AutoGK Additional info

About resolution selection:

AutoGK tries to obtain a Bits/(Pixel*Frame) value that is 70% of the Compressibility test (the Bits/(Pixel*Frame) value obtained when the movie is compressed for maximum quality). If the resolution to obtain this value is below 512x for a 4:3 movie, or 608x for a 16:9 movie, the limit is set to 60% instead of 70%. In addition to changing the resolution, the resizing filter is also changed (instead of a very crisp filter that yields a high Bits/(Pixel*Frame) value like the bicubic resize a neutral bicubic or lanczos filter is used), along with custom quantizer matrices in XviD.

The comp test is performed at a 704x resolution for 2 CDs and 640x for 1 CD. B-frames are used unless the Bits/(Pixel*Frame) value used goes above 85% of the compressibility test and the maximum resolution has been used.

In maximum quality mode, the maximum resolution of 720x is used (but black bars are still cropped away if applicable).

About the source detection

First of all, only motion frames are analyzed.

For PAL content, progressive, interlaced and progressive with switched field order are recognized.

For NTSC, AutoGK can detect progressive NTSC (30 fps), interlaced NTSC (30 fps), FILM (24 fps), hybrid content with a high amount of FILM (24 fps) and hybrid with mostly NTSC content (30 fps).

Interlaced sources are deinterlaced using KernelDeInt. FILM or hybrid sources are processed by Decomb, with different Decimate parameters in function of the source. For pure FILM sources, Decimate mode 0 is used, for hybrid FILM sources, Decimate mode 3 is used, and mode 1 is used for hybrid NTSC sources.

This document was last updated on November 30, 2003