Converting MKV or AVI to MP4 (h264, aac)

convert.sh

# with handbrake cli
for i in *.mkv; do
  handbrake --preset-import-file fast.json --ab 192 -i "$i" -o "${i%.mkv}".mp4;
done

# or with ffmpeg
for f in *.avi; do
  ffmpeg -i "$f" -c:v libx264 -c:a aac "${f%.avi}".mp4;
done

fast.json

{
  "PresetList" : [
    {
      "AlignAVStart" : true,
      "AudioCopyMask" : [
        "copy:aac"
      ],
      "AudioEncoderFallback" : "ca_aac",
      "AudioLanguageList" : [

      ],
      "AudioList" : [
        {
          "AudioBitrate" : 160,
          "AudioCompressionLevel" : -1,
          "AudioDitherMethod" : "auto",
          "AudioEncoder" : "ca_aac",
          "AudioMixdown" : "stereo",
          "AudioNormalizeMixLevel" : false,
          "AudioSamplerate" : "auto",
          "AudioTrackDRCSlider" : 0,
          "AudioTrackGainSlider" : 0,
          "AudioTrackQuality" : -1,
          "AudioTrackQualityEnable" : false
        }
      ],
      "AudioSecondaryEncoderMode" : true,
      "AudioTrackSelectionBehavior" : "first",
      "ChapterMarkers" : true,
      "ChildrenArray" : [

      ],
      "Default" : false,
      "FileFormat" : "av_mp4",
      "Folder" : false,
      "FolderOpen" : false,
      "InlineParameterSets" : false,
      "Mp4HttpOptimize" : false,
      "Mp4iPodCompatible" : false,
      "PictureAutoCrop" : true,
      "PictureBottomCrop" : 0,
      "PictureChromaSmoothCustom" : "",
      "PictureChromaSmoothPreset" : "off",
      "PictureChromaSmoothTune" : "none",
      "PictureCombDetectCustom" : "",
      "PictureCombDetectPreset" : "default",
      "PictureDARWidth" : 0,
      "PictureDeblockCustom" : "strength=strong:thresh=20:blocksize=8",
      "PictureDeblockPreset" : "off",
      "PictureDeblockTune" : "medium",
      "PictureDeinterlaceCustom" : "",
      "PictureDeinterlaceFilter" : "decomb",
      "PictureDeinterlacePreset" : "default",
      "PictureDenoiseCustom" : "",
      "PictureDenoiseFilter" : "off",
      "PictureDenoisePreset" : "light",
      "PictureDenoiseTune" : "none",
      "PictureDetelecine" : "off",
      "PictureDetelecineCustom" : "",
      "PictureForceHeight" : 0,
      "PictureForceWidth" : 0,
      "PictureHeight" : 1080,
      "PictureItuPAR" : false,
      "PictureKeepRatio" : true,
      "PictureLeftCrop" : 0,
      "PictureLooseCrop" : false,
      "PictureModulus" : 2,
      "PicturePAR" : "auto",
      "PicturePARHeight" : 720,
      "PicturePARWidth" : 853,
      "PictureRightCrop" : 0,
      "PictureRotate" : "angle=0:hflip=0",
      "PictureSharpenCustom" : "",
      "PictureSharpenFilter" : "off",
      "PictureSharpenPreset" : "medium",
      "PictureSharpenTune" : "none",
      "PictureTopCrop" : 0,
      "PictureWidth" : 1920,
      "PresetDescription" : "H.264 video (up to 1080p30) and AAC stereo audio, in an MP4 container.",
      "PresetName" : "Fast 1080p30",
      "SubtitleAddCC" : false,
      "SubtitleAddForeignAudioSearch" : true,
      "SubtitleAddForeignAudioSubtitle" : false,
      "SubtitleBurnBDSub" : true,
      "SubtitleBurnBehavior" : "foreign",
      "SubtitleBurnDVDSub" : true,
      "SubtitleLanguageList" : [

      ],
      "SubtitleTrackSelectionBehavior" : "none",
      "Type" : 1,
      "UsesPictureFilters" : true,
      "UsesPictureSettings" : 1,
      "VideoAvgBitrate" : 6000,
      "VideoColorMatrixCodeOverride" : 0,
      "VideoEncoder" : "x264",
      "VideoFramerate" : "30",
      "VideoFramerateMode" : "pfr",
      "VideoGrayScale" : false,
      "VideoLevel" : "4.0",
      "VideoOptionExtra" : "",
      "VideoPreset" : "fast",
      "VideoProfile" : "main",
      "VideoQSVAsyncDepth" : 4,
      "VideoQSVDecode" : false,
      "VideoQualitySlider" : 22,
      "VideoQualityType" : 2,
      "VideoScaler" : "swscale",
      "VideoTune" : "",
      "VideoTurboTwoPass" : true,
      "VideoTwoPass" : true,
      "x264Option" : "",
      "x264UseAdvancedOptions" : false
    }
  ],
  "VersionMajor" : 42,
  "VersionMicro" : 0,
  "VersionMinor" : 0
}

result.md

➜  02 du -ach *.mp4 | tail -1
 24G    total
➜  02 du -ach *.mkv | tail -1
 43G    total