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• Heroku FFMPEG HEVC Video with Alpha support ?

  15 septembre 2022, par Patrick Vellia

  I am looking for a way to handle converting videos like Webm VP9 with alpha channel to HEVC with alpha mov or mp4 files that are playable in Safari (The Webm will work in all other browsers).

  


  While I can do this locally in my Rails app using streamio-ffmpeg gem and the havoc_videotoolbox encoder, this only works on Apple hardware.

  


  Therefore if I push it up to Heroku and use the Heroku ffmpeg build pack, the HEVC VideoToolbox is not available for use.

  


  FFMPEG does have the libx265 encoder but I can't find the property for this one to preserve the alpha channel.

  


  ffmpeg -I INPUT -c:v libx265 -preset medium -crf 26 -tag:v hvc1 OUTput.mp4


  


  there is a -x265-params flag, but I can't figure out which param will enable the alpha channel.

  


  I am hoping this is actually possible for my production app, otherwise I'd have to process this segment of our media locally and manually upload the HEVC components.

  


  Local Configuration
Apple Monterey with ffmpeg 5.1.1 installed on Intel
Rails 7

  


  Heroku

  


  FFMPEG build pack

  


  Hobby Plan

  


  Rails 7

  


• App Intents FFmpeg-iOS operation not permitted

  2 octobre 2023, par apo_p9

  Using latest iOS and Xcode, I have an AppIntent to which Im passing a video file from iOS Shortcuts, Im using an IntentFile parameter to read that in the intent. Then Im using FFmpeg-iOS to generate a single frame from the video.

  


  ...
@Parameter(title: "Media", supportedTypeIdentifiers: ["public.image", "public.video"], inputConnectionBehavior: .connectToPreviousIntentResult)
var media: IntentFile
...
let mediaPath = media.fileURL!.absoluteString;
let posterPath = mediaPath.replacingOccurrences(of: media.filename, with: "poster.jpg")
_ = ffmpeg(["FFmpeg-iOS", "-i", mediaPath, "-frames:v", "1", posterPath])


  


  Here is the output :

  


  ffmpeg(_:) ["FFmpeg-iOS", "-i", "file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/IMG_2751.mov", "-frames:v", "1", "file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/poster.jpg"]
ffmpeg version N-109970-g7dc0944ce2 Copyright (c) 2000-2023 the FFmpeg developers
  built with Apple clang version 14.0.0 (clang-1400.0.29.202)
  configuration: --prefix=/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64 --enable-cross-compile --disable-debug --disable-doc --enable-pic --disable-audiotoolbox --disable-sdl2 --disable-libxcb --target-os=darwin --arch=arm64 --cc='xcrun -sdk iphoneos clang' --as='gas-preprocessor.pl -arch aarch64 -- xcrun -sdk iphoneos clang' --extra-cflags='-arch arm64 -mios-version-min=13.0 -I/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64/include' --extra-ldflags='-arch arm64 -mios-version-min=13.0 -L/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64/lib'
HookMain: setjmp=0
FFmpeg_exit=1, will longjmp
HookMain: setjmp=1
  libavutil      58.  3.100 / 58.  3.100
  libavcodec     60.  6.100 / 60.  6.100
  libavformat    60.  4.100 / 60.  4.100
  libavdevice    60.  2.100 / 60.  2.100
  libavfilter     9.  4.100 /  9.  4.100
  libswscale      7.  2.100 /  7.  2.100
  libswresample   4. 11.100 /  4. 11.100
file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/IMG_2751.mov: Operation not permitted


  


  The issue is in the last line : Operation not permitted

  


  I also tried just writing a file to the same directory as the media file :

  


  let str = "Super long string here"
let filename = media.fileURL!.absoluteString.replacingOccurrences(of: media.filename, with: "asd.txt")

do {
    try str.write(to: URL(string: filename)!, atomically: true, encoding: String.Encoding.utf8)
} catch {
    print(error)
}


  


  But got the error :

  


  Error Domain=NSCocoaErrorDomain Code=513 "You don’t have permission to save the file “asd.txt” in the folder “com.apple.WorkflowKit.BackgroundShortcutRunner”." UserInfo={NSFilePath=/var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/asd.txt, NSUnderlyingError=0x280f09aa0 {Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"}}


  


  Apparently there is a permission issue, I tried googling about "AppIntents file permissions"/"shortcut permissions"/etc but found nothing. Im not a mobile developer so Im totally clueless. The same code though works fine in the simulator, it gets the permission issue only on device.

  


• movenc : Timecode in MP4 Although MP4 does not have a concrete specification to store...

  21 janvier 2016, par Syed Andaleeb Roomy

  movenc : Timecode in MP4 Although MP4 does not have a concrete specification to store timecode information, the following technical note from Apple describes a way to achieve this via timecode track, similar to how it is done for MOV files.
  https://developer.apple.com/library/mac/technotes/tn2174/_index.html
   Enabled creation of timecode tracks for MP4 in the same way as MOV.
  
   Used nmhd as media information header of timecode track of MP4 instead
  
    of gmhd used in MOV, thus avoiding tcmi also, as recommended above.
  
   Bypassed adding source reference field for MP4, as suggested above.
  Issue : https://trac.ffmpeg.org/ticket/4704
  Signed-off-by : Syed Andaleeb Roomy <andaleebcse@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/movenc.c