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• How do I upscale an iOS App Preview video to 1080 x 1920 ? [closed]

  12 avril 2024, par Benjamin Thiel

  I just captured a video of my new app running on an iPhone 6 using QuickTime Player and a Lightning cable. Afterwards I created an App Preview project in iMovie, exported it and could successfully upload it to iTunes Connect.

  



  Apple requires developers to upload App Previews in different resolutions dependent on screen size, namely :

  



  

  • iPhone 5(S) : 1080 x 1920 or 640 x 1136

  


  • iPhone 6 : 750 x 1334 (what I have)

  


  • iPhone 6+ : 1080 x 1920

  


  



  Obviously, 1080 x 1920 is killing two birds with one stone. I know that upscaling isn't the perfect solution, but it's meeting my needs. Since I don't own a 6+, another recording session won't do the trick.

  



  Unfortunately, iTunes Connect is extremely picky about what to accept. Here's what I tried, to no avail :

  



  

  • Handbrake, iMovie, QuickTime do not support upscaling

  


  • MPEG Streamclip

  


  • ffmpeg -i input.mp4 -acodec copy -vf scale=1080:1920 output.mp4

  


  



  Strangely enough, iTunes Connect keeps complaining about the wrong resolution when I try to upload the output.mp4 of ffmpeg.

  


• corrupted HEIC tile when converting to JPEG

  27 mars 2018, par Kim Bowles Sørhus

  I’m having trouble converting a .HEIC image to a jpeg. The .HEIC file an image taken with an iphone running the latest ios public beta. I’m using the library nokia provided to parse the file and extract the image tiles from the .HEIC file, convert them to jpeg and glue them together using ffmpeg/montage.

  There is a bit too much code to paste it all into this question so i put all of it in this github repo. Its pretty self explanatory and should be runnable with just a few dependencies. They are explained in the repo’s README. This has all been done on osx btw.

  The .HEIC files contains a 8x6 grid of images(tiles) and if you put them together you get the complete image. Simply put whatever image i input the 7th tile is corrupted as shown below and i really don’t understand why. I’ve filed an issue with nokia, but the repo seems pretty dead and i don’t really expect an answer there.

  

• C - FFmpeg streaming from a C program ?

  16 août 2017, par golmschenk

  I’m looking to replicate an FFmpeg command-line command in my C code. Specifically I would like to be able to run :

  ffmpeg -re -i video.mp4 -f mpegts udp://localhost:7777

  One thing I’ve noticed when looking at people’s code who have used the libraries of FFmpeg in their own code is that they often have a few hundred lines of code for a single command similar to an FFmpeg command-line command. I’m guessing this is just because they are doing something very specific, because if I can run that short command on my command line and get what I want it should probably only take about ten lines of code to do the same thing in my C code. This should only take about that much work right ? Why would it take much more ?

  I’m having a bit of difficulty finding explanations on how to use the streaming capabilities of the FFmpeg libraries that aren’t overly complex because they’re for a very specific purpose. Can anyone explain how I might go about writing the code for the above command ? Or at the very least point me to some documentation explaining how to write such a script/program ? Thank you much !

  EDIT : I do hope to run this from an iPhone app eventually so I won’t just be able to straight up call FFmpeg from my program. I’ll need to use the libraries used by FFmpeg.