Solid-State Society

Month: January 2015

  • How to Use FFmpeg to Extract Audio from Video File Without Re-encoding

    Try -c copy:

    $ ffmpeg -i video.mp4 -c copy audio.aac

    How ever you have to know the original audio format to extract audio without re-encoding, for example:

    $ ffmpeg -i video.mp4
...
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2015-01-17 20:39:33
  Duration: 00:23:59.94, start: 0.000000, bitrate: 1983 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], 1787 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
    Metadata:
      creation_time   : 2015-01-17 20:39:33
      handler_name    : 264:[email protected]
    Stream #0:1(jpn): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 191 kb/s (default)
    Metadata:
      creation_time   : 2015-01-17 15:55:11
      handler_name    : Sound Media Handler
...

    Then you should know what format and which track to extract.

  • How to Report Disputed Apps in App Store

    There’re many fake / disputed / copycat apps made by Chinese in iTunes App Store, here’s how to report these shit to Apple:

    First, open iTunes Content Dispute to start dispute process. Enter some basic information and continue.

    Then you can provide a link to the app from the App Store. Alternatively, you may use the search tab below to search for the app at issue. If there is more than one app you wish to dispute, for example I just searched “Screeny” and got the following result:

    Then select them all and continue, you can get a dropdown to choose the nature of your dispute, and a text box for every app you can write details information about your dispute, here’s an example:

    Cheers:

  • How to Uninstall NoMachine on OS X

    After uninstalling the app, you have to remove these shit:

    In /System/Library/Extensions/:

    • nxaudio.kext
    • nxfs.kext
    • nxtun.kext

    In /System/Library/StartupItems/:

    • nxfs/
    • nxtun/

    In /private/etc/:

    • NX/