Recherche avancée

Sur d’autres sites (6578)

• ffmpeg/avconv mp4 to webm libvorbis buffer overflow

  4 janvier 2013, par Halsafar

  Trying to convert a bunch of mp4 files into webm. So I run the following command. I tried a similar command with ffmpeg.

  avconv -i input.mp4 -threads 8 -s 1280x720 -pre libvpx-720p -b 3900k -pass 2 -acodec libvorbis -b:a 128k -ac 2 -f webm -y output/webm

  Results in :

      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2mp41
  
      creation_time   : 1970-01-01 00:00:00
  
      encoder         : Lavf52.32.0
  
    Duration: 00:01:02.90, start: 0.000000, bitrate: 1649 kb/s
  
      Stream #0.0(und): Video: mpeg4 (Simple Profile), yuv420p, 640x480 [PAR 4:3 DAR 16:9], 1492 kb/s, PAR 853:640 DAR 853:480, 23.94 fps, 30 tbr, 30 tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
      Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 152 kb/s
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
  [buffer @ 0x1232600] w:640 h:480 pixfmt:yuv420p
  
  [scale @ 0x123c300] w:640 h:480 fmt:yuv420p -> w:1280 h:720 fmt:yuv420p flags:0x4
  
  [libvpx @ 0x1256d60] v1.0.0
  
  Output #0, webm, to 'output.webm':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2mp41
  
      creation_time   : 1970-01-01 00:00:00
  
      encoder         : Lavf53.21.0
  
      Stream #0.0(und): Video: libvpx, yuv420p, 1280x720 [PAR 2559:2560 DAR 853:480], q=11-51, pass 2, 3900 kb/s, 1k tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
      Stream #0.1(und): Audio: libvorbis, 44100 Hz, stereo, s16, 152 kb/s
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mpeg4 -> libvpx)
  
    Stream #0:1 -> #0:1 (aac -> libvorbis)
  
  Press ctrl-c to stop encoding
  
  [libvorbis @ 0x1221240] libvorbis: buffer overflow.Audio encoding failed

  Notice the nice error. buffer overflow in libvorbis.

  Any assistance ? An Alternative conversion command ?

  UPDATE

  The first pass looks like this :

   avconv -i input.mp4 -threads 8 -s 1280x720 -pre libvpx-720p -b 3900k -pass 1 -an -f webm -y output.webm

  Thanks !

• ffmpeg - Incompatible sample format '(null)'

  17 juin 2012, par abrahab

  I convert videos from different sources with ffmpeg to mp4 with libx264 codec. After conversation time to time I got incorrect format error when trying to load already converted video with ffmpeg : Incompatible sample format '(null)' for codec 'aac', auto-selecting format 's16'

  Seems, it is audio stream problem with aac codec ? How to fix or how to convert videos to mp4 to be sure that I will not get the following error ? Maybe somehow need to specify audio format at the ffmpeg convert command ?

  ps. Video must work at Iphone/Ipad.
  pps. the main problem, that such videos with the following error can not be pseudo-streamed with nginx (got 500 Error)
  ppps. and sorry for my bad english, please, correct my text if need. thanks.

  Some additional info from file :

    Duration: 00:00:10.30, start: 0.000000, bitrate: 614 kb/s
  
      Stream #0.0(rus): Video: h264 (High), yuv420p, 1024x576, 567 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
      Stream #0.1(rus): Audio: aac, 22050 Hz, stereo, s16, 57 kb/s
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00

• ffmpeg converts .flv video to .gif with awful quality [migrated]

  22 février 2013, par Kamil Hismatullin

  I'm converting .flv movie to .gif file with ffmpeg.

  ffmpeg -i input.flv -ss 00:00:00.000 -pix_fmt rgb24 -r 10 -s 320x240 -t 00:00:10.000  output.gif

  It works great, but output gif file has a very law quality.

  Any ideas how can I improve quality of converted gif ?

  Output of command :

  $ ffmpeg -i input.flv -ss 00:00:00.000 -pix_fmt rgb24 -r 10 -s 320x240 -t 00:00:10.000  output.gif 
  
  
  
  ffmpeg version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers
  
    built on Jan 24 2013 14:52:53 with gcc 4.7.2
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.flv':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      creation_time   : 2013-02-14 04:00:07
  
    Duration: 00:00:18.85, start: 0.000000, bitrate: 3098 kb/s
  
      Stream #0.0(und): Video: h264 (High), yuv420p, 1280x720, 2905 kb/s, 25 fps, 25 tbr, 50 tbn, 50 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
      Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 192 kb/s
  
      Metadata:
  
        creation_time   : 2013-02-14 04:00:07
  
  [buffer @ 0x92a8ea0] w:1280 h:720 pixfmt:yuv420p
  
  [scale @ 0x9215100] w:1280 h:720 fmt:yuv420p -> w:320 h:240 fmt:rgb24 flags:0x4
  
  Output #0, gif, to 'output.gif':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      creation_time   : 2013-02-14 04:00:07
  
      encoder         : Lavf53.21.1
  
      Stream #0.0(und): Video: rawvideo, rgb24, 320x240, q=2-31, 200 kb/s, 90k tbn, 10 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press ctrl-c to stop encoding
  
  frame=  101 fps= 32 q=0.0 Lsize=    8686kB time=10.10 bitrate=7045.0kbits/s dup=0 drop=149    
  
  video:22725kB audio:0kB global headers:0kB muxing overhead -61.778676%

  Thanks.