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• Fluent-ffmpeg and complex filter in Electron (node)

  9 juillet 2016, par Matt Sergej Rinc

  I want to use fluent-ffmpeg module to call ffmpeg with complex filter from Electron but have no success. The error ’[AVFilterGraph @ 0xb8.......] No such filter " Error initalizing complex filters . Invalid argument’ is the same as in this question Error : Running FFmpeg command in Android ,splitting command in array not working but the context is different.

  What is needed ?
  Run this ffmpeg command using fluent-ffmpeg :

  ffmpeg -i safework-background-0.mp4 -i image1.png -i image2.png -i
  image3.png -filter_complex "[0:v][1:v]
  overlay=1:1:enable=’between(t,5,8.5)’ [tmp] ; [tmp][2:v]
  overlay=1:1:enable=’between(t,8.5,12)’ [tmp] ; [tmp][3:v]
  overlay=1:1:enable=’between(t,12,15)’" test-video-safework3.mp4

  It uses a complex filter to overlay three images on a video in sequence and exports a new video.

  What doesn’t work ?
  Obviously fluent-ffmpeg chokes with required quotes for complex filter, that is my conclusion (and is the same as for the Android variant question above).

  What works without fluent-ffmpeg in Electron ?
  As you can guess I have to resort to calling ffmpeg directly. To help others, the following command, with input and output video filenames parametrized, translates to Electron as :

    var spawn = require('child_process').spawn
  
    var fargs = ['-y', '-i', sourceDir.path() + '/' + inVideoName, '-i', tempDir.path() + '/' + 'image1.png',
  
    '-i', tempDir.path() + '/' + 'image2.png', '-i', tempDir.path() + '/' + 'image3.png',
  
    '-filter_complex', '[0:v][1:v]overlay=1:1:enable=\'between(t,5,8.5)\'[tmp];' +
  
    '[tmp][2:v]overlay=1:1:enable=\'between(t,8.5,12)\'[tmp];[tmp][3:v]' +
  
    'overlay=1:1:enable=\'between(t,12,15)\'', targetDir.path() + '/' + outVideoName]
  
    var ffmpeg = spawn(ffmpegc, fargs, { cwd:jetpack.cwd(app.getPath('home')).path() })
  
  // some code ommitted
  
    ffmpeg.on('close', (code) => {
  
      console.log(`child process exited with code ${code}`)
  
      webContents.send('notify-user-reply', 'Video processing done.')
  
    })

  The above command already has removed spaces between various filters (in complex filter) for each image or it would also choke.

  I would really love to use fluent-ffmpeg in Electron, not just for the convenience of calling ffmpeg more elegantly but also for some additional features like easy progress reporting.

• pixfmt : Add ARIB STD-B76 color transfer characteristic

  15 juin 2016, par Neil Birkbeck

  pixfmt : Add ARIB STD-B76 color transfer characteristic
  Adding hybrid log-gamma (https://en.wikipedia.org/wiki/Hybrid_Log-Gamma)
  
  based on the standardization in ARIB STD-B67 :
  
  http://www.arib.or.jp/english/html/overview/doc/2-STD-B67v1_0.pdf
  The choice of enum value of 18 is consistent with HEVC :
  
  http://phenix.it-sudparis.eu/jct/doc_end_user/current_document.php?id=10481
  And also with latest proposal for color format in mkv :
  
  https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&q=Colour+Format+proposal
  Signed-off-by : Vittorio Giovara <vittorio.giovara@gmail.com>
  

  • [DBH] libavcodec/options_table.h
  • [DBH] libavcodec/version.h
  • [DBH] libavutil/pixdesc.c
  • [DBH] libavutil/pixfmt.h
  • [DBH] libavutil/version.h

• FFmpeg, videotoolbox and avplayer in iOS

  9 janvier 2017, par Hwangho Kim

  I have a question how these things are connected and what they exactly do.

  FYI, I have a few experience about video player and encoding and decoding.

  In my job I deal udp streaming from server and take it with ffmpeg and decodes it and draw it with openGL. And also using ffmpeg for video player.

  These are the questions...

  1. Only ffmpeg can decodes UDP streaming (encoded with ffmpeg from the server) or not ?

  I found some useful information about videotoolbox which can decode streaming with hardware acceleration in iOS. so could I also decode the streaming from the server with videotoolbox ?

  2. If it is possible to decode with videotoolbox (I mean if the videotoolbox could be the replacement for ffmpeg), then what is the videotoolbox source code in ffmpeg ? why it is there ?

  In my decoder I make AVCodecContext from the streaming and it has hwaccel and hwaccel_context field which set null both of them. I thought this videotoolbox is kind of API which can help ffmpeg to use hwaccel of iOS. But it looks not true for now...

  3. If videotoolbox can decode streaming, Does this also decode for H264 in local ? or only streaming possible ?

  AVPlayer is a good tool to play a video but if videotoolbox could replace this AVPlayer then, what’s the benefit ? or impossible ?

  4. FFmpeg only uses CPU for decoding (software decoder) or hwaccel also ?

  When I play a video with ffmpeg player, CPU usage over 100% and Does it means this ffmpeg uses only software decoder ? or there is a way to use hwaccel ?

  Please understand my poor english and any answer would be appreciated.

  Thanks.