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• Write Live Photo metadata to video using FFMPEG

  13 août 2021, par Luke Burns

  According to Apple Live Photo file format, there are three pieces of metadata that need to be written for a JPEG and MOV to be accepted as a live photo. I can use exiftool and ffmpeg to write the necessary content identifier metadata.

  


  For the JPEG :

  


  exiftool -TagsFromFile reference.jpeg -makernotes -ContentIdentifier image.jpeg
exiftool -ContentIdentifier="$id" image.jpeg


  


  Similarly, ffmpeg can be used to write the top-level Quicktime metadata with matching id.

  


  However I'm having trouble with the timed metadata : ["com.apple.quicktime.still-image-time" : 0xFF].

  


  I can't even manage to produce a copy of an existing live photo MOV file using ffmpeg that preserves the necessary timed metadata.

  


  ffmpeg -i original.mov -map 0 -c copy -movflags use_metadata_tags copy.mov


  


  copies the global metadata (i.e. com.apple.quicktime.content.identifier), but loses the necessary still-image-time which can be confirmed using exiftool :

  


  > exiftool -G -U -ee original.mov | grep 'Still Image Time'
[QuickTime]     Still Image Time                : -1
> exiftool -G -U -ee copy.mov | grep 'Still Image Time'
> 


  


  How can I write the timed metadata using ffmpeg—specifically the still-image-time data ?

  


  Edit : it looks like this may be happening because ffmpeg does not know how to handle the mebx tag on data streams :

  


  [mov @ 0x7fb232091400] Unknown hldr_type for mebx, writing dummy values


  


  And ffmpeg doesn't seem to have a way to copy unknown streams. This appears to also be a problem for dealing with the fdsc tag in GoPro metadata streams (e.g. see https://gist.github.com/radimklaska/8974637522a751adb49db0de3be482c9#file-gopro_hevc_to_dnxhd-sh-L125), so it's often copied over as gpmd data, which ensures it's not overwritten with dummy values, but this trick doesn't work in the case of live photos mebx metadata.

  


• Bad audio quality with electron FFmpeg live streaming application [closed]

  5 janvier 2021, par Vivek Thumar

  Getting bad audio quality with electron FFmpeg live streaming app. (It's not the frequent ratio is around 10 good and 1 bad quality).

  


  From the command line, it's not happened but when tried inside electron it's happened.

  


  I tried with too many things

  


  #1 Check with all FFmpeg versions.
  
#2 Increase memory allocation of electron app.
  
#3 Check with multiple electron versions.

  


• Play a HLS live m3u8 playlist, with expiring key

  3 novembre 2016, par maxgalbu

  I’m trying to play an HLS url from the NBA servers, from Kodi (which is using ffmpeg).

  http://nlds16.cdnak.neulion.com/nlds/nba/nba247/as/live/ipad_20161102200000_003000.mp4.m3u8?hdnea=expires%3D1478128277%7Eaccess%3D%2Fnlds%2Fnba%2Fnba247%2Fas%2Flive%2F*%7Emd5%3Dmd5&nltid=nba&nltdt=6&nltnt=1&uid=2312934

  It’s behind a login, so you won’t be able to play it.

  This url has an expiring encryption key, and if I try to play that playlist from the NBA website, I can see that the player, every 5 seconds, does a request for the same playlist, and every time it downloads a new encryption key. If i play it with ffmpeg, there’s only one request, and the key eventually expires interrupting the streaming. Is it possible to do the same with ffmpeg ?

  (Searching for ffmpeg hls refresh key yields no results :()