Recherche avancée

Sur d’autres sites (11664)

• Extract image from video (ffmpeg)

  22 avril 2015, par user1391023

  I am trying to extract images from video using ffmpeg :

  ffmpeg -i sample.mp4 -vf fps=1/30 img%03d.jpg

  But I am getting this following error

  ffmpeg version 2.2.1 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Apr 13 2014 13:00:18 with gcc 4.4.6 (GCC) 20120305 (Red Hat 4.4.6-4)
  
    configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --enable-runtime-cpudetect --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --enable-pthreads --enable-x11grab --enable-vdpau --disable-avisynth --enable-frei0r --enable-libopencv --enable-libdc1394 --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC' --disable-stripping
  
    libavutil      52. 66.100 / 52. 66.100
  
    libavcodec     55. 52.102 / 55. 52.102
  
    libavformat    55. 33.100 / 55. 33.100
  
    libavdevice    55. 10.100 / 55. 10.100
  
    libavfilter     4.  2.100 /  4.  2.100
  
    libswscale      2.  5.102 /  2.  5.102
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/sites/filemanager.dev/public_html/wout/image/sample.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 1
  
      compatible_brands: mp42mp41
  
      creation_time   : 2009-05-25 21:58:02
  
    Duration: 00:04:03.12, start: 0.000000, bitrate: 309 kb/s
  
      Stream #0:0(eng): Audio: aac (mp4a / 0x6134706D), 22050 Hz, stereo, fltp, 26 kb/s (default)
  
      Metadata:
  
        creation_time   : 2009-05-25 21:58:02
  
        handler_name    : Apple Sound Media Handler
  
      Stream #0:1(eng): Video: mpeg4 (Advanced Simple Profile) (mp4v / 0x7634706D), yuv420p, 480x320 [SAR 1:1 DAR 3:2], 120 kb/s, 30.12 fps, 30.12 tbr, 2500 tbn, 1k tbc (default)
  
      Metadata:
  
        creation_time   : 2009-05-25 21:58:02
  
        handler_name    : Apple Video Media Handler
  
      Stream #0:2(eng): Data: none (rtp  / 0x20707472), 128 kb/s
  
      Metadata:
  
        creation_time   : 2009-05-25 21:58:02
  
        handler_name    : hint media handler
  
      Stream #0:3(eng): Data: none (rtp  / 0x20707472), 29 kb/s
  
      Metadata:
  
        creation_time   : 2009-05-25 21:58:02
  
        handler_name    : hint media handler
  
  [NULL @ 0x1d25ea0] Unable to find a suitable output format for 'image2'
  
  image2: Invalid argument

  The final out required is I need to extract image at fps 30.

• avformat/mpegtsenc : Changed Video PES packet length to 0.

  12 avril 2014, par Graham Booker

  avformat/mpegtsenc : Changed Video PES packet length to 0.
  The rational for this is another issue that plex has exposed.  When it is
  
  conducting a transcode of video to HLS for streaming, my father noticed
  
  artifacts when played on his GoogleTV (NSZ-GT1).  He sent me a test file
  
  and I reproduced it on my device of the same model.  It is important to
  
  note that the artifacts were not present when streaming to VLC or QuickTime
  
  Player.  I copied the command-line that plex used, and conducted all of the
  
  following tests using FFmpeg git.
  Transcode to HLS : artifacts on playback
  
  Transcode to TS : playback is fine
  
  Cat HLS segments into a single TS : playback is fine
  
  Segment single TS file to segments : artifacts on playback
  
  Segment single TS file to segments using Apple’s HLS segmenter : playback is
  
  fine
  At this point I carefully examined the differences between Apple’s HLS
  
  segmenter output and FFmpeg’s.  Among the considerable differences, I
  
  noticed that the video PES packets always had a 0 length.  So I continued :
  Transcode to HLS using FFmpeg with 0 length PES packets : playback is fine.
  
  Segment single TS to segments with 0 length PES packets : playback is fine.
  All failures mentioned are only on the GTV since it is the only player on
  
  which I could reproduce artifacts.  I only tested the GTV, VLC, and
  
  QuickTime Player though, so my test case is limited.  I do not know if
  
  other players exhibit this issue.
  Since it was useful last time, I have uploaded the test file as
  
  hls_pes_packet_length.m4v along with its associated txt file which contains
  
  the transcode command-line that was used.
  Reviewed-by : Kieran Kunhya <kierank@obe.tv>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/mpegtsenc.c
  • [DH] tests/ref/lavf/ts

• Adding chapters to MP4 files, and being identified on iOS 12 podcast app

  5 avril 2019, par Craig Francis

  I have an MP4 file, where I’ve added chapters via ffmpeg.

  But in the iOS 12 Podcasts app, from Apple, the chapters don’t appear. This should happen, as noted by idownloadblog.com

  

  In comparison, when using QuickLook on MacOS, the list of chapters can be seen by clicking the chapters button (in the bottom right hand side of the window).

  

  And opening in QuickTime Player, while there isn’t a list of chapters to view, you can use the "View > Next Chapter" menu item.

  So I’m assuming this is a bug in iOS... but I’m wondering if there is another way to add chapters ? or if I’ve made a mistake ?

  ---

  My current process is to create a "ffmetadata" file, as noted in the ffmpeg documentation :

  ;FFMETADATA1
  
  title=Example
  
  
  
  [CHAPTER]
  
  TIMEBASE=1/1000
  
  START=0
  
  END=221913
  
  title=Chapter 1
  
  
  
  [CHAPTER]
  
  TIMEBASE=1/1000
  
  START=221913
  
  END=1169241
  
  title=Chapter 2

  https://ffmpeg.org/ffmpeg-formats.html#Metadata-1

  Then I’ve tried each of the following commands :

  ffmpeg -i 2019-01-02.mp4 -i 2019-01-02.meta -map_metadata 1 -codec copy 2019-01-02-chapters.mp4
  
  ffmpeg -i 2019-01-02.mp4 -i 2019-01-02.meta -map_metadata 1 2019-01-02-chapters.mp4
  
  ffmpeg -i 2019-01-02.mp4 -i 2019-01-02.meta -map_metadata 1 2019-01-02-chapters.mp3

  • The first one is from the ffmpeg documentation, where -codec copy means the audio file is not re-encoded.
  • The second one takes longer, while it re-encodes the audio data.
  • The third one requires re-encoding to convert it into an MP3 file (which uses ID3 tags for the chapter data).

  ---

  On a slightly unrelated note, the third party app "RSSRadio" does list the chapters, but the feature added in version 4 that allows you to "skip directly to the start of the next chapter", if the next chapter starts within the next 3 minutes, does not seem to work.