Mac video production: Framerate Conversion Strategies & Tools

Gleaned from Philip Bloom’s presentation on using a 30p native cam to produce to other standards (e.g. 24p):

  • Edit native, convert the edit result, not the source (rushes). Saves render time (& space)
  • Don’t edit H264 – current machines are not fast enough to avoid jerkiness.
    • Before edit, convert to ProRes (standard is sufficient, no need for HQ).  If disk space at a premium then could instead use XDCAM EX format but that is not compatible with Cinema Tools.
      • Conversion to ProRes is done twice as fast by Mpeg StreamClip (free) than by Compressor.
        • Mpeg StreamClip:
          • [File > Open Files, File> Export to QuickTime, choose format ProRes 422, change top-slider to Full 100% Quality (default is less)
          • Can also use it to batch-convert, result can be either separate files or all concatenated in sequence.
  • (DO THE EDIT)
  • FrameRate Conversion:
    • Simplest: speed change – change the timebase (the rate at which the existing frames are presented).  OK when speed change does not matter (e.g. static scene).
      • Can be done e.g. via Cinema Tools.
        • Stages: Analysis then select desired new framerate then Conform.
        • (or [Cinema Tools: File > Batch Conform],  select a folder containing set of files, select any example file in it, Open, change speed, go: all the files are done)
    • Speed-preserving frameRate conversion can be done by Compressor or by JES Deinterlacer (free)
      • Compressor
        • Open Compressor
        • Drag file to job-strip
        • Create a Setting if needed
        • Geometry (5th icon along) – set Frame Size to “100% of source” (to ensure Compressor setting doesn’t re-scale)
        • Frame Controls: Unlock
        • (ignore settings that don’t apply e.g. resize method)
        • Rate Conversion: choose the fastest you can get away with
        • It is not compulsory to set a Destination.
          • (what happens if not? same directory as source?  what filename gets generated)
            • If no destination specified then file goes to same directory, auto-named as the original filename plus the name of the export format Setting.  Example: From TRV 12-39 AvidGrade.mov it generated TRV 12-39 AvidGrade-QT ProRes Interlaced.mov, where QT ProRes Interlaced was a compression setting (previously defined by myself).  Incidentally the QT-DV was 35MB, the generated QT-ProRes was 47MB.
      • JES Deinterlacer
        • Choose >  (input your file)
        • Output > Compressor > Export
          • (nothing to do with Apple’s Compressor, at least I assume…)

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