BATS - QTGMC

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The reference deinterlacer for Avisynth – shipped in BAT Server as ready-made presets

QTGMC is the established deinterlacing standard for Avisynth in video restoration: it separates the fields of interlaced material and reconstructs progressive frames from them, using motion estimation to decide how objects moved between the fields – this keeps even moving objects clean instead of “dissolving”. BAT Server ships QTGMC (version 3.383s) as a portable Avisynth+ installation and offers it through two presets: “Upscale & Deinterlace” (2× to progressive HD) and “Upscale” (upscale to 1080i). This article explains what the presets do technically and what quality levels exist.

What QTGMC does

  • Field separation + reconstruction: QTGMC analyzes the material with motion estimation (MVTools/NNEDI3) and produces clean progressive frames from it – the proven way to remove interlacing artifacts even in motion.
  • Field order automatic: the script queries the field order (TFF/BFF) and actively refuses progressive sources (clear error message “Source is Progressive”) – QTGMC is exclusively for interlaced material.
  • Correct pixel aspect: non-square pixels (e.g. DV 4:3 with PAR) are converted to square pixels before processing.

How BAT Server works with QTGMC

Under C:\ProgramData\EdiusPowerTools\tools\avisynth\ there is a complete, portable Avisynth+ installation (FFMS2 video loader, QTGMC, Zs_RF_Shared, LimitedSharpenFaster, and a dedicated FFmpeg). For each job, BAT Server fills the shipped script template with the values of the chosen clip (file path, IN/OUT, field order, pixel aspect, frame rate, CPU count, quality preset) – and the shipped FFmpeg renders the finished .avs script directly into the target format. For you that means: right-click, done – no Avisynth knowledge required.

The two QTGMC-based presets

  • “Upscale & Deinterlace – 2x Upscale”: deinterlace plus 2× upscaling and doubled frame rate – e.g. 576i50 → 1152p50. The result is progressive HD material with square pixels (color space converted from Rec.601 to Rec.709) – the route for DV/DVD/VHS material in progressive projects. Details in the Upscale & Deinterlace article.
  • “Upscale – SD interlaced to 1080i”: deinterlace plus resolution to 1080 lines – the material stays interlaced (the fields are recombined into 1080i lines, upper field first): 576i50 → 1080i50. The route for workflows that need full-HD interlaced (e.g. 1080i broadcast sequences).

Both presets use the same QTGMC core; the difference is the post-processing: nnedi3 generates the missing frames for the doubled rate and doubled resolution in the 2× preset, while the 1080i preset scales to 1080 lines and then re-merges the fields into interlaced frames.

Quality presets: Medium, Very Fast, Very Slow

Both presets offer three quality levels (chosen in the assistant, baked into the .bat0): Medium (recommended – balanced quality/render time), Very Fast (significantly faster, lower quality) and Very Slow (highest quality, longest computation – QTGMC uses additional analysis passes in this level, e.g. FFT 3D filtering). For very long material, budget realistically for the render time.

Good to know

  • Interlaced sources only: progressive inputs are refused with a clear error message – for progressive upscaling use the AI upscale presets (see UpscalePro).
  • Optimized for SD: the presets are tuned for SD material (4:3 or 16:9, e.g. DV); HD-interlaced material can technically be processed as well, but is not the target case.
  • New file, original kept: the result is created as a new file and registered in the BIN under __BAT Server\Deinterlace; the source file is never touched.
  • IN/OUT are respected: the script trims internally to the clip’s IN/OUT (no IN/OUT = the entire clip).

Managing the presets

Both entries are created via the “Add function...” assistant and are therefore user presets: the .bat0 files live under C:\ProgramData\EdiusPowerTools\BAT-server\bat_files\BIN\ or …\bat_files\timeline\ depending on your choice, and can be freely edited, renamed or deleted (deleting removes the context-menu entry). QTGMC level, target format and field-order logic are baked into the .bat0 – changes take effect from the next run.