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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.

  


• time progress bar does not scale by sec in FFMPEG chopped mp4 in iOS and Android devices

  10 juillet 2017, par Xi Xiao

  I have used the below command to cut out a 44sec length video. The result video can be found here.

  ffmpeg -i friends.mkv -ss 00:15:30.0 -t 44 -vf scale=640:360  video.mp4

  One odd issue appears from the generated video.mp4.

  when playing it in iphone 7 and huawei honor8 android, the time progress bar does not scale by second.

  What I mean is, for example, the video can start to play either from 0 second or 6 second. But, if I drag the progress bar to time between 0 - 6, such as 4, the video player will jump to 0 and play, instead of playing from 4 second.

  When I use Javascript to setTime for 2 second for html5 video player, it does not work either, i.e. the player will play from 0 second instead of 2. Code is as below :

  var vid = document.getElementById("video1");
  
  vid.currentTime = 2;
  
  vid.play();

  screenshot made in iphone 7

  I stop the video, try set the progress bar between 0 and 6 as in screenshot. When I click play, the player will play from 0.

  

  In what devices have I tested it ?

  • This issue appears in iphone 7, huawei honor8 android phone.
  • This issue does not appear in PC browser, nor in ipad.

  At last, I suspect that the issue roots from video codec, but had no success to locate the keyword to explain my issue and google the solution.

• How can I reencode a video to match another's codec exactly ?

  24 janvier 2020, par Stephen Schrauger

  When I’m on vacation, I usually use our camcorder to record videos. Since they’re all the same format, I can use ffmpeg to concat them into one large, smooth video without re-encoding.

  However, sometimes I will use a phone or other camera to record a video (if the camcorder ran out of space/battery or was left at a hotel).

  I’d like to determine the codec, framerate, etc used by my camcorder and use those parameters to convert the phone vidoes into the same format. That way, I will be able to concatonate all the videos without re-encoding the camcorder videos.

  Using ffprobe, I found my camcorder has this encoding :

    Input #0, mpegts, from 'camcorderfile.MTS':
  
    Duration: 00:00:09.54, start: 1.936367, bitrate: 24761 kb/s
  
    Program 1 
  
      Stream #0:0[0x1011]: Video: h264 (High) (HDPR / 0x52504448), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
  
      Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
  
      Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090), 1920x1080

  The phone (iPhone 5s) encoding is :

    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'mov.MOV':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 0
  
      compatible_brands: qt  
  
      creation_time   : 2017-01-02T03:04:05.000000Z
  
      com.apple.quicktime.location.ISO6709: +12.3456-789.0123+456.789/
  
      com.apple.quicktime.make: Apple
  
      com.apple.quicktime.model: iPhone 5s
  
      com.apple.quicktime.software: 10.2.1
  
      com.apple.quicktime.creationdate: 2017-01-02T03:04:05-0700
  
    Duration: 00:00:14.38, start: 0.000000, bitrate: 11940 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 11865 kb/s, 29.98 fps, 29.97 tbr, 600 tbn, 1200 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
        encoder         : H.264
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 63 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
      Stream #0:2(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler
  
      Stream #0:3(und): Data: none (mebx / 0x7862656D), 0 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-02T03:04:05.000000Z
  
        handler_name    : Core Media Data Handler

  I’m presuming that ffmpeg will automatically take any acceptable video format, and that I only need to figure out the output settings. I think I need to use -s 1920x1080 and -pix_fmt yuv420p for the output, but what other flags do I need in order to make the phone video into the same encoding as the camcorder video ?

  Can I get some pointers as to how I can translate the ffprobe output into the flags I need to give to ffmpeg ?

  Edit : Added the entire Input #0 for both media files.