_file1.mp4’ already exists. Overwrite ? [y/N] y

  [buffer @ 0x747ec0] w:1920 h:1080 pixfmt:yuv420p [scale @ 0x745a40] [Eval @ 0x7fffac94b220] Missing ’)’ or too many args in
  ’if(gt(a,1),650,-2)’ [scale @ 0x745a40] [Eval @ 0x7fffac94b220]
  Missing ’)’ or too many args in ’if(gt(a,1),-2,650)’ Error when
  evaluating the expression ’if(gt(a,1),-2,650)’ Error opening
  filters !

  What should I do ?

• ffmpeg alternative to -ss to something with % ? [duplicate]

  9 juin 2020, par Akhilleus Uggo

  Is there anyway to start cutting a video, or indicate the start point by a percent of the video ?

  



  Let's suppose a video has a duration of 40 minutes. Starting at 25% of the video would be -ss 600, but not all videos are 40 minutes.

  



  Any replacement for -ss to something working by % ?