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VIDEOCONFIG.MD

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VIDEOCONFIG.MD

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Video driver configuration

The video driver used in NeoYume supports many different output formats with different sub-modes.

There are 6 variables to control this:

  • VIDEO_MODE selects the broad output type
  • VIDEO_SUBMODE selects a sub-variant. Can be SUBMODE_AUTO to select the default.
  • ANALOG_BASEPIN determines which pins the analog output is sent to (this must be a multiple of 4)
  • VSYNC_PIN determines where VSync goes (for modes that have it)
  • DIGITAL_BASEPIN determines which pins the digital output is sent to (this must be a multiple of 8)
  • DIGITAL_REVERSED sets if digital TMDS signalling should use reverse pin order

MODE_HDMI

Digital HDMI output with embedded audio. 8 TMDS signals are sent to DIGITAL_BASEPIN.

HDMI audio packet generation is semi-experimental, please report if it works or doesn't work for you.

Supported submodes are:

  • SUBMODE_TMDS_640x480 standard 4:3 signal (default)
  • SUBMODE_TMDS_768x480 extra horizontal padding for 16:10 monitors
  • SUBMODE_TMDS_800x480 extra horizontal padding for certain LCD panels
  • SUBMODE_TMDS_854x480 extra horizontal padding for 16:9 monitors

(Older versions of NeoYume used to default to 800x480)

MODE_DVI

Same as MODE_HDMI, but using plain DVI signalling (no data islands or guard bands)

MODE_HDMI_VGA / MODE_DVI_VGA

Same as the the above, but with simultaneous analog output. The analog timing is off-spec, so this is not very useful.

MODE_VGA / MODE_RGBHV

Analog RGB output with separate sync signals. HSync, R, G and B are sent, in that order, to four pins at ANALOG_BASEPIN. VSync is sent to VSYNC_PIN.

Supported submodes are SUBMODE_1X through SUBMODE_3X, corrosponding to different scaling settings. The default SUBMODE_2X results in a standard 640x480 signal.

MODE_RGBS

Analog RGB output with composite sync. CSync, R, G and B are sent, in that order, to four pins at ANALOG_BASEPIN.

Everything else is the same as MODE_VGA

MODE_SoG

Analog RGB output with Sync-On-Green. R, G and B are sent, in that order, to three pins at ANALOG_BASEPIN + 1.

Everything else is the same as MODE_VGA

MODE_YPBPR

Analog YPbPr output. Pr, Y and Pb are sent, in that order, to three pins at ANALOG_BASEPIN + 1.

This supports the same scaling modes as MODE_VGA, but additionally allows overriding the color space with SUBMODE_FORCE_REC601 and SUBMODE_FORCE_REC709. By default Rec. 601 is used for 1X and 2X, Rec. 709 above that.

MODE_COMPOSITE

Analog composite video. This can be sent to any ANALOG_BASEPIN (does not need to be a multiple of 4).

Supports SUBMODE_NTSC (default) and SUBMODE_PAL. The latter is infact PAL60.

MODE_SVIDEO

Analog S-Video. Luma and Chroma are sent, in that order, to two pins at ANALOG_BASEPIN.

Everything else is the same as MODE_COMPOSITE

MODE_SVID_AND_COMP

Analog S-Video and composite simultaneously. Luma, Chroma and Composite are sent, in that order, to three pins at ANALOG_BASEPIN.

Everything else is the same as MODE_COMPOSITE

MODE_LCD6

6-bit digital output for ILI9342-based LCD screen.

TODO